Interplanetary dust. [survey of last four years' research

NASA Technical Reports Server (NTRS)

Brownlee, D. E.

1979-01-01

Progress in the study of interplanetary dust during the past four years is reviewed. Attention is given to determinations of the relative contributions of interstellar dust grains, collisional debris from the asteroid belt and short-period comets to the interplanetary dust cloud. Effects of radiation pressure and collisions on particle dynamics are discussed, noting the discovery of the variation of the orbital parameters of dust particles at 1 AU with size and in situ measurements of dust density between 0.3 and 5 AU by the Helios and Pioneer spacecraft. The interpretation of the zodiacal light as produced by porous absorbing particles 10 to 100 microns in size is noted, and measurements of the Doppler shift, light-producing-particle density, UV spectrum, photometric axis and angular scattering function of the zodiacal light are reported. Results of analyses of lunar rock microcraters as to micrometeoroid density, flux rate, size distribution and composition are indicated and interplanetary dust particles collected from the stratosphere are discussed. Findings concerning the composition of fragile meteoroid types found as cosmic spherules in deep sea sediments are also presented.

The radiation-induced rotation of cosmic dust particles: A feasibility study

NASA Technical Reports Server (NTRS)

Misconi, N. Y.; Ratcliff, K. F.

1981-01-01

A crossed beam, horizontal optical trap, used to achieve laser levitation of particles in an effort to determine how solar radiation produces high spin rate in interplanetary dust particles, is described. It is suggested that random variations in albedo and geometry give rise to a nonzero effective torque when the influence of a unidrectional source of radiaton (due to the Sun) over the surface of a interplanetary dust particle is averaged. This resultant nonzero torque is characterized by an asymmetry factor which is the ratio of the effective moment arm to the maximum linear dimension of the body and is estimated to be 5 X 10 to the minus four power. It is hoped that this symmetry factor, which stabilizes the nonstatistical response of the particle, can be measured in a future Spacelab experiment.

Cosmic dust

NASA Technical Reports Server (NTRS)

Brownlee, Donald E.; Sandford, Scott A.

1992-01-01

Dust is a ubiquitous component of our galaxy and the solar system. The collection and analysis of extraterrestrial dust particles is important to exobiology because it provides information about the sources of biogenically significant elements and compounds that accumulated in distant regions of the solar nebula and that were later accreted on the planets. The topics discussed include the following: general properties of interplanetary dust; the carbonaceous component of interplanetary dust particles; and the presence of an interstellar component.

Optical spectroscopy of interplanetary dust collected in the earth's stratosphere

NASA Technical Reports Server (NTRS)

Fraundorf, P.; Patel, R. I.; Shirck, J.; Walker, R. M.; Freeman, J. J.

1980-01-01

Optical absorption spectra of interplanetary dust particles 2-30 microns in size collected in the atmosphere at an altitude of 20 km by inertial impactors mounted on NASA U-2 aircraft are reported. Fourier transform absorption spectroscopy of crushed samples of the particles reveals a broad feature in the region 1300-800 kaysers which has also been found in meteorite and cometary dust spectra, and a weak iron crystal field absorption band at approximately 9800 kaysers, as is observed in meteorites. Work is currently in progress to separate the various components of the interplanetary dust particles in order to evaluate separately their contributions to the absorption.

Extracting lunar dust parameters from image charge signals produced by the Lunar Dust Experiment

NASA Astrophysics Data System (ADS)

Stanley, J.; Kempf, S.; Horanyi, M.; Szalay, J.

2015-12-01

The Lunar Dust Experiment (LDEX) onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) is an impact ionization dust detector used to characterize the lunar dust exosphere generated by the impacts of large interplanetary particles and meteor streams (Horanyi et al., 2015). In addition to the mass and speed of these lofted particles, LDEX is sensitive to their charge. The resulting signatures of impact events therefore provide valuable information about not only the ambient plasma environment, but also the speed vectors of these dust grains. Here, impact events produced from LDEX's calibration at the Dust Accelerator Laboratory are analyzed using an image charge model derived from the electrostatic simulation program, Coulomb. We show that parameters such as dust grain speed, size, charge, and position of entry into LDEX can be recovered and applied to data collected during LADEE's seven-month mission.

Direct Measurements of Interplanetary Dust Particles in the Vicinity of Earth

NASA Technical Reports Server (NTRS)

McCracken, C. W.; Alexander, W. M.; Dubin, M.

1961-01-01

The direct measurements made by the Explorer VIII satellite provide the first sound basis for analyzing all available direct measurements of the distribution of interplanetary dust particles. The model average distribution curve established by such an analysis departs significantly from that predicted by the (uncertain) extrapolation of results from meteor observations. A consequence of this difference is that the daily accretion of interplanetary particulate matter by the earth is now considered to be mainly dust particles of the direct measurements range of particle size. Almost all the available direct measurements obtained with microphone systems on rockets, satellites, and spacecraft fit directly on the distribution curve defined by Explorer VIII data. The lack of reliable datum points departing significantly from the model average distribution curve means that available direct measurements show no discernible evidence of an appreciable geocentric concentration of interplanetary dust particles.

Skylab's Astronomy and Space Sciences

NASA Technical Reports Server (NTRS)

Lundquist, C. A. (Editor)

1979-01-01

The capabilities of Skylab for multidisciplinary investigations are reviewed. Experiments and results are discussed for observations of stars and galaxies, energetic particles, interplanetary dust, Comet Kohoutek, the earth's atmosphere, and the nature and effects of space environments on man.

Organic matter on the early surface of Mars: An assessment of the contribution by interplanetary dust

NASA Technical Reports Server (NTRS)

Flynn, G. J.

1993-01-01

Calculations by Anders and Chyba et al. have recently revived interest in the suggestion that organic compounds important to the development of life were delivered to the primitive surface of the Earth by comets, asteroids or the interplanetary dust derived from these two sources. Anders has shown that the major post-accretion contribution of extraterrestrial organic matter to the surface of the Earth is from interplanetary dust. Since Mars is a much more favorable site for the gentle deceleration of interplanetary dust particles than is Earth, model calculations show that biologically important organic compounds are likely to have been delivered to the early surface of Mars by the interplanetary dust in an order-of-magnitude higher surface density than onto the early Earth. Using the method described by Flynn and McKay, the size frequency distribution, and the atmospheric entry velocity distribution of IDP's at Mars were calculated. The entry velocity distribution, coupled with the atmospheric entry heating model developed by Whipple and extended by Fraundorf was used to calculate the fraction of the particles in each mass decade which survives atmospheric entry without melting (i.e., those not heated above 1600K). The incident mass and surviving mass in each mass decade are shown for both Earth and Mars.

Mid-Infrared Spectrum of the Zodiacal Emission: Detection of Crystalline Silicates in Interplanetary Dust

NASA Technical Reports Server (NTRS)

Ootsubo, T.; Onaka, T.; Yamamura, I.; Ishihara, D.; Tanabe, T.; Roellig, T. L.

2003-01-01

Within a few astronomical units of the Sun the solar system is filled with interplanetary dust, which is believed to be dust of cometary and asteroidal origin. Spectroscopic observations of the zodiacal emission with moderate resolution provide key information on the composition and size distribution of the dust in the interplanetary space. They can be compared directly to laboratory measurements of candidate materials, meteorites, and dust particles collected in the stratosphere. Recently mid-infrared spectroscopic observations of the zodiacal emission have been made by two instruments on board the Infrared Space Observatory; the camera (ISOCAM) and the spectrophotometer (ISOPHOT-S). A broad excess emission feature in the 9-11 micron range is reported in the ISOCAM spectrum, whereas the ISOPHOT-S spectra in 6-12 microns can be well fitted by a blackbody radiation without spectral features.

The search for refractory interplanetary dust particles from preindustrial aged Antarctic ice

NASA Technical Reports Server (NTRS)

Zolensky, Michael E.; Webb, Susan J.; Thomas, Kathie

1988-01-01

In a study of refractory interplanetary dust particles, preindustrial-aged Antarctic ice samples have been collected, melted, and filtered to separate the particle load. Particles containing a significant amount of aluminum, titanium, and/or calcium were singled out for detailed SEM and STEM characterization. The majority of these particles are shown to be volcanic tephra from nearby volcanic centers. Six spherical aggregates were encountered that consist of submicron-sized grains of rutile within polycrystalline cristobalite. These particles are probably of terrestrial volcanic origin, but have not been previously reported from any environment. One aggregate particle containing fassaite and hibonite is described as a probable interplanetary dust particle. The constituent grain sizes of this particle vary from 0.1 to 0.3 microns, making it significantly more fine-grained than meteoritic calcium-aluminum-rich inclusions. This particle is mineralogically and morphologically similar to recently reported refractory interplanetary dust particles collected from the stratosphere, and dissimilar to the products of modern spacecraft debris.

Estimation of micrometeorites and satellite dust flux surrounding Mars in the light of MAVEN results

NASA Astrophysics Data System (ADS)

Pabari, J. P.; Bhalodi, P. J.

2017-05-01

Recently, MAVEN observed dust around Mars from ∼150 km to ∼1000 km and it is a puzzling question to the space scientists about the presence of dust at orbital altitudes and about its source. A continuous supply of dust from various sources could cause existence of dust around Mars and it is expected that the dust could mainly be from either the interplanetary source or the Phobos/Deimos. We have studied incident projectiles or micrometeorites at Mars using the existing model, in this article. Comparison of results with the MAVEN results gives a new value of the population index S, which is reported here. The index S has been referred in a power law model used to describe the number of impacting particles on Mars. In addition, the secondary ejecta from natural satellites of Mars can cause a dust ring or torus around Mars and remain present for its lifetime. The dust particles whose paths are altered by the solar wind over its lifetime, could present a second plausible source of dust around Mars. We have investigated escaping particles from natural satellites of Mars and compared with the interplanetary dust flux estimation. It has been found that flux rate at Mars is dominated (∼2 orders of magnitude higher) by interplanetary particles in comparison with the satellite originated dust. It is inferred that the dust at high altitudes of Mars could be interplanetary in nature and our expectation is in agreement with the MAVEN observation. As a corollary, the mass loss from Martian natural satellites is computed based on the surface erosion by incident projectiles.

Interstellar chemistry recorded in organic matter from primitive meteorites.

PubMed

Busemann, Henner; Young, Andrea F; Alexander, Conel M O'd; Hoppe, Peter; Mukhopadhyay, Sujoy; Nittler, Larry R

2006-05-05

Organic matter in extraterrestrial materials has isotopic anomalies in hydrogen and nitrogen that suggest an origin in the presolar molecular cloud or perhaps in the protoplanetary disk. Interplanetary dust particles are generally regarded as the most primitive solar system matter available, in part because until recently they exhibited the most extreme isotope anomalies. However, we show that hydrogen and nitrogen isotopic compositions in carbonaceous chondrite organic matter reach and even exceed those found in interplanetary dust particles. Hence, both meteorites (originating from the asteroid belt) and interplanetary dust particles (possibly from comets) preserve primitive organics that were a component of the original building blocks of the solar system.

Workshop on the Analysis of Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Zolensky, Michael E. (Editor)

1994-01-01

Great progress has been made in the analysis of interplanetary dust particles (IDP's) over the past few years. This workshop provided a forum for the discussion of the following topics: observation and modeling of dust in the solar system, mineralogy and petrography of IDP's, processing of IDP's in the solar system and terrestrial atmosphere, comparison of IDP's to meteorites and micrometeorites, composition of IDP's, classification, and collection of IDP's.

Mineralogy of Interplanetary Dust Particles from the Comet Giacobini-Zinner Dust Stream Collections

NASA Technical Reports Server (NTRS)

Nakamura-Messenger, K.; Messenger, S.; Westphal, A. J.; Palma, R. L.

2015-01-01

The Draconoid meteor shower, originating from comet 21P/Giacobini-Zinner, is a low-velocity Earth-crossing dust stream that had a peak anticipated flux on Oct. 8, 2012. In response to this prediction, NASA performed dedicated stratospheric dust collections to target interplanetary dust particles (IDPs) from this comet stream on Oct 15-17, 2012 [3]. Twelve dust particles from this targeted collection were allocated to our coordinated analysis team for studies of noble gas (Univ. Minnesota, Minnesota State Univ.), SXRF and Fe-XANES (SSL Berkeley) and mineralogy/isotopes (JSC). Here we report a mineralogical study of 3 IDPs from the Draconoid collection..

Effects of interplanetary coronal mass ejections on the transport of nano-dust generated in the inner solar system

NASA Astrophysics Data System (ADS)

O'Brien, Leela; Juhász, Antal; Sternovsky, Zoltan; Horányi, Mihály

2018-07-01

This article reports on an investigation of the effect of interplanetary coronal mass ejections (ICMEs) on the transport and delivery of nano-dust to 1 AU. Charged nanometer-sized dust particles are expected to be generated close to the Sun and interact strongly with the solar wind as well as solar transient events. Nano-dust generated outside of ∼0.2 AU are picked up and transported away from the Sun due to the electromagnetic forces exerted by the solar wind. A numerical model has been developed to calculate the trajectories of nano-dust through their interaction with the solar wind and explore the potential for their detection near Earth's orbit (Juhasz and Horanyi, 2013). Here, we extend the model to include the interaction with interplanetary coronal mass ejections. We report that ICMEs can greatly alter nano-dust trajectories, their transport to 1 AU, and their distribution near Earth's orbit. The smallest nano-dust (<10 nm) can be delivered to 1 AU in high concentration. Thus, the nature of the interaction between nano-dust and ICMEs could potentially be revealed by simultaneous measurements of nano-dust fluxes and solar wind particles/magnetic fields.

SIMS chemical analysis of extended impact features from the trailing edge portion of experiment AO187-2

NASA Technical Reports Server (NTRS)

Amari, Sachiko; Foote, John; Simon, Charles; Jessberger, Elmar K.; Lange, Gundolf; Stadermann, Frank; Swan, Pat; Walker, Robert M.; Zinner, Ernst

1992-01-01

One hundred capture cells from the trailing edge, which had lost their cover foils during flight, were optically scanned for extended impact features caused by high velocity projectiles impinging on the cells while the foils were still intact. Of the 53 candidates, 24 impacts were analyzed by secondary ion mass spectroscopy for the chemical composition of the deposits. Projectile material was found in all impacts, and at least 75 percent of them appear to be caused by interplanetary dust particles. Elemental ratios are fractionated, with refractory elements enriched in the impacts relative to interplanetary dust particles collected in the stratosphere. Although this could be due to systematic differences in the compositions, a more likely explanation is volatility fractionation during the impact process.

Summary of the results from the Lunar Dust Experiment (LDEX) onboard the Lunar Atmosphere and Dust Environment (LADEE) Mission

NASA Astrophysics Data System (ADS)

Horanyi, Mihaly

2016-07-01

The Lunar Dust Experiment (LDEX) onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission (9/2013 - 4/2014) discovered a permanently present dust cloud engulfing the Moon. The size, velocity, and density distributions of the dust particles are consistent with ejecta clouds generated from the continual bombardment of the lunar surface by sporadic interplanetary dust particles. Intermittent density enhancements were observed during several of the annual meteoroid streams, especially during the Geminids. LDEX found no evidence of the expected density enhancements over the terminators where electrostatic processes were predicted to efficiently loft small grains. LDEX is an impact ionization dust detector, it captures coincident signals and full waveforms to reliably identify dust impacts. LDEX recorded average impact rates of approximately 1 and 0.1 hits/minute of particles with impact charges of q > 0.5 and q > 5 fC, corresponding to particles with radii of a > 0.3 and a> 0.7~μm, respectively. Several of the yearly meteor showers generated sustained elevated levels of impact rates, especially if their radiant direction intersected the lunar surface near the equatorial plane, greatly enhancing the probability of crossing their ejecta plumes. The characteristic velocities of dust particles in the cloud are on the order of ~100 m/s which we neglect compared to the typical spacecraft speeds of 1.6 km/s. Hence, with the knowledge of the spacecraft orbit and attitude, impact rates can be directly turned into particle densities as functions of time and position. LDEX observations are the first to identify the ejecta clouds around the Moon sustained by the continual bombardment of interplanetary dust particles. Most of the dust particles generated in impacts have insufficient energy to escape and follow ballistic orbits, returning to the surface, 'gardening' the regolith. Similar ejecta clouds are expected to engulf all airless planetary objects, including the Moon, Mercury, and the moons of Mars: Phobos and Deimos.

Kuiper Belt Dust Grains as a Source of Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Liou, Jer-Chyi; Zook, Herbert A.; Dermott, Stanley F.

1996-01-01

The recent discovery of the so-called Kuiper belt objects has prompted the idea that these objects produce dust grains that may contribute significantly to the interplanetary dust population. In this paper, the orbital evolution of dust grains, of diameters 1 to 9 microns, that originate in the region of the Kuiper belt is studied by means of direct numerical integration. Gravitational forces of the Sun and planets, solar radiation pressure, as well as Poynting-Robertson drag and solar wind drag are included. The interactions between charged dust grains and solar magnetic field are not considered in the model. Because of the effects of drag forces, small dust grains will spiral toward the Sun once they are released from their large parent bodies. This motion leads dust grains to pass by planets as well as encounter numerous mean motion resonances associated with planets. Our results show that about 80% of the Kuiper belt grains are ejected from the Solar System by the giant planets, while the remaining 20% of the grains evolve all the way to the Sun. Surprisingly, the latter dust grains have small orbital eccentricities and inclinations when they cross the orbit of the Earth. This makes them behave more like asteroidal than cometary-type dust particles. This also enhances their chances of being captured by the Earth and makes them a possible source of the collected interplanetary dust particles; in particular, they represent a possible source that brings primitive/organic materials from the outer Solar System to the Earth. When collisions with interstellar dust grains are considered, however, Kuiper belt dust grains around 9 microns appear likely to be collisionally shattered before they can evolve toward the inner part of the Solar System. The collision destruction can be applied to Kuiper belt grains up to about 50 microns. Therefore, Kuiper belt dust grains within this range may not be a significant part of the interplanetary dust complex in the inner Solar System.

Inferring Sources in the Interplanetary Dust Cloud, from Observations and Simulations of Zodiacal Light and Thermal Emission

NASA Technical Reports Server (NTRS)

Levasseur-Regourd, A. C.; Lasue, J.

2011-01-01

Interplanetary dust particles physical properties may be approached through observations of the solar light they scatter, specially its polarization, and of their thermal emission. Results, at least near the ecliptic plane, on polarization phase curves and on the heliocentric dependence of the local spatial density, albedo, polarization and temperature are summarized. As far as interpretations through simulations are concerned, a very good fit of the polarization phase curve near 1.5 AU is obtained for a mixture of silicates and more absorbing organics material, with a significant amount of fluffy aggregates. In the 1.5-0.5 AU solar distance range, the temperature variation suggests the presence of a large amount of absorbing organic compounds, while the decrease of the polarization with decreasing solar distance is indeed compatible with a decrease of the organics towards the Sun. Such results are in favor of the predominance of dust of cometary origin in the interplanetary dust cloud, at least below 1.5 AU. The implication of these results on the delivery of complex organic molecules on Earth during the LHB epoch, when the spatial density of the interplanetary dust cloud was orders of magnitude greater than today, is discussed.

Curation of Microscopic Astromaterials by NASA: "Gathering Dust Since 1981"

NASA Technical Reports Server (NTRS)

Frank, D. R.; Bastien, R. K.; Rodriguez, M.; Gonzalez, C.; Zolensky, M. E.

2013-01-01

Employing the philosophy that "Small is Beautiful", NASA has been collecting and curating microscopic astromaterials since 1981. These active collections now include interplanetary dust collected in Earth's stratosphere by U-2, ER-2 and WB-57F aircraft (the Cosmic Dust Program - our motto is "Gathering dust since 1981"), comet Wild-2 coma dust (the Stardust Mission), modern interstellar dust (also the Stardust Mission), asteroid Itokawa regolith dust (the Hayabusa Mission - joint curation with JAXA-ISAS), and interplanetary dust impact features on recovered portions of the following spacecraft: Skylab, the Solar Maximum Satellite, the Palapa Satellite, the Long Duration Exposure Facility (LDEF), the MIR Space Station, the International Space Station, and the Hubble Space Telescope (all in the Space Exposed Hardware Laboratory).

Experiments on Dust Grain Charging

NASA Technical Reports Server (NTRS)

Abbas, M. N.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; West, E. A.

2004-01-01

Dust particles in various astrophysical environments are charged by a variety of mechanisms generally involving collisional processes with other charged particles and photoelectric emission with UV radiation from nearby sources. The sign and the magnitude of the particle charge are determined by the competition between the charging processes by UV radiation and collisions with charged particles. Knowledge of the particle charges and equilibrium potentials is important for understanding of a number of physical processes. The charge of a dust grain is thus a fundamental parameter that influences the physics of dusty plasmas, processes in the interplanetary medium and interstellar medium, interstellar dust clouds, planetary rings, cometary and outer atmospheres of planets etc. In this paper we present some results of experiments on charging of dust grains carried out on a laboratory facility capable levitating micron size dust grains in an electrodynamic balance in simulated space environments. The charging/discharging experiments were carried out by exposing the dust grains to energetic electron beams and UV radiation. Photoelectric efficiencies and yields of micron size dust grains of SiO2, and lunar simulates obtained from NASA-JSC will be presented.

Chemical and isotopic measurements of micrometeoroids by secondary ion mass spectrometry (A0187-2)

NASA Technical Reports Server (NTRS)

Foote, J. H.; Swan, P. D.; Walker, R. M.; Zinner, E. K.; Bahr, D.; Fechtig, H.; Jessberger, E.; Igenbergs, E.; Kreitmayr, U.; Kuczera, H.

1984-01-01

The objective of this experiment is to measure the chemical and isotopic composition of interplanetary dust particles of mass greater than 10 to the minus 10 power G for most of thermator elements expected to be present.

Synchrotron FTIR Examination of Interplanetary Dust Particles: An Effort to Determine the Compounds and Minerals in Interstellar and Circumstellar Dust

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Keller, L. P.

2002-01-01

Some interplanetary dust particles (IDPs), collected by NASA from the Earth's stratosphere, are the most primitive extraterrestrial material available for laboratory analysis. Many exhibit isotopic anomalies in H, N, and O, suggesting they contain preserved interstellar matter. We report the preliminary results of a comparison of the infrared absorption spectra of subunits of the IDPs with astronomical spectra of interstellar grains.

Infrared spectroscopy of interplanetary dust in the laboratory

NASA Technical Reports Server (NTRS)

Fraundorf, P.; Patel, R. I.; Freeman, J. J.

1981-01-01

A mount containing three crushed chondritic interplanetary dust particles (IDPs) collected in the earth's stratosphere and subjected to infrared spectroscopic measurements shows features near 1000 and 500/cm, suggesting crystalline pyroxene rather than crystalline olivine, amorphous olivine, or meteoritic clay minerals. Chondritic IDP structural diversity and atmospheric heating effects must be considered when comparing this spectrum with interplanetary and cometary dust astrophysical spectra. TEM and infrared observations of one member of the rare subset of IDPs resembling hydrated carbonaceous chondrite matrix material shows a close infrared spectrum resemblance between 4000 and 400/cm to the C2 meteorite Murchison. TEM observations suggest that this class of particles may be used as an atmospheric entry heating-process thermometer.

Physical properties of interplanetary dust: laboratory and numerical simulations

NASA Astrophysics Data System (ADS)

Hadamcik, Edith; Lasue, Jeremie; Levasseur-Regourd, Anny-Chantal; Renard, Jean-Baptiste; Buch, Arnaud; Carrasco, Nathalie; Cottin, Hervé; Fray, Nicolas; Guan, Yuan Yong; Szopa, Cyril

Laboratory light scattering measurements with the PROGRA2 experiment, in A300-CNES and ESA dedicated microgravity flights or in ground based configurations, offer an alternative to models for exploring the scattering properties of particles with structures too complex to be easily handled by computer simulations [1,2]. The technique allows the use of large size distributions (nanometers to hundreds of micrometers) and a large variety of materials, similar to those suspected to compose the interplanetary particles [3]. Asteroids are probably the source of compact particles, while comets have been shown to eject compact and fluffy materials [4]. Moreover giant planets provide further a small number of interplanetary particles. Some interstellar particles are also present. To choose the best samples and size distributions, we consider previous numerical models for the interplanetary particles and their evolution with solar distance. In this model, fluffy particles are simulated by fractal aggregates and compact particles by ellipsoids. The materials considered are silicates and carbonaceous compound. The silicate grains can be coated by the organics. Observations are fitted with two parameters: the size distribution of the particles and the ratio of silicates over carbonaceous compounds. From the light scattering properties of the particles, their equilibrium temperature can be calculated for different structures and composition. The variation of their optical properties and temperatures are studied with the heliocentric distance [5,6]. Results on analogs of cometary particles [7] and powdered meteorites as asteroidal particles will be presented and compared to numerical simulations as well as observations. Organics on cometary grains can constitute distributed sources if degraded by solar UV and heat [8, 9]. The optical properties of CxHyNz compounds are studied after thermal evolution [10]. As a first approach, they are used to simulate the evolution of cometary or interplanetary dust organics approaching the Sun. Albedo and polarization variations will be discussed. The polarization evolution will be compared to those obtained through observations [11]. Studies of the properties of our interplanetary dust cloud should provide information to better interpret observations of dust around exoplanets. Some of these planets are very close to their star. The thermal evolution of organics driven by chemical reactions will represent a fundamental knowledge to interpret the relevant polarimetric observations. We acknowledge CNES for funding the PROGRA2 experiment, CNES and ESA for the micro-gravity flights. [1] Renard J.-B. et al., Appl. Opt. 41, 609 (2002) [2] Hadamcik E. et al., In: Light scattering rev. 4, 31 (Kokhanovszky ed.), Springer -Praxis, Berlin (2009) [3] Mann I. et al., Space Sci. Rev. 110, 269 (2004) [4] Hoertz F. et al., Science 314, 716 (2006) [5] Lasue J. et al., Astron. Astrophys. 473, 641 (2007) [6] Levasseur-Regourd A.C et al., Planet Space Sci. 55, 1010 (2007) [7] Hadamcik E. et al., Icarus 190, 660 (2007) [8] Cottin H. et al., Adv. Space Res. 42, 2019 (2008) [9] Fray N. et al., Planet. Space Sci. 53, 1243 (2005) [10] Sciamma-O'Brien E. et al., Icarus, accepted [11] Levasseur-Regourd A.C., et al., In: Interplanetary dust, Gruen, Gustafson B., Dermott S., Fechtig H. (Eds), Springer, Berlin, 57 (2001)

Temporal Variability in the Accretion Rate of Interplanetary Dust Using (3)He as a Tracer

NASA Technical Reports Server (NTRS)

Farley, K. A.

2005-01-01

The research supported by this grant falls under three topics: 1) Weekly Interplanetary Dust Sampling via (3)He; 2) Extraterrestrial (3)He at Major Impact Boundaries; 3) Completing a Moderately-High Resolution Record of Extraterrestrial (3)He Flux: A Major Asteroidal Break up Event at 8.2 Ma.

10 years of Cassini/VIMS observations at Titan

NASA Astrophysics Data System (ADS)

Sotin, C.; Brown, R. H.; Baines, K. H.; Barnes, J.; Buratti, B. J.; Clark, R. N.; Jaumann, R.; LeMouelic, S.; Nicholson, P. D.; Rodriguez, S.; Soderblom, J.; Soderblom, L.; Stephan, K.

2014-04-01

The interplanetary space probe Cassini/Huygens reached Saturn in July 2004 after seven years of cruise phase. Today, the German-lead Cosmic Dust Analyser (CDA) is operated continuously for 10 years in orbit around Saturn. During the cruise phase CDA measured the interstellar dust flux at one AU distance from the Sun, the charge and composition of interplanetary dust grains and the composition of the Jovian nanodust streams. The first discovery of CDA related to Saturn was the measurement of nanometer sized dust particles ejected by its magnetosphere to interplanetary space with speeds higher than 100 km/s. Their origin and composition was analysed and an their dynamical studies showed a strong link to the conditions of the solar wind plasma flow. A recent surprising result was, that stream particles stem from the interior of Enceladus. Since 2004 CDA measured millions of dust impacts characterizing the dust environment of Saturn. The instrument showed strong evidence for ice geysers located at the south pole of Saturn's moon Enceladus in 2005. Later, a detailed compositional analysis of the salt-rich water ice grains in Saturn's E ring system lead to the discovery of liquid water below the icy crust connected to an ocean at depth feeding the icy jets. CDA was even capable to derive a spatially resolved compositional profile of the plume during close Enceladus flybys. A determination of the dust-magnetosphere interaction and the discovery of the extended E ring allowed the definition of a dynamical dust model of Saturn's E ring describing the observed properties. The measured dust density profiles in the dense E ring revealed geometric asymmetries. Cassini performed shadow crossings in the ring plane and dust grain charges were measured in shadow regions delivering important data for dust-plasma interaction studies. In the last years, dedicated measurement campaigns were executed by CDA to monitor the flux of interplanetary and interstellar dust particles reaching Saturn. Currently, the composition of interstellar grains and the meteoroid flux into the Saturnian system are in analysis.

Interplanetary dust - Trace element analysis of individual particles by neutron activation

NASA Technical Reports Server (NTRS)

Ganapathy, R.; Brownlee, D. E.

1979-01-01

Although micrometeorites of cometary origin are thought to be the dominant component of interplanetary dust, it has never been possible to positively identify such micrometer-sized particles. Two such particles have been identified as definitely micrometeorites since their abundances of volatile and nonvolatile trace elements closely match those of primitive solar system material.

Tin in a chondritic interplanetary dust particle

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1989-01-01

Submicron platey Sn-rich grains are present in chondritic porous interplanetary dust particle (IDP) W7029 A and it is the second occurrence of a tin mineral in a stratospheric micrometeorite. Selected Area Electron Diffraction data for the Sn-rich grains match with Sn2O3 and Sn3O4. The oxide(s) may have formed in the solar nebula when tin metal catalytically supported reduction of CO or during flash heating on atmospheric entry of the IDP. The presence of tin is consistent with enrichments for other volatile trace elements in chondritic IDPs and may signal an emerging trend toward nonchondritic volatile element abundances in chondritic IDPs. The observation confirms small-scale mineralogical heterogeneity in fine-grained chondritic porous interplanetary dust.

On the origin of extraterrestrial stratospheric particles: Interplanetary dust or meteor ablation debris?. M.S. Thesis

NASA Technical Reports Server (NTRS)

Kyte, F. T.

1977-01-01

Meteor ablation debris was distinguished from unablated interplanetary dust in a collection of extraterrestrial particles collected in the stratosphere using NASA U-2 aircraft. A 62 g sample of the Murchison (C2) meteorite was artificially ablated to characterize ablation debris for comparison with the stratospheric particles. By using proper experimental conditions, artificial ablation debris can be produced that is similar to natural ablation debris. Analyses of natural fusion crusts, artificial fusion crust, and artificial ablation debris of the Murchison meteorite produced criteria for recognizing debris ablated by a primitive meteoroid. Ninety-five percent of the stratospheric particles can be described as either ablation debris from a primitive meteoroid, or as very primitive interplanetary dust.

STEREO SECCHI and S/WAVES Observations of Spacecraft Debris Caused by Micron-Size Interplanetary Dust Impacts

NASA Astrophysics Data System (ADS)

St. Cyr, O. C.; Kaiser, M. L.; Meyer-Vernet, N.; Howard, R. A.; Harrison, R. A.; Bale, S. D.; Thompson, W. T.; Goetz, K.; Maksimovic, M.; Bougeret, J.-L.; Wang, D.; Crothers, S.

2009-05-01

Early in the STEREO mission observers noted that the white-light instruments of the SECCHI suite were detecting significantly more spacecraft-related “debris” than any previously flown coronagraphic instruments. Comparison of SECCHI “debris storms” with S/WAVES indicates that almost all are coincident with the most intense transient emissions observed by the radio and plasma waves instrument. We believe the debris is endogenous ( i.e., from the spacecraft thermal blanketing), and the storms appear to be caused by impacts of large interplanetary dust grains that are detected by S/WAVES. Here we report the observations, compare them to interplanetary dust distributions, and document a reminder for future spacebased coronagraphic instrument builders.

Physics of spacecraft-based interplanetary dust collection by impact into low-density media

NASA Technical Reports Server (NTRS)

Anderson, William W.; Ahrens, T. J.

1994-01-01

A spacecraft encountering an interplanetary dust particle (IDP) at a relative velocity of several kilometers per second may be used to capture that particle for in situ analysis or for analysis upon Earth return. In this paper we study the impact of a dust particle into a low-density medium (i.e., a foam) such that the foam dissipates the kinetic energy of impact over a sufficient distance to stop the particle without destroying it.

The Distribution of Interplanetary Dust Near 1-AU: An MMS Perspective

NASA Astrophysics Data System (ADS)

Adrian, M. L.; St Cyr, O. C.; Wilson, L. B., III; Schiff, C.; Sacks, L. W.; Chai, D. J.; Queen, S. Z.; Sedlak, J. E.

2017-12-01

The distribution of dust in the ecliptic plane in the vicinity of 1-AU has been inferred from impacts on the four Magnetospheric Multiscale (MMS) mission spacecraft as detected by the Acceleration Measurement System (AMS) during periods when no other spacecraft activities are in progress. Consisting of four identically instrumented spacecraft, with an inter-spacecraft separation ranging from 10-km to 400-km, the MMS constellation forms a dust "detector" with approximately four-times the collection area of any previous dust monitoring framework. Here we introduce the MMS-AMS and the inferred dust impact observations, provide a preliminary comparison of the MMS distribution of dust impacts to previously reported interplanetary dust distributions — namely those of the STEREO mission — and report on our initial comparison of the MMS distribution of dust impacts with known meteor showers.

A new method to generate dust with astrophysical properties

NASA Astrophysics Data System (ADS)

Hansen, J. F.; van Breugel, W.; Bringa, E. M.; Eberly, B.; Graham, G. A.; Remington, B. A.; Taylor, E. A.; Tielens, A. G. G. M.

2011-05-01

To model the size distribution and composition of interstellar and interplanetary dust grains, and their effect on a wide range of phenomena, it is vital to understand the mechanism of dust-shock interaction. We demonstrate a new laser experiment that subjects dust grains to pressure spikes similar to those of colliding astrophysical dust, and that accelerates the grains to astrophysical velocities. This new method generates much larger data sets than earlier methods; we show how large quantities (thousands) of grains are accelerated at once, rather than accelerating individual grains, as is the case of earlier methods using electric fields. We also measure the in-flight velocity ( ~ 4.5km/s) of hundreds of grains simultaneously by use of a particle image velocimetry (PIV) technique.

CHARGED DUST GRAIN DYNAMICS SUBJECT TO SOLAR WIND, POYNTING–ROBERTSON DRAG, AND THE INTERPLANETARY MAGNETIC FIELD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lhotka, Christoph; Bourdin, Philippe; Narita, Yasuhito, E-mail: christoph.lhotka@oeaw.ac.at, E-mail: philippe.bourdin@oeaw.ac.at, E-mail: yasuhito.narita@oeaw.ac.at

We investigate the combined effect of solar wind, Poynting–Robertson drag, and the frozen-in interplanetary magnetic field on the motion of charged dust grains in our solar system. For this reason, we derive a secular theory of motion by the means of an averaging method and validate it with numerical simulations of the unaveraged equations of motions. The theory predicts that the secular motion of charged particles is mainly affected by the z -component of the solar magnetic axis, or the normal component of the interplanetary magnetic field. The normal component of the interplanetary magnetic field leads to an increase ormore » decrease of semimajor axis depending on its functional form and sign of charge of the dust grain. It is generally accepted that the combined effects of solar wind and photon absorption and re-emmision (Poynting–Robertson drag) lead to a decrease in semimajor axis on secular timescales. On the contrary, we demonstrate that the interplanetary magnetic field may counteract these drag forces under certain circumstances. We derive a simple relation between the parameters of the magnetic field, the physical properties of the dust grain, as well as the shape and orientation of the orbital ellipse of the particle, which is a necessary conditions for the stabilization in semimajor axis.« less

Highlights and discoveries of the Cosmic Dust Analyser (CDA) during its 15 years of exploration

NASA Astrophysics Data System (ADS)

Srama, R.; Moragas-Klostermeyer, G.; Kempf, S.; Postberg, F.; Albin, T.; Auer, S.; Altobelli, N.; Beckmann, U.; Bugiel, S.; Burton, M.; Economou, T.; Fliege, K.; Grande, M.; Gruen, E.; Guglielmino, M.; Hillier, J. K.; Schilling, A.; Schmidt, J.; Seiss, M.; Spahn, F.; Sterken, V.; Trieloff, M.

2014-04-01

The interplanetary space probe Cassini/Huygens reached Saturn in July 2004 after seven years of cruise phase. Today, the German-lead Cosmic Dust Analyser (CDA) is operated continuously for 10 years in orbit around Saturn. During the cruise phase CDA measured the interstellar dust flux at one AU distance from the Sun, the charge and composition of interplanetary dust grains and the composition of the Jovian nanodust streams. The first discovery of CDA related to Saturn was the measurement of nanometer sized dust particles ejected by its magnetosphere to interplanetary space with speeds higher than 100 km/s. Their origin and composition was analysed and an their dynamical studies showed a strong link to the conditions of the solar wind plasma flow. A recent surprising result was, that stream particles stem from the interior of Enceladus. Since 2004 CDA measured millions of dust impacts characterizing the dust environment of Saturn. The instrument showed strong evidence for ice geysers located at the south pole of Saturn's moon Enceladus in 2005. Later, a detailed compositional analysis of the salt-rich water ice grains in Saturn's E ring system lead to the discovery of liquid water below the icy crust connected to an ocean at depth feeding the icy jets. CDA was even capable to derive a spatially resolved compositional profile of the plume during close Enceladus flybys. A determination of the dust-magnetosphere interaction and the discovery of the extended E ring allowed the definition of a dynamical dust model of Saturn's E ring describing the observed properties. The measured dust density profiles in the dense E ring revealed geometric asymmetries. Cassini performed shadow crossings in the ring plane and dust grain charges were measured in shadow regions delivering important data for dust-plasma interaction studies. In the last years, dedicated measurement campaigns were executed by CDA to monitor the flux of interplanetary and interstellar dust particles reaching Saturn. Currently, the composition of interstellar grains and the meteoroid flux into the Saturnian system are in analysis.

GEO Debris and Interplanetary Dust: Fluxes and Charging Behavior

NASA Astrophysics Data System (ADS)

Graps, A. L.; Green, S. F.; McBride, N. M.; McDonnell, J. A. M.; Drolshagen, G.; Svedhem, H.; Bunte, K. D.

2005-08-01

A population of cosmic dust mixed with a population of man-made debris exists within the Earth's magnetosphere. Measurements of these provide the data samples for studies of the interplanetary dust particles that travel through our magnetosphere from the outside and for studies of the local byproducts of our space endeavours. Even though instruments to detect natural meteoroids and space debris particles have been flown in Low Earth Orbits (LEO) and on interplanetary missions, very little information on the particle environment for Earth orbits above about 600 km altitude have been available. In particular, knowledge about particles smaller than 1 m in the geostationary (GEO) region was largely unknown before GORID. In September 1996, a dust/debris detector: GORID was launched into GEO as a piggyback instrument on the Russian Express-2 telecommunications spacecraft. The instrument began its normal operation in April 1997 and ended its mission in July 2002. The goal of this work was to use GORID's particle data to identify and separate the space debris from the interplanetary dust particles (IDPs) in GEO, to more finely determine the instrument's measurement characteristics and to derive impact fluxes. Here we present some results of that study. We give GORID flux distributions for debris and IDPs and then present intriguing debris clustering features that might be the result of electrostatic fragmentation of the rocket slag particles.

Modeling the Solar Dust Environment at 9.5 Solar Radii: Revealing Radiance Trends with MESSENGER Star Tracker Data

NASA Astrophysics Data System (ADS)

Strong, S. B.; Strikwerda, T.; Lario, D.; Raouafi, N.; Decker, R.

2010-12-01

The main components of interplanetary dust are created through destruction, erosion, and collision of asteroids and comets (e.g. Mann et al. 2006). Solar radiation forces distribute these interplanetary dust particles throughout the solar system. The percent contribution of these source particulates to the net interplanetary dust distribution can reveal information about solar nebula conditions, within which these objects are formed. In the absence of observational data (e.g. Helios, Pioneer), specifically at distances less than 0.3 AU, the precise dust distributions remain unknown and limited to 1 AU extrapolative models (e.g. Mann et al. 2003). We have developed a model suitable for the investigation of scattered dust and electron irradiance incident on a sensor for distances inward of 1 AU. The model utilizes the Grün et al. (1985) and Mann et al. (2004) dust distribution theory combined with Mie theory and Thomson electron scattering to determine the magnitude of solar irradiance scattered towards an optical sensor as a function of helio-ecliptic latitude and longitude. MESSENGER star tracker observations (launch to 2010) of the ambient celestial background combined with Helios data (Lienert et al. 1982) reveal trends in support of the model predictions. This analysis further emphasizes the need to characterize the inner solar system dust environment in anticipation of near-Solar missions.

Dust Flux Monitor Instrument for the Stardust mission to comet Wild 2

NASA Astrophysics Data System (ADS)

Tuzzolino, A. J.; Economou, T. E.; McKibben, R. B.; Simpson, J. A.; McDonnell, J. A. M.; Burchell, M. J.; Vaughan, B. A. M.; Tsou, P.; Hanner, M. S.; Clark, B. C.; Brownlee, D. E.

2003-10-01

The Dust Flux Monitor Instrument (DFMI) is part of the Stardust instrument payload. The prime goal of the DFMI is to measure the particle flux, intensity profile, and mass distribution during passage through the coma of comet Wild 2 in January 2004. This information is valuable for assessment of spacecraft risk and health and also for interpretation of the laboratory analysis of dust captured by the Aerogel dust collectors and returned to Earth. At the encounter speed of 6.1 km/s, the DFMI measurements will extend over the particle mass range of 8 decades, from 10-11 to >10-3 g. A secondary science goal is to measure the particle flux and mass distribution during the ~7 year interplanetary portions of the mission, where, in addition to measurements of the background interplanetary dust over the radial range 0.98 AU to 2.7 AU, multiple opportunities exist for possible detection by the DFMI of interplanetary meteor-stream particles and interstellar dust. The DFMI consists of two different dust detector systems: a polyvinylidene fluoride (PVDF) Dust Sensor Unit (SU), which measures particles with mass <~10-4 g, and a Dual Acoustic Sensor System (DASS), which utilizes two quartz piezoelectric accelerometers mounted on the first two layers of the spacecraft Whipple dust shield to measure the flux of particles with mass >10-4 g. The large Whipple shield structures provide the large effective sensitive area required for detection of the expected low flux of high-mass particles.

Hypervelocity Dust Impacts in Space and the Laboratory

NASA Astrophysics Data System (ADS)

Horanyi, Mihaly; Colorado CenterLunar Dust; Atmospheric Studies (CCLDAS) Team

2013-10-01

Interplanetary dust particles continually bombard all objects in the solar system, leading to the excavation of material from the target surfaces, the production of secondary ejecta particles, plasma, neutral gas, and electromagnetic radiation. These processes are of interest to basic plasma science, planetary and space physics, and engineering to protect humans and instruments against impact damages. The Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) has recently completed a 3 MV dust accelerator, and this talk will summarize our initial science results. The 3 MV Pelletron contains a dust source, feeding positively charged micron and sub-micron sized particles into the accelerator. We will present the technical details of the facility and its capabilities, as well as the results of our initial experiments for damage assessment of optical devices, and penetration studies of thin films. We will also report on the completion of our dust impact detector, the Lunar Dust Experiment (LDEX), is expected to be flying onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission by the time of this presentation. LDEX was tested, and calibrated at our dust accelerator. We will close by offering the opportunity to use this facility by the planetary, space and plasma physics communities.

The asteroid-comet continuum from laboratory and space analyses of comet samples and micrometeorites

NASA Astrophysics Data System (ADS)

Engrand, Cécile; Duprat, Jean; Bardin, Noémie; Dartois, Emmanuel; Leroux, Hugues; Quirico, Eric; Benzerara, Karim; Remusat, Laurent; Dobrică, Elena; Delauche, Lucie; Bradley, John; Ishii, Hope; Hilchenbach, Martin

2016-10-01

Comets are probably the best archives of the nascent solar system, 4.5 Gyr ago, and their compositions reveal crucial clues on the structure and dynamics of the early protoplanetary disk. Anhydrous minerals (olivine and pyroxene) have been identified in cometary dust for a few decades. Surprisingly, samples from comet Wild2 returned by the Stardust mission in 2006 also contain high temperature mineral assemblages like chondrules and refractory inclusions, which are typical components of primitive meteorites (carbonaceous chondrites - CCs). A few Stardust samples have also preserved some organic matter of comet Wild 2 that share some similarities with CCs. Interplanetary dust falling on Earth originate from comets and asteroids in proportions to be further constrained. These cosmic dust particles mostly show similarities with CCs, which in turn only represent a few percent of meteorites recovered on Earth. At least two (rare) families of cosmic dust particles have shown strong evidences for a cometary origin: the chondritic porous interplanetary dust particles (CP-IDPs) collected in the terrestrial stratosphere by NASA, and the ultracarbonaceous Antarctic Micrometeorites (UCAMMs) collected from polar snow and ice by French and Japanese teams. Analyses of dust particles from the Jupiter family comet 67P/Churyumov-Gerasimenko by the dust analyzers on Rosetta orbiter (COSIMA, GIADA, MIDAS) suggest a relationship to interplanetary dust/micrometeorites. A growing number of evidences highlights the existence of a continuum between asteroids and comets, already in the early history of the solar system.

Infrared Observations of Cometary Dust and Nuclei

NASA Technical Reports Server (NTRS)

Lisse, Carey

2004-01-01

This bibliography lists citations for publications published under the grant. Subjects of the publications include cometary dust, instellar and interplanetary dust, comet nuclei and comae, Comet Hale-Bopp, infrared observations of comets, mass loss, and comet break-up.

The Cassini Cosmic Dust Analyser CDA - A 10 year exploration of Saturn's dust environment

NASA Astrophysics Data System (ADS)

Srama, Ralf

2014-05-01

The interplanetary space probe Cassini/Huygens reached Saturn in July 2004 after seven years of cruise phase. Since then, the German-lead Cosmic Dust Analyser (CDA) was operated continuously for 10 years in orbit around Saturn. The first discovery of CDA related to Saturn was the measurement of nanometer sized dust particles ejected by its magnetosphere to interplanetary space with speeds higher than 100 km/s. Their origin and composition was analysed and an their dynamical studies showed a strong link to the conditions of the solar wind plasma flow. A recent surprising result was, that stream particles stem from the interior of Enceladus. Since 2004 CDA measured millions of dust impacts characterizing the dust environment of Saturn. The instrument showed strong evidence for ice geysers located at the south pole of Saturn's moon Enceladus in 2005. Later, a detailed compositional analysis of the salt-rich water ice grains in Saturn's E ring system lead to the discovery of liquid water below the crust connected to an ocean at depth feeding the icy jets. CDA was even capable to derive a spatially resolved compositional profile of the plume during close Enceladus flybys. A determination of the dust-magnetosphere interaction and the discovery of the extended E ring (at least twice as large as previously known) allowed the definition of a dynamical dust model of Saturns E ring describing the observed properties. Cassini performed shadow crossings in the ring plane and dust grain charges were measured in shadow regions delivering important data for dust-plasma interaction studies. In the last years, dedicated measurement campaigns were executed by CDA to monitor the flux of interplanetary and interstellar dust particles reaching Saturn.

The Impact Ejecta Environment of Near Earth Asteroids

NASA Astrophysics Data System (ADS)

Szalay, Jamey R.; Horányi, Mihály

2016-10-01

Impact ejecta production is a ubiquitous process that occurs on all airless bodies throughout the solar system. Unlike the Moon, which retains a large fraction of its ejecta, asteroids primarily shed their ejecta into the interplanetary dust population. These grains carry valuable information about the chemical compositions of their parent bodies that can be measured via in situ dust detection. Here, we use recent Lunar Atmosphere and Dust Environment Explorer/Lunar Dust Experiment measurements of the lunar dust cloud to calculate the dust ejecta distribution for any airless body near 1 au. We expect this dust distribution to be highly asymmetric, due to non-isotropic impacting fluxes. We predict that flybys near these asteroids would collect many times more dust impacts by transiting the apex side of the body compared to its anti-apex side. While these results are valid for bodies at 1 au, they can be used to qualitatively infer the ejecta environment for all solar-orbiting airless bodies.

Do we detect interplanetary dust with Faraday cups?

NASA Astrophysics Data System (ADS)

Kočiščák, S.; Pavlů, J.; Šafránková, J.; Němeček, Z.; Přech, L.

2018-07-01

Transient clouds of a plasma generated by hypervelocity dust particles impacting onto the spacecraft were observed in-situ by many experiments over the last 20 years. The reported observations analyze sensitive measurements of plasma waves that are transmitted to the Earth with a sufficient time resolution. The detection is based on a fact that hypervelocity impacts generate plumes of the ionized gas expanding into a space. The present paper analyzes five years of the operation of the Bright Monitor of the Solar Wind (BMSW) onboard the Spektr-R spacecraft with a motivation to demonstrate that such type of the instruments is capable to observe the dust impacts into its detectors. The results of analysis are compared with Wind electric field measurements used for a detection of hypervelocity dust impacts.

Accretion of Interplanetary Dust: A New Record from He-3 In Polar Ice Cores

NASA Technical Reports Server (NTRS)

Brook, Edward

2002-01-01

This grant funded measurements of extraterrestrial He-3 in particles extracted from polar ice samples. The overall objective was to develop measurements of He-3 as tracers of the flux of interplanetary dust particles (IDP's) to the earth. To our knowledge these are the first such measurements, apart from our earlier work. The project also funded an EPO activity - a climate and global change workshop for high school science teachers.

A Database of Interplanetary and Interstellar Dust Detected by the Wind Spacecraft

NASA Technical Reports Server (NTRS)

Malaspina, David M.; Wilson, Lynn B., III

2016-01-01

It was recently discovered that the WAVES instrument on the Wind spacecraft has been detecting, in situ, interplanetary and interstellar dust of approximately 1 micron radius for the past 22 years. These data have the potential to enable advances in the study of cosmic dust and dust-plasma coupling within the heliosphere due to several unique properties: the Wind dust database spans two full solar cycles; it contains over 107,000 dust detections; it contains information about dust grain direction of motion; it contains data exclusively from the space environment within 350 Earth radii of Earth; and it overlaps by 12 years with the Ulysses dust database. Further, changes to the WAVES antenna response and the plasma environment traversed by Wind over the lifetime of the Wind mission create an opportunity for these data to inform investigations of the physics governing the coupling of dust impacts on spacecraft surfaces to electric field antennas. A Wind dust database has been created to make the Wind dust data easily accessible to the heliophysics community and other researchers. This work describes the motivation, methodology, contents, and accessibility of the Wind dust database.

The thermal history of interplanetary dust particles collected in the Earth's stratosphere

NASA Technical Reports Server (NTRS)

Nier, A. O.; Schlutter, D. J.

1993-01-01

Fragments of 24 individual interplanetary dust particles (IDPs) collected in the Earth's stratosphere were obtained from NASA's Johnson Space Center collection and subjected to pulse-heating sequences to extract He and Ne and to learn about the thermal history of the particles. A motivation for the investigation was to see if the procedure would help distinguish between IDPs of asteroidal and cometary origin. The use of a sequence of short-duration heat pulses to perform the extractions is an improvement over the employment of a step-heating sequence, as was used in a previous investigation. The particles studied were fragments of larger parent IDPs, other fragments of which, in coordinated experiments, are undergoing studies of elemental and mineralogical composition in other laboratories. While the present investigation will provide useful temperature history data for the particles, the relatively large size of the parent IDPs (approximately 40 micrometers in diameter) resulted in high entry deceleration temperatures. This limited the usefulness of the study for distinguishing between particles of asteroidal and cometary origin.

Discovery of nuclear tracks in interplanetary dust

NASA Technical Reports Server (NTRS)

Bradley, J. P.; Brownlee, D. E.; Fraundorf, P.

1984-01-01

Nuclear tracks have been identified in interplanetary dust particles (IDP's) collected from the stratosphere. The presence of tracks unambiguously confirms the extraterrestrial nature of IDP's, and the high track densities (10 to the 10th to 10 to the 11th per square centimeter) suggest an exposure age of approximately 10,000 years within the inner solar system. Tracks also provide an upper temperature limit for the heating of IDP's during atmospheric entry, thereby making it possible to distinguish between pristine and thermally modified micrometeorites.

Laboratory Investigations of the Physical and Optical Properties of the Analogs of Individual Cosmic Dust Grains

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Tankosic, D.; Craven, P. D.; Spann, J. F.; LeClair, A.; West, E. A.

2005-01-01

Microdsub-micron size cosmic dust grains play an important role in the physical and dynamical process in the galaxy, the interstellar medium, and the interplanetary and planetary environments. The dust grains in various astrophysical environments are generally charged by a variety of mechanisms that include collisional process with electrons and ions, and photoelectric emissions with UV radiation. The photoelectric emission process is believed to be the dominant process in many astrophysical environments with nearby UV sources, such as the interstellar medium, diffuse clouds, the outer regions of the dense molecular clouds, interplanetary medium, dust in planetary environments and rings, cometary tails, etc. Also, the processes and mechanisms involved in the rotation and alignment of interstellar dust grains are of great interest in view of the polarization of observed starlight as a probe for evaluation of the galactic magnetic field.

Science & Technology Review September 2005

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aufderheide III, M B

2005-07-19

This month's issue has the following articles: (1) The Pursuit of Fusion Energy--Commentary by William H. Goldstein; (2) A Dynamo of a Plasma--The self-organizing magnetized plasmas in a Livermore fusion energy experiment are akin to solar flares and galactic jets; (3) How One Equation Changed the World--A three-page paper by Albert Einstein revolutionized physics by linking mass and energy; (4) Recycled Equations Help Verify Livermore Codes--New analytic solutions for imploding spherical shells give scientists additional tools for verifying codes; and (5) Dust That.s Worth Keeping--Scientists have solved the mystery of an astronomical spectral feature in interplanetary dust particles.

Bismuth Oxide Nanoparticles in the Stratosphere

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.; Mackinnon, Ian D. R.

1997-01-01

Platey grains of cubic Bi2O3, alpha-Bi2O3, and Bi2O(2.75), nanograins were associated with chondritic porous interplanetary dust particles W7029C1, W7029E5, and 2011C2 that were collected in the stratosphere at 17-19 km altitude. Similar Bi oxide nanograins were present in the upper stratosphere during May 1985. These grains are linked to the plumes of several major volcanic eruptions during the early 1980s that injected material into the stratosphere. The mass of sulfur from these eruptions is a proxy for the mass of stratospheric Bi from which we derive the particle number densities (p/cu m) for "average Bi2O3 nanograins" due to this volcanic activity and those necessary to contaminate the extraterrestrial chondritic porous interplanetary dust particles via collisional sticking. The match between both values supports the idea that Bi2O3 nanograins of volcanic origin could contaminate interplanetary dust particles in the Earth's stratosphere.

The status of measurement technologies concerning micrometer and submicrometer space articulate matter capture, recovery, velocity and trajectory

NASA Technical Reports Server (NTRS)

Alexander, W. M.; Tanner, William G.; Mcdonald, R. A.; Schaub, G. E.; Stephenson, Stepheni L.; Mcdonnell, J. A. M.; Maag, Carl R.

1994-01-01

The return of a pristine sample from a comet would lead to greater understanding of cometary structures, as well as offering insights into exobiology. The paper presented at the Discovery Program Workshop outlined a set of measurements for what was identified as a SOCCER-like interplanetary mission. Several experiments comprised the total instrumentation. This paper presents a summary of CCSR with an overview of three of the four major instruments. Details of the major dust dynamics experiment including trajectory are given in this paper. The instrument proposed here offers the opportunity for the return of cometary dust particles gathered in situ. The capture process has been employed aboard the space shuttle with successful results in returning samples to Earth for laboratory analysis. In addition, the sensors will measure the charge, mass, velocity, and size of cometary dust grains during the encounter. This data will help our understanding of dusty plasmas.

IDE spatio-temporal impact fluxes and high time-resolution studies of multi-impact events and long-lived debris clouds

NASA Technical Reports Server (NTRS)

Mulholland, J. Derral; Singer, S. Fred; Oliver, John P.; Weinberg, Jerry L.; Cooke, William J.; Montague, Nancy L.; Wortman, Jim J.; Kassel, Phillip C.; Kinard, William H.

1992-01-01

The purpose of the Interplanetary Dust Experiment (IDE) on the Long Duration Exposure Facility (LDEF) was to sample the cosmic dust environment and to use the spatio-temporal aspect of the experiment to distinguish between the various components of the environment: zodiacal cloud, beta meteoroids, meteor streams, interstellar dust, and orbital debris. It was found that the introduction of precise time and even rudimentary directionality as co-lateral observables in sampling the particulate environment in near-Earth space produces an enormous qualitative improvement in the information content of the impact data. The orbital debris population is extremely clumpy, being dominated by persistent clouds in which the fluxes may rise orders of magnitude above the background. The IDE data suggest a strategy to minimize the damage to sensitive spacecraft components, using the observed characteristics of cloud encounters.

Hyperdust : An advanced in-situ detection and chemical analysis of microparticles in space

NASA Astrophysics Data System (ADS)

Sternovsky, Z.; Gruen, E.; Horanyi, M.; Kempf, S.; Maute, K.; Srama, R.

2014-12-01

Interplanetary dust that originates from comets and asteroids may be in different stages of Solar System evolution. Atmosphereless planetary bodies, e.g., planetary satellites, asteroids, or Kuiper belt objects are enshrouded in clouds of dust released by meteoroid impacts or by volcanism. The ejecta grains are samples from the surface of these objects and their analysis can be performed from orbit or flyby to determine the surface composition, interior structure and ongoing geochemical processes. Early dust mass spectrometers on the Halley missions had sufficient mass resolution in order to provide important cosmochemical information in the near-comet high dust flux environment. The Ulysses dust detector discovered interstellar grains within the planetary system (Gruen et al. A&A, 1994) and its twin detector on Galileo discovered the tenuous dust clouds around the Galilean satellites (Krueger et al., Icarus, 2003). The similar-sized Cosmic Dust Analyzer onboard the Cassini mission combined a highly sensitive dust detector with a low-mass resolution mass spectrometer. Compositional dust measurements from this instrument probed the deep interior of Saturn's Enceladus satellite (Postberg et al., Nature, 2009). Based on this experience new instrumentation was developed that combined the best attributes of all these predecessors and exceeded their capabilities in accurate trajectory determination. The Hyperdust instrument is a combination of a Dust Trajectory Sensor (DTS) together with an analyzer for the chemical composition of dust particles in space. Dust particles' trajectories are determined by the measurement of induced electric signals. Large area chemical analyzers of 0.1 m2 sensitive area have been tested at a dust accelerator and it was demonstrated that they have sufficient mass resolution to resolve ions with atomic mass number >100. The Hyperdust instrument is capable of distinguishing interstellar and interplanetary grains based on their trajectory composition information. In orbit or flyby near airless planetary bodies the instrument can map the surface compositional down to a spatial resolution of ~10 km. The Hyperdust instrument is currently being developed to TRL 6 funded by NASA's MatISSE program to be a low-mass, high performance instrument for future in-situ exploration.

Silica aerogel for capturing intact interplanetary dust particles for the Tanpopo experiment.

PubMed

Tabata, Makoto; Yano, Hajime; Kawai, Hideyuki; Imai, Eiichi; Kawaguchi, Yuko; Hashimoto, Hirofumi; Yamagishi, Akihiko

2015-06-01

In this paper, we report the progress in developing a silica-aerogel-based cosmic dust capture panel for use in the Tanpopo experiment on the International Space Station (ISS). Previous studies revealed that ultralow-density silica aerogel tiles, comprising two layers with densities of 0.01 and 0.03 g/cm(3) developed using our production technique, were suitable for achieving the scientific objectives of the astrobiological mission. A special density configuration (i.e., box framing) aerogel with a holder was designed to construct the capture panels. Qualification tests for an engineering model of the capture panel as an instrument aboard the ISS were successful. Sixty box-framing aerogel tiles were manufactured in a contamination-controlled environment.

Interrelationships between interstellar and interplanetary grains

NASA Technical Reports Server (NTRS)

Clayton, D. D.

1986-01-01

The relationship between solar system dust (SSD) and interstellar dust particles (ISMD) is being reconsidered because of the discovery of isotopic anomalies in meteorites. Meteoritic, circumstellar/meteoritic, interstellar/meteoritic, planetary, and cometary data are reviewed.

Dust Observations by Faraday Cups Onboard Spektr-R

NASA Astrophysics Data System (ADS)

Pavlu, J.; Kociscak, S.; Safrankova, J.; Nemecek, Z.; Prech, L.

2017-12-01

Dust of both interstellar and interplanetary origins was reported in many in-situ experiments devoted to dust detection during past tens of years. Recently, a number of reports employed unintended devices to observe dust (Voyager, Cassini, STEREO …). Most of such observations is based on impact ionization occurring when hypervelocity grains hit a surface being vaporized together with a portion of the surface material. The thermal ionization generates a plasma plume and the dust detection is based on collection of plasma particles by, e.g., antennas. In this contribution, we apply a similar approach to dust impact detection using the multi Faraday cup instrument (BMSW) onboard the Spektr-R spacecraft. It is orbiting the Earth along the highly elliptical trajectory with perigee of 2 and apogee of 50 Re. The BMSW instrument consists of 6 Faraday cups measuring local environmental properties with a rate as high as 30 Hz, i.e., high enough to detect aforementioned plasma plumes. The advantages of the multiple Faraday cup instrument include an easy recognition of dust impacts among plasma disturbances/solitons — dust grain impact can be detected only by one Faraday cup at a given time. We analyze Faraday cup waveforms applying simple criteria on impact spike shape and find a number of dust impact candidates. Based on this experience, we suggest a modification of future devices with a similar detection system.

Interrelationships among Circumstellar, Interstellar and Interplanetary Dust

NASA Technical Reports Server (NTRS)

Nuth, J. A., III (Editor); Stencel, R. E. (Editor)

1986-01-01

Proceedings of a workshop held from February 27 to March 1, l985. The workshop was attended by 50 astronomers, astrophysicists, planetary scientists and meteoriticists; and emphasized the interdisciplinary nature of studies of cosmic dust.

Study of cosmic dust particles on board LDEF: The FRECOPA experiments AO138-1 and AO138-2

NASA Technical Reports Server (NTRS)

Mandeville, J. C.; Borg, Janet

1992-01-01

Two experiments, within the French Cooperative Payload (FRECOPA) and devoted to the detection of cosmic dust, were flown on the LDEF. A variety of sensors and collecting devices have made possible the study of impact processes on materials of technological interest. Preliminary examination of hypervelocity impact features gives valuable data on size distribution and nature of interplanetary dust particles in low earth orbit, within the 0.5 to 300 micrometer size range. Most of the events detected on the trailing face of LDEF are expected to be the result of impacts of meteoritic particles only. So far, chemical analysis of craters by EDS clearly shows evidence of elements (Na, Mg, Si, S, Ca, and Fe) consistent with cosmic origin. Systematic occurrence of C and O in crater residues is an important result, to be compared with the existence of CHON particles detected in P-Halley comet nucleus. Crater size distribution is in good agreement with results from other dust experiments flown on LDEF. However, no crater smaller than 1.5 micron was observed, thus suggesting a cutoff in the near earth particle distribution. Possible origin and orbital evolution of micrometeoroids is discussed.

Nucleus structure and dust morphology: Post-Rosetta understanding and implications

NASA Astrophysics Data System (ADS)

Levasseur-Regourd, A.; Bentley, Mark; Ciarletti, Valérie; Kofman, Woldek; Lasue, Jeremie; Mannel, Thurid; Herique, Alain

2017-10-01

The structure of cometary nuclei and the morphology of dust particles they eject have long been unknowns in cometary science. The combination of these two subjects, as revealed by the Rosetta mission at 67P/C-G, is currently providing an unprecedented insight about Solar System formation and early evolution.Rosetta has established that the bulk porosity of 67P/C-G nucleus is high, in the 70% to 85% range, both from the determination of its density and from permittivity measurements with CONSERT bistatic radar experiment [1-2]. CONSERT, through operations after Philae landing on 12-13 November 2014, has also allowed us to estimate that i) the porosity is likely to be higher inside the nucleus than on its subsurface, ii) a major component of the nucleus is refractory carbonaceous compounds, and iii) the small lobe is homogeneous at a scale of a few wavelengths (i.e., about 10 m), while heterogeneities in the 3-m range (similar to the rounded nodules noticed on walls of large pits) cannot be ruled out [2-4].Rosetta has also established, through its 26 months rendezvous with 67P/C-G, the aggregated structure of dust particles within a wide range of sizes in the inner cometary coma. The MIDAS atomic force microscope experiment has given us evidence (from 3D topographic images with nano- to micrometer resolution) for i) a hierarchical structure of aggregated dust particles, down to tens of nm-sized grains, ii) one extremely porous dust particle, with a fractal dimension of (1.7 ± 0.1) [5-6]. The accuracy of comparisons between cometary dust particles and interplanetary dust particles collected in the stratosphere (including CP-IDPs) could thus be improved.Such results should further refine the main processes (e.g., low velocity aggregation) that allowed the formation of comets in the early Solar System, and the implications of a possible late heavy bombardment on the interplanetary dust clouds and on telluric planets.References. 1. Pätzold et al. Nature 530 63 2016. 2. Kofman et al. Science 349 6247 2015. 3. Herique et al. MNRAS 462 S516 2016. 4. Ciarletti et al. A&A 583 A40 2015. 5. Bentley et al., Nature 537 73 2016. 6. Mannel et al., MNRAS 462 S304 2016.

Dust Measurements by the Student Dust Counter (SDC) onboard the New Horizons Mission

NASA Astrophysics Data System (ADS)

James, David; Horanyi, Mihaly; Poppe, Andrew

The Venetia Burney Student Dust Counter (VSDC) on the New Horizons spacecraft is a dust impact detector designed to map the interplanetary dust distribution along the trajectory of the New Horizons spacecraft as it traverses our solar system. VSDC is the first student built instrument on a deep space mission and is currently operated by a small group of undergraduate and graduate students at the Laboratory for Atmospheric and Space Physics (LASP), University of Colorado. VSDC is based on permanently polarized thin plastic film sensors that generate an electrical signal when an impacting dust particle penetrates them. The total surface area is about 0.1 square meters and the detection threshold is about 1 micron in radius. By the time of this meeting (7/2008), VSDC will have operated for about 500 days, covering an approximate distance of 1.2 to 10.5 AU. In this talk, we will briefly review the VSDC instrument, including the in-flight calibrations and tests. We will report on the measured spatial and size distribution of interplanetary dust particles before and after the New Horizons encounter with Jupiter. These data will also be compared to earlier measurements by Ulysses, Galileo and Cassini.

Division F Commission 22: Meteors, Meteorites, and Interplanetary Dust

NASA Astrophysics Data System (ADS)

Jenniskens, Peter; Borovička, Jiří; Watanabe, Jun-Ichi; Jopek, Tadeusz; Abe, Shinsuke; Consolmagno, Guy J.; Ishiguro, Masateru; Janches, Diego; Ryabova, Galina O.; Vaubaillon, Jérémie; Zhu, Jin

2016-04-01

Commission 22 (Meteors, Meteorites and Interplanetary Dust) was established at the first IAU General Assembly held in Rome in 1922, with William Frederick Denning as its first President. Denning was an accountant by profession, but as an amateur astronomer he contributed extensively to meteor science. Commission 22 thus established a pattern that has continued to this day that non-professional astronomers were welcomed and valued and could play a significant role in its affairs. The field of meteors, meteorites and interplanetary dust has played a disproportional role in the astronomical perception of the general public through the majestic displays of our annual meteor showers. Those in the field deployed many techniques uncommon in other fields of astronomy, studying the ``vermin of space'', the small solid bodies that pervade interplanetary space and impact Earth's atmosphere, the surface of the Moon, and that of our satellites in orbit. Over time, the field has tackled a wide array of problems, from predicting the encounter with meteoroid streams, to the origin of our meteorites and the nature of the zodiacal cloud. Commission 22 has played an important role in organizing the field through dedicated meetings, a data centre, and working groups that developed professional-amateur relationships and that organized the nomenclature of meteor showers. The contribution of Commission 22 to the field is perhaps most readily seen in the work of the presidents that followed in the footsteps of Denning.

Derivation of particulate directional information from analysis of elliptical impact craters on LDEF

NASA Technical Reports Server (NTRS)

Newman, P. J.; Mackay, N.; Deshpande, S. P.; Green, S. F.; Mcdonnell, J. A. M.

1993-01-01

The Long Duration Exposure Facility provided a gravity gradient stabilized platform which allowed limited directional information to be derived from particle impact experiments. The morphology of impact craters on semi-infinite materials contains information which may be used to determine the direction of impact much more accurately. We demonstrate the applicability of this technique and present preliminary results of measurements from LDEF and modelling of interplanetary dust and space debris.

New Manganese Silicide Mineral Phase in an Interplanetary Dust Particle

NASA Technical Reports Server (NTRS)

Nakamura-Messenger, K.; Keller, L. P.; Clemett, S. J.; Jones, J. H.; Palma, R. L.; Pepin, R. O.; Kloeck, W.; Zolensky, M. E.; Messenger, S.

2008-01-01

Comet 26P/Grigg-Skjellerup was identified as a source of an Earth-crossing dust stream with low Earth-encounter velocities, with peak anticipated fluxes during April in 2003 and 2004 [1]. In response to this prediction, NASA performed dedicated stratospheric dust collections using high altitude aircraft to target potential interplanetary dust particles (IDPs) from this comet stream in April 2003. Several IDPs from this collection have shown unusually low noble gas abundances [2] consistent with the predicted short space exposure ages of Grigg-Skjellerup dust particles [1]. High abundances of large D enrichments [3] and presolar grains [4] in IDPs from this collection are also consistent with an origin from the comet Grigg-Skjellerup. Here we report a new mineral from one of the cluster IDPs of the "Grigg-Skjellerup" collection, L2055. Our report focuses on an unusual manganese-iron-chromium silicide phase that, to our knowledge, has not been observed previously in nature. This unique phase may also shed light on the genesis of the enigmatic low-Fe,Mn-enriched (LIME) olivine that has been previously reported in IDPs and meteorites [5].

Final Reports of the Stardust ISPE: Seven Probable Interstellar Dust Particles

NASA Technical Reports Server (NTRS)

Allen, Carlton; Sans Tresseras, Juan-Angel; Westphal, Andrew J.; Stroud, Rhonda M.; Bechtel, Hans A.; Brenker, Frank E.; Butterworth, Anna L.; Flynn, George J.; Frank, David R.; Gainsforth, Zack;

ICPP: Introduction to Dusty Plasma Physics

NASA Astrophysics Data System (ADS)

Kant Shukla, Padma

2000-10-01

Two omnipresent ingredients of the Universe are plasmas and charged dust. The interplay between these two has opened up a new and fascinating research area, that of dusty plasmas, which are ubiquitous in in different parts of our solar system, namely planetary rings, circumsolar dust rings, interplanetary medium, cometary comae and tails, interstellar molecular clouds, etc. Dusty plasmas also occur in noctilucent clouds in the arctic troposphere and mesosphere, cloud-to-ground lightening in thunderstorms containing smoke-contaminated air over the US, in the flame of humble candle, as well as in microelectronics and in low-temperature laboratory discharges. In the latter, charged dust grains are strongly correlated. Dusty plasma physics has appeared as one of the most rapidly growing field of science, besides the field of the Bose-Einstein condensate, as demonstrated by the number of published papers in scientific journals and conference proceedings. In fact, it is a truly interdisciplinary science because it has many potential applications in astrophysics (viz. in understanding the formation of dust clusters and structures, instabilities of interstellar molecular clouds and star formation, decoupling of magnetic fields from plasmas, etc.) as well as in the planetary magnetospheres of our solar system [viz. the Saturn (particularly, the physics of spokes and braids in B and F rings), Jupiter, Uranus, Neptune, and Mars] and in strongly coupled laboratory dusty plasmas. Since dusty plasma system involves the charging and the dynamics of extremely massive charged dust particulates, it can be characterized as a complex plasma system with new physics insights. In this talk, I shall describe the basic physics of dusty plasmas and present the status of numerous collective processes that are relevant to space research and laboratory experiments. The focus will be on theoretical and experimental observations of novel waves and instabilities, various forces, and some nonlinear structures (such as dust ion-acoustic shocks, Mach cones, dust voids, vortices, etc). The latter are typical in astrophysical settings and in microgravity experiments. It appears that collective processes in a complex dusty plasma would have excellent future perspectives in the twenty first century, because they have not only potential applications in interplanetary space environments, or in understanding the physics of our universe, but also in advancing our scientific knowledge in multi-disciplinary areas of science.

Cellular Precipitates Of Iron Oxide in Olivine in a Stratospheric Interplanetary Dust Particle

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1996-01-01

The petrology of a massive olivine-sulphide interplanetary dust particle shows melting of Fe,Ni-sulphide plus complete loss of sulphur and subsequent quenching to a mixture of iron-oxides and Fe,Ni-metal. Oxidation of the fayalite component in olivine produced maghemite discs and cellular intergrowths with olivine and rare andradite-rich garnet. Cellular reactions require no long-range solid-state diffusion and are kinetically favourable during pyrometamorphic oxidation. Local melting of the cellular intergrowths resulted in three dimensional symplectic textures. Dynamic pyrometamorphism of this asteroidal particle occurred at approx. 1100 C during atmospheric entry flash (5-15 s) heating.

Combined infrared and analytical electron microscope studies of interplanetary dust particles

NASA Technical Reports Server (NTRS)

Bradley, J. P.; Humecki, H. J.; Germani, M. S.

1992-01-01

Ultramicrotomed thin sections (less than 100 nm thick) of eight chondritic interplanetary dust particles (IDPs) were studied by analytical electron microscopy and IR microspectroscopy with the objective of identifying IDPs or their specific components with IR spectral transmission characteristics at 10 microns similar to those of comets. Two IDPs are identified whose silicate emission characteristics between 8 and 12 microns are similar to those of comets Halley and Bradfield. Implanted solar flare tracks and sputtered rims resulting from solar wind damage suggest that the minerology and petrography of these IDPs have not been significantly perturbed since ejection from their parent bodies.

Carbon Raman Spectroscopy of 36 Inter-Planetary Dust Particles

NASA Technical Reports Server (NTRS)

Busemann, H.; Nittler, L. R.; Davidson, J.; Franchi, I. A.; Messenger, S.; Nakamura-Messenger, K.; Palma, R. L.; Pepin, R. O.

2009-01-01

Carbon Raman spectroscopy is a useful tool to determine the degree of order of organic material (OM) in extra-terrestrial matter. As shown for meteoritic OM [e.g., 2], peak parameters of D and G bands are a measure of thermal alteration, causing graphitization (order), and amorphization, e.g. during protoplanetary irradiation, causing disorder. Th e most pristine interplanetary dust particles (IDPs) may come from comets. However, their exact provenance is unknown. IDP collection during Earth?s passage through comet Grigg-Skjellerup?s dust stream ("GSC" collectors) may increase the probability of collecting fresh IDPs from a known, cometary source. We used Raman spectroscopy to compare 21 GSC-IDPs with 15 IDPs collected at different periods, and found that the variation among GSC-IDPs is larger than among non-GSC IDPs, with the most primitive IDPs being mostly GSC-IDPs.

Ultrafine-grained mineralogy and matrix chemistry of olivine-rich chondritic interplanetary dust particles

NASA Technical Reports Server (NTRS)

Rietmeijer, F. J. M.

1989-01-01

Olivine-rich chondritic interplanetary dust particles (IDPs) are an important subset of fluffy chondritic IDPs collected in the earth's stratosphere. Particles in this subset are characterized by a matrix of nonporous, ultrafine-grained granular units. Euhedral single crystals, crystals fragments, and platey single crystals occur dispersed in the matrix. Analytical electron microscopy of granular units reveals predominant magnesium-rich olivines and FeNi-sulfides embedded in amorphous carbonaceous matrix material. The variable ratio of ultrafine-grained minerals vs. carbonaceous matrix material in granular units support variable C/Si ratios, and some fraction of sulfur is associated with carbonaceous matrix material. The high Mg/(Mg+Fe) ratios in granular units is similar to this distribution in P/Comet Halley dust. The chondritic composition of fine-grained, polycrystalline IDPs gradually breaks down into nonchondritic, and ultimately, single mineral compositions as a function of decreased particle mass. The relationship between particle mass and composition in the matrix of olivine-rich chondritic IDPs is comparable with the relationship inferred for P/Comet Halley dust.

Micrometeoroids and debris on LDEF

NASA Technical Reports Server (NTRS)

Mandeville, Jean-Claude

1993-01-01

Two experiments within the French Cooperative Payload (FRECOPA) and devoted to the detection of cosmic dust were flown on the Long Duration Exposure Facility (LDEF). A variety of sensors and collecting devices have made possible the study of impact processes on dedicated sensors and on materials of technological interest. Examination of hypervelocity impact features on these experiments gives valuable information on the size distribution and nature of interplanetary dust particles in low-Earth orbit (LEO), within the 0.5-300 micrometer size range. However no crater smaller than 1.5 microns has been observed, thus suggesting a cut-off in the near Earth particle distribution. Chemical investigation of craters by EDX clearly shows evidence of elements (Na, Mg, Si, S, Ca, and Fe) consistent with cosmic origin. However, remnants of orbital debris have been found in a few craters; this can be the result of particles in eccentric orbits about the Earth and of the 8 deg offset in the orientation of LDEF. Crater size distribution is compared with results from other dust experiments flown on LDEF and with current models. Possible origin and orbital evolution of micrometeoroids is discussed. Use of thin foil detectors for the chemical study of particle remnants looks promising for future experiments.

Laboratory Studies of the Optical Properties and Condensation Processes of Cosmic Dust Grains

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; West, E.; Sheldon, R.; Witherow, W. K.; Gallagher, D. L.; Adrian, M. L.

2002-01-01

A laboratory facility for conducting a variety of experiments on single isolated dust particles of astrophysical interest levitated in an electrodynamics balance has been developed at NASA/Marshall Space Flight Center. The objective of the research is to employ this experimental technique for studies of the physical and optical properties of individual cosmic dust grains of 0.1-100 micron size in controlled pressure/temperatures environments simulating astrophysical conditions. The physical and optical properties of the analogs of interstellar and interplanetary dust grains of known composition and size distribution will be investigated by this facility. In particular, we will carry out three classes of experiments to study the micro-physics of cosmic dust grains. (1) Charge characteristics of micron size single dust grains to determine the photoelectric efficiencies, yields, and equilibrium potentials when exposed to UV radiation. (2) Infrared optical properties of dust particles (extinction coefficients and scattering phase functions) in the 1-30 micron region using infrared diode lasers and measuring the scattered radiation. (3) Condensation experiments to investigate the condensation of volatile gases on colder nucleated particles in dense interstellar clouds and lower planetary atmospheres. The condensation experiments will involve levitated nucleus dust grains of known composition and initial mass (or m/q ratio), cooled to a temperature and pressure (or scaled pressure) simulating the astrophysical conditions, and injection of a volatile gas at a higher temperature from a controlled port. The increase in the mass due to condensation on the particle will be monitored as a function of the dust particle temperature and the partial pressure of the injected volatile gas. The measured data will permit determination of the sticking coefficients of volatile gases and growth rates of dust particles of astrophysical interest. Some preliminary results based on measurements of photoelectric emission and radiation pressure on single isolated 0.2 to 6.6 micron size silica particles exposed to UV radiation at 120-200 nm and green laser light at 532 nm are presented.

Dust Measurements Between Earth and Saturn by the Venetia Burney Student Dust Counter of the New Horizons Mission

NASA Astrophysics Data System (ADS)

James, D.; Poppe, A.; Horanyi, M.

2008-12-01

The Venetia Burney Student Dust Counter (VSDC) on the New Horizons mission is a dust impact detector designed to map the interplanetary dust distribution along the trajectory of the spacecraft as it traverses our solar system. VSDC is the first student-built instrument on a deep space mission and is currently operated by a small group of undergraduate and graduate students at the Laboratory for Atmospheric and Space Physics (LASP), University of Colorado. VSDC is based on permanently polarized thin plastic film sensors that generate an electrical signal when a dust particle impacts them. The total surface area is about 0.1 square meters and the detection threshold is about 1 micron in radius. By the time of this meeting (12/2008), VSDC will have operated for about 500 days, and will have data covering an approximate distance of 1.2 to 11.0 AU from the Sun. In this talk, we will briefly review the VSDC instrument, including the in-flight calibrations and tests. We will report on the measured spatial and size distribution of interplanetary dust particles before and after the New Horizons encounter with Jupiter. These data will also be compared to earlier measurements by Ulysses and Galileo.

Investigations of the Formation of Carbon Grains in Circumstellar Outflows

NASA Technical Reports Server (NTRS)

Contreras, Cesar; Salama, Farid

2013-01-01

The study of formation and destruction processes of cosmic dust is essential to understand and to quantify the budget of extraterrestrial organic molecules. Although dust with all its components plays an important role in the evolution of interstellar chemistry and in the formation of organic molecules, little is known on the formation and destruction processes of carbonaceous dust. PAHs are important chemical building blocks of interstellar dust. They are detected in interplanetary dust particles and in meteoritic samples. Additionally, observational, laboratory, and theoretical studies have shown that PAHs, in their neutral and ionized forms, are an important, ubiquitous component of the interstellar medium. Also, the formation of PAHs from smaller molecules has not been extensively studied. Therefore, it is imperative that laboratory experiments be conducted to study the dynamic processes of carbon grain formation from PAH precursors. Studies of interstellar dust analogs formed from a variety of PAH and hydrocarbon precursors as well as species that include the atoms O, N, and S, have recently been performed in our laboratory under conditions that simulate interstellar and circumstellar environments. The species formed in the pulsed discharge nozzle (PDN) plasma source are detected and characterized with a high-sensitivity cavity ringdown spectrometer (CRDS) coupled to a Reflectron time-of-flight mass spectrometer (ReTOF-MS), thus providing both spectroscopic and ion mass information in-situ. We report the first set of measurements obtained in these experiments and identify the species present in the experiments and the ions that are formed in the plasma process. From these unique measurements, we derive information on the size and the structure of interstellar dust grain particles, the growth and the destruction processes of interstellar dust and the resulting budget of extraterrestrial organic molecules.

Metastable Eutectic Equilibrium in Natural Environments: Recent Development and Research Opportunities

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.; Nuth, Joseph A., III; Jablonska, Mariola; Karner, James M.

2000-01-01

Chemical ordering at metastable eutectics was recognized in non-equilibrium gas-to- solid condensation experiments to constrain 'silicate' dust formation in O-rich circumstellar environments. The predictable metastable eutectic behavior successfully predicted the observed ferromagnesiosilica compositions of circumstellar dust presolar and solar nebula grains in the matrix of the collected aggregate IDPs (Interplanetary Dust Particles). Many of the experimentally determined metastable eutectic solids match the fundamental building blocks of common rock-forming layer silicates: this could have implications for the origin of Life. The physical conditions conducive to metastable eutectic behavior, i.e. high temperature and (ultra) fast quenching, lead to unique amorphous, typically nano- to micrometer-sized, materials. The new paradigm of metastable eutectic behavior opens the door to new and exciting research opportunities in uncovering the many implications of these unique amorphous, and typically nano-to micrometer-sized, metastable eutectic materials.

Principal components - Petrology and chemistry of polyphase units in chondritic porous interplanetary dust particles

NASA Astrophysics Data System (ADS)

Rietmeijer, Frans J. M.

1997-03-01

Chondritic porous (CP) interplanetary dust particles (IDPs) can be described as 'cosmic sediments'. It should be possible to recognize in these IDPs the 4500 Myrs old solar nebula dusts. The studies of unaltered chondritic IDPs show that their matrices are a mixture of three different principal components (PCs) that also describe variable C/Si ratios of chondritic IDPs. Among others, PCs include polyphase units (PUs) that are amorphous to holocrystalline, both ultrafine- and coarse-grained, ferromagnesiosilica(te) materials with minor Al and Ca. The properties of PCs and their alteration products define the physical and chemical processes that produced and altered these components. PCs are also cornerstones of IDP classification. For example, the bulk composition of ultrafine-grained PCs can be reconstructed using the 'butterfly method' and also allows an evaluation of the metamorphic signatures, (e.g., dynamic pyrometamorphism), in chondritic IDPs.

Observations of interplanetary dust by the Juno magnetometer investigation

NASA Astrophysics Data System (ADS)

Benn, M.; Jorgensen, J. L.; Denver, T.; Brauer, P.; Jorgensen, P. S.; Andersen, A. C.; Connerney, J. E. P.; Oliversen, R.; Bolton, S. J.; Levin, S.

2017-05-01

One of the Juno magnetometer investigation's star cameras was configured to search for unidentified objects during Juno's transit en route to Jupiter. This camera detects and registers luminous objects to magnitude 8. Objects persisting in more than five consecutive images and moving with an apparent angular rate of between 2 and 18,000 arcsec/s were recorded. Among the objects detected were a small group of objects tracked briefly in close proximity to the spacecraft. The trajectory of these objects demonstrates that they originated on the Juno spacecraft, evidently excavated by micrometeoroid impacts on the solar arrays. The majority of detections occurred just prior to and shortly after Juno's transit of the asteroid belt. This rather novel detection technique utilizes the Juno spacecraft's prodigious 60 m2 of solar array as a dust detector and provides valuable information on the distribution and motion of interplanetary (>μm sized) dust.

The effects of electrostatic charging on the dust distribution at Halley's Comet

NASA Technical Reports Server (NTRS)

Horanyi, M.; Mendis, D. A.

1986-01-01

The distribution of fine dust near Comet Halley at its 1910 and 1986 apparitions is investigated by means of computer simulations, taking the effects of EM forces due to the dust electrostatic charge into account. It is found that the nucleus spin period and orbital obliquity estimated by Sekanina and Larson (1984) from the 1910 observations are unaffected by these EM forces because the 1910 dust morphology involved mainly large grains. For 1986, the orientation of the smaller dust is shown to depend on the interplanetary magnetic field, with implications for the dust distribution encountered by the Halley probes.

Automated thin-film analyses of anhydrous interplanetary dust particles in the analytical electron microscope

NASA Technical Reports Server (NTRS)

Bradley, J. P.; Germani, M. S.; Brownlee, D. E.

1989-01-01

An AEM apparatus equipped with digital beam control has obtained quantitative point-count analyses of thin sections taken from eight anhydrous chondritic interplanetary dust particles (IDPs); between 200 and 500 X-ray analyses were collected from each thin section and analyzed for Mg, Al, Si, S, Ca, Cr, Mn, Fe, and Ni. Two types of anhydrous chondritic aggregates were observed in the eight IDPs: one highly porous, the other less so. The eight anhydrous IDPs are characterizable as mixtures of fine- and coarse-grained aggregates, large mineral grains, glass, and carbonaceous materials. Their elemental concentrations follow those of solar abundances, suggesting that they are unperturbed by aqueous alteration.

Coordinated Stem and NanoSIMS Analysis of Enstatite Whiskers in Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Nakamura-Messenger, K.; Messenger, Scott; Keller, L. P.

2009-01-01

Enstatite whiskers (less than 10 micrometer length, less than 200 nanometer width) occur in chondritic-porous interplanetary dust particles (CP IDPs), an Antarctic micrometeorite and a comet 81P/Wild-2 sample. The whiskers are typically elongated along the [100] axis and contain axial screw dislocations, while those in terrestrial rocks and meteorites are elongated along [001]. The unique crystal morphologies and microstructures are consistent with the enstatite whiskers condensing above approximately 1300 K in a low-pressure nebular or circumstellar gas. To constrain the site of enstatite whisker formation, we carried out coordinated mineralogical, chemical and oxygen isotope measurements on enstatite whiskers in a CP IDP.

Charging of interplanetary grains

NASA Technical Reports Server (NTRS)

Baragiola, R. A.; Johnson, R. E.; Newcomb, John L.

1995-01-01

The objective of this program is to quantify, by laboratory experiments, the charging of ices and other insulators subject to irradiation with electrons, ions and ultraviolet photons and to model special conditions based on the data. The system and conditions to be studied are those relevant for charging of dust in magnetospheric plasmas. The measurements are supplemented by computer simulations of charging or grains under a variety of conditions. Our work for this period involved experiments on water ice, improved models of charging of ice grains for Saturn's E-ring, and the construction of apparatus for electron impact studies and measurements of electron energy distributions.

Meteoroid Measurements in the Deep Space Cruising and the Jupiter Trojan Rendezvous Phases of the Solar Power Sail Mission by the Arrayed Large-Area Dust Detectors in INterplanetary Space (ALADDIN)-II

NASA Astrophysics Data System (ADS)

Yano, H.; Hirai, T.; Arai, K.; Fujii, M.

2017-12-01

The PVDF thin films have been long, space-proven instruments for hypervelocity impact detection in the diverse regions of the Solar System from orbits of Venus by IKAROS and of Pluto by New Horizons. In particular, light weight but large area membranes of a solar sail spacecraft is an ideal location for such detectors to be deployed for detecting statistically enough nubers of so large micrometeoroids that are sensitive to mean motion resonances and other gravitational effects of flux enhancements and voids with planets. The IKAROS spacecraft first detected in situ dust flux enhancement and gap region within the Earth's circumsolar dust ring as well as those of Venus by 0.54 m^2 detection area of ALADDIN sensors on the slar sail membrane. Advancing this heritage, the Solar Power Sail membrane will carry 0.4+ m^2 ALADDIN-II PVDF sensors with improved impact signal prosessng units to detect both hyperveloity dust impacts in the interplanetary space cruising phase and slow dust impacts bound to the Jupiter Trojan region in its rendezvours phase.

On the Contribution of Asteroid Disruptions to the Interplanetary Dust Flux

NASA Astrophysics Data System (ADS)

Kehoe, T. J. J.; Kehoe, A. E.

2017-12-01

Recent modeling has shown the significant contribution of micron- to millimeter-sized particles released by the disruption of main-belt asteroids (MBAs) to the interplanetary dust particle (IDP) flux (e.g., Dermott et al., 2002; Nesvorný et al., 2003; Espy Kehoe et al., 2015). In this paper, we present the results of a study that indicates that the dust injected into the zodiacal cloud due to the catastrophic disruption of an asteroid is dominated by the release of its surface regolith particles. Our research suggests that disrupting a single asteroid with diameter O(100 km) will be enough to regenerate the entire zodiacal cloud. The breakup of smaller asteroids with diameters O(10 km) will likely produce more moderate, but still significant, changes in the dust environment of the inner solar system. As collisional disruptions of asteroids in this size range occur more frequently, it is important that we develop a better understanding of the injection of asteroidal material into the zodiacal cloud as a result of these type of events in order to determine the temporal evolution of the interplanetary dust flux. The results presented in this paper will lead to a better understanding of the threat to exploration activities due to the enhanced IDP flux resulting from the disruption of asteroidal regoliths. These findings can be employed to improve engineering models, for example, the NASA Meteoroid Engineering Model (MEM) that is widely utilized to assess the impact hazard to space hardware and activities in the inner solar system due to the natural meteoroid environment (McNamara et al., 2004). This is an important area of concern for current and future mission development purposes.

Interplanetary Dust Observations by the Juno MAG Investigation

NASA Astrophysics Data System (ADS)

Jørgensen, John; Benn, Mathias; Denver, Troelz; Connerney, Jack; Jørgensen, Peter; Bolton, Scott; Brauer, Peter; Levin, Steven; Oliversen, Ronald

2017-04-01

The spin-stabilized and solar powered Juno spacecraft recently concluded a 5-year voyage through the solar system en route to Jupiter, arriving on July 4th, 2016. During the cruise phase from Earth to the Jovian system, the Magnetometer investigation (MAG) operated two magnetic field sensors and four co-located imaging systems designed to provide accurate attitude knowledge for the MAG sensors. One of these four imaging sensors - camera "D" of the Advanced Stellar Compass (ASC) - was operated in a mode designed to detect all luminous objects in its field of view, recording and characterizing those not found in the on-board star catalog. The capability to detect and track such objects ("non-stellar objects", or NSOs) provides a unique opportunity to sense and characterize interplanetary dust particles. The camera's detection threshold was set to MV9 to minimize false detections and discourage tracking of known objects. On-board filtering algorithms selected only those objects tracked through more than 5 consecutive images and moving with an apparent angular rate between 15"/s and 10,000"/s. The coordinates (RA, DEC), intensity, and apparent velocity of such objects were stored for eventual downlink. Direct detection of proximate dust particles is precluded by their large (10-30 km/s) relative velocity and extreme angular rates, but their presence may be inferred using the collecting area of Juno's large ( 55m2) solar arrays. Dust particles impact the spacecraft at high velocity, creating an expanding plasma cloud and ejecta with modest (few m/s) velocities. These excavated particles are revealed in reflected sunlight and tracked moving away from the spacecraft from the point of impact. Application of this novel detection method during Juno's traversal of the solar system provides new information on the distribution of interplanetary (µm-sized) dust.

Origins and Dynamics of Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Dermott, Stanley F.

2005-01-01

This is a final report for research supported by the National Aeronautics and Space Administration issued through the Office of Space Science Planetary Geology and Geophysics Program, covering all relevant activities during its 3-year period of funding from 02/01/2002 through to 01/31/2005. The ongoing aim of the research supported through this grant, and now through a successor award, is to investigate the origin of interplanetary dust particles (IDPs) and their dynamical and collisional evolution, in order to: (1) understand the provenance of zodiacal cloud particles and their transport from their source regions to the inner solar system; (2) produce detailed models of the zodiacal cloud and its constituent components; (3) determine the origin of the dust particles accreted by the Earth; (4) ascertain the level of temporal variations in the dust environment of the inner solar system and the accretion rate of IDPs by the Earth, and evaluate potential effects on global climate; and to (5) exploit this research as a basis for interpreting the structure observed in exozodiacal clouds that may result from the collisional evolution of planetesimals and the presence of unseen planets.

Nitrogen Isotopic Anomalies in a Hydrous Interplanetary Dust Particle

NASA Technical Reports Server (NTRS)

Smith, J. B.; Dai, Z. R.; Weber, P. K.; Graham, G. A.; Hutcheon, I. D.; Bajt, S.; Ishii, H.; Bradley, J. P.

2005-01-01

Interplanetary dust particles (IDPs) collected in the stratosphere are the fine-grained end member (5 - 50 microns in size) of the meteoritic material available for investigation in the laboratory. IDPs are derived from either cometary or asteroidal sources. Some IDPs contain cosmically primitive materials with isotopic signatures reflecting presolar origins. Recent detailed studies using the NanoSIMS have shown there is a wide variation of isotopic signatures within individual IDPs; grains with a presolar signature have been observed surrounded by material with a solar isotopic composition. The majority of IDPs studied have been anhydrous. We report here results from integrated NanoSIMS/FIB/TEM/Synchrotron IR studies of a hydrous IDP, focused on understanding the correlations between the isotopic, mineralogical and chemical compositions of IDPs.

Multielement analysis of interplanetary dust particles using TOF-SIMS

NASA Technical Reports Server (NTRS)

Stephan, T.; Kloeck, W.; Jessberger, E. K.; Rulle, H.; Zehnpfenning, J.

1993-01-01

Sections of three stratospheric particles (U2015G1, W7029*A27, and L2005P9) were analyzed with TOF-SIMS (Time Of Flight-Secondary Ion Mass Spectrometry) continuing our efforts to investigate the element distribution in interplanetary dust particles (IDP's) with high lateral resolution (approximately 0.2 micron), to examine possible atmospheric contamination effects, and to further explore the abilities of this technique for element analysis of small samples. The samples, previously investigated with SXRF (synchrotron X-ray fluorescence analysis), are highly enriched in Br (Br/Fe: 59 x CI, 9.2 x CI, and 116 x CI, respectively). U2015G1 is the IDP with the by far highest Zn/Fe-ratio (81 x CI) ever reported in chondritic particles.

What predictions can be made on the nature of carbon and carbon-bearing compounds (hydrocarbons) in the interstellar medium based on studies of interplanetary dust particles?

NASA Technical Reports Server (NTRS)

Rietmeijer, F. J. M.

1986-01-01

The nature of hydrocarbons and properties of elemental carbon in circumstellar, interstellar, and interplanetary dust is a long standing problem in astronomy and meteorite research. The textures and crystallographical properties of poorly graphitized carbon (PGC) from carbonaceous chondrites and Chondritic Porous Aggregates (CPAs) are comparable with PGCs formed by dehydrogenation and carbonization of hydrocarbon precursors under natural terrestrial and experimental conditions. A multistage model of hydrocarbon diagenesis in CPA and carbonaceous chondrite (proto-) planetary parent bodies was proposed in which hydrocarbons are subjected to low temperature hydrous pyrolysis. Continued efforts to recognize hydrocarbons and elemental phases in CPAs may allow understanding of the multistage hydrocarbon/elemental carbon model.

LDEF Interplanetary Dust Experiment (IDE) results

NASA Technical Reports Server (NTRS)

Oliver, John P.; Singer, S. F.; Weinberg, J. L.; Simon, C. G.; Cooke, W. J.; Kassel, P. C.; Kinard, W. H.; Mulholland, J. D.; Wortman, J. J.

1995-01-01

The Interplanetary Dust Experiment (IDE) provided high time resolution detection of microparticle impacts on the Long Duration Exposure Facility satellite. Particles, in the diameter range from 0.2 microns to several hundred microns, were detected impacting on six orthogonal surfaces of the gravity-gradient stabilized LDEF spacecraft. The total sensitive surface area was about one square meter, distributed between LDEF rows 3 (Wake or West), 6 (South), 9 (Ram or East), 12 (North), as well as the Space and Earth ends of LDEF. The time of each impact is known to an accuracy that corresponds to better than one degree in orbital longitude. Because LDEF was gravity-gradient stabilized and magnetically damped, the direction of the normal to each detector panel is precisely known for each impact. The 11 1/2 month tape-recorded data set represents the most extensive record gathered of the number, orbital location, and incidence direction for microparticle impacts in low Earth orbit. Perhaps the most striking result from IDE was the discovery that microparticle impacts, especially on the Ram, South, and North surfaces, were highly episodic. Most such impacts occurred in localized regions of the orbit for dozens or even hundreds of orbits in what we have termed Multiple Orbit Event Sequences (MOES). In addition, more than a dozen intense and short-lived 'spikes' were seen in which impact fluxes exceeded the background by several orders of magnitude. These events were distributed in a highly non-uniform fashion in time and terrestrial longitude and latitude.

Prototype detector development for measurement of high altitude Martian dust using a future orbiter platform

NASA Astrophysics Data System (ADS)

Pabari, Jayesh; Patel, Darshil; Chokhawala, Vimmi; Bogavelly, Anvesh

2016-07-01

Dust devils mostly occur during the mid of Southern hemisphere summer on Mars and play a key role in the background dust opacity. Due to continuous bombardment of micrometeorites, secondary ejecta come out from the Moons of the Mars and can easily escape. This phenomenon can contribute dust around the Moons and therefore, also around the Mars. Similar to the Moons of the Earth, the surfaces of the Martian Moons get charged and cause the dust levitation to occur, adding to the possible dust source. Also, interplanetary dust particles may be able to reach the Mars and contribute further. It is hypothesized that the high altitude Martian dust could be in the form of a ring or tori around the Mars. However, no such rings have been detected to the present day. Typically, width and height of the dust torus is ~5 Mars radii wide (~16950 km) in both the planes as reported in the literature. Recently, very high altitude dust at about 1000 km has been found by MAVEN mission and it is expected that the dust may be concentrated at about 150 to 500 km. However, a langmuir probe cannot explain the source of such dust particles. It is a puzzling question to the space scientist how dust has reached to such high altitudes. A dedicated dust instrument on future Mars orbiter may be helpful to address such issues. To study origin, abundance, distribution and seasonal variation of Martian dust, a Mars Orbit Dust Experiment (MODEX) is proposed. In order to measure the Martian dust from a future orbiter, design of a prototype of an impact ionization dust detector has been initiated at PRL. This paper presents developmental aspects of the prototype dust detector and initial results. The further work is underway.

Dynamics of nanoparticules detected at 1 AU by S/WAVES onboard STEREO spacecraft

NASA Astrophysics Data System (ADS)

Belheouane, Soraya; Issautier, Karine; Meyer-Vernet, Nicole; Le Chat, Gaétan; Czechowski, Andrzej; Zaslavsky, Arnaud; Zouganelis, Yannis; Mann, Ingrid

In order to interpret in detail the S/WAVES data on the interplanetary nanodust discovered by STEREO at 1 AU [Meyer-Vernet et al., 2009], we study the dynamics of nanoparticles in the inner interplanetary medium as well as the distribution of their velocities and directions of arrival, with a model based on [Czechowski and Mann, 2012]. We deduce the charges released by their impacts on the STEREO spacecraft at 1 AU and their dependence on the position of the spacecraft on their orbits. The model studies nanoparticles of size equal or smaller than about 70 nm, assumed to be created via collisional fragmentation of dust grains of larger size moving on keplerian orbits, and sublimation of dust, meteoroids and comets. The nanoparticles are released near the Sun with initial velocities close to keplerian, and mainly subjected to the Lorentz force calculated with a simple solar wind model. A part of the nanoparticles is accelerated to high speeds of the order of 300 km/s, thereby providing impact charges between 10(-14) and 10(-11) Cb [Belheouane, 2014] which enable them to be detected by S/WAVES, whereas another part is trapped within about 0.2 AU from the Sun. We discuss how the fluxes and direction of arrival at 1 AU are expected to change in function of the solar cycle. These results enable us to interpret in detail the STEREO/WAVES observations [Zaslavsky et al., 2012]; [Pantellini et al., 2013]; [Le Chat et al., 2013]. Belheouane, S. (2014). Nanoparticules dans le vent solaire, observations spatiales et theorie. PhD thesis, Pierre and Marie Curie University UPMC. Czechowski, A. and Mann, I. (2012). Nanodust Dynamics in Interplanetary Space, chapter Nanodust Dynamics in Interplanetary Space. Springer Berlin Heidelberg. Le Chat, G., Zaslavsky, A., Meyer-Vernet, N., Issautier, K., Belheouane, S., Pantellini, F., Maksimovic, M., Zouganelis, I., Bale, S., and Kasper, J. (2013). Interplanetary Nanodust Detection by the Solar Terrestrial Relations Observatory/WAVES Low Frequency Receiver. Solar Physics, 286(2):549-559. Meyer-Vernet, N., Maksimovic, M., Czechowski, A., Mann, I., Zouganelis, I., Goetz, K., Kaiser, M., Cyr, O. S., Bougeret, J.-L., and Bale, S. (2009). Dust Detection by the Wave Instrument on STEREO : Nanoparticles Picked up by the Solar Wind? Solar Phys, 256:463-474. Pantellini, F., Le Chat, G., Belheouane, S., Meyer-Vernet, N., and Zaslavsky, A. (2013). On the detection of nano dust using spacecraft based boom antennas. Solar Wind 13: Proceedings of the Thirteenth International Solar Wind Conference, 1539:414-417. Zaslavsky, A., Meyer-Vernet, N., Mann, I., Czechowski, A., Issautier, K., Le Chat, G., Pantellini, F., Goetz, K., Maksimovic, M., Bale, S. D., and Kasper, J. K. (2012). Interplanetary dust detection by radio antennas: Mass calibration and fluxes measured by STEREO/WAVES. J. Geophys. Res., 117.

Optimization of high-inclination orbits using planetary flybys for a zodiacal light-imaging mission

NASA Astrophysics Data System (ADS)

Soto, Gabriel; Lloyd, James; Savransky, Dmitry; Grogan, Keith; Sinha, Amlan

2017-09-01

The zodiacal light caused by interplanetary dust grains is the second-most luminous source in the solar system. The dust grains coalesce into structures reminiscent of early solar system formation; their composition has been predicted through simulations and some edge-on observations but better data is required to validate them. Scattered light from these dust grains presents challenges to exoplanet imaging missions: resolution of their stellar environment is hindered by exozodiacal emissions and therefore sets the size and scope of these imaging missions. Understanding the composition of this interplanetary dust in our solar system requires an imaging mission from a vantage point above the ecliptic plane. The high surface brightness of the zodiacal light requires only a small aperture with moderate sensitivity; therefore a 3cm camera is enough to meet the science goals of the mission at an orbital height of 0.1AU above the ecliptic. A 6U CubeSat is the target mass for this mission which will be a secondary payload detaching from an existing interplanetary mission. Planetary flybys are utilized to produce most of the plane change Δv deep space corrective maneuvers are implemented to optimize each planetary flyby. We developed an algorithm which determines the minimum Δv required to place the CubeSat on a transfer orbit to a planet's sphere of influence and maximizes the resultant orbital height with respect to the ecliptic plane. The satellite could reach an orbital height of 0.22 AU with an Earth gravity assist in late 2024 by boarding the Europa Clipper mission.

Cosmic Carbon Chemistry: From the Interstellar Medium to the Early Earth

PubMed Central

Ehrenfreund, Pascale; Cami, Jan

2010-01-01

Astronomical observations have shown that carbonaceous compounds in the gas and solid state, refractory and icy are ubiquitous in our and distant galaxies. Interstellar molecular clouds and circumstellar envelopes are factories of complex molecular synthesis. A surprisingly large number of molecules that are used in contemporary biochemistry on Earth are found in the interstellar medium, planetary atmospheres and surfaces, comets, asteroids and meteorites, and interplanetary dust particles. In this article we review the current knowledge of abundant organic material in different space environments and investigate the connection between presolar and solar system material, based on observations of interstellar dust and gas, cometary volatiles, simulation experiments, and the analysis of extraterrestrial matter. Current challenges in astrochemistry are discussed and future research directions are proposed. PMID:20554702

Delivery of Exogenous Complex Organic Compounds by Solar System Small Bodies and Space Dusts and Its Relevance to Origins of Life

NASA Astrophysics Data System (ADS)

Kobayashi, Kensei; Fushimi, Hidehiko; Motoyama, Takuya; Kaneko, Takeo; Obayashi, Yumiko; Yoshida, Satoshi; Mita, Hajime; Yabuta, Hikaru; Okudaira, Kyoko; Hashimoto, Hirofumi; Yokobori, Shin-Ichi; Yamagishi, Akihiko

A wide variety of organic compounds including amino acid precursors have been detected in such extraterrestrial bodies as carbonaceous chondrites and comets. It was suggested that these organics were formed in quite cold environments. We irradiated frozen mixtures of possible constituents of ice mantles of interstellar dust particles including water, methanol and ammonia with high-energy heavy ions from HIMAC, National Institute of Radiological Science, Japan. Amino acid precursors with complex structures were detected whose molecular weights are up to a few thousands. Such complex amino acid precursors are much stronger than free amino acids against radiation. Such organics could have been incorporated in solar system small bodies after the formation of the solar system and delivered to the primitive Earth. Possible carriers of such organics are meteorites, comets and interplanetary dust particles (IDPs) that were formed from comets and meteorites. It is suggested that IDPs brought much more organics than meteorites and comets. However, nature of organics in IDPs is little known, since they have been collected only in terrestrial biosphere. We are planning a space experiments named Tanpopo, where IDPs would be collected in aerogel equipped on the Exposure Facility of the International Space Station. In addition, amino acids and their relating compounds would be exposed to space environments to see their possible alteration processes in the interplanetary space. We will report some preliminary results for the preparation of the mission including the capture of amino acid-containing particles at high velocity with ultra-low density aerogel.

Analysis of organic grain coatings in primitive interplanetary dust particles: Implications for the origin of Solar System organic matter

NASA Astrophysics Data System (ADS)

Flynn, George

Analysis of organic grain coatings in primitive interplanetary dust particles: Implications for the origin of Solar System organic matter Chondritic, porous interplanetary dust particles (CP IDPs), the most primitive samples of extraterrestrial material available for laboratory analysis [1], are unequilibrated aggregates of mostly submicron, anhydrous grains of a diverse mineralogy. They contain organic matter not produced by parent body aqueous processing [2], some carrying H and N isotopic anomalies consistent with molecular cloud or outer Solar System material [3]. Scanning Transmission X-Ray Microscope (STXM) imaging at the C K-edge shows the individual grains in 10 micron aggregate CP IDPs are coated by a layer of carbonaceous material 100 nm thick. This structure implies a three-step formation sequence. First, individual grains condensed from the cooling nebular gas. Then complex, refractory organic molecules covered the surfaces of the grains either by deposition, formation in-situ, or a combination of both processes. Finally, the grains collided and stuck together forming the first dust-size material in the Solar System. Ultramicrotome sections, 70 to 100 nm thick were cut from several CP IDPs, embedded in elemental S to avoid exposure to C-based embedding media. X-ray Absorption Near Edge Structure (XANES) spectra were derived from image stacks obtained using a STXM. "Cluster analysis" was used to compare the C-XANES spectra from each of the pixels in an image stack and identify pixels exhibiting similar spectra. When applied to a CP IDP, cluster analysis identifies most carbonaceous grain coatings in a particle as having similar C-XANES spectra. Two processes are commonly suggested in the literature for production of organic grain coatings. The similarity in thickness and C-XANES spectra of the coatings on different minerals in the same IDP indicates the first, mineral specific catalysis, was not the process that produced these organic rims. Our results are consistent with this primitive organic matter being produced by the alternative process of condensation of C-bearing ices onto the grain surfaces and production of refractory organic matter by UV or other ionizing radiation bombardment of the ices [4]. The processes by which primitive grains aggregate to form the first dust of our Solar System are not well understood. Collision experiments indicate that bare rocky grains bounce apart at collision speeds ¡30 to 50 m/s and shatter at larger speeds [5]. However, experiments indicate grains coated with organic matter stick quite easily, even at speeds up to 5 m/s -an order of magnitude higher than the speed at which silicate grains accrete [6]. Thus the organic grain coatings we identified likely played a critical role in dust aggregation in the early Solar System. References: [1] Ishii, H. et al. Science 2009. [2] Flynn, G. J. et al. (2003) Geochim. Cosmochim. Acta, 67, 4791-4806. [3] Keller L. P. et al. GCA (2004) Geochim. Cosmochim. Acta, 68, 2577-2589. [4] Bernstein, M. P. et al. (1995) Astrophys. J., 454, 327-344. [5] Hartmann, W. K. (1978) Icarus, 33, 50-61. [6] Kudo, T. et al. (2002) Meteoritics Planet. Sci., 37, 1975-1983.

The Ultrafine Mineralogy of a Molten Interplanetary Dust Particle as an Example of the Quench Regime of Atmospheric Entry Heating

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1996-01-01

Melting and degassing of interplanetary dust particle L2005B22 at approx. 1200 C was due to flash heating during atmospheric entry. Preservation of the porous particle texture supports rapid quenching from the peak heating temperature whereby olivine and pyroxene nanocrystals (3 nm-26 nm) show partial devitrification of the quenched melt at T approx. = 450 C - 740 C. The implied ultrahigh cooling rates are calculated at approx. 105 C/h-106 C/h, which is consistent with quench rates inferred from the temperature-time profiles based on atmospheric entry heating models. A vesicular rim on a nonstoichiometric relic forsterite grain in this particle represents either evaporative magnesium loss during flash heating or thermally annealed ion implantation texture.

The spectral properties of interplanetary dust particles

NASA Technical Reports Server (NTRS)

Sandford, Scott A.

1988-01-01

The observed spectral and mineralogical properties of interplanetary dust particles (IDP) allows the conclusion that: (1) the majority of IDP infrared spectra are dominated by olivine, pyroxene, or layer lattice silicate minerals, (2) to the first order the emission spectra of comets Halley and Kohoutek can be matched by mixtures of these IDP infrared types, implying that comets contain mixtures of these different crystalline silicates and may vary from comet to comet and perhaps even within a single comet, (3) do not expect to observe a single 20 micron feature in cometary spectra, (4) carbonaceous materials dominate the visible spectra properties of the IDPs even though the mass in these particles consists primarily of silicates, and (5) the particle characteristics summarized need to be properly accounted for in future cometary emission models.

The Nature and Origin of Interplanetary Dust: High Temperature Components

NASA Technical Reports Server (NTRS)

Keller, L. P.; Messenger, S.

2004-01-01

The specific parent bodies of individual interplanetary dust particles (IDPs) are un-known, but the anhydrous chondritic-porous (CP) sub-set has been linked directly to cometary sources [1]. The CP IDPs escaped the thermal processing and water-rock interactions that have severely modified or destroyed the original mineralogy of primitive meteorites. Their origin in the outer regions of the solar system suggests they should retain primitive chemical and physical characteristics from the earliest stages of solar system formation (including abundant presolar materials). Indeed, CP IDPs are the most primitive extraterrestrial materials available for laboratory studies based on their unequilibrated mineralogy [2], high concentrations of carbon, nitrogen and volatile trace elements relative to CI chondrites [3, 4, 5], presolar hydrogen and nitrogen isotopic signatures [6, 7] and abundant presolar silicates [8].

Interplanetary dust particles collected in the stratosphere: observations of atmospheric heating and constraints on their interrelationships and sources.

PubMed

Sandford, S A; Bradley, J P

1989-01-01

The majority of the interplanetary dust particles (IDPs) collected in the stratosphere belong to one of three major classes, the first two dominated by the anhydrous minerals olivine and pyroxene, and the third by hydrous layer-lattice silicates. Infrared spectroscopy and transmission electron microscopy studies show that the different IDP classes represent different types of dust that exist as individual particles in interplanetary space. The majority of the collected IDPs smaller than 30 micrometers in diameter in the layer-lattice silicate and pyroxene classes appear not to have been heated to temperatures above 600 degrees C during atmospheric entry. The relatively low maximum temperatures experienced by these IDPs during atmospheric entry imply that they arrive at the top of the atmosphere with low geocentric encounter velocities. This limits the possible encounter trajectories for these particles to relatively circular, prograde orbits. As a result, it is unlikely that these IDPs are from Earth-crossing comets or asteroids. Asteroids, and comets having low inclinations and perihelia outside 1.2 AU, appear to be the best candidates for the parent bodies of the pyroxene and layer-lattice silicate particles. Chemical and mineralogical information suggests that the pyroxene-rich IDPs are from comets and the layer-lattice silicate-rich IDPs are from asteroids. The collected IDPs dominated by olivine appear to include a larger fraction of particles heating above 600 degrees C, suggesting that these particles were captured from more eccentric orbits. This, and the observation of the infrared spectral features of olivine in several comets suggest these particles have a cometary origin. Since much of the collected dust has apparently been captured from nearly circular, prograde orbits and since there are no appropriate parent bodies presently in such orbits, these results provide an experimental confirmation that the Poynting-Robertson effect exists as a nongravitational force important in the orbital evolution of dust in the Solar System.

A survey of dusty plasma physics

NASA Astrophysics Data System (ADS)

Shukla, P. K.

2001-05-01

Two omnipresent ingredients of the Universe are plasmas and charged dust. The interplay between these two has opened up a new and fascinating research area, that of dusty plasmas, which are ubiquitous in different parts of our solar system, namely planetary rings, circumsolar dust rings, the interplanetary medium, cometary comae and tails, as well as in interstellar molecular clouds, etc. Dusty plasmas also occur in noctilucent clouds in the arctic troposphere and mesosphere, cloud-to-ground lightening in thunderstorms containing smoke-contaminated air over the United States, in the flame of a humble candle, as well as in microelectronic processing devices, in low-temperature laboratory discharges, and in tokamaks. Dusty plasma physics has appeared as one of the most rapidly growing fields of science, besides the field of the Bose-Einstein condensate, as demonstrated by the number of published papers in scientific journals and conference proceedings. In fact, it is a truly interdisciplinary science because it has many potential applications in astrophysics (viz. in understanding the formation of dust clusters and structures, instabilities of interstellar molecular clouds and star formation, decoupling of magnetic fields from plasmas, etc.) as well as in the planetary magnetospheres of our solar system [viz. Saturn (particularly, the physics of spokes and braids in the B and F rings), Jupiter, Uranus, Neptune, and Mars] and in strongly coupled laboratory dusty plasmas. Since a dusty plasma system involves the charging and dynamics of massive charged dust grains, it can be characterized as a complex plasma system providing new physics insights. In this paper, the basic physics of dusty plasmas as well as numerous collective processes are discussed. The focus will be on theoretical and experimental observations of charging processes, waves and instabilities, associated forces, the dynamics of rotating and elongated dust grains, and some nonlinear structures (such as dust ion-acoustic shocks, Mach cones, dust voids, vortices, etc). The latter are typical in astrophysical settings and in several laboratory experiments. It appears that collective processes in a complex dusty plasma would have excellent future perspectives in the twenty-first century, because they have not only potential applications in interplanetary space environments, or in understanding the physics of our universe, but also in advancing our scientific knowledge in multidisciplinary areas of science.

Lunar Dust Monitor for the orbiter of the next Japanese lunar mission SELENE2

NASA Astrophysics Data System (ADS)

Hirai, Takayuki; Sasaki, Sho; Ohashi, Hideo; Kobayashi, Masanori; Fujii, Masayuki; Shibata, Hiromi; Iwai, Takeo; Nogami, Ken-Ichi; Kimura, Hiroshi; Nakamura, Maki

2010-05-01

The next Japanese lunar mission SELENE2, after a successful mission Kaguya (a project named SELENE), is planned to launch in mid 2010 and to consists of a lander, a rover, and an orbiter, as a transmitting satellite to the earth [1]. A dust particle detector is proposed to be onboard the orbiter that is planned to be in operation for one year or more. Dust particles around the Moon include interplanetary dust, beta-meteoroids, interstellar dust, and possibly lunar dust that originate from the subsurface materials of the Moon. It is considered that several tens of thousands of tons of dust particles per year fall onto the Moon and supply materials to its surface layer. "Inflow" and "outflow" dust particles are very important for understanding material compositions of lunar surface. In past missions, dust detectors onboard the Hiten and Nozomi (Hiten-MDC and Nozomi-MDC) measured the flues of dust particles in the lunar orbit [2, 3]. These observations by Hiten- and Nozomi-MDCs created a small dataset of statistics of dust particles excluding earth-orbiting dust once in a week, because the dust detectors had small sensitive areas, 0.01 m2 and 0.014 m^2, respectively. The Lunar Dust EXperiment (LDEX) is designed to map a spatial and temporal variability of the dust size and density distributions in the lunar environment and will be onboard LADEE, which will be launched in 2012 [4]. LDEX will observe the lunar environment for 90 days in a nominal case or for a maximum of 9 months. It has a sensor area of 0.01 m2 at 50 km altitude. For a quantitative study of circumlunar dust, we propose a dust monitoring device with a large aperture size and a large sensor area, called the lunar dust monitor (LDM). The LDM is an impact ionization detector with dimensions 25 cm × 25 cm × 30 cm, and it has a large target (gold-plated Al) of 400 cm^2, to which a high voltage of +500 V is applied. The LDM also has two meshed grids parallel to the target. The grids are 90% transparent: the inner grid is 2 cm apart from the target and the outer grid is 15 cm from the target. We can deduce the mass and velocity information of the impacted dust particle from the recorded signal waveforms generated by the impacts of dust particles. Dust particles around the Moon are classified based on their origins: interstellar dust, interplanetary dust, beta meteoroids, and possibly dust that originated on the Moon. They can be inferred from their kinematic properties: the velocities and the arrival directions. If the proportion of dust components around the Moon is determined by observation, we can increase our knowledge of the contribution of inflow and outflow dust particles to lunar surface materials. References: [1] Matsumoto, K. et al., Joint Annual Meeting of LEAG-ICEUM-SRR (2008) LPI Contribution No.1446, 86. [2] Iglseder H. et al., Adv. Space Res. 17 (1996) 177-182. [3] Sasaki S., et al., Adv. Space Res., 39 (2007), 485-488. [4] Horanyi, M. et al., (2009) LPSC 40th, Abstract #1741.

What if chondritic porous interplanetary dust particles are not the real McCoy

NASA Astrophysics Data System (ADS)

Rietmeijer, Frans J. M.

To select a target comet for a Comet Nucleus Sample Return Mission (CNSRM) it is necessary to have an experimental data base to evaluate the extent of diversity and similarity of comets. For example, the physical properties (e.g., low density) of chondritic porous (CP) interplanetary dust particles (IDPs) are believed to resemble these properties of cometary dust although it is yet to be demonstrated that the porous structure of CP IDPs is inherent to presolar dust particles stored in comet nuclei. Porous structures of IDPs could conceivably form during sublimation at the surface of active comet nuclei. Porous structures are also obtained during annealing of amorphous Mg-SiO smokes which initially forms porous aggregates of olivine + platey tridymite and which, upon continued annealing, react to fluffy enstatite aggregates. It is therefore uncertain that CP IDPs are entirely composed of unmetamorphosed presolar dust. Conceivably, new minerals and textures may form in situ in nuclei of active comets as a function of their individual thermal history. Unmetamorphosed comet dust is probably structurally amorphous. Thermal annealing of this dust can produce ultra fine-grained minerals and this ultrafine grain size of CP IDPs should be considered in assessments of aqueous alterations that could affect presolar dust in comet nuclei between 200 and 400 K. Devitrification and hydration may occur in situ in ice-dust mixtures and the mantle of active comet nuclei. Devitrification, or uncontrolled crystallization, of amorphous precursor dust can produce a range of chemical compositions of ultrafine-grained minerals and (non-equilibrium) mineral assemblages and textures in dust contained in comet nuclei as a function of period and trajectory of orbit and number of perihelion passages (not considering internal heating). Thus, experimental data on relevant processes and reaction rates between 200 and 400 K are needed in order to evaluate comet selection, penetration depth for sampling device and curation of samples for CNSRM.

What if chondritic porous interplanetary dust particles are not the real McCoy

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1989-01-01

To select a target comet for a Comet Nucleus Sample Return Mission (CNSRM) it is necessary to have an experimental data base to evaluate the extent of diversity and similarity of comets. For example, the physical properties (e.g., low density) of chondritic porous (CP) interplanetary dust particles (IDPs) are believed to resemble these properties of cometary dust although it is yet to be demonstrated that the porous structure of CP IDPs is inherent to presolar dust particles stored in comet nuclei. Porous structures of IDPs could conceivably form during sublimation at the surface of active comet nuclei. Porous structures are also obtained during annealing of amorphous Mg-SiO smokes which initially forms porous aggregates of olivine + platey tridymite and which, upon continued annealing, react to fluffy enstatite aggregates. It is therefore uncertain that CP IDPs are entirely composed of unmetamorphosed presolar dust. Conceivably, new minerals and textures may form in situ in nuclei of active comets as a function of their individual thermal history. Unmetamorphosed comet dust is probably structurally amorphous. Thermal annealing of this dust can produce ultra fine-grained minerals and this ultrafine grain size of CP IDPs should be considered in assessments of aqueous alterations that could affect presolar dust in comet nuclei between 200 and 400 K. Devitrification and hydration may occur in situ in ice-dust mixtures and the mantle of active comet nuclei. Devitrification, or uncontrolled crystallization, of amorphous precursor dust can produce a range of chemical compositions of ultrafine-grained minerals and (non-equilibrium) mineral assemblages and textures in dust contained in comet nuclei as a function of period and trajectory of orbit and number of perihelion passages (not considering internal heating). Thus, experimental data on relevant processes and reaction rates between 200 and 400 K are needed in order to evaluate comet selection, penetration depth for sampling device and curation of samples for CNSRM.

Searching for Lunar Horizon Glow With the Lunar Orbiter Laser Altimeter (LOLA)

NASA Astrophysics Data System (ADS)

Barker, M. K.; Mazarico, E. M.; McClanahan, T. P.; Sun, X.; Smith, D. E.; Neumann, G. A.; Zuber, M. T.; Head, J. W., III

2017-12-01

The dust environment of the Moon is sensitive to the interplanetary meteoroid population and dust transport processes near the lunar surface, and this affects many aspects of lunar surface science and planetary exploration. The interplanetary meteoroid population poses a significant risk to spacecraft, yet it remains one of the more uncertain constituents of the space environment. Observed and hypothesized lunar dust transport mechanisms have included impact-generated dust plumes, electrostatic levitation, and dynamic lofting. Many details of the impactor flux and impact ejection process are poorly understood, a fact highlighted by recent discrepant estimates of the regolith mixing rate. Apollo-era observations of lunar horizon glow (LHG) were interpreted as sunlight forward-scattered by exospheric dust grains levitating in the top meter above the surface or lofted to tens of kilometers in altitude. However, recent studies have placed limits on the dust density orders of magnitude less than what was originally inferred, raising new questions on the time variability of the dust environment. Motivated by the need to better understand dust transport processes and the meteoroid population, the Lunar Orbiter Laser Altimeter (LOLA) aboard the Lunar Reconnaissance Orbiter (LRO) is conducting a campaign to search for LHG with the LOLA Laser Ranging (LR) system. Advantages of this LOLA LHG search include: (1) the LOLA-LR telescope can observe arbitrarily close to the Sun at any time during the year without damaging itself or the other instruments, (2) a long temporal baseline with observations both during and outside of meteor streams, which will improve the chances of detecting LHG, and (3) a focus on altitudes < 20 km, the same range as the majority of Apollo 15 LHG measurements. In this contribution, we describe the instrument, methodology, and preliminary results.

The asteroid-comet continuum from laboratory and space analyses of comet samples and micrometeorites

NASA Astrophysics Data System (ADS)

Engrand, Cecile; Duprat, Jean; Bardin, Noemie; Dartois, Emmanuel; Leroux, Hugues; Quirico, Eric; Benzerara, Karim; Rémusat, Laurent; Dobrică, Elena; Delauche, Lucie; Bradley, John; Ishii, Hope; Hilchenbach, Martin; COSIMA Team

2015-08-01

Comets are probably the best archives of the nascent solar system, 4.5 Gyr ago, and their compositions reveal crucial clues on the structure and dynamics of the early protoplanetary disk. Anhydrous minerals (olivine and pyroxene) have been identified in cometary dust for a few decades. Surprisingly, samples from comet Wild2 returned by the Stardust mission in 2006 also contain high temperature mineral assemblages like chondrules and refractory inclusions, which are typical components of primitive meteorites (carbonaceous chondrites - CCs). A few Stardust samples have also preserved some organic matter of comet Wild 2 that share some similarities with CCs. Interplanetary dust falling on Earth originate from comets and asteroids in proportions to be further constrained. These cosmic dust particles mostly show similarities with CCs, which in turn only represent a few percent of meteorites recovered on Earth. At least two (rare) families of cosmic dust particles have shown strong evidences for a cometary origin: the chondritic porous interplanetary dust particles (CP-IDPs) collected in the terrestrial stratosphere by NASA, and the ultracarbonaceous Antarctic Micrometeorites (UCAMMs) collected from polar snow and ice by French and Japanese teams. The Rosetta mission currently carries dust analyzers capable of measuring dust flux, sizes, physical properties and compositions of dust particles from the Jupiter family comet 67P/Churyumov-Gerasimenko (COSIMA, GIADA, MIDAS), as well as gas analyzers (ROSINA, PTOLEMY, COSAC). A growing number of evidences highlights the existence of a continuum between asteroids and comets, already in the early history of the solar system. We will present the implications of the analyses of samples in the laboratory and in space to a better understanding of the early protoplanetary disk.

Bioastrophysical aspects of low energy ion irradiation of frozen anthracene containing water.

PubMed

Tuleta, M; Gabła, L; Madej, J

2001-08-13

The origin of life on Earth remains a fascinating mystery in spite of many theories existing on this subject. However, it seems that simple prebiotic molecules could play an essential role in the formation of more complex organisms. In our experiment, we synthesized a class of these molecules (quinones) bombarding frozen anthracene containing water with low energy hydrogen ions. This experiment roughly simulated the astrophysical conditions which one can find in the solar system. Thus, we can hypothesize that prebiotic molecules could be created by interaction of the solar wind with interplanetary dust grains. The delivery of these molecules to early Earth may have contributed to the generation of life on our planet.

SPICE: An innovative, flexible instrument concept

NASA Technical Reports Server (NTRS)

Nishioka, Kenji; Cauffman, D. P.; Jurcevich, B.; Mendez, David J.; Ryder, James T.

1994-01-01

Studies and plans for orbital capture of cosmic dust and interplanetary dust particles (IDP's) looked very bright with the advent of space station Freedom (SSF) and formal selection of Cosmic Dust Collection Facility (CDCF) as an attached payload in 1990. Unfortunately it has been downhill since its selection, culminating in CDCF being dropped as attached payload in the SSF redesign process this year. This action was without any input from the science or cosmic dust communities. The Exobiology Intact Capture Experiment (Exo-ICE) as an experiment on CDCF was also lost. Without CDCF, no facility-class instrument for cosmic dust studies is available or planned. When CDCF (and Exo-ICE) was selected as a SSF attached payload, an exercise called the small particle intact capture experiment (SPICE) was started for Exo-ICE to develop an understanding and early testing of the necessary expertise and technology for intact capture of cosmic dust and IDP's. This SPICE activity looks to fly small, meter square or less, collection area experiments on early orbital platforms of opportunity such as EURECA, MIR, WESTAR, and others, including the shuttle. The SPICE activity has focused on developing techniques and instrument concepts to capture particles intact and without inadvertent contamination. It began with a survey and screening of available capture media concepts and then focused on the development of a capture medium that can meet these requirements. Evaluation and development of the chosen capture medium, aerogel (a silicon oxide gel), has so far lived up to the expectations of meeting the requirements and is highlighted in a companion paper at this workshop. Others such as McDonnell's Timeband Capture Cell Experiment (TICCE) on EuReCa and Tsuo's GAS-CAN lid experiments on STS 47 and 57 have flown aerogel, but without addressing the contamination issue/requirement, especially regarding organics. Horz, Zolenskym and others have studied and have also been advocates for its development. The SPICE instrument's experiment design builds on the knowledge gained from these efforts to meet the intact capture, noncontamination requirements. An overview of a possible SPICE experimental instrument concept using the MIR space station as a host platform for cosmic dust collection is provided in this paper. The SPICE concept is nonplatform-specified and can fly on any platform that provides a mode for experiment recovery.

Coordinates Analyses of Hydrated Interplanetary Dust Particles: Samples of Primitive Solar System Bodies

NASA Technical Reports Server (NTRS)

Keller, L. P.; Snead, C.; McKeegan, K. D.

2016-01-01

Interplanetary dust particles (IDPs) collected in the stratosphere fall into two major groups: an anhydrous group termed the "chondritic-porous (CP) IDPs and a hydrated group, the "chondritic-smooth (CS) IDPs, although rare IDPs with mineralogies intermediate between these two groups are known [1]. The CP-IDPs are widely believed to be derived from cometary sources [e.g. 2]. The hydrated CS-IDPs show mineralogical similarities to heavily aqueously altered carbonaceous chondrites (e.g. CI chondrites), but only a few have been directly linked to carbonaceous meteorite parent bodies [e.g. 3, 4]. Most CS-IDPs show distinct chemical [5] and oxygen isotopic composition differences [6-8] from primitive carbonaceous chondrites. Here, we report on our coordinated analyses of a suite of carbon-rich CS-IDPs focusing on their bulk compositions, mineralogy, mineral chemistry, and isotopic compositions.

Carbon abundances, major element chemistry, and mineralogy of hydrated interplanetary dust particles

NASA Technical Reports Server (NTRS)

Keller, L. P.; Thomas, K. L.; Mckay, D. S.

1993-01-01

Hydrated interplanetary dust particles (IDP's) comprise a major fraction of the interplanetary dust particles collected in the stratosphere. While much is known about the mineralogy and chemistry of hydrated IDP's, little is known about the C abundance in this class of IDP's, the nature of the C-bearing phases, and how the C abundance is related to other physical properties of hydrated IDP's. Bulk compositional data (including C and O) for 11 hydrated IDP's that were subsequently examined by the transition electron microscopy (TEM) to determine their mineralogy and mineral chemistry are reported. Our analysis indicates that these hydrated IDP's are strongly enriched in C relative to the most C-rich meteorites. The average abundance of C in these hydrated IDP's is 4X CI chondrite values. The bulk compositions (including C and O) of 11 hydrated IDP's were determined by thin-window, energy-dispersive x ray (EDX) spectroscopy of the uncoated IDP's on Be substrates in the scanning electron microscopy (SEM). As a check on our C measurements, one of the IDP's (L2006H5) was embedded in glassy S, and microtome thin sections were prepared and placed onto Be substrates. Thin-film EDX analyses of multiple thin sections of L2006H5 show good agreement with the bulk value determined in the SEM. Following EDX analysis, the mineralogy and mineral chemistry of each IDP was determined by analyzing ultramicrotome thin sections in a TEM equipped with an EDX spectrometer.

Laboratory Studies of the Optical Properties and Condensation Processes of Cosmic Dust Particles

NASA Technical Reports Server (NTRS)

Abbas, Mian M.; Craven, Paul D.; Spann, James F.; Tankosic, Dragana; Six, N. Frank (Technical Monitor)

2002-01-01

A laboratory facility for levitating single isolated dust particles in an electrodynamics balance has been developing at NASA/Marshall Space Flight Center for conducting a variety of experimental, of astrophysical interest. The objective of this research is to employ this innovative experimental technique for studies of the physical and optical properties of the analogs of cosmic grains of 0.2-10 micron size in a chamber with controlled pressure/temperatures simulating astrophysical environments. In particular, we will carry out three classes of experiments to investigate the microphysics of the analogs of interstellar and interplanetary dust grains. (1) Charge characteristics of micron size single dust grains to determine the photoelectric efficiencies, yields, and equilibrium potentials when exposed to UV radiation. These measurements will provide the much-needed photoelectric emission data relating to individual particles as opposed to that for the bulk materials available so far. (2) Infrared optical properties of dust particles obtained by irradiating the particles with radiation from tunable infrared diode lasers and measuring the scattered radiation. Specifically, the complex refractive indices, the extinction coefficients, the scattering phase functions, and the polarization properties of single dust grains of interest in interstellar environments, in the 1-25 micron spectral region will be determined. (3) Condensation experiments to investigate the deposition of volatile gases on colder nucleated particles in dense interstellar clouds and lower planetary atmospheres. The increase in the mass or m/q ratio due to condensation on the particle will be monitored as a function of the dust particle temperature and the partial pressure of the injected volatile gas. The measured data wild permit determination of the sticking efficiencies of volatile gases of astrophysical interest. Preliminary results based on photoelectric emission experiments on 0.2-6.6 micron size silica particles exposed to UV radiation in the 120-200 nm spectral region will be presented.

Principal Components Constrain Dynamic Pyrometamorphism in a Partially Melted Interplanetary Dust Particle

NASA Astrophysics Data System (ADS)

Rietmeijer, F. J. M.

1996-03-01

All interplanetary dust particles [IDPs] that decelerate in the Earth's atmosphere experience flash heating whereby their orbital velocity (km s^-1) is reduced to cm s^-1. Iron-oxide rims that may either be continuous on the particle surface, or discontinuous along its perimeter, occur on many IDPs. It is the most conspicuous mineralogical indicator of dynamic pyrometamorphism and its formation is interpreted as 'intense' IDP heating. It appears that the formation of these magnetite and maghemite rims is intimately linked to the presence of Fe,Ni-sulfides in the pre-entry particle. In this regard chondritic porous (CP) IDP L2011K7 may be an unusual particle. This porous aggregate consists of S-free polyphase units (PUs), nonstoichiometric diopside and Mg-rich wollastonite single-crystals and small, accessory Fe,Ni-sulfide grains. Only a few Fe-oxide nanograins are present along its perimeter. The nonstoichiometry of its Ca,Mg-clinopyroxenes indicates incongruent melting or vaporization that was experimentally determined at 1300 degrees-1400 degrees C. The CP IDP L2011K7 is probably of cometary origin since active comet nuclei are the most likely sources for uncompacted aggregate IDPs whereby their low density (< 1 g cm^-3) enhances atmospheric entry survival of large particles. In addition, the fluffy texture which inhibits chemical exchange among its components further enhances their survival unless compaction occurs during deceleration in the Earth's atmosphere.

Analytical electron microscopy of fine-grained phases in primitive interplanetary dust particles and carbonaceous chondrites

NASA Technical Reports Server (NTRS)

Mackinnon, Ian D. R.; Rietmeijer, Frans J. M.; Mckay, David S.

1987-01-01

In order to describe the total mineralogical diversity within primitive extraterrestrial materials, individual interplanetary dust particles (IDPs) collected from the stratosphere as part of the JSC Cosmic Dust Curatorial Program were analyzed using a variety of AEM techniques. Identification of over 250 individual grains within one chondritic porous (CP) IDP shows that most phases could be formed by low temperature processes and that heating of the IDP during atmospheric entry is minimal and less than 600 C. In a review of the mineralogy of IDPs, it was suggested that the occurrence of other silicates such as enstatite whiskers is consistent with the formation in an early turbulent period of the solar nebula. Experimental confirmation of fundamental chemical and physical processes in a stellar environment, such as vapor phase condensation, nucleation, and growth by annealing, is an important aspect of astrophysical models for the evolution of the Solar System. A detailed comparison of chondritic IDP and carbonaceous chondrite mineralogies shows significant differences between the types of silicate minerals as well as the predominant oxides.

GEMS Revealed: Spectrum Imaging of Aggregate Grains in Interplanetary Dust

NASA Technical Reports Server (NTRS)

Keller, L. P.; Messenger, S.; Christoffersen, R.

2005-01-01

Anhydrous interplanetary dust particles (IDPs) of cometary origin contain abundant materials that formed in the early solar nebula. These materials were transported outward and subsequently mixed with molecular cloud materials and presolar grains in the region where comets accreted [1]. GEMS (glass with embedded metal and sulfides) grains are a major component of these primitive anhydrous IDPs, along with crystalline Mg-rich silicates, Fe-Ni sulfides, carbonaceous material, and other trace phases. Some GEMS grains (5%) are demonstrably presolar based on their oxygen isotopic compositions [2]. However, most GEMS grains are isotopically solar and have bulk chemical compositions that are incompatible with inferred compositions of interstellar dust, suggesting a solar system origin [3]. An alternative hypothesis is that GEMS grains represent highly irradiated interstellar grains whose oxygen isotopic compositions were homogenized through processing in the interstellar medium (ISM) [4]. We have obtained the first quantitative X-ray maps (spectrum images) showing the distribution of major and minor elements in individual GEMS grains. Nanometer-scale chemical maps provide critical data required to evaluate the differing models regarding the origin of GEMS grains.

The geocentric particulate distribution: Cometary, asteroidal, or space debris?

NASA Technical Reports Server (NTRS)

Mcdonnell, J. A. M.; Ratcliff, P. R.

1992-01-01

Definition of the Low Earth Orbit (LEO) particulate environment has been refined considerably with the analysis of data from NASA's Long Duration Exposure Facility (LDEF). Measurements of the impact rates from particulates ranging from sub-micron to millimetres in dimension and, especially, information on their directionality has permitted new scrunity of the sources of the particulates. Modelling of the dynamics of both bound (Earth orbital) and unbound (hyperbolic interplanetary) particulates intercepting LDEF's faces leads to the conclusion that the source is dominantly interplanetary for particle dimensions of greater than some 5 microns diameter; however the anisotropy below this dimension demands lower velocities and is compatible with an orbital component. Characteristics of the LDEF interplanetary component are compatible with familiar meteoroid sources and deep space measurements. Understanding of the orbital component which exceeds the interplanetary flux by a factor of 4 is less clear; although the very small particulates in orbit have been associated with space debris (Lawrance and Brownlee, 1986) this data conflicts with other measurements (McDonnell, Carey and Dixon, 1984) at the same epoch. By analysis of trajectories approaching the Earth and its atmosphere, we have shown that a significant contribution could be captured by aerocapture, i.e., atmospheric drag, from either asteroidal or cometary sources; such enhancement is unlikely however to provide the temporal and spatial fluctuations observed by the LDEF Interplanetary Dust Experiment (Mullholland et al. 1992). A further new mechanism is also examined, that of aerofragmentation capture, where an atmospheric grazing trajectory, which would not normally lead to capture, leads to fragmentation by thermal or mechanical shock; the microparticulates thus created can be injected in large numbers, but only into short-lifetime orbits. The concentration in one particular orbit plane, could explain the temporal fluctuations seen on LDEF; space debris could also explain the phenomenon.

Stardust in meteorites.

PubMed

Davis, Andrew M

2011-11-29

Primitive meteorites, interplanetary dust particles, and comets contain dust grains that formed around stars that lived their lives before the solar system formed. These remarkable objects have been intensively studied since their discovery a little over twenty years ago and they provide samples of other stars that can be studied in the laboratory in exquisite detail with modern analytical tools. The properties of stardust grains are used to constrain models of nucleosynthesis in red giant stars and supernovae, the dominant sources of dust grains that are recycled into the interstellar medium by stars.

Stardust in meteorites

PubMed Central

Davis, Andrew M.

2011-01-01

Primitive meteorites, interplanetary dust particles, and comets contain dust grains that formed around stars that lived their lives before the solar system formed. These remarkable objects have been intensively studied since their discovery a little over twenty years ago and they provide samples of other stars that can be studied in the laboratory in exquisite detail with modern analytical tools. The properties of stardust grains are used to constrain models of nucleosynthesis in red giant stars and supernovae, the dominant sources of dust grains that are recycled into the interstellar medium by stars. PMID:22106261

Cometary and interstellar dust grains - Analysis by ion microprobe mass spectrometry and other techniques

NASA Technical Reports Server (NTRS)

Zinner, Ernst

1991-01-01

A survey of microanalytical measurements on interplanetary dust particles (IDPs) and interstellar dust grains from primitive meteorites is presented. Ion-microprobe mass spectrometry with its capability to determine isotopic compositions of many elements on a micron spatial scale has played a special role. Examples are measurements of H, N, and O isotopes and refractory trace elements in IDPs; C, N, Mg, and Si isotopes in interstellar SiC grains; and C and N isotopes and H, N, Al, and Si concentrations in interstellar graphite grains.

Status of the Stardust ISPE and the Origin of Four Interstellar Dust Candidates

NASA Technical Reports Server (NTRS)

Westphal, A. J.; Allen, C.; Ansari, A.; Bajt, S.; Bastien, R. S.; Bassim, N.; Bechtel, H. A.; Borg, J.; Brenker, F. E.; Bridges, J.;

Calibration of impact ionization cosmic dust detectors: first tests to investigate how the dust density influences the signal

NASA Astrophysics Data System (ADS)

Jasmin Sterken, Veerle; Moragas-Klostermeyer, Georg; Hillier, Jon; Fielding, Lee; Lovett, Joseph; Armes, Steven; Fechler, Nina; Srama, Ralf; Bugiel, Sebastian; Hornung, Klaus

2016-10-01

Impact ionization experiments have been performed since more than 40 years for calibrating cosmic dust detectors. A linear Van de Graaff dust accelerator was used to accelerate the cosmic dust analogues of submicron to micron-size to speeds up to 80 km s^-1. Different materials have been used for calibration: iron, carbon, metal-coated minerals and most recently, minerals coated with conductive polymers. While different materials with different densities have been used for instrument calibration, a comparative analysis of dust impacts of equal material but different density is necessary: porous or aggregate-like particles are increasingly found to be present in the solar system: e.g. dust from comet 67P Churyumov-Gerasimenko [Fulle et al 2015], aggregate particles from the plumes of Enceladus [Gao et al 2016], and low-density interstellar dust [Westphal 2014 et al, Sterken et al 2015]. These recalibrations are relevant for measuring the size distributions of interplanetary and interstellar dust and thus mass budgets like the gas-to-dust mass ratio in the local interstellar cloud.We report about the calibrations that have been performed at the Heidelberg dust accelerator facility for investigating the influence of particle density on the impact ionization charge. We used the Cassini Cosmic Dust Analyzer for the target, and compared hollow versus compact silica particles in our study as a first attempt to investigate experimentally the influence of dust density on the signals obtained. Also, preliminary tests with carbon aerogel were performed, and (unsuccessful) attempts to accelerate silica aerogel. In this talk we explain the motivation of the study, the experiment set-up, the preparation of — and the materials used, the results and plans and recommendations for future tests.Fulle, M. et al 2015, The Astrophysical Journal Letters, Volume 802, Issue 1, article id. L12, 5 pp. (2015)Gao, P. et al 2016, Icarus, Volume 264, p. 227-238Westphal, A. et al 2014, Science, Volume 345, Issue 6198, pp. 786-791 (2014)Sterken, V.J. et al 2015, The Astrophysical Journal, Volume 812, Issue 2, article id. 141, 24 pp. (2015)

Lunar and Planetary Science XXXVI, Part 6

NASA Technical Reports Server (NTRS)

2005-01-01

Contents include the following: A Model for Multiple Populations of Presolar Diamonds. Characterization of Martian North Polar Geologic Units Using Mars Odyssey THEMIS Data. Effect of Flow on the Internal Structure of the Martian North Polar Layered Deposits. Elemental Abundance Distributions in Basalt Clays and Meteorites: Is It a Biosignature? Early Results on the Saturn System from the Composite Infrared Spectrometer. NanoSIMS D/H Imaging of Isotopically Primitive Interplanetary Dust Particles. Presolar (Circumstellar and Interstellar) Phases in Renazzo: The Effects of Parent Body Processing. Catastrophic Disruption of Hydrated Targets: Implications for the Hydrated Asteroids and for the Production of Interplanetary Dust Particles. Chemical and Mineralogical Analyses of Particles from the Stratospheric Collections Coinciding with the 2002 Leonid Storm and the 2003 Comet Grigg-Skjellerup Trail Passage. An Analysis of the Solvus in the CaS-MnS System. ESA s SMART-1 Mission at the Moon: First Results, Status and Next Steps. Europa Analog Ice-splitting Measurements and Experiments with Ice-Hunveyor on the Frozen Balaton-Lake, Hungary. Chromium on Eros: Further Evidence of Ordinary Chondrite Composition. Dust Devil Tracks on Mars: Observation and Analysis from Orbit and the Surface. Spatial Variation of Methane and Other Trace Gases Detected on Mars: Interpretation with a General Circulation Model. Mars Water Ice and Carbon Dioxide Seasonal Polar Caps: GCM Modeling and Comparison with Mars Express Omega Observations. Component Separation of OMEGA Spectra with ICA. Clathrate Formation in the Near-Surface Environment of Titan. Space Weathering: A Proposed Laboratory Approach to Explaining the Sulfur Depletion on Eros. Sample Collection from Small Airless Bodies: Examination of Temperature Constraints for the TGIP. Sample Collector for the Hera Near-Earth Asteroid Sample Return Mission. A Rugged Miniature Mass-Spectrometer for Measuring Aqueous Geochemistry on Mars. Martian and Lunar Pyroxene Microstructures Studied by Single-Crystal X-Ray Diffraction.

Trace element content of chondritic cosmic dust: Volatile enrichments, thermal alterations, and the possibility of contamination

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Sutton, S. R.; Bajt, S.

1993-01-01

Trace element abundances in 51 chondritic Interplanetary Dust Particles (IDP's) were measured by Synchrotron X-Ray Fluorescence (SXRF). The data allow us to determine an average composition of chondritic IDP's and to examine the questions of volatile loss during the heating pulse experienced on atmospheric entry and possible element addition due to contamination during atmospheric entry, stratospheric residence, and curation.

Dust evolution from comets

NASA Technical Reports Server (NTRS)

Sekanina, Z.

1977-01-01

The studies of the evolution of cometary debris are reviewed. The subject is divided into three major sections: (1) the developments in the immediate vicinity of the cometary nucleus, which is the source of the dust; (2) the formation of the dust tail; and (3) the blending of the debris with the dust component of interplanetary matter. The importance of the physical theory of comets is emphasized for the understanding of the early phase of the evolution of cometary dust. A physico-dynamical model designed to analyze the particle-emission mechanism from the distribution of light in the dust tails is described and the results are presented. Increased attention is paid to large particles because of their importance for the evolution of the zodiacal cloud. Finally, implications are discussed for the future in situ investigations of comets.

Comets as a possible source of nanodust in the Solar System cloud and in planetary debris discs

NASA Astrophysics Data System (ADS)

Mann, Ingrid

2017-05-01

Comets, comet-like objects and their fragments are the most plausible source for the dust in both the inner heliosphere and planetary debris discs around other stars. The smallest size of dust particles in debris discs is not known and recent observational results suggest that the size distribution of the dust extends down to sizes of a few nanometres or a few tens of nanometres. In the Solar System, electric field measurements from spacecraft observe events that are explained with high-velocity impacts of nanometre-sized dust. In some planetary debris discs an observed mid- to near-infrared emission supposedly results from hot dust located in the vicinity of the star. And the observed emission is characteristic of dust of sizes a few tens of nanometres. Rosetta observations, on the other hand, provide little information on the presence of nanodust near comet 67P/Churyumov-Gerasimenko. This article describes why this is not in contradiction to the observations of nanodust in the heliosphere and in planetary debris discs. The direct ejection of nanodust from the nucleus of the comet would not contribute significantly to the observed nanodust fluxes. We discuss a scenario that nanodust forms in the interplanetary dust cloud through the high-velocity collision process in the interplanetary medium for which the production rates are highest near the Sun. Likewise, fragmentation by collisions occurs near the star in planetary debris discs. The collisional fragmentation process in the inner Solar System occurs at similar velocities to those of the collisional evolution in the interstellar medium. A question for future studies is whether there is a common magic size of the smallest collision fragments and what determines this size. This article is part of the themed issue 'Cometary science after Rosetta'.

Proceedings of the 38th Lunar and Planetary Science Conference

NASA Technical Reports Server (NTRS)

2007-01-01

The sessions in the conference include: Titan, Mars Volcanism, Mars Polar Layered Deposits, Early Solar System Isotopes, SPECIAL SESSION: Mars Reconnaissance Orbiter: New Ways of Studying the Red Planet, Achondrites: Exploring Oxygen Isotopes and Parent-Body Processes, Solar System Formation and Evolution, SPECIAL SESSION: SMART-1, . Impact Cratering: Observations and Experiments, SPECIAL SESSION: Volcanism and Tectonism on Saturnian Satellites, Solar Nebula Composition, Mars Fluvial Geomorphology, Asteroid Observations: Spectra, Mostly, Mars Sediments and Geochemistry: View from the Surface, Mars Tectonics and Crustal Dichotomy, Stardust: Wild-2 Revealed, Impact Cratering from Observations and Interpretations, Mars Sediments and Geochemistry: The Map View, Chondrules and Their Formation, Enceladus, Asteroids and Deep Impact: Structure, Dynamics, and Experiments, Mars Surface Process and Evolution, Martian Meteorites: Nakhlites, Experiments, and the Great Shergottite Age Debate, Stardust: Mainly Mineralogy, Astrobiology, Wind-Surface Interactions on Mars and Earth, Icy Satellite Surfaces, Venus, Lunar Remote Sensing, Space Weathering, and Impact Effects, Interplanetary Dust/Genesis, Mars Cratering: Counts and Catastrophes?, Chondrites: Secondary Processes, Mars Sediments and Geochemistry: Atmosphere, Soils, Brines, and Minerals, Lunar Interior and Differentiation, Mars Magnetics and Atmosphere: Core to Ionosphere, Metal-rich Chondrites, Organics in Chondrites, Lunar Impacts and Meteorites, Presolar/Solar Grains, Topics for Print Only papers are: Outer Planets/Satellites, Early Solar System, Interplanetary Dust, Comets and Kuiper Belt Objects, Asteroids and Meteoroids, Chondrites, Achondrites, Meteorite Related, Mars Reconnaissance Orbiter, Mars, Astrobiology, Planetary Differentiation, Impacts, Mercury, Lunar Samples and Modeling, Venus, Missions and Instruments, Global Warming, Education and Public Outreach, Poster sessions are: Asteroids/Kuiper Belt Objects, Galilean Satellites: Geology and Mapping, Titan, Volcanism and Tectonism on Saturnian Satellites, Early Solar System, Achondrite Hodgepodge, Ordinary Chondrites, Carbonaceous Chondrites, Impact Cratering from Observations and Interpretations, Impact Cratering from Experiments and Modeling, SMART-1, Planetary Differentiation, Mars Geology, Mars Volcanism, Mars Tectonics, Mars: Polar, Glacial, and Near-Surface Ice, Mars Valley Networks, Mars Gullies, Mars Outflow Channels, Mars Sediments and Geochemistry: Spirit and Opportunity, Mars Reconnaissance Orbiter: New Ways of Studying the Red Planet, Mars Reconnaissance Orbiter: Geology, Layers, and Landforms, Oh, My!, Mars Reconnaissance Orbiter: Viewing Mars Through Multicolored Glasses; Mars Science Laboratory, Phoenix, and ExoMars: Science, Instruments, and Landing Sites; Planetary Analogs: Chemical and Mineral, Planetary Analogs: Physical, Planetary Analogs: Operations, Future Mission Concepts, Planetary Data, Imaging, and Cartography, Outer Solar System, Presolar/Solar Grains, Stardust Mission; Interplanetary Dust, Genesis, Asteroids and Comets: Models, Dynamics, and Experiments, Venus, Mercury, Laboratory Instruments, Methods, and Techniques to Support Planetary Exploration; Instruments, Techniques, and Enabling Techologies for Planetary Exploration; Lunar Missions and Instruments, Living and Working on the Moon, Meteoroid Impacts on the Moon, Lunar Remote Sensing, Lunar Samples and Experiments, Lunar Atmosphere, Moon: Soils, Poles, and Volatiles, Lunar Topography and Geophysics, Lunar Meteorites, Chondrites: Secondary Processes, Chondrites, Martian Meteorites, Mars Cratering, Mars Surface Processes and Evolution, Mars Sediments and Geochemistry: Regolith, Spectroscopy, and Imaging, Mars Sediments and Geochemistry: Analogs and Mineralogy, Mars: Magnetics and Atmosphere, Mars Aeolian Geomorphology, Mars Data Processing and Analyses, Astrobiology, Engaging Student Educators and the Public in Planetary Science,

Unusual olivine and pyroxene composition in interplanetary dust and unequilibrated ordinary chondrites

NASA Technical Reports Server (NTRS)

Klock, W.; Mckay, D. S.; Thomas, K. L.; Palme, H.

1989-01-01

The presence, in both a number of interplanetary dust particles (IDPs) and in meteorite matrices, of olivine and orthopyroxene grains, low in FeO but containing up to 5 wt pct MnO, is reported. The majority of olivines and pyroxenes in meteorites contain less than 0.5 wt pct MnO. The presence of these low-iron, manganese-enriched (LIME) olivines and pyroxenes in IDPs and meteorites may indicate a link between the origin and history of IDPs and the matrix material of primitive meteorites. The origin of the LIME silicates could be explained by condensation from a gas of solar composition. Forsterite is the first major silicate phase to condense from a solar nebula gas, and Mn, which is not stable as a metal under solar nebula conditions, would condense at about 1100 K as Mn2SiO4 in solid solution with forsterite.

Automated thin-film analyses of hydrated interplanetary dust particles in the analytical electron microscope

NASA Technical Reports Server (NTRS)

Germani, M. S.; Bradley, J. P.; Brownlee, D. E.

1990-01-01

A 200 keV electron microscope was used to obtain elemental analyses from over 4000 points on thin sections of eight 'layer silicate' class interplanetary dust particles (IDPs). Major and minor element abundances from a volume approaching that of a cylinder 50 nm in diameter were observed. Mineral phases and their relative abundances in the thin sections were identified and petrographic characteristics were determined. Three of the particles contained smectite (1.0-1.2 nm basal spacing) and two contained serpentine (0.7 nm basal spacing). The point count analyses and Mg-Si-Fe ternary diagrams show that one of the serpentine-containing IDPs is similar to CI and CM chondritic meteorites. The IDPs exhibit evidence of aqueous processing, but they have typically experienced only short range, submicrometer scale alteration. The IDPs may provide a broad sampling of the asteroid belt.

Infrared Spectroscopy of Anhydrous Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Keller, L. P.; Flynn, G. J.

2003-01-01

Infrared (IR) spectroscopy is the primary means of mineralogical analysis of materials outside our solar system. The identity and properties of circumstellar grains are inferred from spectral comparisons between astronomical observations and laboratory data from natural and synthetic materials. These comparisons have been facilitated by the Infrared Space Observatory (ISO), which obtained IR spectra from numerous astrophysical objects over a wide spectral range (out to 50/cm) where crystalline silicates and other phases have distinct features. The anhydrous interplanetary dust particles (IDPs) are particularly important comparison materials because some IDPs contain carbonaceous material with non-solar D/H and N-15/N-14 ratios and amorphous and crystalline silicates with non-solar 0- isotopic ratios, demonstrating that these IDPs contain preserved interstellar material. Here, we report on micro- Fourier transform (FT) IR spectrometry of IDPs, focusing on the inorganic components of primitive IDPs (FTIR spectra from the organic/carbonacecous materials in IDPs are described elsewhere).

Analysis of the Organic Matter in Interplanetary Dust Particles: Clues to the Organic Matter in Comets, Asteroids, and Interstellar Grains

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Keller, L. P.

2003-01-01

Reflection spectroscopy suggests the C- , P-, and D-types of asteroids contain abundant carbon, but these Vis-nearIR spectra are featureless, providing no information on the type(s) of carbonaceous matter. Infrared spectroscopy demonstrates that organic carbon is a significant component in comets and as grains or grain coatings in the interstellar medium. Most of the interplanetary dust particles (IDPs) recovered from the Earth s stratosphere are believed to be fragments from asteroids or comets, thus characterization of the carbon in IDPs provides the opportunity to determine the type(s) and abundance of organic matter in asteroids and comets. Some IDPs exhibit isotopic excesses of D and N-15, indicating the presence of interstellar material. The characterization of the carbon in these IDPs, and particularly any carbon spatially associated with the isotopic anomalies, provides the opportunity to characterize interstellar organic matter.

Clay minerals in primitive meteorites and interplanetary dust 1

NASA Technical Reports Server (NTRS)

Zolensky, M. E.; Keller, L. P.

1991-01-01

Many meteorites and interplanetary dust particles (IDPs) with primitive compositions contain significant amounts of phyllosilicate minerals, which are generally interpreted as evidence of protoplanetary aqueous alteration at an early period of the solar system. These meteorites are chondrites (near solar composition) of the carbonaceous and ordinary varieties. The former are subdivided (according to bulk composition and petrology) into CI, CM, CV, CO, CR, and ungrouped classes. IDPs are extraterrestrial particulates, collected in stratosphere, which have chemical compositions indicative of a primitive origin; they are typically distinct from the primitive meteorites. Characterization of phyllosilicates in these materials is a high priority because of the important physico-chemical information they hold. The most common phyllosilicates present in chondritic extraterrestrial materials are serpentine-group minerals, smectites, and micas. We discuss these phyllosilicates and describe the interpretation of their occurrence in meteorites and IDPs and what this indicates about history of their parent bodies, which are probably the hydrous asteroids.

Clementine Observations of the Zodiacal Light and the Dust Content of the Inner Solar System

NASA Technical Reports Server (NTRS)

Hahn, Joseph M.; Zook, Herbert A.; Cooper, Bonnie; Sunkara, Bhaskar

2002-01-01

Using the Moon to occult the Sun, the Clementine spacecraft used its navigation cameras to map the inner zodiacal light at optical wavelengths over elongations of 3 approx. less than epsilon approx. less than 30 deg from the Sun. This surface brightness map is then used to infer the spatial distribution of interplanetary dust over heliocentric distances of about 10 solar radii to the orbit of Venus. The averaged ecliptic surface brightness of the zodiacal light falls off as Z(epsilon) is a member of epsilon(sup -2.45 +/- 0.05), which suggests that the dust cross-sectional density nominally falls off as sigma(r) is a member of r(sup - 1.45 +/- 0.05). The interplanetary dust also has an albedo of alpha approx. = 0.1 that is uncertain by a factor of approx. 2. Asymmetries of approx. 10% are seen in directions east-west and north-south of the Sun, and these may be due the giant planets' secular gravitational perturbations. We apply a simple model that attributes the zodiacal light as due to three dust populations having distinct inclination distributions, namely, dust from asteroids and Jupiter-family comets (JFCs) having characteristic inclinations of i approx. 7 deg, dust from Halley-type comets having i approx. 33 deg, and an isotropic cloud of dust from Oort Cloud comets. The best-fitting scenario indicates that asteroids + JFCs are the source of about 45% of the optical dust cross section seen in the ecliptic at 1 AU but that at least 89% of the dust cross section enclosed by a 1-AU-radius sphere is of a cometary origin. Each population's radial density variations can also deviate somewhat from the nominal sigma(r) is a member of r(sup -1.45). When these results are extrapolated out to the asteroid belt, we find an upper limit on the mass of the light-reflecting asteroidal dust that is equivalent to a 12-km asteroid, and a similar extrapolation of the isotropic dust cloud out to Oort Cloud distances yields a mass equivalent to a 30-km comet, although the latter mass is uncertain by orders of magnitude.

Investigations of Wind/WAVES Dust Impacts

NASA Astrophysics Data System (ADS)

St Cyr, O. C.; Wilson, L. B., III; Rockcliffe, K.; Mills, A.; Nieves-Chinchilla, T.; Adrian, M. L.; Malaspina, D.

2017-12-01

The Wind spacecraft launched in November 1994 with a primary goal to observe and understand the interaction between the solar wind and Earth's magnetosphere. The waveform capture detector, TDS, of the radio and plasma wave investigation, WAVES [Bougeret et al., 1995], onboard Wind incidentally detected micron-sized dust as electric field pulses from the recollection of the impact plasma clouds (an unintended objective). TDS has detected over 100,000 dust impacts spanning almost two solar cycles; a dataset of these impacts has been created and was described in Malaspina & Wilson [2016]. The spacecraft continues to collect data about plasma, energetic particles, and interplanetary dust impacts. Here we report on two investigations recently conducted on the Wind/WAVES TDS database of dust impacts. One possible source of dust particles is the annually-recurring meteor showers. Using the nine major showers defined by the American Meteor Society, we compared dust count rates before, during, and after the peak of the showers using averaging windows of varying duration. However, we found no statistically significant change in the dust count rates due to major meteor showers. This appears to be an expected result since smaller grains, like the micron particles that Wind is sensitive to, are affected by electromagnetic interactions and Poynting-Robertson drag, and so are scattered away from their initial orbits. Larger grains tend to be more gravitationally dominated and stay on the initial trajectory of the parent body so that only the largest dust grains (those that create streaks as they burn up in the atmosphere) are left in the orbit of the parent body. Ragot and Kahler [2003] predicted that coronal mass ejections (CMEs) near the Sun could effectively scatter dust grains of comparable size to those observed by Wind. Thus, we examined the dust count rates immediately before, during, and after the passage of the 350 interplanetary CMEs observed by Wind over its 20+ year lifetime. We found a statistically significant and consistent trend of count rate deficits during the ICMEs compared to the periods immediately before and after the ICMEs. These preliminary results suggest that ICMEs may scatter micron-sized dust, or that they may exclude it during their initiation.

Impact Vaporization as a Possible Source of Mercury's Calcium Exosphere

NASA Technical Reports Server (NTRS)

Killen, Rosemary M.; Hahn, Joseph M.

2015-01-01

Mercury's calcium exosphere varies in a periodic way with that planet's true anomaly. We show that this pattern can be explained by impact vaporization from interplanetary dust with variations being due to Mercury's radial and vertical excursions through an interplanetary dust disk having an inclination within 5 degrees of the plane of Mercury's orbit. Both a highly inclined dust disk and a two-disk model (where the two disks have a mutual inclination) fail to reproduce the observed variation in calcium exospheric abundance with Mercury true anomaly angle. However, an additional source of impacting dust beyond the nominal dust disk is required near Mercury's true anomaly (?) 25deg +/-5deg. This is close to but not coincident with Mercury's true anomaly (?=45deg) when it crosses comet 2P/Encke's present day orbital plane. Interestingly, the Taurid meteor storms at Earth, which are also due to Comet Encke, are observed to occur when Earth's true anomaly is +/-20 or so degrees before and after the position where Earth and Encke orbital planes cross. The lack of exact correspondence with the present day orbit of Encke may indicate the width of the potential stream along Mercury's orbit or a previous cometary orbit. The extreme energy of the escaping calcium, estimated to have a temperature greater than 50000 K if the source is thermal, cannot be due to the impact process itself but must be imparted by an additional mechanism such as dissociation of a calcium-bearing molecule or ionization followed by recombination.

Dynamics of Solar System Dust

NASA Technical Reports Server (NTRS)

Dermott, Stanley F.

2002-01-01

The ongoing aim of the research is to investigate the dynamical and physical evolution of interplanetary dust particles in order to produce a detailed global model of the zodiacal cloud and its constituent components that is capable of predicting thermal fluxes in mid-infrared wave bands to an accuracy of 1% or better; with the additional aim of exploiting this research as a basis for predicting structure in exozodiacal clouds that may be signatures of unseen planets.

Trapped Xenon in Interplanetary Dust Particles and Antarctic Micrometeorites

NASA Astrophysics Data System (ADS)

Spring, N. H.; Busemann, H.; Crowther, S. A.; Gilmour, J. D.

2014-09-01

We analysed the Xe inventory of several IDPs and AMMs and infer that cometary solids may contain the same mix of organic matter and trapped Xe carriers as found in carbonaceous chondrite matrices, although in higher relative abundances.

The Cosmic Dust Analyzer for Cassini

NASA Technical Reports Server (NTRS)

Bradley, James G.; Gruen, Eberhard; Srama, Ralf

1996-01-01

The Cosmic Dust Analyzer (CDA) is designed to characterize the dust environment in interplanetary space, in the Jovian and in the Saturnian systems. The instrument consists of two major components, the Dust Analyzer (DA) and the High Rate Detector (HRD). The DA has a large aperture to provide a large cross section for detection in low flux environments. The DA has the capability of determining dust particle mass, velocity, flight direction, charge, and chemical composition. The chemical composition is determined by the Chemical Analyzer system based on a time-of-flight mass spectrometer. The DA is capable of making full measurements up to one impact/second. The HRD contains two smaller PVDF detectors and electronics designed to characterize dust particle masses at impact rates up to 10(exp 4) impacts/second. These high impact rates are expected during Saturn ring, plane crossings.

CM-like Interplanetary Dust Particles in Lower Stratosphere During 1989 October and 1991 June/July

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1996-01-01

The stratospheric interplanetary dust particles L2005T12 and L2011O3 are linked to CM chondrite matrix. Particle L2005T12 is dominated by tabular grains of partially dehydrated greenalite-rich serpentine. Its amorphous matrix contains abundant smectite nanocrystals and annular Fe,Ni,S units. A uniquely stratified (partial) maghemite rim occurs only on S-rich parts of the matrix. Formation of this rim and Mg depletions in the matrix occurred during atmospheric entry heating of this particle. Particle L2011O3 has large iron sulfide and magnesiowustite grains in an amorphous low-Al, ferromagnesiosilica matrix. Hydrous crystallisation of this matrix produced ultrafine-grained smectites and disseminated iron sulfides. Atmospheric entry heating of both particles is indicated by the partial iron oxide rim, vesicular sulfides, and the scatter of matrix compositions due to loss of Mg. While many uncertainties remain, the high incidence of chondritic rough particles, which include an unknown amount of CM-like particles, in the lower stratosphere during 1984, 1989, and 1991 suggests annual variations in their abundances. The timing of lower stratospheric dust samplings is critical to collect these particles.

Stardust Interstellar Preliminary Examination II: Curating the Interstellar Dust Collector, Picokeystones, and Sources of Impact Tracks

NASA Technical Reports Server (NTRS)

Frank, David R.; Westphal, Andrew J.; Zolensky, Michael E.; Gainsforth, Zack; Butterworth, Anna L.; Bastien, Ronald K.; Allen, Carlton; Anderson, David; Bechtel, Hans A.; Sandford, Scott A.

2013-01-01

We discuss the inherent difficulties that arise during "ground truth" characterization of the Stardust interstellar dust collector. The challenge of identifying contemporary interstellar dust impact tracks in aerogel is described within the context of background spacecraft secondaries and possible interplanetary dust particles and beta-meteoroids. In addition, the extraction of microscopic dust embedded in aerogel is technically challenging. Specifically, we provide a detailed description of the sample preparation techniques developed to address the unique goals and restrictions of the Interstellar Preliminary Exam. These sample preparation requirements and the scarcity of candidate interstellar impact tracks exacerbate the difficulties. We also illustrate the role of initial optical imaging with critically important examples, and summarize the overall processing of the collection to date.

Dust evolution from comets

NASA Technical Reports Server (NTRS)

Sekanina, Z.

1976-01-01

The studies of the evolution of cometary debris are reviewed. The subject is divided into three major sections: (1) the developments in the immediate vicinity of the cometary nucleus, which is the source of the dust; (2) the formation of the dust tail; and (3) the blending of the debris with the dust component of interplanetary matter. The importance of the physical theory of comets is emphasized for the understanding of the early phase of evolution. A physico-dynamical model designed to analyze the particle-emission mechanism from the distribution of light in the dust tail is described and the results are presented. Increased attention is paid to large particles because of their importance for the evolution of the zodiacal cloud. Finally, implications are discussed for the future in situ investigations of comets.

Characteristics of the dust trail of 67P/Churyumov-Gerasimenko: an application of the IMEX model

NASA Astrophysics Data System (ADS)

Soja, R. H.; Sommer, M.; Herzog, J.; Agarwal, J.; Rodmann, J.; Srama, R.; Vaubaillon, J.; Strub, P.; Hornig, A.; Bausch, L.; Grün, E.

2015-11-01

Context. Here we describe a new model of the dust streams of comet 67P/Churyumov-Gerasimenko that has been developed using the Interplanetary Meteoroid Environment for Exploration (IMEX). This is a new universal model for recently created cometary meteoroid streams in the inner solar system. Aims: The model can be used to investigate characteristics of cometary trails: here we describe the model and apply it to the trail of comet 67P/Churyumov-Gerasimenko to develop our understanding of the trail and assess the reliability of the model. Methods: Our IMEX model provides trajectories for a large number of dust particles released from ~400 short-period comets. We use this to generate optical depth profiles of the dust trail of comet 67P/Churyumov-Gerasimenko and compare these to Spitzer observations of the trail of this comet from 2004 and 2006. Results: We find that our model can match the observed trails if we use very low ejection velocities, a differential size distribution index of α ≈ -3.7, and a dust production rate of 300-500 kg s-1 at perihelion. The trail is dominated by mm-sized particles and can contain a large proportion of dust produced before the most recent apparition. We demonstrate the strength of IMEX in providing time-resolved histories of meteoroid streams. We find that the passage of Mars through the stream in 2062 creates visible gaps. This indicates the utility of this model in providing insight into the dynamical evolution of streams and trails, as well as impact hazard assessment for spacecraft on interplanetary missions. A movie is available in electronic form at http://www.aanda.org

Discovery of Brownleeite: a New Manganese Silicide Mineral in an Interplanetary Dust Particle

NASA Technical Reports Server (NTRS)

Keller, Lindsay P.; Nakamura-Messenger, Keiko; Clemett, Simon J.; Messenger, Scott; Jones, John H.; Palma, Russell L.; Pepin, Robert O.; Klock, Wolfgang; Zolensky, Michael E.; Tatsuoka, Hirokazu

2011-01-01

The Earth accretes approximately 40,000 tons of cosmic dust annually, originating mainly from the disintegration of comets and collisions among asteroids. This cosmic dust, also known as interplanetary dust particles (IDPs), is a subject of intense interest since it is made of the original building blocks of our Solar System. Although the specific parent bodies of IDPs are unknown, the anhydrous chondritic-porous IDPs (CP-IDPs) subset has been potentially linked to a cometary source. The CP-IDPs are extremely primitive materials based on their unequilibrated mineralogy, C-rich chemistry, and anomalous isotopic signatures. In particular, some CP-IDPs escaped the thermal, aqueous and impact shock processing that has modified or destroyed the original mineralogy of meteorites. Thus, the CP-IDPs represent some of the most primitive solar system materials available for laboratory study. Most CP-IDPs are comprised of minerals that are common on Earth. However, in the course of an examination of one of the CP-IDPs, we encountered three sub-micrometer sized grains of manganese silicide (MnSi), a phase that has heretofore not been found in nature. In the seminar, we would like to focus on IDP studies and this manganese silicide phase that has been approved as the first new mineral identified from a comet by the International Mineralogical Association (IMA) in 2008. The mineral is named in honour of Donald E. Brownlee, an American astronomer and a founder of the field of cosmic dust research who is the principal investigator of the NASA Stardust Mission that collected dust samples from Comet 81P/Wild-2 and returned them to Earth. Much of our current view and understanding of the early solar system would not exist without the pioneering work of professor Don Brownlee in the study of IDPs.

A close-up of the sun. [solar probe mission planning conference

NASA Technical Reports Server (NTRS)

Neugebauer, M. (Editor); Davies, R. W. (Editor)

1978-01-01

NASA's long-range plan for the study of solar-terrestrial relations includes a Solar Probe Mission in which a spacecraft is put into an eccentric orbit with perihelion near 4 solar radii (0.02 AU). The scientific experiments which might be done with such a mission are discussed. Topics include the distribution of mass within the Sun, solar angular momentum, the fine structure of the solar surface and corona, the acceleration of the solar wind and energetic particles, and the evolution of interplanetary dust. The mission could also contribute to high-accuracy tests of general relativity and the search for cosmic gravitational radiation.

Physical characteristics of cometary dust from dynamical studies - A review

NASA Technical Reports Server (NTRS)

Sekanina, Z.

1980-01-01

Progress made in the determination of the physical characteristics of cometary dust particles from studies of dust tail dynamics is reviewed. Applications of the combined dynamical photometric approach of Finson and Probstein (1968) to studies of cometary tails exhibiting continuous light intensity variations are discussed, with attention given to determinations of the particle-size-related distribution function of the solar radiation pressure exerted on the particles, the contribution of comets to the interplanetary dust, calculations of dust ejection rates and a Monte Carlo approach to the analysis of dust tails. Investigations of dust streamers and striae, which are believed to be related to comet outbursts entailing brief but sharp enhancements of dust production, are then reviewed, with particular attention given to observations of Comet West 1976 VI. Finally, the question of cometary particle type is addressed, and it is pointed out that the presence of submicron absorbing particles in the striae of Comet West is not incompatible with the presence of micron-size dielectric particles in the inner coma.

Low-temperature crystallization of silicate dust in circumstellar disks.

PubMed

Molster, F J; Yamamura, I; Waters, L B; Tielens, A G; de Graauw, T; de Jong, T; de Koter, A; Malfait, K; van den Ancker, M E; van Winckel, H; Voors, R H; Waelkens, C

1999-10-07

Silicate dust in the interstellar medium is observed to be amorphous, yet silicate dust in comets and interplanetary dust particles is sometimes partially crystalline. The dust in disks that are thought to be forming planets around some young stars also appears to be partially crystalline. These observations suggest that as the dust goes from the precursor clouds to a planetary system, it must undergo some processing, but the nature and extent of this processing remain unknown. Here we report observations of highly crystalline silicate dust in the disks surrounding binary red-giant stars. The dust was created in amorphous form in the outer atmospheres of the red giants, and therefore must be processed in the disks to become crystalline. The temperatures in these disks are too low for the grains to anneal; therefore, some low-temperature process must be responsible. As the physical properties of the disks around young stars and red giants are similar, our results suggest that low-temperature crystallization of silicate grains also can occur in protoplanetary systems.

Impacts of Cosmic Dust on Planetary Atmospheres and Surfaces

NASA Astrophysics Data System (ADS)

Plane, John M. C.; Flynn, George J.; Määttänen, Anni; Moores, John E.; Poppe, Andrew R.; Carrillo-Sanchez, Juan Diego; Listowski, Constantino

2018-02-01

Recent advances in interplanetary dust modelling provide much improved estimates of the fluxes of cosmic dust particles into planetary (and lunar) atmospheres throughout the solar system. Combining the dust particle size and velocity distributions with new chemical ablation models enables the injection rates of individual elements to be predicted as a function of location and time. This information is essential for understanding a variety of atmospheric impacts, including: the formation of layers of metal atoms and ions; meteoric smoke particles and ice cloud nucleation; perturbations to atmospheric gas-phase chemistry; and the effects of the surface deposition of micrometeorites and cosmic spherules. There is discussion of impacts on all the planets, as well as on Pluto, Triton and Titan.

Life from the stars?. [extraterrestrial sources contributing to chemical evolution on Earth

NASA Technical Reports Server (NTRS)

Pendleton, Yvonne J.; Cruikshank, Dale P.

1994-01-01

Scientists are now seriously considering the possibility that organic matter from interstellar space could have influenced, or even spurred, the origin of life on Earth. Various aspects of chemical evolution are discussed along with possible extraterrestrial sources responsible for contributing to Earth's life-producing, chemical composition. Specific topics covered include the following: interstellar matter, molecular clouds, asteroid dust, organic molecules in our solar system, interplanetary dust and comets, meteoritic composition, and organic-rich solar-system bodies.

Cosmic dust and space debris; Proceedings of the Topical Meetings and Workshop 6 of the 26th COSPAR Plenary Meeting, Toulouse, France, June 30-July 11, 1986

NASA Technical Reports Server (NTRS)

Mcdonnell, J. A. M. (Editor); Hanner, M. S. (Editor); Kessler, D. J. (Editor)

1986-01-01

These proceedings encompass topics in the fields of extraterrestrial material samples, IRAS solar system and dust model results, and earth orbit debris. Attention is given to chemical fractionation during high velocity impact, particle deceleration and survival in multiple thin foil targets, and IRAS studies of asteroids, comets, cometary tails, the zodiacal background, and the three-dimensional modeling of interplanetary dust. Also discussed are the evolution of an earth orbit debris cloud, orbital debris due to future space activities, collision probabilities in geosynchronous orbits, and a bitelescopic survey of low altitude orbital debris.

Development of a high resolution interstellar dust engineering model - overview of the project

NASA Astrophysics Data System (ADS)

Sterken, V. J.; Strub, P.; Soja, R. H.; Srama, R.; Krüger, H.; Grün, E.

2013-09-01

Beyond 3 AU heliocentric distance, the flow of interstellar dust through the solar system is a dominant component of the total dust population. The modulation of this flux with the solar cycle and the position in the solar system has been predicted by theoretical studies since the seventies. The modulation was proven to exist by matching dust trajectory simulations with real spacecraft data from Ulysses in 1998. The modulations were further analyzed and studies in detail in 2012. The current ESA interplanetary meteoroid model IMEM includes an interstellar dust component, but this component was modelled only with straight line trajectories through the solar system. For the new ESA IMEX model, a high-resolution interstellar dust component is implemented separately from a dust streams module. The dust streams module focuses on dust in streams that was released from comets (cf. Abstract R. Soja). Parallel processing techniques are used to improve computation time (cf. Abstract P. Strub). The goal is to make predictions for the interstellar dust flux as close to the Sun as 1 AU or closer, for future space mission design.

Origin of cometary and chondritic refractory organics: Ion irradiation experiments

NASA Astrophysics Data System (ADS)

Quirico, E.; Faure, M.; Faure, A.; Baklouti, D.; Boduch, P.; Rothard, H.; Ballanzat, E.; Dartois, E.; Brunetto, R.; Bonal, L.; Beck, P.; Schmitt, B.; Duprat, J.; Engrand, C.

2017-09-01

The formation process of Refractory Organic matter present in chondrites and Interplanetary Dust Particles (IDPs) of cometary and asteroidal origin is a debated issue. Earlier studies have advocated a formation step in a hot environment, however the potential role of ion irradiation has been so far poorly constrained. We present here experimental simulations that address this issue, comprising thermal degradation and ion irradiation experiments conducted at GANIL (Caen France) and CSNSM (Orsay France). We show that unlike thermal reactions, ion irradiation might lead to ROM-like material under very stringent conditions on both the nuclear dose and the nature of precursor. These very narrow conditions suggest that forming ROM without any action of thermal reactions is extremely difficult in astrophysical environments, either ISM or the proto-solar disk.

Mineralogy of interplanetary dust particles from the 'olivine' infrared class

NASA Technical Reports Server (NTRS)

Christoffersen, R.; Buseck, P. R.

1986-01-01

Analytical electron microscopy observations establish that olivine is abundant and the predominant silicate phase in three interplanetary dust particles (IDPs) from the 'olivine' infrared spectra category. Two of the particles have microstructures resembling those of most nonhydrous chondritic IDPs, consisting of micron to submicron grains together with a matrix composed of amorphous carbonaceous material and sub-500 A grains. In addition to olivine these particles respectively contain enstatite and magnetite, and pentlandite plus Ca-rich clinopyroxene. The third IDP consists mostly of olivine and pyrrhotite with little or no matrix material. Olivine grains in this particle contain prominent solar-flare ion tracks with densities corresponding to a space-exposure age between 1000 to 100,000 years. Although the three particles have olivine-rich mineralogies in common, other aspects of their mineralogies and microstructures suggest that they experienced different formation histories. The differences between the particles indicate that the olivine infrared spectral category is a diverse collection of IDPs that probably incorporates several genetic groups.

Comets as a possible source of nanodust in the Solar System cloud and in planetary debris discs.

PubMed

Mann, Ingrid

2017-07-13

Comets, comet-like objects and their fragments are the most plausible source for the dust in both the inner heliosphere and planetary debris discs around other stars. The smallest size of dust particles in debris discs is not known and recent observational results suggest that the size distribution of the dust extends down to sizes of a few nanometres or a few tens of nanometres. In the Solar System, electric field measurements from spacecraft observe events that are explained with high-velocity impacts of nanometre-sized dust. In some planetary debris discs an observed mid- to near-infrared emission supposedly results from hot dust located in the vicinity of the star. And the observed emission is characteristic of dust of sizes a few tens of nanometres. Rosetta observations, on the other hand, provide little information on the presence of nanodust near comet 67P/Churyumov-Gerasimenko. This article describes why this is not in contradiction to the observations of nanodust in the heliosphere and in planetary debris discs. The direct ejection of nanodust from the nucleus of the comet would not contribute significantly to the observed nanodust fluxes. We discuss a scenario that nanodust forms in the interplanetary dust cloud through the high-velocity collision process in the interplanetary medium for which the production rates are highest near the Sun. Likewise, fragmentation by collisions occurs near the star in planetary debris discs. The collisional fragmentation process in the inner Solar System occurs at similar velocities to those of the collisional evolution in the interstellar medium. A question for future studies is whether there is a common magic size of the smallest collision fragments and what determines this size.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Author(s).

Dust arcs in the region of Jupiter's Trojan asteroids

NASA Astrophysics Data System (ADS)

Liu, Xiaodong; Schmidt, Jürgen

2018-01-01

Aims: The surfaces of the Trojan asteroids are steadily bombarded by interplanetary micrometeoroids, which releases ejecta of small dust particles. These particles form the faint dust arcs that are associated with asteroid clouds. Here we analyze the particle dynamics and structure of the arc in the region of the L4 Trojan asteroids. Methods: We calculate the total cross section of the L4 Trojan asteroids and the production rate of dust particles. The motion of the particles is perturbed by a variety of forces. We simulate the dynamical evolution of the dust particles, and explore the overall features of the Trojan dust arc. Results: The simulations show that the arc is mainly composed of grains in the size range 4-10 microns. Compared to the L4 Trojan asteroids, the dust arc is distributed more widely in the azimuthal direction, extending to a range of [30, 120] degrees relative to Jupiter. The peak number density does not develop at L4. There exist two peaks that are azimuthally displaced from L4.

Isotopic Ratios Measured in the Dust of Comet 67P/Churyumov-Gerasimenko Using Rosetta/COSIMA

NASA Astrophysics Data System (ADS)

Paquette, J. A.; Engrand, C.; Hilchenbach, M.; Fray, N.; Stenzel, O.; Merouane, S.

2017-12-01

The COSIMA instrument aboard the Rosetta orbiter captured dust from the coma of comet 67P/Churyumov-Gerasimenko on metal targets. The dust was then imaged, and some of it was subjected to Time of Flight Secondary Ion Mass Spectrometry, yielding information on the dust composition. Isotopic ratios for species such as oxygen and sulfur have been measured for a number of COSIMA dust particles and these measurements are presented in this talk. Isotopic ratios for several species have been measured for a number of comets, but with the exception of the Stardust results, these have been measurements in the gas phase. The measurements presented here are from the solid phase, most probably from silicate or carbonaceous material. The isotopic ratios measured in the dust are compared to the measurements in the gas, to values measured in the insoluble organic matter of meteorites, and to the values measured in interplanetary dust particles and Antarctic micrometeorites.

Dust Infall Onto Phobos and Deimos Can Explain Their Carbonaceous Reflectance Signature, Perhaps Overlying a Mars-Impact-Origin Core: A Hypothesis

NASA Technical Reports Server (NTRS)

Fries, M.; Cintala, M.; Steele, A.; Welzenbach, L. C.

2017-01-01

Discussions of Phobos' and Deimos' (henceforth P&D) origin(s) include an unresolved conflict: dynamical studies which favor coalescence of the moons from a large impact on Mars [1,2], versus reflectance spectroscopy of the moons showing a carbonaceous composition that is not consistent with martian surface materials [3-5]. One way to reconcile this discrepancy is to consider the combined options of a Mars impact origin for Phobos and Deimos, followed by deposition of carbon-rich materials by interplanetary dust particle (IDP) infall. This is significant because, unlike asteroidal bodies, P&D experience a high IDP flux due to their location in Mars' gravity well. We present some relatively simple, initial calculations which indicate that accreted carbon may be sufficient to produce a surface with sufficient added carbon to account for P&D's reflectance spectra. If this is true, then a major objection to an impact origin for P&D is resolved.

Organic and inorganic correlations for Northwest Africa 852 by synchrotron-based Fourier transform infrared microspectroscopy

NASA Astrophysics Data System (ADS)

Yesiltas, Mehmet; Peale, Robert E.; Unger, Miriam; Sedlmair, Julia; Hirschmugl, Carol J.

2015-10-01

Relationships between organic molecules and inorganic minerals are investigated in a single 34 μm diameter grain of the CR2 chondrite Northwest Africa 852 (NWA) 852 with submicron spatial resolution using synchrotron-based imaging micro-FTIR spectroscopy. Correlations based on absorption strength for the various constituents are determined using statistical correlation analysis. The silicate band is found to be correlated with the hydration band, and the latter is highly correlated with stretching modes of aliphatic hydrocarbons. Spatial distribution maps show that water+organic combination, silicate, OH, and C-H distributions overlap, suggesting a possible catalytic role of phyllosilicates in the formation of organics. In contrast, the carbonate band is anticorrelated with water+organic combination, however uncorrelated with any other spectral feature. The average ratio of asymmetric CH2 and CH3 band strengths (CH2/CH3 = 2.53) for NWA 852 is similar to the average ratio of interplanetary dust particles (~2.40) and Wild 2 cometary dust particles (2.50), but it significantly exceeds that of interstellar medium objects (~1.00) and several aqueously altered carbonaceous chondrites (~1.40). This suggests organics of similar length/branching, and perhaps similar formation regions, for NWA 852, Wild 2 dust particles, and interplanetary dust particles. The heterogeneous spatial distribution of ratio values indicates the presence of a mixture of aliphatic organic material with different length/branching, and thus a wide range of parent body processes, which occurred before the considered grain was formed.

High Precision Oxygen Three Isotope Analysis of Wild-2 Particles and Anhydrous Chondritic Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Nakashima, D.; Ushikubo, T.; Zolensky, Michael E.; Weisberg, M. K.; Joswiak, D. J.; Brownlee, D. E.; Matrajt, G.; Kita, N. T.

2011-01-01

One of the most important discoveries from comet Wild-2 samples was observation of crystalline silicate particles that resemble chondrules and CAIs in carbonaceous chondrites. Previous oxygen isotope analyses of crystalline silicate terminal particles showed heterogeneous oxygen isotope ratios with delta(sup 18)O to approx. delta(sup 17)O down to -50% in the CAI-like particle Inti, a relict olivine grain in Gozen-sama, and an olivine particle. However, many Wild-2 particles as well as ferromagnesian silicates in anhydrous interplanetary dust particles (IDPs) showed Delta(sup 17)O values that cluster around -2%. In carbonaceous chondrites, chondrules seem to show two major isotope reservoirs with Delta(sup 17)O values at -5% and -2%. It was suggested that the Delta(sup 17)O = -2% is the common oxygen isotope reservoir for carbonaceous chondrite chondrules and cometary dust, from the outer asteroid belt to the Kuiper belt region. However, a larger dataset with high precision isotope analyses (+/-1-2%) is still needed to resolve the similarities or distinctions among Wild-2 particles, IDPs and chondrules in meteorites. We have made signifi-cant efforts to establish routine analyses of small particles (< or =10micronsm) at 1-2% precision using IMS-1280 at WiscSIMS laboratory. Here we report new results of high precision oxygen isotope analyses of Wild-2 particles and anhydrous chondritic IDPs, and discuss the relationship between the cometary dust and carbonaceous chondrite chondrules.

Asteroids, Comets, Meteors 1991

NASA Technical Reports Server (NTRS)

Harris, Alan W. (Editor); Bowell, Edward (Editor)

1992-01-01

Papers from the conference are presented and cover the following topics with respect to asteroids, comets, and/or meteors: interplanetary dust, cometary atmospheres, atmospheric composition, comet tails, astronomical photometry, chemical composition, meteoroid showers, cometary nuclei, orbital resonance, orbital mechanics, emission spectra, radio astronomy, astronomical spectroscopy, photodissociation, micrometeoroids, cosmochemistry, and interstellar chemistry.

Application of Dusty Plasmas for Space

NASA Astrophysics Data System (ADS)

Bhavasar, Hemang; Ahuja, Smariti

In space, dust particles alone are affected by gravity and radiation pressure when near stars and planets. When the dust particles are immersed in plasma, the dust is usually charged either by photo ionization, due to incident UV radiation, secondary electron emission, due to collisions with energetic ions and electrons, or absorption of charged particles, due to collisions with thermal ions and electrons. A 1 micron radius dust particle in a plasma with an electron temperature of a few eV, will have a charge corresponding to a few thousand electron volts, with a resulting charge to mass ratio, Q/m ¡1. They will also be affected by electric and magnetic fields. Since the electrons are magnetized in these regions, electron E B or diamagnetic cross-field drifts may drive instabilities. Dust grains (micron to sub-micron sized solid particles) in plasma and/or radiative environments can be electrically charged by processes such as plasma current collection or photoemission. The effect of charged dust on known electrojet instabil-ities and low frequency dust acoustic and dust drift instabilities. As the plasma affects the dust particles, the dust particles can affect the plasma environment. In Dust Plasma, Plasma is Combination of ions and electrons. Dusty plasmas (also known as complex plasmas) are ordinary plasmas with embedded solid particles consisting of electrons, ions, and neutrals. The particles can be made of either dielectric or conducting materials, and can have any shape. The typical size range is anywhere from 100 nm up to say 100 m. Most often, these small objects or dust particles are electrically charged. Dusty plasmas are ubiquitous in the universe as proto-planetary and solar nebulae, molecular clouds, supernova explosions, interplanetary medium, circumsolar rings, and steroids. Closer to earth, there are the noctilucent clouds, clouds of tiny (charged) ice particles that form in the summer polar mesosphere at an altitude of about 85 km. In processing plasmas, dust particles are actually grown in the discharge from the reactive gases used to form the plasmas. Perhaps the most intriguing aspect of dusty plasmas is that the particles can be directly imaged and their dynamic behavior recorded as digital images. This is accomplished by laser light scattering from the particles. Since the particle mass is relatively high, their dynamical timescales are much longer than that of the ions or electrons. Dusty plasmas has a broad range of applications including interplanetary space dust, comets, planetary rings, dusty surfaces in space, and aerosols in the atmosphere.

Dust ablation on the giant planets: Consequences for stratospheric photochemistry

NASA Astrophysics Data System (ADS)

Moses, Julianne I.; Poppe, Andrew R.

2017-11-01

Ablation of interplanetary dust supplies oxygen to the upper atmospheres of Jupiter, Saturn, Uranus, and Neptune. Using recent dynamical model predictions for the dust influx rates to the giant planets (Poppe et al., 2016), we calculate the ablation profiles and investigate the subsequent coupled oxygen-hydrocarbon neutral photochemistry in the stratospheres of these planets. We find that dust grains from the Edgeworth-Kuiper Belt, Jupiter-family comets, and Oort-cloud comets supply an effective oxygen influx rate of 1.0-0.7+2.2 ×107 O atoms cm-2 s-1 to Jupiter, 7.4-5.1+16 ×104 cm-2 s-1 to Saturn, 8.9-6.1+19 ×104 cm-2 s-1 to Uranus, and 7.5-5.1+16 ×105 cm-2 s-1 to Neptune. The fate of the ablated oxygen depends in part on the molecular/atomic form of the initially delivered products, and on the altitude at which it was deposited. The dominant stratospheric products are CO, H2O, and CO2, which are relatively stable photochemically. Model-data comparisons suggest that interplanetary dust grains deliver an important component of the external oxygen to Jupiter and Uranus but fall far short of the amount needed to explain the CO abundance currently seen in the middle stratospheres of Saturn and Neptune. Our results are consistent with the theory that all of the giant planets have experienced large cometary impacts within the last few hundred years. Our results also suggest that the low background H2O abundance in Jupiter's stratosphere is indicative of effective conversion of meteoric oxygen to CO during or immediately after the ablation process - photochemistry alone cannot efficiently convert the H2O into CO on the giant planets.

Spatially Resolved Acid Dissolution of IDPs: The State of Carbon and the Abundance of Diamonds in the Dust

NASA Technical Reports Server (NTRS)

Brownlee, D. E.; Joswiak, D. J.; Bradley, J. P.; Gezo, J. C.; Hill, H. G. M.

2000-01-01

Ultramicrotome sections of IDPs have been successfully etched with HF to isolate and reveal the microdistribution of carbonaceous material. The sections are evaluated for nanodiamonds, 3.4 micron feature, GEMS and the origin of low albedo in small interplanetary particles.

Transmission electron microscope studies of extraterrestrial materials

NASA Technical Reports Server (NTRS)

Keller, Lindsay P.

1995-01-01

Transmission Electron Microscopy, X-Ray spectrometry and electron-energy-loss spectroscopy are used to analyse carbon in interplanetary dust particles. Optical micrographs are shown depicting cross sections of the dust particles embedded in sulphur. Selected-area electron diffraction patterns are shown. Transmission Electron Microscope specimens of lunar soil were prepared using two methods: ion-milling and ultramicrotomy. A combination of high resolution TEM imaging and electron diffraction is used to characterize the opaque assemblages. The opaque assemblages analyzed in this study are dominated by ilmenite with lesser rutile and spinel exsolutions, and traces of Fe metal.

Element Mapping in Anhydrous IDPs: Identification of the Host Phases of Major/Minor Elements as a Test of Nebula Condensation Models

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Keller, L. P.; Wirick, S.; Jacobsen, C.

2004-01-01

Many anhydrous interplanetary dust particles (IDPs) are the most pristine samples of primitive solar system dust currently available for laboratory analysis. Their primitive nature is demonstrated by: 1) the high content of moderately volatile elements, indicating they have not been heated significantly since formation, 2) the absence of hydrated material, indicating they never experienced aqueous processing, 3) the presence of unequilibrated mineral assemblages, 4) the presence of large isotopic anomalies (e.g., D and 15N enrichment), in these IDPs.

Rotational bursting of interplanetary dust particles

NASA Technical Reports Server (NTRS)

Paddack, S. J.; Rhee, J. W.

1974-01-01

Solar radiation pressure is discussed as a cause of rotational bursting, and of eventual elimination of asymmetric dust particles from the solar system, by a windmill effect. The predicted life span with this process for metallic particles with radii of 0.00001 to 0.01 cm ranges from 10 to 10,000 years. The effects of magnetic spin damping were considered. This depletion mechanism works faster than the traditional Poynting-Robertson effect by approximately one order of magnitude for metallic particles and about two orders of magnitude for nonmetallic particles.

Cometary Dust

NASA Astrophysics Data System (ADS)

Levasseur-Regourd, Anny-Chantal; Agarwal, Jessica; Cottin, Hervé; Engrand, Cécile; Flynn, George; Fulle, Marco; Gombosi, Tamas; Langevin, Yves; Lasue, Jérémie; Mannel, Thurid; Merouane, Sihane; Poch, Olivier; Thomas, Nicolas; Westphal, Andrew

2018-04-01

This review presents our understanding of cometary dust at the end of 2017. For decades, insight about the dust ejected by nuclei of comets had stemmed from remote observations from Earth or Earth's orbit, and from flybys, including the samples of dust returned to Earth for laboratory studies by the Stardust return capsule. The long-duration Rosetta mission has recently provided a huge and unique amount of data, obtained using numerous instruments, including innovative dust instruments, over a wide range of distances from the Sun and from the nucleus. The diverse approaches available to study dust in comets, together with the related theoretical and experimental studies, provide evidence of the composition and physical properties of dust particles, e.g., the presence of a large fraction of carbon in macromolecules, and of aggregates on a wide range of scales. The results have opened vivid discussions on the variety of dust-release processes and on the diversity of dust properties in comets, as well as on the formation of cometary dust, and on its presence in the near-Earth interplanetary medium. These discussions stress the significance of future explorations as a way to decipher the formation and evolution of our Solar System.

Jovian dust streams: A monitor of Io's volcanic plume activity

USGS Publications Warehouse

Kruger, H.; Geissler, P.; Horanyi, M.; Graps, A.L.; Kempf, S.; Srama, R.; Moragas-Klostermeyer, G.; Moissl, R.; Johnson, T.V.; Grun, E.

2003-01-01

Streams of high speed dust particles originate from Jupiter's moon Io. After release from Io, the particles collect electric charges in the Io plasma torus, gain energy from the co-rotating electric field of Jupiter's magnetosphere, and leave the Jovian system into interplanetary space with escape speeds over 200 km s-1. The Galileo spacecraft has continuously monitored the dust streams during 34 revolutions about Jupiter between 1996 and 2002. The observed dust fluxes exhibit large orbit-to-orbit variability due to systematic and stochastic changes. After removal of the systematic variations, the total dust emission rate of Io has been calculated. It varies between 10-3 and 10 kg s-1, and is typically in the range of 0.1 to 1 kg s-1. We compare the dust emission rate with other markers of volcanic activity on Io like large-area surface changes caused by volcanic deposits and sightings of volcanic plumes. Copyright 2003 by the American Geophysical Union.

Elemental analyses of hypervelocity micro-particle impact sites on interplanetary dust experiment sensor surfaces

NASA Technical Reports Server (NTRS)

Simon, Charles G.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. R.; Wortman, Jim J.

1992-01-01

The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity micro-particles that struck the active sensors with enough energy to breakdown the 0.4 to 1.0 micron thick SiO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. These discharge features, which include 50 micron diameter areas where the aluminum top layer has been vaporized, facilitate the location of the impacts. The high purity Al-SiO2-Si substrates allow detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) is used to create two-dimensional elemental ion intensity maps of micro-particle impact sites on the IDE sensors. The element intensities in the central craters of the impacts are corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results are used to classify the particles' origins as 'manmade', 'natural' or 'indeterminate'. The last classification results from the presence of too little impactor residue (a frequent occurrence on leading edge impacts), analytical interference from high background contamination, the lack of information on silicon residue, the limited usefulness of data on aluminum in the central craters, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters, of these features. A total of 35 impacts on leading edge sensors and 22 impacts on trailing edge sensors were analyzed.

Comparison of the orbital properties of Jupiter Trojan asteroids and Trojan dust

NASA Astrophysics Data System (ADS)

Liu, Xiaodong; Schmidt, Jrgen

2018-06-01

In a previous paper we simulated the orbital evolution of dust particles from the Jupiter Trojan asteroids ejected by the impacts of interplanetary particles, and evaluated their overall configuration in the form of dust arcs. Here we compare the orbital properties of these Trojan dust particles and the Trojan asteroids. Both Trojan asteroids and most of the dust particles are trapped in the Jupiter 1:1 resonance. However, for dust particles, this resonance is modified because of the presence of solar radiation pressure, which reduces the peak value of the semi-major axis distribution. We find also that some particles can be trapped in the Saturn 1:1 resonance and higher order resonances with Jupiter. The distributions of the eccentricity, the longitude of pericenter, and the inclination for Trojans and the dust are compared. For the Trojan asteroids, the peak in the longitude of pericenter distribution is about 60 degrees larger than the longitude of pericenter of Jupiter; in contrast, for Trojan dust this difference is smaller than 60 degrees, and it decreases with decreasing grain size. For the Trojan asteroids and most of the Trojan dust, the Tisserand parameter is distributed in the range of two to three.

Sky Glow from Cities: The Army Illumination Model v2

DTIC Science & Technology

2011-09-01

magnetic field and is negligible. Zodiacal light is sunlight scattered by interplanetary dust and contributes up to half the brightness of the ...Sky Glow from Cities: The Army Illumination Model v2 by Richard C. Shirkey ARL-TR-5719 September 2011...Approved for public release; distribution is unlimited. NOTICES Disclaimers The

Measurement of polycyclic aromatic hydrocarbon (PAHs) in interplanetary dust particles

NASA Technical Reports Server (NTRS)

Clemett, S. J.; Maechling, C. R.; Zare, R. N.; Swan, P. D.; Walker, R. M.

1993-01-01

We report here the first definitive measurements of specific organic molecules (polycyclic aromatic hydrocarbons (PAH's)) in interplanetary dust particles (IDP's). An improved version of the microbeam-two-step laser mass spectrometer was used for the analysis. Two IDP's gave similar mass spectra showing an abundance of PAH's. Control samples, including particles of probable terrestrial origin from the same stratospheric collector, gave either null results or quite different spectra. We conclude that the PAH's are probably indigenous to the IDP's and are not terrestrial contaminants. The instrument used to study the particles is a two-step laser mass spectrometer. Constituent neutral molecules of the sample are first desorbed with a pulsed infrared laser beam focussed to 40 micrometers. In the second step, PAH's in the desorbed plume are preferentially ionized by a pulsed UV laser beam. Resulting ions produced by resonant absorption are extracted into a reflectron time-of-flight mass spectrometer. This instrument has high spatial resolution, high ion transmission, unlimited mass range, and multichannel detection of all ion masses from a single laser shot.

Laser microprobe characterization of C species in Interplanetary Dust Particles (IDP)

NASA Technical Reports Server (NTRS)

Dibrozolo, F. R.; Bunch, T. E.; Chang, S.; Brownlee, D. E.

1986-01-01

Preliminary results of a study whose aim is the characterization of carbon (C) species in microvolumes of materials by means of laser ionization mass spectrometry (LIMS) are presented. The LIMS instrument employs a pulsed UV laser to produce nearly instantaneous vaporization and ionization of materials, followed by acceleration and time-of-flight analysis of the ions produced. LIMS provides a survey technique with nearly simultaneous acquisition of mass spectra covering the entire elemental range. The main limitation of the LIMS technique at present is its limited ability to perform quantitative analysis, due in part to insufficient knowledge of the mechanism of laser-solid interaction. However, considerable effort is now being directed at making LIMS a more quantitative technique. A variety of different C samples, both natural and man made were analyzed to establish the ability of LIMS to differentiate among the various C phases. The results of preliminary analyses performed on meteoritical and interplanetary dust samples are also presented. The C standards selected for the LIMS characterization range from essentially amorphous soot to diamond, which exhibits the highest degree of ordering.

Interplanetary dust in the transmission electron microscope - Diverse materials from the early solar system

NASA Technical Reports Server (NTRS)

Fraundorf, P.

1981-01-01

An analytical electron microscope study of dispersed interplanetary dust aggregates collected in the earth's stratosphere shows that, in spite of their similarities, the aggregates exhibit significant differences in composition, internal morphology, and mineralogy. Of 11 chondritic particles examined, two consist mostly of a noncrystalline chondritic material with an atomic S/Fe ratio equal to or greater than 2 in places, one consists of submicron metal and reduced silicate 'microchondrules' and sulfide grains embedded in a carbonaceous matrix, and another consists of submicron magnetic-decorated unequilibrated silicate and sulfide grains with thick low-Z coatings. Although the particles are unmetamorphosed by criteria commonly applied for chondritic meteorites, the presence of reduced chemistries and the ubiquity of mafic, instead of hydrated, silicates confirm that they are not simply C1 or C2 chondrite matrix material. The observations indicate that portions of some particles have not been significantly altered by thermal or radiation processes since their assembly, and that the particles probably contain fine debris from diverse processes in the early solar system.

On the Origin of GEMS

NASA Technical Reports Server (NTRS)

Keller, L. P.; Messenger, S.

2004-01-01

GEMS (glass with embedded metal and sulfides) are a major component of anhydrous interplanetary dust particles (IDPs) their physical and chemical characteristics show marked similarities to contemporary interstellar dust. Recent oxygen isotopic measurements confirm that at least a small fraction (less than 5%) of GEMS are demonstrably presolar, while the remainder have ratios that are indistinguishable from solar values. GEMS with solar oxygen isotopic compositions either (1) had their isotopic compositions homogenized through processing in the interstellar medium (ISM), or (2) formed in the early solar system. Isotopic homogenization necessarily implies chemical homogenization, so (interstellar) GEMS compositions should reflect the average composition of dust in the local ISM. We performed a systematic examination of the bulk chemistry of GEMS in primitive IDPs in order to test this hypothesis.

Dust in the Outer Solar System as measured by Cassini-CDA: KBOs, Centaurs and TNOs as parent bodies?

NASA Astrophysics Data System (ADS)

Altobelli, N.; Kempf, S.; Srama, R.

2017-09-01

We analyse 13 years of data acquired by the Cosmic Dust Analyser (CDA)-Entrance Grid (EG) subsystem on-board the Cassini spacecraft around Saturn. We confirm the presence of exogenous dust, originating from the interplanetary space and permanently crossing the Saturnian system. We analyse the range of possible heliocentric orbital elements in order to identify their possible origin. We observe particles whose dynamics is compatible with 'old' collisional debris from the Kuiper-Belt, migrating inward the Solar System under influence of the Poynting-Robertson drag, or relatively fresh grains from recently discovered cometary activity of Centaurs. A population of particles entering the Saturn's system with high velocities can be linked to Halley-type comets as parent bodies.

A late Miocene dust shower from the break-up of an asteroid in the main belt.

PubMed

Farley, Kenneth A; Vokrouhlický, David; Bottke, William F; Nesvorný, David

2006-01-19

Throughout the history of the Solar System, Earth has been bombarded by interplanetary dust particles (IDPs), which are asteroid and comet fragments of diameter approximately 1-1,000 microm. The IDP flux is believed to be in quasi-steady state: particles created by episodic main belt collisions or cometary fragmentation replace those removed by comminution, dynamical ejection, and planetary or solar impact. Because IDPs are rich in 3He, seafloor sediment 3He concentrations provide a unique means of probing the major events that have affected the IDP flux and its source bodies over geological timescales. Here we report that collisional disruption of the >150-km-diameter asteroid that created the Veritas family 8.3 +/- 0.5 Myr ago also produced a transient increase in the flux of interplanetary dust-derived 3He. The increase began at 8.2 +/- 0.1 Myr ago, reached a maximum of approximately 4 times pre-event levels, and dissipated over approximately 1.5 Myr. The terrestrial IDP accretion rate was overwhelmingly dominated by Veritas family fragments during the late Miocene. No other event of this magnitude over the past approximately 10(8) yr has been deduced from main belt asteroid orbits. One remarkably similar event is present in the 3He record 35 Myr ago, but its origin by comet shower or asteroid collision remains uncertain.

Long Duration Exposure Facility (LDEF) attitude measurements of the interplanetary dust experiment

NASA Technical Reports Server (NTRS)

Kassel, Philip C., Jr.; Singer, S. Fred; Mulholland, J. Derral; Oliver, John P.; Weinberg, Jerry L.; Cooke, William J.; Wortman, Jim J.; Motley, William R., III

1992-01-01

The Long Duration Exposure Facility (LDEF) Interplanetary Dust Experiment (IDE) was unique in providing a time history of impacts of micron-sized particles on six orthogonal faces of LDEF during the first year in orbit. The value of this time resolved data depended on and was enhanced by the proper operation of some basic LDEF systems. Thus, the value of the data is greatly enhanced when the location and orientation of LDEF is known for each time of impact. The location and velocity of LDEF as a function of time can be calculated from the 'two-line elements' published by GSFC during the first year of the LDEF mission. The attitude of LDEF was passively stabilized in a gravity-gradient mode and a magnetically anchored viscous damper was used to dissipate roll, pitch, and yaw motions. Finally, the IDE used a standard LDEF Experiment Power and Data System (EPDS) to collect and store data and also to provide a crystal derived clock pulse (1 count every 13.1072 seconds) for all IDE time measurements. All that remained for the IDE was to provide a system to calibrate the clock, eliminating accumulative errors, and also verify the attitude of LDEF. The IDE used solar cells on six orthogonal faces to observe the LDEF sunrise and provide data about the LDEF attitude. The data was recorded by the EPDS about 10 times per day for the first 345 days of the LDEF mission. This data consist of the number of IDE counts since the last LDEF sunrise and the status of the six solar cells (light or dark) at the time of the last IDE count. The EPDS determined the time that data was recorded and includes, with each record, the master EPDS clock counter (1 count every 1.6384 seconds) that provided the range and resolution for time measurements. The IDE solar cells provided data for an excellent clock calibration, meeting their primary purpose, and the time resolved LDEF attitude measurements that can be gleaned from this data are presented.

Everyone Wins: A Mars-Impact Origin for Carbonaceous Phobos and Deimos

NASA Technical Reports Server (NTRS)

Fries, M.; Welzenbach, L.; Steele, A.

2016-01-01

Discussions of Phobos' and Deimos' origin(s) tend to feature an orthogonally opposed pair of observations: dynamical studies which favor coalescence of the moons from an orbital debris ring arising from a large impact on Mars; and reflectance spectroscopy of the moons that indicate a carbonaceous composition that is not consistent with Martian surface materials. One way to reconcile this discrepancy is to consider the option of a Mars-impact origin for Phobos and Deimos, followed by surficial decoration of carbon-rich materials by interplanetary dust particles (IDP). The moons experience a high IDP flux because of their location in Mars' gravity well. Calculations show that accreted carbon is sufficient to produce a surface with reflectance spectra resembling carbonaceous chondrites.

Dust coagulation in ISM

NASA Technical Reports Server (NTRS)

Chokshi, Arati; Tielens, Alexander G. G. M.; Hollenbach, David

1989-01-01

Coagulation is an important mechanism in the growth of interstellar and interplanetary dust particles. The microphysics of the coagulation process was theoretically analyzed as a function of the physical properties of the coagulating grains, i.e., their size, relative velocities, temperature, elastic properties, and the van der Waal interaction. Numerical calculations of collisions between linear chains provide the wave energy in individual particles and the spectrum of the mechanical vibrations set up in colliding particles. Sticking probabilities are then calculated using simple estimates for elastic deformation energies and for the attenuation of the wave energy due to absorption and scattering processes.

Comet or asteroid shower in the late Eocene?

PubMed

Tagle, Roald; Claeys, Philippe

2004-07-23

The passage of a comet shower approximately 35 million years ago is generally advocated to explain the coincidence during Earth's late Eocene of an unusually high flux of interplanetary dust particles and the formation of the two largest craters in the Cenozoic, Popigai and the Chesapeake Bay. However, new platinum-group element analyses indicate that Popigai was formed by the impact of an L-chondrite meteorite. Such an asteroidal projectile is difficult to reconcile with a cometary origin. Perhaps instead the higher delivery rate of extraterrestrial matter, dust, and large objects was caused by a major collision in the asteroid belt.

Ground truth of (sub-)micrometre cometary dust - Results of MIDAS onboard Rosetta

NASA Astrophysics Data System (ADS)

Mannel, Thurid; Bentley, Mark; Schmied, Roland; Torkar, Klaus; Jeszenszky, Harald; Romsted, Jens; Levasseur-Regourd, A.; Weber, Iris; Jessberger, Elmar K.; Ehrenfreund, Pascale; Köberl, Christian; Havnes, Ove

2016-10-01

The investigation of comet 67P by Rosetta has allowed the comprehensive characterisation of pristine cometary dust particles ejected from the nucleus. Flying alongside the comet at distances as small as a few kilometres, and with a relative velocity of only centimetres per second, the Rosetta payload sampled almost unaltered dust. A key instrument to study this dust was MIDAS (the Micro-Imaging Dust Analysis System), a dedicated atomic force microscope that scanned the surfaces of hundreds of (sub-)micrometre sized particles in 3D with resolutions down to nanometres. This offers the unique opportunity to explore the morphology of smallest cometary dust and expand our current knowledge about cometary material.Here we give an overview of dust collected and analysed by MIDAS and highlight its most important features. These include the ubiquitous agglomerate nature of the dust, which is found at all size scales from the largest (>10 µm) through to the smallest (<1 µm) dust particles. The sub-units show characteristic sizes and shapes that are compared with model predictions for interstellar dust.Our findings constrain key parameters of the evolution of the early Solar System. We will discuss which dust growth model is favoured by the observed morphology and how the results restrict cometary formation. Finally, dust particles detected by MIDAS resemble primitive interplanetary dust which is a strong argument for a common cometary origin.

Stardust from Supernovae and Its Isotopes

NASA Astrophysics Data System (ADS)

Hoppe, Peter

Primitive solar system materials, namely, meteorites, interplanetary dust particles, and cometary matter contain small quantities of nanometer- to micrometer-sized refractory dust grains that exhibit large isotopic abundance anomalies. These grains are older than our solar system and have been named "presolar grains." They formed in the winds of red giant and asymptotic giant stars and in the ejecta of stellar explosions, i.e., represent a sample of stardust that can be analyzed in terrestrial laboratories for isotopic compositions and other properties. The inventory of presolar grains is dominated by grains from red giant and asymptotic giant branch stars. Presolar grains from supernovae form a minor but important subpopulation. Supernova (SN) minerals identified to date include silicon carbide, graphite, silicon nitride, oxides, and silicates. Isotopic studies of major, minor, and trace elements in these dust grains have provided detailed insights into nucleosynthetic and mixing processes in supernovae and how dust forms in these violent environments.

Secondary electron emission and its role in the space environment

NASA Astrophysics Data System (ADS)

Němeček, Z.; Pavlů, J.; Richterová, I.; Šafránková, J.; Vaverka, J.

2018-01-01

The role of dust in the space environment is of increasing interest in recent years and also the fast development of fusion devices with a magnetic confinement brought new issues in the plasma-surface interaction. Among other processes, secondary electron emission plays an important role for dust charging in interplanetary space and its importance increases at and above the surfaces of airless bodies like planets, moons, comets or asteroids. A similar situation can be found in many industrial applications where the dust is a final product or an unintentional impurity. The present paper reviews the progress in laboratory investigations of the secondary emission process as well as an evolution of the modeling of the interaction of energetic electrons with dust grains of different materials and sizes. The results of the model are discussed in view of latest laboratory simulations and they are finally applied on the estimation of an interaction of the solar wind and magnetospheric plasmas with the dust attached to or levitating above the lunar surface.

Abiogenic synthesis of nucleotides on the surface of small space bodies with high energy particles

NASA Astrophysics Data System (ADS)

Simakov, M. B.; Kuzicheva, E. A.; Antropov, A. E.; Dodonova, N. Ya

Abiotic formation of such complex biochemical compounds as nucleotides and oligopeptides on the surface of interstellar and interplanetary dust particles (IDP) by cosmic radiation was examined. In order to study the formation of organic compounds on IDPs, solid films prepared from nucleososide and inorganic phosphate were irradiated with high energy protons. Irradiated products were analyzed with HPLC. The natural nucleotides were detected. The main products were 5' AMP (3.2%) and 2'3' cAMP (2.7%). The results were compared with others experiments on the action of ultraviolet radiation with different wavelengths, γ-radiation and heat on solid mixtures of biologically significant compounds. The experiment on abiogenic synthesis of nucleotides on board of space satellite "BION-11" was compared also. The present results suggest that a considerable amount of complex biochemical compounds formed in extraterrestrial environments could have been supplied to the primitive earth before the origin of life.

Mineral Surface Rearrangement at High Temperatures: Implications for Extraterrestrial Mineral Grain Reactivity.

PubMed

King, Helen E; Plümper, Oliver; Putnis, Christine V; O'Neill, Hugh St C; Klemme, Stephan; Putnis, Andrew

2017-04-20

Mineral surfaces play a critical role in the solar nebula as a catalytic surface for chemical reactions and potentially acted as a source of water during Earth's accretion by the adsorption of water molecules to the surface of interplanetary dust particles. However, nothing is known about how mineral surfaces respond to short-lived thermal fluctuations that are below the melting temperature of the mineral. Here we show that mineral surfaces react and rearrange within minutes to changes in their local environment despite being far below their melting temperature. Polished surfaces of the rock and planetary dust-forming silicate mineral olivine ((Mg,Fe) 2 SiO 4 ) show significant surface reorganization textures upon rapid heating resulting in surface features up to 40 nm in height observed after annealing at 1200 °C. Thus, high-temperature fluctuations should provide new and highly reactive sites for chemical reactions on nebula mineral particles. Our results also may help to explain discrepancies between short and long diffusion profiles in experiments where diffusion length scales are of the order of 100 nm or less.

Spatially Resolved Analysis of Amines Using a Fluorescence Molecular Probe: Molecular Analysis of IDPs

NASA Technical Reports Server (NTRS)

Clemett, S. J.; Messenger, S.; Thomas-Keprta, K. L.; Wentworth, S. J.; Robinson, G. A.; McKay, D. S.

2002-01-01

Some Interplanetary Dust Particles (IDPs) have large isotope anomalies in H and N. To address the nature of the carrier phase, we are developing a procedure to spatially resolve the distribution of organic species on IDP thin sections utilizing fluorescent molecular probes. Additional information is contained in the original extended abstract.

Instrument study of the Lunar Dust eXplorer (LDX) for a lunar lander mission

NASA Astrophysics Data System (ADS)

Li, Yanwei; Srama, Ralf; Henkel, Hartmut; Sternovsky, Zoltan; Kempf, Sascha; Wu, Yiyong; Grün, Eberhard

2014-11-01

One of the highest-priority issues for a future human or robotic lunar exploration is the lunar dust. This problem should be studied in depth in order to develop an environment model for a future lunar exploration. A future ESA lunar lander mission requires the measurement of dust transport phenomena above the lunar surface. Here, we describe an instrument design concept to measure slow and fast moving charged lunar dust which is based on the principle of charge induction. LDX has a low mass and measures the speed and trajectory of individual dust particles with sizes below one micrometer. Furthermore, LDX has an impact ionization target to monitor the interplanetary dust background. The sensor consists of three planes of segmented grid electrodes and each electrode is connected to an individual charge sensitive amplifier. Numerical signals were computed using the Coulomb software package. The LDX sensitive area is approximately 400 cm2. Our simulations reveal trajectory uncertainties of better than 2° with an absolute position accuracy of better than 2 mm.

Oxygen isotopic composition of chondritic interplanetary dust particles: A genetic link between carbonaceous chondrites and comets

NASA Astrophysics Data System (ADS)

Aléon, J.; Engrand, C.; Leshin, L. A.; McKeegan, K. D.

2009-08-01

Oxygen isotopes were measured in four chondritic hydrated interplanetary dust particles (IDPs) and five chondritic anhydrous IDPs including two GEMS-rich particles (Glass embedded with metal and sulfides) by a combination of high precision and high lateral resolution ion microprobe techniques. All IDPs have isotopic compositions tightly clustered around that of solar system planetary materials. Hydrated IDPs have mass-fractionated oxygen isotopic compositions similar to those of CI and CM carbonaceous chondrites, consistent with hydration of initially anhydrous protosolar dust. Anhydrous IDPs have small 16O excesses and depletions similar to those of carbonaceous chondrites, the largest 16O variations being hosted by the two GEMS-rich IDPs. Coarse-grained forsteritic olivine and enstatite in anhydrous IDPs are isotopically similar to their counterparts in comet Wild 2 and in chondrules suggesting a high temperature inner solar system origin. The small variations in the 16O content of GEMS-rich IDPs suggest that most GEMS either do not preserve a record of interstellar processes or the initial interstellar dust is not 16O-rich as expected by self-shielding models, although a larger dataset is required to verify these conclusions. Together with other chemical and mineralogical indicators, O isotopes show that the parent-bodies of carbonaceous chondrites, of chondritic IDPs, of most Antarctic micrometeorites, and comet Wild 2 belong to a single family of objects of carbonaceous chondrite chemical affinity as distinct from ordinary, enstatite, K- and R-chondrites. Comparison with astronomical observations thus suggests a chemical continuum of objects including main belt and outer solar system asteroids such as C-type, P-type and D-type asteroids, Trojans and Centaurs as well as short-period comets and other Kuiper Belt Objects.

Solar wind and the motion of dust grains

NASA Astrophysics Data System (ADS)

Klačka, J.; Petržala, J.; Pástor, P.; Kómar, L.

2012-04-01

In this paper, we investigate the action of solar wind on an arbitrarily shaped interplanetary dust particle. The final relativistically covariant equation of motion of the particle also contains the change of the particle's mass. The non-radial solar wind velocity vector is also included. The covariant equation of motion reduces to the Poynting-Robertson effect in the limiting case when a spherical particle is treated, when the speed of the incident solar wind corpuscles tends to the speed of light and when the corpuscles spread radially from the Sun. The results of quantum mechanics have to be incorporated into the physical considerations, in order to obtain the limiting case. If the solar wind affects the motion of a spherical interplanetary dust particle, then ?. Here, p'in and p'out are the incoming and outgoing radiation momenta (per unit time), respectively, measured in the proper frame of reference of the particle, and ? and ? are the solar wind pressure and the total scattering cross-sections, respectively. An analytical solution of the derived equation of motion yields a qualitative behaviour consistent with numerical calculations. This also holds if we consider a decrease of the particle's mass. Using numerical integration of the derived equation of motion, we confirm our analytical result that the non-radial solar wind (with a constant value of angle between the radial direction and the direction of the solar wind velocity) causes outspiralling of the dust particle from the Sun for large values of the particle's semimajor axis. The non-radial solar wind also increases the time the particle spirals towards the Sun. If we consider the periodical variability of the solar wind with the solar cycle, then there are resonances between the particle's orbital period and the period of the solar cycle.

Characterization of biogenic elements in interplanetary dust particles

NASA Technical Reports Server (NTRS)

Bunch, T. E.

1986-01-01

Those particles that were designated cometary are aggregates of amorphous materials including carbon, iron-magnesium silicates, sulfides, metal and trace amounts of unusual phases. Most aggregates are carbon-rich with major and minor element abundances similar to a fine grained matrix of carbonaceous chondrites. Several particles were analyzed by a laser microprobe. The negative ionic species identified to date include carbon clusters, protonated carbon clusters, CN-, HCN-, CNO-, PO2-, PO3-, S-, S2- asnd OH-. These species are similar to those observed in cometary spectra and they support the assumption that organic materials are present. The occurance of phosphate ions suggests the presence of apatite or whitlockite. Cometary particle characteristics may indicate that the component grains represent primitive unaltered dust whose overall properties are extremely similar to altered primitive dust in carbonaceous chondrites.

Preliminary Examination of Impact Craters on Al Foil from the Stardust Interstellar Dust Collector

NASA Astrophysics Data System (ADS)

Stroud, R.; Stardust Interstellar Preliminary Examination Team; 29,000 Stardust@home Dusters

2011-12-01

The Interstellar Dust Collector from the NASA Stardust mission provides an unprecedented opportunity for direct laboratory study of particles from the contemporary interstellar dust (ISD) stream in order to obtain such information as grain composition and microstructure. The collector is comprised of two collection media: silica aerogel tiles and Al foil strips. Preliminary examination (PE) of particles captured in each medium is on-going. To-date, four grains analyzed in situ in aerogel with synchrotron X-ray techniques show track trajectories and elemental composition that indicate a probable interstellar origin. In addition, we report here the discovery of one crater on an Al foil for which the residue elemental composition and crater shape are consistent with the impact of a grain of interstellar origin, although an interplanetary origin has not been ruled out. Automated mapping by SEM is the primary tool for identifi-cation of craters on the Al foils. A complete map of each foil requires collection of several thousand images at a resolution of ~ 50 nm/px. Automated software has been developed to identify crater candidates, but so far it has not replaced manual efforts. Identified candidates are then re-imaged at ~ 15 nm/px, for confirmation as impact craters. Fifteen foils have been imaged; crater identification is complete for eight, yielding 32 craters. The average areal density of craters is 9.7 cm-2, which extrapolates to ~1500 craters on the total foil collection area. Initial elemental analysis of residues in six craters has been performed with a combination of Auger spectroscopy, conventional, off-axis energy dispersive X-ray spectroscopy (EDX), on-axis, silicon drift-detector EDX. Additional analysis by TEM of the residue composition and crater morphology was obtained on FIB cross-sections of four of the craters. All craters contained detectable levels of Si and O. One crater was found to contain Mg, Si, O, Fe, Ni, S, Ca and Cr, indicative of an interstellar or interplanetary origin. The shape of this crater is consistent with the impact of a fluffy aggregate grain at < 10 km/s, similar to three of the four ISD candidates identified in the aerogel, and slower than expected for an interplanetary dust grain. In three cases the impacting grain was determined by detection of additional Ce, Zn, Ti, K, or Na to be a fragment of the solar cell cover glass.

The Giotto radio-science experiment

NASA Technical Reports Server (NTRS)

Edenhofer, P.; Bird, M. K.; Buschert, H.; Esposito, P. B.; Porsche, H.; Volland, H.

1986-01-01

The scientific objectives of the Giotto Radio Science Experiment (GRE) are to determine the columnar electron content of Comet Halley/s ionosphere and the cometary mass fluence from atmospheric drag by using the radio signals from Giotto during the Halley encounter. The radio science data (S and X-band Doppler and range measurements) will be collected at NASA/s deep-space 64 m tracking antenna at Tidbinbilla near Canberra, in Australia. In order to separate the effects of the terrestrial ionosphere and the interplanetary plasma, S-band Doppler measurements will also be taken at Tidbinbilla along the line-of-sight of Japan/s cometary probe Sakigake during the Giotto-Halley Encounter. The measurements of cometary electron content and mass fluence will be inverted to derive the spatial distribution of the electron and mass (dust and gas) density within Halley/s coma. The GRE is the only experiment on Giotto capable of measuring the low-energy (10 eV) electron bulk population of Halley/s ionosphere and the total cometary mass flow impacting upon the spacecraft.

Using the Geminids to Characterize the Surface Response of an Airless Body to Meteoroid Bombardment

NASA Astrophysics Data System (ADS)

Szalay, J.; Pokorny, P.; Jenniskens, P. M. M.; Horanyi, M.

2017-12-01

All airless bodies in the solar system are exposed to the continual bombardment by interplanetary meteoroids. These impacts can eject orders of magnitude more mass than the primary impactors, sustaining bound and/or unbound ejecta clouds that vary both spatially and temporally from changes in impactor fluxes. The dust environment in the vicinity of an airless body provides both a scientific resource and a hazard for exploration. Characterizing the spatial and temporal variability of the dust environment of airless planetary bodies provides a novel way to understand their meteoroid environment by effectively using these objects as large surface area meteoroid detectors. Additionally, were a dust detector with chemical sensing capability to be flown near such a body, it would be able to directly measure the composition of the body without requiring the mission design complexity involved in landing and sampling surface material. Paramount to understanding the current and future impact ejecta measurements is a sufficient understanding of the impact ejecta processes at the surface. In this presentation, we focus on data taken by the Lunar Dust Experiment (LDEX), an impact ionization dust detector onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission, designed to measure impact ejecta around the Moon. We use the Geminids meteoroid shower as a well constrained input function, and via comparison to existing ground-based measurements of this shower, to "calibrate" the response of the lunar surface to meteoroid bombardment. Understanding the response of the lunar surface to meteoroid bombardment can by extension allow us to better understand the ejecta response at other regolith airless bodies in the solar system. Future missions equipped with dust detectors sent to the Moon, large Near Earth Asteroids, the Martian moons Phobos and Deimos, or many other airless bodies in the solar system would greatly improve our knowledge of their local meteoroid environments, characterize their chemical compositions, and improve the safety for future manned and unmanned missions to these bodies.

Cosmic Genes in the Cretaceous-Tertiary transition

NASA Astrophysics Data System (ADS)

Wallis, M. K.

2003-07-01

It is proposed that genes coding for Aib-polypeptides arose early on in the K/T transition, presumed from the Earth's accretion of interplanetary (comet) dust. Aib-fungi flourished because of the evolutionary advantage of novel antibiotics. The stress on Cretaceous biology led directly and indirectly to mass species extinctions, including many dinosaur species, in the epoch preceding the Chicxulub impact.

Collection and curation of IDPs in the stratosphere and below. Part 2: The Greenland and Antarctic ice sheets

NASA Technical Reports Server (NTRS)

Maurette, Michel; Hammer, C.; Harvey, R.; Immel, G.; Kurat, G.; Taylor, S.

1994-01-01

In a companion paper, Zolensky discusses interplanetary dust particles (IDP's) collected in the stratosphere. Here, we describe the recovery of much larger unmelted to partially melted IDP's from the Greenland and Antarctica ice sheet, and discuss problems arising in their collection and curation, as well as future prospects for tackling these problems.

PROGRA2 experiment: new results for dust clouds and regoliths

NASA Astrophysics Data System (ADS)

Renard, J.-B.; Hadamcik, E.; Worms, J.-C.; Levasseur-Regourd, A.-C.; Daugeron, D.

With the CNES-sponsored PROGRA2 facility, linear polarization of scattered light is performed on various types of dust clouds in microgravity during parabolic flights onboard the CNES- and ESA-sponsored A300 Zéro-G aircraft. Clouds of fluffy aggregates are also studied on the ground when lifted by an air-draught. The effect of the physical properties of the particles, such as the grains size and size distribution, the real part of the refractive index, and the structure is currently being studied. The size distribution of the agglomerates is measured in the field of view from the polarized component images. The large number of phase curves already obtained in the various conditions of measurements, in order to build a database (about 160 curves) allows us to better connect the physical properties with the observed polarization of the dust in the clouds. The aim is to compare these curves with those obtained in the solar system by remote-sensing and in-situ techniques for interplanetary dust, cometary coma, and solid particles in planetary atmospheres (Renard et al., 2003). Measurements on layers of particles (i.e. on the ground) are then compared with remote measurements on asteroidal regoliths and planetary surfaces. New phase curves will be presented and discussed i.e. for quartz samples, crystals, fluffy mixtures of alumina and silica, and a high porosity ``regolith'' analogue made of micron-sized silica spheres. This work will contribute to the choice of the samples to be studied with the IMPACT/ICAPS instrument onboard the ISS. J.-B. Renard, E. Hadamcik, T. Lemaire, J.-C. Worms and A.-C. Levasseur-Regourd (2003). Polarization imaging of dust cloud particles: improvement and applications of the PROGRA2 instrument, ASR 31, 12, 2511-2518.

Risk Assessment of Cassini Sun Sensor Integrity Due to Hypervelocity Impact of Saturn Dust Particles

NASA Technical Reports Server (NTRS)

Lee, Allan Y.

2016-01-01

A sophisticated interplanetary spacecraft, Cassini is one of the heaviest and most sophisticated interplanetary spacecraft humans have ever built and launched. Since achieving orbit at Saturn in 2004, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for first and second extended missions through September 2017. In late 2016, the Cassini spacecraft will begin a daring set of ballistic orbits that will hop the rings and dive between the upper atmosphere of Saturn and its innermost D-ring twenty-two times. The "dusty" environment of the inner D-ring region the spacecraft must fly through is hazardous because of the possible damage that dust particles, travelling at speeds as high as 31.4 km/s, can do to spacecraft hardware. During hazardous proximal ring-plane crossings, the Cassini mission operation team plans to point the high-gain antenna to the RAM vector in order to protect most of spacecraft instruments from the incoming energetic ring dust particles. However, this particular spacecraft attitude will expose two Sun sensors (that are mounted on the antenna dish) to the incoming dust particles. High-velocity impacts on the Sun sensor cover glass might penetrate the 2.54-mm glass cover of the Sun sensor. Even without penetration damage, craters created by these impacts on the surface of the cover glass will degrade the transmissibility of light through it. Apart from being directly impacted by the dust particles, the Sun sensors are also threatened by some fraction of ricochet ejecta that are produced by dust particle impacts on the large antenna dish (made of graphite fiber epoxy composite material). Finally, the spacecraft attitude control system must cope with disturbances due to both the translational and angular impulses imparted on the large antenna dish and the long magnetometer boom by the incoming high-velocity projectiles. Analyses performed to quantify the risks the Sun sensors must contend with during these hazardous ring-plane crossings are given in this paper

GEMS and New Pre-Accretionally Irradiated RELICT Grains in Interplanetary Dust - The Plot Thickens

NASA Astrophysics Data System (ADS)

Bradley, J.

1995-09-01

The hypothesis that GEMS (glass with embedded metal and sulfides) in interplanetary dust particles (IDPs) might be the long-sought interstellar silicate grains is undergoing close scrutiny [1-3]. GEMS are proposed to be interstellar because: (a) they are abundant in cometary IDPs; (b) they were irradiated prior to incorporation into IDPs; (c) both their size distribution and Oamorphous silicate" microstructures are consistent with those of interstellar silicates; (d) they contain nanometer-sized (superparamagnetic) alpha-iron inclusions, which provides a simple explanation for the observed interstellar grain alignment and polarization [4,5]. Challenges to the GEMS hypothesis include the following: (a) GEMS may have formed and been irradiated in the solar nebula rather than a presolar interstellar environment; (b) non-solar isotope abundances have yet to be measured in GEMS; (c) the irradiation regime required to produce the observed effects in GEMS might be incompatible with the interstellar medium; (b) relationships between GEMS and carbon (e.g. core/mantle) need clarification; (c) major element abundances in GEMS should be consistent with observed interstellar gas phase depletions [2,3]. GEMS may indeed have formed in the solar nebula, in which case they would be the oldest known solar nebula solids [2]. An interstellar origin for GEMS does not require detection of non-solar isotope abundances [6]. Irradiation experiments are in progress to simulate the properties of GEMS. The petrographic relationship between GEMS and carbon in IDPs is being investigated (by examining IDPs embedded and thin-sectioned in carbon-free media). Major element abundances in GEMS are being evaluated in terms on interstellar gas phase abundances. For example, sulfur is not highly depleted in the interstellar gas, implying that it must be significantly depleted in interstellar grains [3]. GEMS are significantly depleted in sulfur relative to solar abundances. Analytical electron microscopic studies of the local petrographic environment of GEMS in IDPs are continuing. There is evidence of a population of relict grains associated with GEMS. Some of these relict grains have distinctive compositions and they appear to have functioned as (pre-existing) depositional substrates while GEMS were being formed. Thus, it may be possible to begin to assign a chronology to the seemingly complex admixture of grains that make up the ultrafine-grained matrices of anhydrous chondritic IDPs. References: [1] Bradley J. P. (1994) Science, 265, 925-929. [2] Flynn G. J. (1994) Nature, 371, 287-288. [3] Martin P. G. (1995) Astrophys. J., 445, L63-L66. [4] Mathis J. S. (1986) Astrophys. J., 308, 281-287. [5] Mathis J. S. (1993) Rept. Prog. Phys., 56, 605-652. [6] Walker R. M. (1994) in Analysis of Interplanetary Dust (M. E. Zolensky et al., eds.), pp. 203-209, AIP Conf. Proc. 310.

Trace Element Abundance Measurements on Cosmic Dust Particles

NASA Technical Reports Server (NTRS)

Flynn, George

1996-01-01

The X-Ray Microprobe on beamline X-26A at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was used to determine the abundances of elements from Cr through Sr in individual interplanetary dust particles (IDPs) collected from the Earth's stratosphere and the Scanning Transmission X-ray Microscope (STXM) on beamline X-1A at the NSLS was used to determine the carbon abundances and spatial distributions in IDPs. In addition, modeling was performed in an attempt to associate particular types of IDPs with specific types of parent bodies, and thus to infer the chemistry, mineralogy, and structural properties of those parent bodies.

Depletions of sulfur and/or zinc in IDPs: Are they reliable indicators of atmospheric entry heating?

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Sutton, S. R.; Bajt, S.; Kloeck, W.; Thomas, K. L.; Keller, L. P.

1993-01-01

The degree of heating of interplanetary dust particles (IDP's) on Earth atmospheric entry is important in distinguishing cometary particles from main-belt asteroidal particles. Depletions in the volatile elements S and Zn were proposed as chemical indicators of significant entry heating. The S and Zn contents of cosmic dust particles were correlated with physical indicators of atmospheric entry heating, such as the production of magnetite and the loss of solar wind implanted He. The results indicate that the Zn content of IDP's is a useful indicator of entry heating, but the S content seems to be less useful.

Clay minerals in primitive meteorites and interplanetary dust 2. Smectites and micas

NASA Technical Reports Server (NTRS)

Keller, L. P.; Zolensky, M. E.

1991-01-01

The classification is briefly summarized of stony meteorites and cosmic dust, and the mineralogy and chemistry is described of serpentine group minerals. The occurrence of smectites and micas in extraterrestrial materials is examined. The characterization of fine grained minerals in meteorites and IDPs relies heavily on electron beam instruments, especially the transmission electron microscope (TEM). Typically, phyllosilicates are identified by a combination of high resolution imaging of basal spacings, electron diffraction, and chemical analysis. Smectites can be difficult to differentiate from micas because the smectites lose their interlayer water and the interlayer partly collapse in the high vacuum of the TEM.

ESOC's System for Interplanetary Orbit Determination: Implementation and Operational Experience

NASA Astrophysics Data System (ADS)

Budnik, F.; Morley, T. A.; MacKenzie, R. A.

A system for interplanetary orbit determination has been developed at ESOC over the past six years. Today, the system is in place and has been proven to be both reliable and robust by successfully supporting critical operations of ESA's interplanetary spacecraft Rosetta, Mars Express, and SMART-1. To reach this stage a long and challenging way had to be travelled. This paper gives a digest about the journey from the development and testing to the operational use of ESOC's new interplanetary orbit determination system. It presents the capabilities and reflects experiences gained from the performed tests and tracking campaigns.

Accretion of Interplanetary Dust Particles by the Earth

NASA Astrophysics Data System (ADS)

Kortenkamp, Stephen J.; Dermott, Stanley F.

1998-10-01

Analyses of hypervelocity micrometeoroid impact craters preserved in lunar material and on the panels of the Long Duration Exposure Facility (LDEF) indicate that each year Earth accretes about 3 × 107kg of interplanetary dust particles (IDPs) from the zodiacal cloud (E. Grünet al.1985,Astron. Astrophys.286, 915-924; S. G. Love and D. E. Brownlee, 1993,Science262, 550-553). The size distributions of these lunar and LDEF craters indicate that the mass distribution of IDPs encountering Earth peaks at about 200 μm diameter. This particle-size cutoff may be indicative of collisionally evolved asteroidal dust, where the collisional lifetime of dust particles larger than ∼100 μm is shorter than the time required for their orbits to decay under Poynting-Robertson light drag from the asteroid belt to Earth (B. Å. S. Gustafson, 1994,Annu. Rev. Earth Planet. Sci.22, 553-595). Additionally, analyses of IDPs collected from the stratosphere by high-flying aircraft reveal a diversity in chemical composition which is even narrower than that of the meteorites (G. J. Flynn, 1995,Nature376, 114). Together these findings suggest that IDPs present in the atmosphere and our collections may originate from very limited sources in the asteroid belt. The most abundant sources of dust to be unambiguously linked to the zodiacal cloud are the three asteroid families Eos, Themis, and Koronis-the progenitors of the ten-degree and low-latitude dust bands discovered by the Infrared Astronomical Satellite in 1984. We use direct numerical integration of the full equations of motion to model the orbital evolution of dust particles from these three families as well as from other nonfamily asteroids and from the population of known short period comets. Our simulations include gravitational perturbations from the planets, radiation pressure, and solar wind drag. We find that a large, and perhaps the dominant, fraction of the IDPs accreted by Earth comes from the asteroid families Eos, Themis, and Koronis and that probably fewer than 25% of accreted IDPs come from comets. We also find a seasonal variation in the distribution of ascending nodes of the Themis and Koronis dust particle orbits near Earth. Earth-orbiting instruments utilizing aero-gels could exploit these seasonal variations to collect and return intact samples of these two asteroid families. Finally, we demonstrate how the long-term accretion rate of asteroidal dust from all sources should be anti-correlated with Earth's changing orbital eccentricity.

Inward electrostatic precipitation of interplanetary particles

NASA Technical Reports Server (NTRS)

Rulison, Aaron J.; Flagan, Richard C.; Ahrens, Thomas J.

1993-01-01

An inward precipitator collects particles initially dispersed in a gas throughout either a cylindrical or spherical chamber onto a small central planchet. The instrument is effective for particle diameters greater than about 1 micron. One use is the collection of interplanetary dust particles (IDPs) which are stopped in a noble gas (xenon) by drag and ablation after perforating the wall of a thin-walled spacecraft-mounted chamber. First, the particles are positively charged for several seconds by the corona production of positive xenon ions from inward facing needles placed on the chamber wall. Then an electric field causes the particles to migrate toward the center of the instrument and onto the planchet. The collection time (on the order of hours for a 1 m radius spherical chamber) is greatly reduced by the use of optimally located screens which reapportion the electric field. Some of the electric field lines terminate on the wires of the screens so a fraction of the total number of particles in the chamber is lost. The operation of the instrument is demonstrated by experiments which show the migration of carbon soot particles with radius of approximately 1 micron in a 5 cm diameter cylindrical chamber with a single field enhancing screen toward a 3.2 mm central collection rod.

Electrostatic charge on a dust size distribution in a plasma. [in interplanetary space

NASA Technical Reports Server (NTRS)

Houpis, Harry L. F.; Whipple, Elden C., Jr.

1987-01-01

The capacitance of a grain immersed in a steady state plasma containing a size distribution of dust particles is studied. The grain charge is determined by assuming the equilibrium potential has been obtained by a simple balance of electron and ion collection currents. It is shown that the validity of the analytical treatment given here for the linearized Poisson equation is confined to a certain region of space. Within this region and starting at very small plasma Debye length lambda(D), the capacitance at first exhibits a monotonic increase with increasing lambda(D). The capacitance eventually reaches a maximum, followed by a monotonic decrease. The charge density of the dust in the plasma is found to be only a function of the lambda(D); there is no significant dependence on the interparticle spacing.

Migration of Interplanetary Dust and Comets

NASA Astrophysics Data System (ADS)

Ipatov, S. I.; Mather, J. C.

Our studies of migration of interplanetary dust and comets were based on the results of integration of the orbital evolution of 15,000 dust particles and 30,000 Jupiter-family comets (JFCs) [1-3]. For asteroidal and cometary particles, the values of the ratio β between the radiation pressure force and the gravitational force varied from <0.0004 to 0.4. For silicates, such values correspond to particle diameters between >1000 and 1 microns. The probability of a collision of a dust particle started from an asteroid or JFC with the Earth during a lifetime of the particle was maximum at diameter d ˜100 microns. For particles started from asteroids and comet 10P, this maximum probability was ˜0.01. Different studies of migration of dust particles and small bodies testify that the fraction of cometary dust particles of the overall dust population inside Saturn's orbit is considerable and can be dominant: (1) Cometary dust particles produced both inside and outside Jupiter's orbit are needed to explain the observed constant number density of dust particles at 3-18 AU. The number density of migrating trans-Neptunian particles near Jupiter's orbit is smaller by a factor of several than that beyond Saturn's orbit. Only a small fraction of asteroidal particles can get outside Jupiter's orbit. (2) Some (less than 0.1%) JFCs can reach typical near-Earth object orbits and remain there for millions of years. Dynamical lifetimes of most of the former JFCs that have typical near-Earth object orbits are about 106 -109 yr, so during most of these times they were extinct comets. Such former comets could disintegrate and produce a lot of mini-comets and dust. (3) Comparison of the velocities of zodiacal dust particles (velocities of MgI line) based on the distributions of particles over their orbital elements obtained in our runs [3-4] with the velocities obtained at the WHAM observations shows that only asteroidal dust particles cannot explain these observations, and particles produced by comets, including high-eccentricity comets, are needed for such explanation. The fraction of particles started from Encke-type comets is not large (<0.15) in order to fit the observational distributions of particles over their distances from the Sun. Studies of velocities of MgI line and corresponding eccentricities and inclinations in our runs showed that the mean eccentricity of zodiacal dust particles is about 0.5. [1] Ipatov S.I. and Mather J.C. (2004) Annals of the New York Acad. of Sciences, 1017, 46- 65. [2] Ipatov S.I., Mather J.C., and Taylor P. (2004) Annals of the New York Acad. of Sciences, 1017, 66-80. [3] Ipatov S.I. and Mather J.C. (2006) Advances in Space Research, 37, 126-137. [4] Ipatov S.I. et al. (2006) 37th LPSC, #1471.

Electron Beam Analysis of Micrometeoroids Captured in Aerogel as Stardust Analogues

NASA Technical Reports Server (NTRS)

Graham, G. A.; Sheffield-Parker, J.; Bradley, P.; Kearsley, A. T.; Dai, Z. R.; Mayo, S. C.; Teslich, N.; Snead, C.; Westphal, A. J.; Ishii, H.

2005-01-01

In January 2004, NASA s Stardust spacecraft passed through the tail of Comet 81P/Wild-2. The on-board dust flux monitor instrument indicated that numerous micro- and nano-meter sized cometary dust particles were captured by the dedicated silica aerogel capture cell. The collected cometary particles will be returned to Earth in January 2006. Current Stardust analogues are: (i) Light-gas-gun accelerated individual mineral grains and carbonaceous meteoritic material in aerogels at the Stardust encounter velocity ca.approximately 6 kilometers per second. (ii) Aerogels exposed in low-Earth orbit (LEO) containing preserved cosmic dust grains. Studies of these impacts offer insight into the potential state of the captured cometary dust by Stardust and the suitability of various analytical techniques. A number of papers have discussed the application of sophisticated synchrotron analytical techniques to analyze Stardust particles. Yet much of the understanding gained on the composition and mineralogy of interplanetary dust particles (IDPs) has come from electron microscopy studies. Here we discuss the application of scanning electron microscopy (SEM) for Stardust during the preliminary phase of post-return investigations.

Constraining the Origin of Impact Craters on Al Foils from the Stardust Interstellar Dust Collector

NASA Technical Reports Server (NTRS)

Stroud, Rhonda M.; Achilles, Cheri; Allen, Carlton; Ansari, Asna; Bajt, Sasa; Bassim, Nabil; Bastien, Ron S.; Bechtel, H. A.; Borg, Janet; Brenker, Frank E.;

The NASA Solar Probe mission - In situ determination of interplanetary out-of-the ecliptic and near-solar dust environments

NASA Technical Reports Server (NTRS)

Tsurutani, Bruce T.; Randolph, James E.

1991-01-01

The NASA Solar Probe mission will be one of the most exciting dust missions ever flown and will lead to a revolutionary advance in our understanding of dust within our solar system. Solar Probe will map the dust environment from the orbit of Jupiter (5 AU), to within 4 solar radii of the sun's center. The region between 0.3 AU and 4 Rs has never been visited before, so the ten days that the spacecraft spends during each (of the two) orbit is purely exploratory in nature. Solar Probe will also reach heliographic latitudes as high as about 15 to 28 deg above (below) the ecliptic on its trajectory inbound (outbound) to (from) the sun. This, in addition to the ESA/NASA Ulysses mission, will help determine the out-of-the-ecliptic dust environment. A post-perihelion burn will reduce the satellite orbital period to 2.5 years about the sun. A possible extended mission would allow data reception for two more revolutions, mapping out a complete solar cycle. Because the near-solar dust environment is not well understood (or is controversial at best), and it is very important to have better knowledge of the dust environment to protect Solar Probe from high velocity dust hits, we urgently request the scientific community to obtain further measurements of the nearsolar dust properties.

Interaction between solar energetic particles and interplanetary grains

NASA Astrophysics Data System (ADS)

Strazzulla, G.; Calcagno, L.; Foti, G.; Sheng, K. L.

Some laboratory-studied effects induced by the fluence of fast ions on frosts of astrophysical interest are summarized. The results are applied to the interaction between energetic solar ions and interplanetary dust grains assumed to be cometary debris which spends about one-million yr before being collected in the earth's atmosphere or colliding on the moon's surface. The importance of erosion by particles to the stability of ice grains is confirmed. The build up of carbonaceous material by ion fluence on hydrocarbon containing grains is discussed. It is suggested that these new materials could be the glue which cements submicron silicate particles to form a complex agglomeration whose density increases with increasing proton fluence (packing effect). The IR spectra of laboratory synthesized carbonaceous material are compared with those observed in some carbonaceous meteoritic extracts.

In situ observations of dust particles in Martian dust belts using a large-sensitive-area dust sensor

NASA Astrophysics Data System (ADS)

Kobayashi, Masanori; Krüger, Harald; Senshu, Hiroki; Wada, Koji; Okudaira, Osamu; Sasaki, Sho; Kimura, Hiroshi

2018-07-01

In order to determine whether Martian dust belts (ring or torus) actually exist and, if so, to determine the characteristics of the dust, we propose a Circum-Martian Dust Monitor (CMDM) to be deployed on the Martian Moons Exploration (MMX) project, in which JAXA plans to launch the spacecraft in 2024, investigate Phobos and Deimos, and return samples back to Earth. The CMDM is a newly developed instrument that is an impact dust detector. It weighs only 650 g and has a sensor aperture area of ∼1 m2, according to the conceptual design study. Detectable velocities (v) range from 0.5 km/s to more than 70 km/s, which will cover all possible dust particles: circummartian (low v), interplanetary (mid v), and interstellar (high v) particles. The measurable mass ranges from 1.3 × 10-9 g to 7.8 × 10-7 g at v = 0.5 km/s. Since the MMX spacecraft will take a quasi-circular, prograde orbit around Mars, the CMDM will be able to investigate particles from Phobos and Deimos with relative velocities lower than 1 km/s. Therefore, the CMDM will be able to determine whether or not a confined dust ring exists along Phobos' orbit and whether an extended dust torus exists along Deimos' orbit. It may also be able to clarify whether or not any such ring or torus are self-sustained.

Complex Role of Secondary Electron Emissions in Dust Grain Charging in Space Environments: Measurements on Apollo 11 and 17 Dust Grains

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Tankosic, D.; Spann, J. F.; LeClair, A. C.

2010-01-01

Dust grains in various astrophysical environments are generally charged electrostatically by photoelectric emissions with radiation from nearby sources, or by electron/ion collisions by sticking or secondary electron emissions. Knowledge of the dust grain charges and equilibrium potentials is important for understanding of a variety of physical and dynamical processes in the interstellar medium (ISM), and heliospheric, interplanetary, planetary, and lunar environments. The high vacuum environment on the lunar surface leads to some unusual physical and dynamical phenomena involving dust grains with high adhesive characteristics, and levitation and transportation over long distances. It has been well recognized that the charging properties of individual micron/submicron size dust grains are expected to be substantially different from the corresponding values for bulk materials and theoretical models. In this paper we present experimental results on charging of individual dust grains selected from Apollo 11 and Apollo 17 dust samples by exposing them to mono-energetic electron beams in the 10- 400 eV energy range. The charging rates of positively and negatively charged particles of approximately 0.2 to 13 microns diameters are discussed in terms of the secondary electron emission (SEE) process, which is found to be a complex charging process at electron energies as low as 10-25 eV, with strong particle size dependence. The measurements indicate substantial differences between dust charging properties of individual small size dust grains and of bulk materials.

OUTWARD MOTION OF POROUS DUST AGGREGATES BY STELLAR RADIATION PRESSURE IN PROTOPLANETARY DISKS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tazaki, Ryo; Nomura, Hideko, E-mail: rtazaki@kusastro.kyoto-u.ac.jp

2015-02-01

We study the dust motion at the surface layer of protoplanetary disks. Dust grains in the surface layer migrate outward owing to angular momentum transport via gas-drag force induced by the stellar radiation pressure. In this study we calculate the mass flux of the outward motion of compact grains and porous dust aggregates by the radiation pressure. The radiation pressure force for porous dust aggregates is calculated using the T-Matrix Method for the Clusters of Spheres. First, we confirm that porous dust aggregates are forced by strong radiation pressure even if they grow to be larger aggregates, in contrast tomore » homogeneous and spherical compact grains, for which radiation pressure efficiency becomes lower when their sizes increase. In addition, we find that the outward mass flux of porous dust aggregates with monomer size of 0.1 μm is larger than that of compact grains by an order of magnitude at the disk radius of 1 AU, when their sizes are several microns. This implies that large compact grains like calcium-aluminum-rich inclusions are hardly transported to the outer region by stellar radiation pressure, whereas porous dust aggregates like chondritic-porous interplanetary dust particles are efficiently transported to the comet formation region. Crystalline silicates are possibly transported in porous dust aggregates by stellar radiation pressure from the inner hot region to the outer cold cometary region in the protosolar nebula.« less

Organic compounds in circumstellar and interstellar environments.

PubMed

Kwok, Sun

2015-06-01

Recent research has discovered that complex organic matter is prevalent throughout the Universe. In the Solar System, it is found in meteorites, comets, interplanetary dust particles, and planetary satellites. Spectroscopic signatures of organics with aromatic/aliphatic structures are also found in stellar ejecta, diffuse interstellar medium, and external galaxies. From space infrared spectroscopic observations, we have found that complex organics can be synthesized in the late stages of stellar evolution. Shortly after the nuclear synthesis of the element carbon, organic gas-phase molecules are formed in the stellar winds, which later condense into solid organic particles. This organic synthesis occurs over very short time scales of about a thousand years. In order to determine the chemical structures of these stellar organics, comparisons are made with particles produced in the laboratory. Using the technique of chemical vapor deposition, artificial organic particles have been created by injecting energy into gas-phase hydrocarbon molecules. These comparisons led us to believe that the stellar organics are best described as amorphous carbonaceous nanoparticles with mixed aromatic and aliphatic components. The chemical structures of the stellar organics show strong similarity to the insoluble organic matter found in meteorites. Isotopic analysis of meteorites and interplanetary dust collected in the upper atmospheres have revealed the presence of pre-solar grains similar to those formed in old stars. This provides a direct link between star dust and the Solar System and raises the possibility that the early Solar System was chemically enriched by stellar ejecta with the potential of influencing the origin of life on Earth.

In situ 3-D mapping of pore structures and hollow grains of interplanetary dust particles with phase contrast X-ray nanotomography

NASA Astrophysics Data System (ADS)

Hu, Z. W.; Winarski, R. P.

2016-09-01

Unlocking the 3-D structure and properties of intact chondritic porous interplanetary dust particles (IDPs) in nanoscale detail is challenging, which is also complicated by atmospheric entry heating, but is important for advancing our understanding of the formation and origins of IDPs and planetary bodies as well as dust and ice agglomeration in the outer protoplanetary disk. Here, we show that indigenous pores, pristine grains, and thermal alteration products throughout intact particles can be noninvasively visualized and distinguished morphologically and microstructurally in 3-D detail down to ~10 nm by exploiting phase contrast X-ray nanotomography. We have uncovered the surprisingly intricate, submicron, and nanoscale pore structures of a ~10-μm-long porous IDP, consisting of two types of voids that are interconnected in 3-D space. One is morphologically primitive and mostly submicron-sized intergranular voids that are ubiquitous; the other is morphologically advanced and well-defined intragranular nanoholes that run through the approximate centers of ~0.3 μm or lower submicron hollow grains. The distinct hollow grains exhibit complex 3-D morphologies but in 2-D projections resemble typical organic hollow globules observed by transmission electron microscopy. The particle, with its outer region characterized by rough vesicular structures due to thermal alteration, has turned out to be an inherently fragile and intricately submicron- and nanoporous aggregate of the sub-μm grains or grain clumps that are delicately bound together frequently with little grain-to-grain contact in 3-D space.

Comets and the origin of life; Proceedings of the Fifth College Park Colloquium on Chemical Evolution, University of Maryland, College Park, MD, October 29-31, 1980

NASA Technical Reports Server (NTRS)

Ponnamperuma, C.

1981-01-01

Papers are presented concerning the characteristics of comets and their possible role in the origin of life. Specific topics include the characteristics, origin and structure of the cometary nucleus, cometary chemical abundances, the nature of interplanetary dust and its entry into terrestrial planet atmospheres, and the mechanism of ray closure in comet tails. Attention is also given to chemically evolved interstellar dust as a source of prebiotic material, the relation of comets to paleoatmospheric photochemistry, comets as a vehicle for panspermia, limits to life posed by extreme environments, and the status of cometary space missions as of 1980.

Goulds Belt, Interstellar Clouds, and the Eocene Oligocene Helium-3 Enhancement

NASA Technical Reports Server (NTRS)

Rubincam, David Parry

2015-01-01

Drag from hydrogen in the interstellar cloud which formed Gould's Belt may have sent interplanetary dust particle (IDPs) and small meteoroids with embedded helium to the Earth, perhaps explaining part the helium-3 flux increase seen in the sedimentary record near the Eocene-Oligocene transition. Assuming the Solar System passed through part of the cloud, IDPs in the inner Solar System may have been dragged to Earth, while dust and small meteoroids in the asteroid belt up to centimeter size may have been dragged to the resonances, where their orbital eccentricities were pumped up into Earth-crossing orbits; however, this hypotheses does not explain the Popigai and Chesapeake Bay impacts.

LUNAR DUST GRAIN CHARGING BY ELECTRON IMPACT: COMPLEX ROLE OF SECONDARY ELECTRON EMISSIONS IN SPACE ENVIRONMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbas, M. M.; Craven, P. D.; LeClair, A. C.

2010-08-01

Dust grains in various astrophysical environments are generally charged electrostatically by photoelectric emissions with radiation from nearby sources, or by electron/ion collisions by sticking or secondary electron emissions (SEEs). The high vacuum environment on the lunar surface leads to some unusual physical and dynamical phenomena involving dust grains with high adhesive characteristics, and levitation and transportation over long distances. Knowledge of the dust grain charges and equilibrium potentials is important for understanding a variety of physical and dynamical processes in the interstellar medium, and heliospheric, interplanetary/planetary, and lunar environments. It has been well recognized that the charging properties of individualmore » micron-/submicron-size dust grains are expected to be substantially different from the corresponding values for bulk materials. In this paper, we present experimental results on the charging of individual 0.2-13 {mu}m size dust grains selected from Apollo 11 and 17 dust samples, and spherical silica particles by exposing them to mono-energetic electron beams in the 10-200 eV energy range. The dust charging process by electron impact involving the SEEs discussed is found to be a complex charging phenomenon with strong particle size dependence. The measurements indicate substantial differences between the polarity and magnitude of the dust charging rates of individual small-size dust grains, and the measurements and model properties of corresponding bulk materials. A more comprehensive plan of measurements of the charging properties of individual dust grains for developing a database for realistic models of dust charging in astrophysical and lunar environments is in progress.« less

Lunary Dust Grain Charging by Electron Impact: Complex Role of Secondary Electron Emissions in Space Environments

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Tankosic, D.; Crave, P. D.; LeClair, A.; Spann, J. F.

2010-01-01

Dust grains in various astrophysical environments are generally charged electrostatically by photoelectric emissions with radiation from nearby sources, or by electron/ion collisions by sticking or secondary electron emissions (SEES). The high vacuum environment on the lunar surface leads to some unusual physical and dynamical phenomena involving dust grains with high adhesive characteristics, and levitation and transportation over long distances. Knowledge of the dust grain charges and equilibrium potentials is important for understanding a variety of physical and dynamical processes in the interstellar medium, and heliospheric, interplanetary/ planetary, and lunar environments. It has been well recognized that the charging properties of individual micron-/submicron-size dust grains are expected to be substantially different from the corresponding values for bulk materials. In this paper, we present experimental results on the charging of individual 0.2-13 m size dust grains selected from Apollo 11 and 17 dust samples, and spherical silica particles by exposing them to mono-energetic electron beams in the 10-200 eV energy range. The dust charging process by electron impact involving the SEES discussed is found to be a complex charging phenomenon with strong particle size dependence. The measurements indicate substantial differences between the polarity and magnitude of the dust charging rates of individual small-size dust grains, and the measurements and model properties of corresponding bulk materials. A more comprehensive plan of measurements of the charging properties of individual dust grains for developing a database for realistic models of dust charging in astrophysical and lunar environments is in progress.

Cosmic dust collection with a sub-satellite tethered to a space station

NASA Technical Reports Server (NTRS)

Corso, G. J.

1986-01-01

The number concentration and density of 1 micron and submicron sized grains in interplanetary space, as well as their relation to the larger zodical dust particles, and the importance of the Beta meteoroid phenomenon are currently being questioned. The best approach to collecting large numbers of intact micron and submicron sized cosmic dust particles in real time while avoiding terrestrial and man made contamination would be to employ a tethered subsatellite from a space station down into the Earth's atmosphere. Such a subsatellite tied to the space shuttle by a 100 km long tether is being developed. It is also possible that a permanent space station would allow the use of a tether even longer that 100 km. It should be noted that the same tethered collectors could also be employed to study the composition and flux of man made Earth orbiting debris in any direction within 100 km or so of the space station.

Cosmic dust collection with a sub satellite tethered to a Space Station

NASA Technical Reports Server (NTRS)

Corso, George J.

1987-01-01

The number concentration and density of 1 micron and submicron sized grains in interplanetary space, as well as their relation to the larger zodical dust particles, and the importance of the beta meteoroid phenomenon are currently being questioned. The best approach to collecting large numbers of intact micron and submicron sized cosmic dust particles in real time while avoiding terrestrial and man made contamination would be to employ a tethered subsatellite from a space station down into the earth's atmosphere. Such a subsatellite tied to the space shuttle by a 100 km long tether is being developed. It is also possible that a permanent space station would allow the use of a tether even longer than 100 km. It should be noted that the same tethered collectors could also be employed to study the composition and flux of man made earth orbiting debris in any direction within 100 km or so of the space station.

DIRBE obtained at infrared wavelengths of 25, 60 and 100 Aum

NASA Technical Reports Server (NTRS)

2002-01-01

This image combines data from the DIRBE obtained at infrared wavelengths of 25, 60 and 100 Aum. The sky brightness at these wavelengths is represented respectively by blue, green, and red colors in the image. The plane of the Milky Way Galaxy lies horizontally across the middle of the image with the Galactic center at the center. The image is dominated by the thermal emission from interstellar dust in the Milky Way. The wispy-looking dust features are called 'infrared cirrus.' The structured, warmer emission from interplanetary dust, shown in blue, is also prominent. The image shows a number of well-known dusty regions in the Milky Way, such as the Orion molecular clouds (below the plane, far right) which are active 'stellar nurseries' in our Galaxy. Two neighboring galaxies, the Large and Small Magellanic Clouds also can be distinguished (below the plane, approximately halfway between the center and right edge of the image).

Definitions of terms in meteor astronomy

NASA Astrophysics Data System (ADS)

Koschny, Detlef; Borovicka, Jiri

2017-10-01

Over the last year, the IAU commission F1 (Meteors, Meteorites and Interplanetary Dust) has discussed and agreed a new definition of terminology related to our field of interest. It is available online at this link: https://www.iau.org/static/science/scientific_bodies/commissions/f1/meteordefinitions_approved.pdf. For your convenience it is reproduced here. Please keep these definitions in mind in any future communications about our topic.

What can meteorites tell us about comets?

NASA Technical Reports Server (NTRS)

Anders, Edward

1986-01-01

Cometary silicates, carbon, and volatiles are reviewed using data from the Halley probes, interplanetary dust particles, and cometary spectra. The origins of anhydrous Fe(2+)-bearing silicates; whether hydrated silicates, if present, were made by gaseous or liquid H2O3; sources of organic compounds: ion-molecule reactions, photochemistry, grain catalysis; sources of CO2 and of organic polymers; and interstellar molecules and grains in comets are discussed.

Origin of the RNA world: The fate of nucleobases in warm little ponds

PubMed Central

Pudritz, Ralph E.; Semenov, Dmitry A.; Henning, Thomas K.

2017-01-01

Before the origin of simple cellular life, the building blocks of RNA (nucleotides) had to form and polymerize in favorable environments on early Earth. At this time, meteorites and interplanetary dust particles delivered organics such as nucleobases (the characteristic molecules of nucleotides) to warm little ponds whose wet–dry cycles promoted rapid polymerization. We build a comprehensive numerical model for the evolution of nucleobases in warm little ponds leading to the emergence of the first nucleotides and RNA. We couple Earth’s early evolution with complex prebiotic chemistry in these environments. We find that RNA polymers must have emerged very quickly after the deposition of meteorites (less than a few years). Their constituent nucleobases were primarily meteoritic in origin and not from interplanetary dust particles. Ponds appeared as continents rose out of the early global ocean, but this increasing availability of “targets” for meteorites was offset by declining meteorite bombardment rates. Moreover, the rapid losses of nucleobases to pond seepage during wet periods, and to UV photodissociation during dry periods, mean that the synthesis of nucleotides and their polymerization into RNA occurred in just one to a few wet–dry cycles. Under these conditions, RNA polymers likely appeared before 4.17 billion years ago. PMID:28973920

Saturn's largest ring.

PubMed

Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P

2009-10-22

Most planetary rings in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer rings and Saturn's E ring, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous ring associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The ring's vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these ring particles span the Saturnian system from the main rings to the edges of interplanetary space. The ring's normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer ring, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the ring populated with material. Ring particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus.

Comparison of Carbon XANES Spectra from an Iron Sulfide from Comet Wild 2 with an Iron Sulfide Interplanetary Dust Particle

NASA Technical Reports Server (NTRS)

Wirick, S.; Flynn, G. J.; Keller, L. P.; Sanford, S. A.; Zolensky, M. E.; Messenger, Nakamura K.; Jacobsen, C.

2008-01-01

Among one of the first particles removed from the aerogel collector from the Stardust sample return mission was an approx. 5 micron sized iron sulfide. The majority of the spectra from 5 different sections of this particle suggests the presence of aliphatic compounds. Due to the heat of capture in the aerogel we initially assumed these aliphatic compounds were not cometary but after comparing these results to a heated iron sulfide interplanetary dust particle (IDP) we believe our initial interpretation of these spectra was not correct. It has been suggested that ice coating on iron sulfides leads to aqueous alteration in IDP clusters which can then lead to the formation of complex organic compounds from unprocessed organics in the IDPs similar to unprocessed organics found in comets [1]. Iron sulfides have been demonstrated to not only transform halogenated aliphatic hydrocarbons but also enhance the bonding of rubber to steel [2,3]. Bromfield and Coville (1997) demonstrated using Xray photoelectron spectroscopy that "the surface enhancement of segregated sulfur to the surface of sulfided precipitated iron catalysts facilitates the formation of a low-dimensional structure of extraordinary properties" [4]. It may be that the iron sulfide acts in some way to protect aliphatic compounds from alteration due to heat.

Origin of the RNA world: The fate of nucleobases in warm little ponds.

PubMed

Pearce, Ben K D; Pudritz, Ralph E; Semenov, Dmitry A; Henning, Thomas K

2017-10-24

Before the origin of simple cellular life, the building blocks of RNA (nucleotides) had to form and polymerize in favorable environments on early Earth. At this time, meteorites and interplanetary dust particles delivered organics such as nucleobases (the characteristic molecules of nucleotides) to warm little ponds whose wet-dry cycles promoted rapid polymerization. We build a comprehensive numerical model for the evolution of nucleobases in warm little ponds leading to the emergence of the first nucleotides and RNA. We couple Earth's early evolution with complex prebiotic chemistry in these environments. We find that RNA polymers must have emerged very quickly after the deposition of meteorites (less than a few years). Their constituent nucleobases were primarily meteoritic in origin and not from interplanetary dust particles. Ponds appeared as continents rose out of the early global ocean, but this increasing availability of "targets" for meteorites was offset by declining meteorite bombardment rates. Moreover, the rapid losses of nucleobases to pond seepage during wet periods, and to UV photodissociation during dry periods, mean that the synthesis of nucleotides and their polymerization into RNA occurred in just one to a few wet-dry cycles. Under these conditions, RNA polymers likely appeared before 4.17 billion years ago.

Workshop on Parent-Body and Nebular Modification of Chondritic Materials

NASA Technical Reports Server (NTRS)

Krot, A. N. (Editor); Zolensky, M. E. (Editor); Scott, E. R. D. (Editor)

1997-01-01

The purpose of the workshop was to advance our understanding of solar nebula and asteroidal processes from studies of modification features in chondrites and interplanetary dust particles. As reflected in the program contained in this volume, the workshop included five regular sessions, a summary session, and a poster session. Twenty-three posters and 42 invited and contributed talks were presented. Part 1 of this report contains the abstracts of these presentations. The focus of the workshop included: (1) mineralogical, petrologic, chemical, and isotopic observations of the alteration mineralogy in interplanetary dust particles, ordinary and carbonaceous chondrites, and their components (Ca-Al-rich inclusions, chondrules, and matrix) to constrain the conditions and place of alteration; (2) sources of water in chondrites; (3) the relationship between aqueous alteration and thermal metamorphism; (4) short-lived radionuclides, AI-26, Mn-53, and I-129, as isotopic constraints on timing of alteration; (5) experimental and theoretical modeling of alteration reactions; and (6) the oxidation state of the solar nebula. There were approximately 140 participants at the workshop, probably due in part to the timeliness of the workshop goals and the workshop location. In the end few new agreements were achieved between warring factions, but new research efforts were forged and areas of fruitful future exploration were highlighted. Judged by these results, the workshop was successful.

The measurement of trace elements in interplanetary dust and cometary particles by ultra-high sensitivity INAA

NASA Technical Reports Server (NTRS)

Zolensky, M. E.; Lindstrom, David J.; Lindstrom, Richard M.; Lindstrom, M. M.

1989-01-01

Today the major elemental composition of interplanetary dust particles (IDPs) is routinely determined in many laboratories. These and mineralogical studies have revealed the presence of at least two major types of IDPs, chondritic and refractory. Preliminary results of a successful attempt to determine abundances of a large suite of trace elements from both chondritic and refractory IDPs are reported. The analytical procedure can be used in the grain-by-grain analysis of returned cometary samples. Chondritic and refractory IDPs are characterized by standard scanning electron microscopy and energy dispersive x ray spectroscopy (SEM-EDX) techniques. With this system, detection limits for many elements are well below picogram levels, and some approach femtogram levels. This technique is non-destructive, although some sample handling is required, so particles can be analyzed by other techniques after instrument neutron activation analysis (INAA) is completed. Data is presently being reduced from the analyses of 7 IDPs. These are U2015E10, U2015F1, W7029-A2, W7029-A3, W7013A8, LACl (all chondritic) and 705 (refractory). So far, 17 different major and trace elements were detected and measured in these particles, including rare earths and some very volatile elements (Br and Zn).

Identification of a Compound Spinel and Silicate Presolar Grain in a Chondritic Interplanetary Dust Particle

NASA Technical Reports Server (NTRS)

Nguyen, A. N.; Nakamura-Messenger, K.; Messenger, S.; Keller, L. P.; Kloeck, W.

2014-01-01

Anhydrous chondritic porous interplanetary dust particles (CP IDPs) have undergone minimal parent body alteration and contain an assemblage of highly primitive materials, including molecular cloud material, presolar grains, and material that formed in the early solar nebula [1-3]. The exact parent bodies of individual IDPs are not known, but IDPs that have extremely high abundances of presolar silicates (up to 1.5%) most likely have cometary origins [1, 4]. The presolar grain abundance among these minimally altered CP IDPs varies widely. "Isotopically primitive" IDPs distinguished by anomalous bulk N isotopic compositions, numerous 15N-rich hotspots, and some C isotopic anomalies have higher average abundances of presolar grains (375 ppm) than IDPs with isotopically normal bulk N (<10 ppm) [5]. Some D and N isotopic anomalies have been linked to carbonaceous matter, though this material is only rarely isotopically anomalous in C [1, 5, 6]. Previous studies of the bulk chemistry and, in some samples, the mineralogy of select anhydrous CP IDPs indicate a link between high C abundance and pyroxene-dominated mineralogy [7]. In this study, we conduct coordinated mineralogical and isotopic analyses of samples that were analyzed by [7] to characterize isotopically anomalous materials and to establish possible correlations with C abundance.

Origins of GEMS Grains

NASA Technical Reports Server (NTRS)

Messenger, S.; Walker, R. M.

2012-01-01

Interplanetary dust particles (IDPs) collected in the Earth s stratosphere contain high abundances of submicrometer amorphous silicates known as GEMS grains. From their birth as condensates in the outflows of oxygen-rich evolved stars, processing in interstellar space, and incorporation into disks around new stars, amorphous silicates predominate in most astrophysical environments. Amorphous silicates were a major building block of our Solar System and are prominent in infrared spectra of comets. Anhydrous interplanetary dust particles (IDPs) thought to derive from comets contain abundant amorphous silicates known as GEMS (glass with embedded metal and sulfides) grains. GEMS grains have been proposed to be isotopically and chemically homogenized interstellar amorphous silicate dust. We evaluated this hypothesis through coordinated chemical and isotopic analyses of GEMS grains in a suite of IDPs to constrain their origins. GEMS grains show order of magnitude variations in Mg, Fe, Ca, and S abundances. GEMS grains do not match the average element abundances inferred for ISM dust containing on average, too little Mg, Fe, and Ca, and too much S. GEMS grains have complementary compositions to the crystalline components in IDPs suggesting that they formed from the same reservoir. We did not observe any unequivocal microstructural or chemical evidence that GEMS grains experienced prolonged exposure to radiation. We identified four GEMS grains having O isotopic compositions that point to origins in red giant branch or asymptotic giant branch stars and supernovae. Based on their O isotopic compositions, we estimate that 1-6% of GEMS grains are surviving circumstellar grains. The remaining 94-99% of GEMS grains have O isotopic compositions that are indistinguishable from terrestrial materials and carbonaceous chondrites. These isotopically solar GEMS grains either formed in the Solar System or were completely homogenized in the interstellar medium (ISM). However, the chemical compositions of GEMS grains are extremely heterogeneous and seem to rule out this possibility. Based on their solar isotopic compositions and their non-solar elemental compositions we propose that most GEMS grains formed in the nebula as late-stage non-equilibrium condensates.

Stardust@home: A Massively Distributed Public Search for Interstellar Dust in the Stardust Interstellar Dust Collector

NASA Technical Reports Server (NTRS)

Westphal, Andrew J.; Butterworth, Anna L.; Snead, Christopher J.; Craig, Nahide; Anderson, David; Jones, Steven M.; Brownlee, Donald E.; Farnsworth, Richard; Zolensky, Michael E.

2005-01-01

In January 2006, the Stardust mission will return the first samples from a solid solar system body beyond the Moon. Stardust was in the news in January 2004, when it encountered comet Wild2 and captured a sample of cometary dust. But Stardust carries an equally important payload: the first samples of contemporary interstellar dust ever collected. Although it is known that interstellar (IS) dust penetrates into the inner solar system [2, 3], to date not even a single contemporary interstellar dust particle has been captured and analyzed in the laboratory. Stardust uses aerogel collectors to capture dust samples. Identification of interstellar dust impacts in the Stardust Interstellar Dust Collector probably cannot be automated, but will require the expertise of the human eye. However, the labor required for visual scanning of the entire collector would exceed the resources of any reasonably-sized research group. We are developing a project to recruit the public in the search for interstellar dust, based in part on the wildly popular SETI@home project, which has five million subscribers. We call the project Stardust@home. Using sophisticated chemical separation techniques, certain types of refractory ancient IS particles (so-called presolar grains) have been isolated from primitive meteorites (e.g., [4] ). Recently, presolar grains have been identified in Interplanetary Dust Particles[6]. Because these grains are not isolated chemically, but are recognized only by their unusual isotopic compositions, they are probably less biased than presolar grains isolated from meteorites. However, it is entirely possible that the typical interstellar dust particle is isotopically solar in composition. The Stardust collection of interstellar dust will be the first truly unbiased one.

The effects of interplanetary dust impacts on the accumulation of volatiles in the lunar permanently shadowed regions

NASA Astrophysics Data System (ADS)

Horanyi, Mihaly; Szalay, Jamey

2017-10-01

The lunar regolith has been formed, and remains continually reworked, by the intermitten impacts of comets, asteroids, meteoroids, and the continual bombardment by interplanetary dust particles (IDP). Thick atmospheres protect Venus, Earth, and Mars, ablating the incoming IDPs into “shooting stars” that rarely reach the surface. However, the surfaces of airless bodies near 1 AU are directly exposed to the high-speed (>> 1 km/s) IDP impacts. The Moon is expected to be bombarded by 5x103 kg/day of IDPs arriving with a characteristic speed of ~ 20 km/s. The IDP sources impacting the Moon at high latitudes remain largely uncharacterized due to the lack of optical and radar observations in the polar regions on Earth. These high latitude sources have very large impact speeds in the range of 30 < v < 50 km/ hence they are expected to have a significant effect on the lunar surface, including the removal and burial of volatile deposits in the lunar polar regions.Water is thought to be continually delivered to the Moon through geological timescales by water-bearing comets and asteroids, and produced continuously in situ by the impacts of solar wind protons of oxygen rich minerals exposed on the surface. IDPs are an unlikely source of water due to their long UV exposure in the inner solar system, but their high-speed impacts can mobilize secondary ejecta dust particles, atoms and molecules, some with high-enough speed to escape the Moon. Other surface processes that can lead to mobilization, transport and loss of water molecules and other volatiles include solar heating, photochemical processes, and solar wind sputtering. Since none of these are at work in permanently shadowed regions (PSR), dust impacts remain the dominant process to dictate the evolution of volatiles in PSRs. The competing effects of dust impacts are: a) ejecta production leading to loss out of a PSR; b) gardening and overturning the regolith; and c) the possible accumulation of impact ejecta, leading to the burial of the volatiles. This talk will summarize the expected effects of dust impacts on volatile accumulation in the lunar PSRs based on theoretical models, recent laboratory results, and observations by the LADEE spacecraft.

Cometary dust: the diversity of primitive refractory grains

PubMed Central

Ishii, H. A.

2017-01-01

Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive cometary particles has expanded significantly through microscale investigations of cosmic dust samples (anhydrous interplanetary dust particles (IDPs), chondritic porous (CP) IDPs and UltraCarbonaceous Antarctic micrometeorites, Stardust and Rosetta), as well as through remote sensing (Spitzer IR spectroscopy). Comet dust are aggregate particles of materials unequilibrated at submicrometre scales. We discuss the properties and processes experienced by primitive matter in comets. Primitive particles exhibit a diverse range of: structure and typology; distribution of constituents; concentration and form of carbonaceous and refractory organic matter; Mg- and Fe-contents of the silicate minerals; sulfides; existence/abundance of type II chondrule fragments; high-temperature calcium–aluminium inclusions and ameboid-olivine aggregates; and rarely occurring Mg-carbonates and magnetite, whose explanation requires aqueous alteration on parent bodies. The properties of refractory materials imply there were disc processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disc present at the time and in the region where the comets formed. This article is part of the themed issue ‘Cometary science after Rosetta’. PMID:28554979

Photoelectric Emission Measurements on the Analogs of Individual Cosmic Dust Grains

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Tankosic, D.; Craven, P. D.; Spann, J. F.; LeClair, A.; West, E. A.; Weingartner, J. C.; Tielens, A. G. G. M.; Nuth, J. a.; Camata, R. P.

2006-01-01

The photoelectric emission process is considered to be the dominant mechanism for charging of cosmic dust grains in many astrophysical environments. The grain charge and equilibrium potentials play an important role in the dynamical and physical processes that include heating of the neutral gas in the interstellar medium, coagulation processes in the dust clouds, and levitation and dynamical processes in the interplanetary medium and planetary surfaces and rings. An accurate evaluation of photoelectric emission processes requires knowledge of the photoelectric yields of individual dust grains of astrophysical composition as opposed to the values obtained from measurements on flat surfaces of bulk materials, as it is generally assumed on theoretical considerations that the yields for the small grains are much different from the bulk values. We present laboratory measurements of the photoelectric yields of individual dust grains of silica, olivine, and graphite of approx. 0.09-5 micrometer radii levitated in an electrodynamic balance and illuminated with ultraviolet radiation at 120-160 nm wavelengths. The measured yields are found to be substantially higher than the bulk values given in the literature and indicate a size dependence with larger particles having order-of-magnitude higher values than for submicron-size grains.

Phototelectric Emission Measurements on the Analogs of Individual Cosmic Dust Grains

NASA Technical Reports Server (NTRS)

Abbas, Mian M.; Tankosic, D.; Craven, P. D.; Spann, J. F.; LeClair, A.; West, E. A.; Weingartner, J. C.; Tielens, A. G. G. M.; Nuth, J. A.; Camata, R. P.;

Dust Measurements On-board the New Horizons Mission

NASA Astrophysics Data System (ADS)

Poppe, A.; James, D.; Horanyi, M.

2007-12-01

The Venetia Burney Student Dust Counter (VSDC) on the New Horizons spacecraft was successfully commissioned on March 3, 2006 (DOY 2006/061). VSDC is a dust impact detector designed to map the dust distribution along the trajectory of the New Horizons spacecraft as it traverses our solar system. VSDC is the first student built instrument on a deep space mission and it is currently operated by a small group of undergraduate and graduate students at the Laboratory of Atmospheric and Space Physics (LASP), University of Colorado. By the time of this meeting (12/2007), VSDC will have operated for about 330 days, covering an approximate distance from 1.21 to 10 AU. VSDC is based on permanently polarized thin plastic film sensors that generate an electrical signal when an impacting dust particle penetrates them. The total surface area is about 0.1 square meters, and the detection threshold is about a micron in particle radius. In this talk we will briefly review the VSDC instrument. The in-flight tests and calibrations, as well as our initial science results will be discussed. We will report on the measured spatial and size distribution of interplanetary dust particles before and after the encounter with Jupiter. These measurements will be compared with earlier measurements by Ulysses, Galileo, and Cassini.

Enhancing the Scientific Return from HST Imaging of Debris Disks

NASA Astrophysics Data System (ADS)

Weinberger, Alycia

2016-10-01

We propose realistic modeling of scattering of light by small aggregate dust grains that will enable us to interpret visible to near-infrared imaging of debris disks. We will determine if disk colors, phase functions, and polarizations place unique constraints on the composition of debris dust. Ongoing collisions of planetesimals generate dust; therefore, the dust provides unique information on compositions of the parent bodies. These exosolar analogs of asteroids and comets can bear clues to the history of a planetary system including migration and thermal processing. Because directly imaged debris disks are cold, they have no solid state emission features. Grain scattering properties as a function of wavelength are our only tool to reveal their compositions. Solar system interplanetary dust particles are fluffy aggregates, but most previous work on debris disk composition relied on Mie theory, i.e. assumed compact spherical grains. Mie calculations do not reproduce the observed colors and phase functions observed from debris disks. The few more complex calculations that exist do not explore the range of compositions and sizes relevant to debris disk dust. In particular, we expect porosity to help distinguish between cometary-like parent bodies, which are fluffy due to high volatile content and low collisional velocities, and asteroidal-like parent bodies that are compacted.

Update on Automated Classification of Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Maroger, I.; Lasue, J.; Zolensky, M.

2018-01-01

Every year, the Earth accretes about 40,000 tons of extraterrestrial material less than 1 mm in size on its surface. These dust particles originate from active comets, from impacts between asteroids and may also be coming from interstellar space for the very small particles. Since 1981, NASA Jonhson Space Center (JSC) has been systematically collecting the dust from Earth's strastosphere by airborne collectors and gathered them into "Cosmic Dust Catalogs". In those catalogs, a preliminary analysis of the dust particles based on SEM images, some geological characteristics and X-ray energy-dispersive spectrometry (EDS) composition is compiled. Based on those properties, the IDPs are classified into four main groups: C (Cosmic), TCN (Natural Terrestrial Contaminant), TCA (Artificial Terrestrial Contaminant) and AOS (Aluminium Oxide Sphere). Nevertheless, 20% of those particles remain ambiguously classified. Lasue et al. presented a methodology to help automatically classify the particles published in the catalog 15 based on their EDS spectra and nonlinear multivariate projections (as shown in Fig. 1). This work allowed to relabel 155 particles out of the 467 particles in catalog 15 and reclassify some contaminants as potential cosmic dusts. Further analyses of three such particles indicated their probable cosmic origin. The current work aims to bring complementary information to the automatic classification of IDPs to improve identification criteria.

SBDN: an information portal on small bodies and interplanetary dust inside the Europlanet Research Infrastructure

NASA Astrophysics Data System (ADS)

Turrini, Diego; de Sanctis, Maria Cristina; Carraro, Francesco; Fonte, Sergio; Giacomini, Livia; Politi, Romolo

In the framework of the Sixth Framework Programme (FP6) for Research and Technological Development of the European Community, the Europlanet project started the Integrated and Distributed Information Service (IDIS) initiative. The goal of this initiative was to "...offer to the planetary science community a common and user-friendly access to the data and infor-mation produced by the various types of research activities: earth-based observations, space observations, modelling and theory, laboratory experiments...". Four scientific nodes, repre-sentative of a significant fraction of the scientific themes covered by planetary sciences, were created: the Interiors and Surfaces node, the Atmospheres node, the Plasma node and the Small Bodies and Dust node. The original Europlanet program evolved into the Europlanet Research Infrastructure project, funded by the Seventh Framework Programme (FP7) for Research and Technological Development, and the IDIS initiative has been renewed with the addiction of a new scientific node, the Planetary Dynamics node. Here we present the Small Bodies and Dust node (SBDN) and the services it already provides to the scientific community, i.e. a searchable database of resources related to its thematic domains, an online and searchable cat-alogue of emission lines observed in the visible spectrum of comet 153P/2002 C1 Ikeya-Zhang supplemented by a visualization facility, a set of models of the simulated evolution of comet 67P/Churyumov-Gerasimenko with a particular focus on the effects of the distribution of dust and a information system on meteors through the Virtual Meteor Observatory. We will also introduce the new services that will be implemented and made available in the course of the Europlanet Research Infrastructure project.

Scattering Properties of Large Irregular Cosmic Dust Particles at Visible Wavelengths

DOE Office of Scientific and Technical Information (OSTI.GOV)

Escobar-Cerezo, J.; Palmer, C.; Muñoz, O.

The effect of internal inhomogeneities and surface roughness on the scattering behavior of large cosmic dust particles is studied by comparing model simulations with laboratory measurements. The present work shows the results of an attempt to model a dust sample measured in the laboratory with simulations performed by a ray-optics model code. We consider this dust sample as a good analogue for interplanetary and interstellar dust as it shares its refractive index with known materials in these media. Several sensitivity tests have been performed for both structural cases (internal inclusions and surface roughness). Three different samples have been selected tomore » mimic inclusion/coating inhomogeneities: two measured scattering matrices of hematite and white clay, and a simulated matrix for water ice. These three matrices are selected to cover a wide range of imaginary refractive indices. The selection of these materials also seeks to study astrophysical environments of interest such as Mars, where hematite and clays have been detected, and comets. Based on the results of the sensitivity tests shown in this work, we perform calculations for a size distribution of a silicate-type host particle model with inclusions and surface roughness to reproduce the experimental measurements of a dust sample. The model fits the measurements quite well, proving that surface roughness and internal structure play a role in the scattering pattern of irregular cosmic dust particles.« less

Education and Public Outreach for Stardust@home: An Interactive Internet-based Search for Interstellar Dust

NASA Astrophysics Data System (ADS)

Mendez, Bryan J.; Westphal, A. J.; Butterworth, A. L.; Craig, N.

2006-12-01

On January 15, 2006, NASA’s Stardust mission returned to Earth after nearly seven years in interplanetary space. During its journey, Stardust encountered comet Wild 2, collecting dust particles from it in a special material called aerogel. At two other times in the mission, aerogel collectors were also opened to collect interstellar dust. The Stardust Interstellar Dust Collector is being scanned by an automated microscope at the Johnson Space Center. There are approximately 700,000 fields of view needed to cover the entire collector, but we expect only a few dozen total grains of interstellar dust were captured within it. Finding these particles is a daunting task. We have recruited many thousands of volunteers from the public to aid in the search for these precious pieces of space dust trapped in the collectors. We call the project Stardust@home. Through Stardust@home, volunteers from the public search fields of view from the Stardust aerogel collector using a web-based Virtual Microscope. Volunteers who discover interstellar dust particles have the privilege of naming them. The interest and response to this project has been extraordinary. Many people from all walks of life are very excited about space science and eager to volunteer their time to contribute to a real research project such as this. We will discuss the progress of the project and the education and outreach activities being carried out for it.

Stardust@home: An Interactive Internet-based Search for Interstellar Dust

NASA Astrophysics Data System (ADS)

Mendez, B. J.; Westphal, A. J.; Butterworth, A. L.; Craig, N.

2006-12-01

On January 15, 2006, NASA's Stardust mission returned to Earth after nearly seven years in interplanetary space. During its journey, Stardust encountered comet Wild 2, collecting dust particles from it in a special material called aerogel. At two other times in the mission, aerogel collectors were also opened to collect interstellar dust. The Stardust Interstellar Dust Collector is being scanned by an automated microscope at the Johnson Space Center. There are approximately 700,000 fields of view needed to cover the entire collector, but we expect only a few dozen total grains of interstellar dust were captured within it. Finding these particles is a daunting task. We have recruited many thousands of volunteers from the public to aid in the search for these precious pieces of space dust trapped in the collectors. We call the project Stardust@home. Through Stardust@home, volunteers from the public search fields of view from the Stardust aerogel collector using a web-based Virtual Microscope. Volunteers who discover interstellar dust particles have the privilege of naming them. The interest and response to this project has been extraordinary. Many people from all walks of life are very excited about space science and eager to volunteer their time to contribute to a real research project such as this. We will discuss the progress of the project and the education and outreach activities being carried out for it.

Hydrocarbons on Saturns Satellites: Relationship to Interstellar Dust and the Solar Nebula

NASA Technical Reports Server (NTRS)

Cruikshank, D. P.

2012-01-01

To understand the origin and evolution of our Solar System, and the basic components that led to life on Earth, we study interstellar and planetary spectroscopic signatures. The possible relationship of organic material detected in carbonaceous meteorites, interplanetary dust particles (IDPs), comets and the interstellar medium have been the source of speculation over the years as the composition and processes that governed the early solar nebula have been explored to understand the extent to which primitive material survived or became processed. The Cassini VIMS has provided new data relevant to this problem. Three of Saturn's satellites, Phoebe, Iapetus, and Hyperion, are found to have aromatic and aliphatic hydrocarbons on their surfaces. The aromatic hydrocarbon signature (C-H stretching mode at 3.28 micrometers) is proportionally significantly stronger (relative to the aliphatic bands) than that seen in other Solar System bodies (e.g., comets) and materials (Stardust samples, IDPs, meteorites) and the distinctive sub-features of the 3.4 micrometer aliphatic band (CH2 and CH3 groups) are reminiscent of those widely detected throughout the diffuse ISM. Phoebe may be a captured object that originated in the region beyond the present orbit of Neptune, where the solar nebula contained a large fraction of original interstellar ice and dust that was less processed than material closer to the Sun. Debris from Phoebe now resident on Iapetus and Hyperion, as well as o Phoebe itself, thus presents a unique blend of hydrocarbons, amenable to comparisons with interstellar hydrocarbons and other Solar System materials. The dust ring surrounding Saturn, in which Phoebe is embedded, probably originated from a collision with Phoebe. Dust ring particles are the likely source of the organic-bearing materials, and perhaps the recently identified small particles of Fe detected on Saturn's satellites. Lab measurements of the absolute band strengths of representative aliphatic and aromatic molecules, together with measurements from the VIMS data, allow us to calculate the number of C atoms to find the relative abundances of C atoms in the two kinds of organic molecules. The strength of the prominent aromatic C-H stretch band relative to the aliphatic band complex in Phoebe and Iapetus indicates that the relative abundance of aromatic to aliphatic carbon is very large (greater than 200). In contract, the aromatic band is nearly imperceptible in spectra of interplanetary dust particles (IDP), returned samples from comet 91P/Wild 2, insoluable carbonaceous material in most meteorites, and the diffuse interstellar dust (DISM) (although aromatics are known in all these materials-here we consider only the spectroscopic signature)

Nature vs. nurture debate on TNO carbons: constraints from Raman spectroscopy

NASA Astrophysics Data System (ADS)

Brunetto, R.

2012-02-01

We compare spectroscopic data of irradiated laboratory analogs with those of an interplanetary dust particle of cometary origin. We investigate if this comparison can help constraining the origin of carbonaceous materials on small icy bodies in the outer Solar System (TNOs, Centaurs, etc.). We suggest that Raman spectroscopy can help in interpreting the observed heterogeneity of the extraterrestrial carbonaceous component and in constraining the irradiation dose accumulated in space.

High energy astronomy or astrophysics and properties of the interplanetary plasma

NASA Technical Reports Server (NTRS)

1971-01-01

The research activities related to high energy astrophysics and interplanetary plasma are reported. The experimental work in the following areas are described: (1) balloon-and rocket-borne cosmic X-ray, (2) X-ray spectroscopy, and (3) OSO-3 gamma ray experiment. Plasma studies in the interplanetary region, magnetosphere, and geomagnetic tail are included.

Iron, magnesium, and silicon in dust from Comet Halley

NASA Technical Reports Server (NTRS)

Lawler, Mark E.; Brownlee, Donald E.; Temple, Scott; Wheelock, Maya M.

1989-01-01

The highest-quality impact mass spectrometer data from the Vega-1 and Giotto spacecraft are presently used to study the Mg, Si, and Fe composition of dust grains in Comet Halley. The results thus obtained are in general agreement with previously reported data, but differ with respect to ion ratio dispersions. A lack of sharp clustering in the data indicates that none of the detected particles can be characterized as single mineral grains; an abundant glass content in the solids may be indicated. The best match of the distribution of Fe/(Fe+Mg) is with interplanetary particles containing high temperature, Mg-rich silicates dominated by anhydrous minerals, so that Comet Halley may be a mixture of ice and high-temperature anhydrous minerals.

The Interplanetary Meteoroid Environment for eXploration

NASA Astrophysics Data System (ADS)

Soja, R.; Sommer, M.; Srama, R.; Strub, P.; Grün, E.; Rodmann, J.; Vaubaillon, J.; Hornig, A.; Bausch, L.

2014-07-01

The Interplanetary Meteoroid Environment for eXploration (IMEX) project, funded by the European Space Agency (ESA), aims to characterize dust trails and streams produced by comets in the inner solar system. The goal is to predict meteor showers at any position or time in the solar system, such as at specific spacecraft or planets. This model will allow for the assessment of the dust impact hazard to spacecraft, which is important because hypervelocity impacts of micrometeoroids can damage or destroy spacecraft or their subsystems through physical damage or electromagnetic effects. Such considerations are particularly important in the context of human exploration of the solar system. Additionally, such a model will allow for scientific study of specific trails and their connections to observed dust phenomena, such as cometary trails and new meteor showers at Earth. We have recently expanded the model to include explicit integrations of large numbers of particles from each comet, utilizing the Constellation platform to perform the calculations. This is a distributed computing system, where currently 10,000 users are donating their idle computing time at home and thus generating a virtual supercomputer of 40,000 host PCs connected via the Internet (aerospaceresearch.net). This form of citizen science provides the required computing performance for simulating millions of particles ejected by each of the ˜400 comets, while developing the relationship between scientists and the general public. The result will be a unique set of saved orbital information for a large number of cometary streams, allowing efficient computation of their locations at any point in space and time. Here we will present the results from several test streams and discuss the progress towards obtaining the full set of integrated particles for each of the selected ˜400 short-period comets. individual Constellation users for their computing time.

Dust ablation in Pluto's atmosphere

NASA Astrophysics Data System (ADS)

Horanyi, Mihaly; Poppe, Andrew; Sternovsky, Zoltan

2016-04-01

Based on measurements by dust detectors onboard the Pioneer 10/11 and New Horizons spacecraft the total production rate of dust particles born in the Edgeworth Kuiper Belt (EKB) has been be estimated to be on the order of 5 ṡ 103 kg/s in the approximate size range of 1 - 10 μm. Dust particles are produced by collisions between EKB objects and their bombardment by both interplanetary and interstellar dust particles. Dust particles of EKB origin, in general, migrate towards the Sun due to Poynting-Robertson drag but their distributions are further sculpted by mean-motion resonances as they first approach the orbit of Neptune and later the other planets, as well as mutual collisions. Subsequently, Jupiter will eject the vast majority of them before they reach the inner solar system. The expected mass influx into Pluto atmosphere is on the order of 200 kg/day, and the arrival speed of the incoming particles is on the order of 3 - 4 km/s. We have followed the ablation history as function of speed and size of dust particles in Pluto's atmosphere, and found that volatile rich particles can fully sublimate due to drag heating and deposit their mass in narrow layers. This deposition might promote the formation of the haze layers observed by the New Horizons spacecraft. This talk will explore the constraints on the composition of the dust particles by comparing the altitude of the deposition layers to the observed haze layers.

Carbonate in Comets: A Comparison of Comets 1P/Halley, 9P/Temple 1, and 81P/Wild 2

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Leroux, H.; Tomeoka, K.; Tomioka, N.; Ohnishi, I.; Mikouchi, T.; Wirick, S.; Keller, L. P.; Jacobsen, C.; Sanford, S. A.

2008-01-01

Comets are generally believed to have formed in a cold region, trapping in the cometary ices the original low-temperature condensate grains of our Solar System. These grains would have been preserved in cold-storage, at a temperature below the freezing point of CO2, for the last 4.5+ billion years. Carbonates are common in hydrous meteorites and hydrous interplanetary dust particles (IDPs), where they are believed to have formed by parent-body aqueous processing. Since simple models of cometary evolution involve no aqueous processing, carbonates were generally presumed not to occur in comets. However, Toppani et al. [1] have performed experiments that indicate carbonate can be formed by non-equilibrium condensation in circumstellar environments where water is present as a vapor, not as a liquid. This suggests carbonate might have condensed in cold regions of the Solar Nebula, and might be present in comets.

Evolution of Cometary Dust Particles to the Orbit of the Earth: Particle Size, Shape, and Mutual Collisions

NASA Astrophysics Data System (ADS)

Yang, Hongu; Ishiguro, Masateru

2018-02-01

In this study, we numerically investigated the orbital evolution of cometary dust particles, with special consideration of the initial size–frequency distribution (SFD) and different evolutionary tracks according to the initial orbit and particle shape. We found that close encounters with planets (mostly Jupiter) are the dominating factor determining the orbital evolution of dust particles. Therefore, the lifetimes of cometary dust particles (∼250,000 yr) are shorter than the Poynting–Robertson lifetime, and only a small fraction of large cometary dust particles can be transferred into orbits with small semimajor axes. The exceptions are dust particles from 2P/Encke and, potentially, active asteroids that have little interaction with Jupiter. We also found that the effects of dust shape, mass density, and SFD were not critical in the total mass supply rate to the interplanetary dust particle (IDP) cloud complex when these quantities are confined by observations of zodiacal light brightness and SFD around the Earth’s orbit. When we incorporate a population of fluffy aggregates discovered in the Earth’s stratosphere and the coma of 67P/Churyumov–Gerasimenko within the initial ejection, the initial SFD measured at the comae of comets (67P and 81P/Wild 2) can produce the observed SFD around the Earth’s orbit. Considering the above effects, we derived the probability of mutual collisions among dust particles within the IDP cloud for the first time in a direct manner via numerical simulation and concluded that mutual collisions can mostly be ignored.

High-Nickel Iron-Sulfides in Anhydrous, Gems-Rich CP IDPs

NASA Technical Reports Server (NTRS)

FLynn, G. J.; Keller, L. P.; Wirick, S.; Hu, W.; Li, L.; Yan, H.; Huang, X.; Nazaretski, E.; Lauer, K.; Chu, Y. S.

2016-01-01

Chondritic porous interplanetary dust particles (CP IDPs) that were not severly heated during atmospheric deceleration are the best preserved samples of the solids that condensed from the Solar protoplanetary disk, as well as pre-Solar grains thatr survived incorporation into the disk, currently available for laboratory analysis [1]. These CP IDPs never experienced the aqueous and/or thermal processing, gravitational compaction, and shock effects that overprinted the record of Solar nebula processes in meteorites.

Endogenous production, exogenous delivery and impact-shock synthesis of organic molecules - An inventory for the origins of life

NASA Technical Reports Server (NTRS)

Chyba, Christopher; Sagan, Carl

1992-01-01

The contribution of organic-rich comets, carbonaceous asteroids, and interplanetary dust particles and of impact shock-synthesized organics in the atmosphere to the origin of life on earth is studied and quantitatively compared with the principal non-heavy-bombardment sources of prebiotic organics. The results suggest that heavy bombardment before 3.5 Gyr ago either produced or delivered quantities of organics comparable to those produced by other energy sources.

Sediment focusing creates 100-ka cycles in interplanetary dust accumulation on the Ontong Java Plateau

NASA Astrophysics Data System (ADS)

Higgins, Sean M.; Anderson, Robert F.; Marcantonio, Franco; Schlosser, Peter; Stute, Martin

2002-10-01

The accumulation of extraterrestrial 3He, a tracer for interplanetary dust particles (IDPs), in sediments from the Ontong Java Plateau (OJP; western equatorial Pacific Ocean) has been shown previously to exhibit a regular cyclicity during the late Pleistocene, with a period of ∼100 ka. Those results have been interpreted to reflect periodic variability in the global accretion of IDPs that, in turn, has been linked to changes in the inclination of Earth's orbit with respect to the invariable plane of the solar system. Here we show that the accumulation in OJP sediments of authigenic 230Th, produced by radioactive decay of 234U in seawater, exhibits a 100-ka cyclicity similar in phase and amplitude to that evident in the 3He record. We interpret the similar patterns of 230Th and 3He accumulation to reflect a common origin within the ocean-climate system. Comparing spatial and temporal patterns of sediment accumulation against regional patterns of biological productivity and against the well-established pattern of CaCO3 dissolution in the deep Pacific Ocean leads to the further conclusion that a common 100-ka cycle in accumulation of biogenic, authigenic and extraterrestrial constituents in OJP sediments reflects the influence of climate-related changes in sediment focusing, rather than changes in the rate of production or supply of sedimentary constituents.

Carbon analyses of IDP's sectioned in sulfur and supported on beryllium films

NASA Technical Reports Server (NTRS)

Bradley, J. P.; Keller, L.; Thomas, K. L.; Vanderwood, T. B.; Brownlee, D. E.

1993-01-01

Carbon is the only major element in interplanetary dust whose abundance, distribution and chemical state are not well understood. Information about carbon could clarify the relationship between the various classes of IDP's, conventional meteorites, and sources (e.g., comets vs. asteroids). To date, the most reliable estimates of C abundance in Interplanetary Dust Particles (IDP's) have been obtained by analyzing particles on thick-flat Be substrates using thin-window energy-dispersive spectroscopy in the SEM. These estimates of C abundance are valid only if C is homogeneously distributed, because detected C x-rays originate from the outer 0.1 micrometers of the particle. An alternative and potentially more accurate method of measuring C abundances is to analyze multiple thin sections (each less than 0.1 less than 0.1 micrometers thick) of IDP's. These efforts however, have been stymied because of a lack of a suitable non-carbonaceous embedding medium and the availability of C-free conductive substrates. We have embedded and thin-sectioned IDP's in glassy sulfur, and transferred the thin sections to Be support films approximately 25 nm thick. The sections were then analyzed in a 200 KeV analytical TEM. S sublimes rapidly under vacuum in the TEM, leaving non-embedded sections supported on Be. Apart from quantitative C (and O) analyses, S sectioning dramatically expands the range of analytical measurements that can be performed on a single IDP.

Comparison of the oxidation state of Fe in comet 81P/Wild 2 and chondritic-porous interplanetary dust particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogliore, Ryan C.; Butterworth, Anna L.; Fakra, Sirine C.

2010-07-16

The fragile structure of chondritic-porous interplanetary dust particles (CP-IDPs) and their minimal parent-body alteration have led researchers to believe these particles originate in comets rather than asteroids where aqueous and thermal alterations have occurred. The solar elemental abundances and atmospheric entry speed of CP-IDPs also suggest a cometary origin. With the return of the Stardust samples from Jupiter-family comet 81P/Wild 2, this hypothesis can be tested. We have measured the Fe oxidation state of 15 CP-IDPs and 194 Stardust fragments using a synchrotron-based x-ray microprobe. We analyzed {approx}300 ng of Wild 2 material - three orders of magnitude more materialmore » than other analyses comparing Wild 2 and CP-IDPs. The Fe oxidation state of these two samples of material are > 2{sigma} different: the CP-IDPs are more oxidized than the Wild 2 grains. We conclude that comet Wild 2 contains material that formed at a lower oxygen fugacity than the parent-body, or parent bodies, of CP-IDPs. If all Jupiter-family comets are similar, they do not appear to be consistent with the origin of CP-IDPs. However, comets that formed from a different mix of nebular material and are more oxidized than Wild 2 could be the source of CP-IDPs.« less

Assemblage of Presolar Materials and Early Solar System Condensates in Chondritic Porous Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Nguyen, A. N.; Nakamura-Messenger, K.; Messenger, S.; Keller, L. P.; Kloeck, W.

2015-01-01

Anhydrous chondritic porous inter-planetary dust particles (CP IDPs) contain an assortment of highly primitive solar system components, molecular cloud matter, and presolar grains. These IDPs have largely escaped parent body processing that has affected meteorites, advocating cometary origins. Though the stardust abundance in CP IDPs is generally greater than in primitive meteorites, it can vary widely among individual CP IDPs. The average abundance of silicate stardust among isotopically primitive IDPs is approx. 375 ppm while some have extreme abundances up to approx. 1.5%. H and N isotopic anomalies are common in CP IDPs and the carrier of these anomalies has been traced to organic matter that has experienced chemical reactions in cold molecular clouds or the outer protosolar disk. Significant variations in these anomalies may reflect different degrees of nebular processing. Refractory inclusions are commonly observed in carbonaceous chondrites. These inclusions are among the first solar system condensates and display 16O-rich isotopic compositions. Refractory grains have also been observed in the comet 81P/Wild-2 samples re-turned from the Stardust Mission and in CP IDPs, but they occur with much less frequency. Here we conduct coordinated mineralogical and isotopic analyses of CP IDPs that were characterized for their bulk chemistry by to study the distribution of primitive components and the degree of nebular alteration incurred.

Detecting Interplanetary Dust Particles with Radars to Study the Dynamics at the Edge of the Space

NASA Technical Reports Server (NTRS)

Janches, Diego

2015-01-01

The Earth's mesosphere is the region of the atmosphere between approximately 60-120 km altitude, where the transition from hydrodynamic flow to molecular diffusion occurs. It is highly dynamic region where turbulence by wave braking is produced and energy is deposited from sources from both, below and above this altitude range. Because aircraft and nearly all balloons reach altitudes below approximately 50 km and orbital spacecrafts are well above approximately 400 km, the mesosphere has only been accessed through the use of sounding rockets or remote sensing techniques, and as a result, it is the most poorly understood part of the atmosphere. In addition, millions of Interplanetary Dust Particles (IDPs) enter the atmosphere. Within the mesosphere most of these IDPs melt or vaporize as a result of collisions with the air particles producing meteors that can be detected with radars. This provides a mean to study the dynamics of this region. In this lecture the basic principles of the utilization of meteor radars to study the dynamics of the mesosphere will be presented. A system overview of these systems will be provided as well as discuss the advantages/disadvantages of these systems, provide details of the data processing methodology and give a brief overview of the current status of the field as well as the vision for the next decade.

Sintering of highly porous silica-particle samples: analogues of early Solar-System aggregates

NASA Astrophysics Data System (ADS)

Poppe, T.

2003-07-01

I describe a new method to make particle layers which consist of SiO 2 spheres with 0.78 μm radius. The layers were produced by sedimentation of aggregates which had grown in ballistic particle collisions, and the layers had a porosity of 0.95. They were used for experiments on sintering, i.e., the samples were heated in an oven at varying temperatures and heating durations, and the samples were analyzed by scanning electron microscopy. Based on the change of particle diameter, surface diffusion sintering and viscous flow are identified as important transformation mechanisms. The first effect dominated at the start of restructuring and the latter at higher temperatures. The neck growth of adjacent particles was fitted to a surface diffusion sintering model and predicts neck radii as a heating temperature and duration function. Between the temperature range of neck formation and of melting, further restructuring occurred which lead to dissolution of particulate structure and to densification and which resulted in a porous object consisting of straight elongated substructures which connected kinks of higher material density. The thermal transformation is important for the change of strength, collisional behavior, light-scattering properties, and thermal conductivity with relevance to dust aggregates, planetesimals, comets, interplanetary dust particles, and regolith-covered celestial bodies.

Pluto' interaction with its space environment: Solar wind, energetic particles, and dust

NASA Astrophysics Data System (ADS)

Bagenal, F.; Horányi, M.; McComas, D. J.; McNutt, R. L.; Elliott, H. A.; Hill, M. E.; Brown, L. E.; Delamere, P. A.; Kollmann, P.; Krimigis, S. M.; Kusterer, M.; Lisse, C. M.; Mitchell, D. G.; Piquette, M.; Poppe, A. R.; Strobel, D. F.; Szalay, J. R.; Valek, P.; Vandegriff, J.; Weidner, S.; Zirnstein, E. J.; Stern, S. A.; Ennico, K.; Olkin, C. B.; Weaver, H. A.; Young, L. A.; Gladstone, G. R.; Grundy, W. M.; McKinnon, W. B.; Moore, J. M.; Spencer, J. R.; Andert, T.; Andrews, J.; Banks, M.; Bauer, B.; Bauman, J.; Barnouin, O. S.; Bedini, P.; Beisser, K.; Beyer, R. A.; Bhaskaran, S.; Binzel, R. P.; Birath, E.; Bird, M.; Bogan, D. J.; Bowman, A.; Bray, V. J.; Brozovic, M.; Bryan, C.; Buckley, M. R.; Buie, M. W.; Buratti, B. J.; Bushman, S. S.; Calloway, A.; Carcich, B.; Cheng, A. F.; Conard, S.; Conrad, C. A.; Cook, J. C.; Cruikshank, D. P.; Custodio, O. S.; Dalle Ore, C. M.; Deboy, C.; Dischner, Z. J. B.; Dumont, P.; Earle, A. M.; Ercol, J.; Ernst, C. M.; Finley, T.; Flanigan, S. H.; Fountain, G.; Freeze, M. J.; Greathouse, T.; Green, J. L.; Guo, Y.; Hahn, M.; Hamilton, D. P.; Hamilton, S. A.; Hanley, J.; Harch, A.; Hart, H. M.; Hersman, C. B.; Hill, A.; Hinson, D. P.; Holdridge, M. E.; Howard, A. D.; Howett, C. J. A.; Jackman, C.; Jacobson, R. A.; Jennings, D. E.; Kammer, J. A.; Kang, H. K.; Kaufmann, D. E.; Kusnierkiewicz, D.; Lauer, T. R.; Lee, J. E.; Lindstrom, K. L.; Linscott, I. R.; Lunsford, A. W.; Mallder, V. A.; Martin, N.; Mehoke, D.; Mehoke, T.; Melin, E. D.; Mutchler, M.; Nelson, D.; Nimmo, F.; Nunez, J. I.; Ocampo, A.; Owen, W. M.; Paetzold, M.; Page, B.; Parker, A. H.; Parker, J. W.; Pelletier, F.; Peterson, J.; Pinkine, N.; Porter, S. B.; Protopapa, S.; Redfern, J.; Reitsema, H. J.; Reuter, D. C.; Roberts, J. H.; Robbins, S. J.; Rogers, G.; Rose, D.; Runyon, K.; Retherford, K. D.; Ryschkewitsch, M. G.; Schenk, P.; Schindhelm, E.; Sepan, B.; Showalter, M. R.; Singer, K. N.; Soluri, M.; Stanbridge, D.; Steffl, A. J.; Stryk, T.; Summers, M. E.; Tapley, M.; Taylor, A.; Taylor, H.; Throop, H. B.; Tsang, C. C. C.; Tyler, G. L.; Umurhan, O. M.; Verbiscer, A. J.; Versteeg, M. H.; Vincent, M.; Webbert, R.; Weigle, G. E.; White, O. L.; Whittenburg, K.; Williams, B. G.; Williams, K.; Williams, S.; Woods, W. W.; Zangari, A. M.

2016-03-01

The New Horizons spacecraft carried three instruments that measured the space environment near Pluto as it flew by on 14 July 2015. The Solar Wind Around Pluto (SWAP) instrument revealed an interaction region confined sunward of Pluto to within about 6 Pluto radii. The region's surprisingly small size is consistent with a reduced atmospheric escape rate, as well as a particularly high solar wind flux. Observations from the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument suggest that ions are accelerated and/or deflected around Pluto. In the wake of the interaction region, PEPSSI observed suprathermal particle fluxes equal to about 1/10 of the flux in the interplanetary medium and increasing with distance downstream. The Venetia Burney Student Dust Counter, which measures grains with radii larger than 1.4 micrometers, detected one candidate impact in ±5 days around New Horizons' closest approach, indicating an upper limit of <4.6 kilometers-3 for the dust density in the Pluto system.

Constraints on the nanoscale minerals on the surface of Saturnian icy moons

NASA Astrophysics Data System (ADS)

Srama, R.; Hsu, H.; Kempf, S.; Horanyi, M.

2011-12-01

Nano-phase iron particles embedded into the surfaces of Saturn's icy moons as well as in the ring material have been proposed to explain the infrared spectra obtained by Cassini VIMS. Because the continuous influx of interplanetary fast impactors into the Saturnian system erodes any exposed surface, a certain amount of the embedded nano-particles will be ejected into the Saturnian magnetosphere and speed up to velocities high enough to be detected by the Cassini dust detector CDA. Thus, the analysis of the so-called stream particles provides constraints on the amount and the composition of any nano-phase material within the surfaces of the icy moons. Nanoparticles registered by the Cassini dust detector are most likely composed of silica (SiO2). Their dynamical properties indicate that they are relics of E ring dust grains. In this talk we will show that the Cassini stream particle measurements provide strong constraints for the composition and size distribution of any embedded nano-material.

Pluto's interaction with its space environment: Solar wind, energetic particles, and dust.

PubMed

Bagenal, F; Horányi, M; McComas, D J; McNutt, R L; Elliott, H A; Hill, M E; Brown, L E; Delamere, P A; Kollmann, P; Krimigis, S M; Kusterer, M; Lisse, C M; Mitchell, D G; Piquette, M; Poppe, A R; Strobel, D F; Szalay, J R; Valek, P; Vandegriff, J; Weidner, S; Zirnstein, E J; Stern, S A; Ennico, K; Olkin, C B; Weaver, H A; Young, L A

2016-03-18

The New Horizons spacecraft carried three instruments that measured the space environment near Pluto as it flew by on 14 July 2015. The Solar Wind Around Pluto (SWAP) instrument revealed an interaction region confined sunward of Pluto to within about 6 Pluto radii. The region's surprisingly small size is consistent with a reduced atmospheric escape rate, as well as a particularly high solar wind flux. Observations from the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument suggest that ions are accelerated and/or deflected around Pluto. In the wake of the interaction region, PEPSSI observed suprathermal particle fluxes equal to about 1/10 of the flux in the interplanetary medium and increasing with distance downstream. The Venetia Burney Student Dust Counter, which measures grains with radii larger than 1.4 micrometers, detected one candidate impact in ±5 days around New Horizons' closest approach, indicating an upper limit of <4.6 kilometers(-3) for the dust density in the Pluto system. Copyright © 2016, American Association for the Advancement of Science.

Self-Assembling Amphiphilic Molecules: A Possible Relationship Between Interstellar Chemistry and Meteoritic Organics

NASA Technical Reports Server (NTRS)

Sandford, Scott A.; Dworkin, Jason P.; Deamer, David W.; Allamandola, Louis J.; DeVincenzi, Donald (Technical Monitor)

2001-01-01

Interstellar gas and dust comprise the primary material from which the solar system formed. Evidence that some of this material was organic in nature and survived incorporation into the protosolar nebula is provided by the presence of deuterium-enriched organics in meteorites and interplanetary dust particles. Once the inner planets had sufficiently cooled, late accretionary infall of meteoroids and cosmic dust must have seeded them with some of these complex organic compounds. Delivery of such extraterrestrial compounds may have contributed to the organic inventory necessary for the origin of life. Interstellar ices, the building blocks of comets, tie up a large fraction of the biogenic elements available in molecular clouds. In our efforts to understand their synthesis, chemical composition, and physical properties, we report here that a complex mixture of molecules is produced by ultraviolet (UV) photolysis of realistic, interstellar ice analogs, and that some of the components have properties relevant to the origin of life, including the ability to self-assemble into vesicular structures.

Size Dependence of Dust Distribution around the Earth Orbit

NASA Astrophysics Data System (ADS)

Ueda, Takahiro; Kobayashi, Hiroshi; Takeuchi, Taku; Ishihara, Daisuke; Kondo, Toru; Kaneda, Hidehiro

2017-05-01

In the solar system, interplanetary dust particles (IDPs) originating mainly from asteroid collisions and cometary activities drift to Earth orbit due to Poynting-Robertson drag. We analyzed the thermal emission from IDPs that was observed by the first Japanese infrared astronomical satellite, AKARI. The observed surface brightness in the trailing direction of the Earth orbit is 3.7% greater than that in the leading direction in the 9 μm band and 3.0% in the 18 μm band. In order to reveal dust properties causing leading-trailing surface brightness asymmetry, we numerically integrated orbits of the Sun, the Earth, and a dust particle as a restricted three-body problem including radiation from the Sun. The initial orbits of particles are determined according to the orbits of main-belt asteroids or Jupiter-family comets. Orbital trapping in mean motion resonances results in a significant leading-trailing asymmetry so that intermediate sized dust (˜10-100 μm) produces a greater asymmetry than zodiacal light. The leading-trailing surface brightness difference integrated over the size distribution of the asteroidal dust is obtained to be 27.7% and 25.3% in the 9 μm and 18 μm bands, respectively. In contrast, the brightness difference for cometary dust is calculated as 3.6% and 3.1% in the 9 μm and 18 μm bands, respectively, if the maximum dust radius is set to be s max = 3000 μm. Taking into account these values and their errors, we conclude that the contribution of asteroidal dust to the zodiacal infrared emission is less than ˜10%, while cometary dust of the order of 1 mm mainly accounts for the zodiacal light in infrared.

Size Dependence of Dust Distribution around the Earth Orbit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ueda, Takahiro; Takeuchi, Taku; Kobayashi, Hiroshi

In the solar system, interplanetary dust particles (IDPs) originating mainly from asteroid collisions and cometary activities drift to Earth orbit due to Poynting–Robertson drag. We analyzed the thermal emission from IDPs that was observed by the first Japanese infrared astronomical satellite, AKARI . The observed surface brightness in the trailing direction of the Earth orbit is 3.7% greater than that in the leading direction in the 9 μ m band and 3.0% in the 18 μ m band. In order to reveal dust properties causing leading–trailing surface brightness asymmetry, we numerically integrated orbits of the Sun, the Earth, and amore » dust particle as a restricted three-body problem including radiation from the Sun. The initial orbits of particles are determined according to the orbits of main-belt asteroids or Jupiter-family comets. Orbital trapping in mean motion resonances results in a significant leading–trailing asymmetry so that intermediate sized dust (∼10–100 μ m) produces a greater asymmetry than zodiacal light. The leading–trailing surface brightness difference integrated over the size distribution of the asteroidal dust is obtained to be 27.7% and 25.3% in the 9 μ m and 18 μ m bands, respectively. In contrast, the brightness difference for cometary dust is calculated as 3.6% and 3.1% in the 9 μ m and 18 μ m bands, respectively, if the maximum dust radius is set to be s {sub max} = 3000 μ m. Taking into account these values and their errors, we conclude that the contribution of asteroidal dust to the zodiacal infrared emission is less than ∼10%, while cometary dust of the order of 1 mm mainly accounts for the zodiacal light in infrared.« less

Cda Science Today and in Cassini's Final Three Years

NASA Astrophysics Data System (ADS)

Srama, R.

2014-12-01

Today, the German-lead Cosmic Dust Analyser (CDA) is operated continuously for 10 years in orbit around Saturn. The first discovery of CDA related to Saturn was the measurement of nanometer sized dust particles ejected by to interplanetary space with speeds higher than 100 km/s. Their origin and composition was analysed and and their dynamical studies showed a strong link to the conditions of the solar wind plasma flow. A recent surprising result was, that stream particles stem from the interior of Enceladus. Since 2004 CDA measured millions of dust impacts characterizing the dust environment of Saturn. The instrument showed strong evidence for ice geysers located at the south pole of Saturn's moon Enceladus in 2005. Later, a detailed compositional analysis of the salt-rich water ice grains in Saturn's E ring system lead to the discovery of liquid water below the icy crust connected to an ocean at depth feeding the icy jets. CDA was even capable to derive a spatially resolved compositional profile of the plume during close Enceladus flybys. A determination of the dust-magnetosphere interaction and the discovery of the extended E ring allowed the definition of a dynamical dust model of Saturn's E ring describing the observed properties. The measured dust density profiles in the dense E ring revealed geometric asymmetries.In the final three years CDA performs exogenous and interstellar dust campaigns, studies of the composition and origin of Saturn's main rings by unique ring ejecta measurements, long-duration nano-dust stream observations, high-resolution maps of small moon orbit crossings, studies of the dust cloud around Dione and studies of the E-ring interaction with the large moon Titan.

Searching for Biosignatures in Exoplanetary Impact Ejecta.

PubMed

Cataldi, Gianni; Brandeker, Alexis; Thébault, Philippe; Singer, Kelsi; Ahmed, Engy; de Vries, Bernard L; Neubeck, Anna; Olofsson, Göran

2017-08-01

With the number of confirmed rocky exoplanets increasing steadily, their characterization and the search for exoplanetary biospheres are becoming increasingly urgent issues in astrobiology. To date, most efforts have concentrated on the study of exoplanetary atmospheres. Instead, we aim to investigate the possibility of characterizing an exoplanet (in terms of habitability, geology, presence of life, etc.) by studying material ejected from the surface during an impact event. For a number of impact scenarios, we estimate the escaping mass and assess its subsequent collisional evolution in a circumstellar orbit, assuming a Sun-like host star. We calculate the fractional luminosity of the dust as a function of time after the impact event and study its detectability with current and future instrumentation. We consider the possibility to constrain the dust composition, giving information on the geology or the presence of a biosphere. As examples, we investigate whether calcite, silica, or ejected microorganisms could be detected. For a 20 km diameter impactor, we find that the dust mass escaping the exoplanet is roughly comparable to the zodiacal dust, depending on the exoplanet's size. The collisional evolution is best modeled by considering two independent dust populations, a spalled population consisting of nonmelted ejecta evolving on timescales of millions of years, and dust recondensed from melt or vapor evolving on much shorter timescales. While the presence of dust can potentially be inferred with current telescopes, studying its composition requires advanced instrumentation not yet available. The direct detection of biological matter turns out to be extremely challenging. Despite considerable difficulties (small dust masses, noise such as exozodiacal dust, etc.), studying dusty material ejected from an exoplanetary surface might become an interesting complement to atmospheric studies in the future. Key Words: Biosignatures-Exoplanets-Impacts-Interplanetary dust-Remote sensing. Astrobiology 17, 721-746.

COBE'S INFRARED VIEW OF THE UNIVERSE

NASA Technical Reports Server (NTRS)

2002-01-01

These three pictures are maps of the full sky as seen in infrared light. The top two are composite images taken in wavelengths of 60, 100, and 240 micrometers. The 60-micrometer brightness is shown in blue, the 100- micrometer brightness in green, and the 240-micrometer brightness in red. The bottom image shows just the 240-micrometer brightness after foreground light from the solar system and Galaxy has been removed. The images were compiled from data taken between December 1989 and September 1990 by the Diffuse Infrared Background Experiment (DIRBE) on board NASA's Cosmic Background Explorer (COBE). They illustrate the steps scientists used to find the cosmic infrared background, which is a radiative fossil containing cumulative starlight which now appears in the infrared due to the cosmic redshift and by absorption and re-emission by dust in the universe since the Big Bang. The top picture represents the brightness of the full sky as seen in infrared light. The bright yellow-orange line across the center of the image arises from interstellar dust in the plane of our Milky Way Galaxy, with the center of the Galaxy at the center of the image. The red color above and below this line shows additional wispy clouds of interstellar dust. The blue S-shaped color arises from interplanetary dust in the solar system. The middle picture represents a view of the sky after the foreground glow of the solar system dust has been extracted. This image is dominated by emission from interstellar dust in the Milky Way Galaxy. The two bright objects in the center of the lower right quadrant are nearby galaxies, the Large and Small Magellanic Clouds. After the infrared light from our solar system and galaxy has been removed, what remains is a uniform cosmic infrared background. The line across the center is an artifact from removal of galactic light. The DIRBE team reports detection of this cosmic background light also at 140 micrometers, and has set limits to its brightness at eight other infrared wavelengths from 1.25 to 100 micrometers. Credits: Michael Hauser (Space Telescope Science Institute), the COBE/DIRBE Science Team, and NASA's Office of Space Science

Measuring the level of interstellar inheritance in the solar protoplanetary disk

NASA Astrophysics Data System (ADS)

Alexander, Conel M. O'd.; Nittler, Larry R.; Davidson, Jemma; Ciesla, Fred J.

2017-09-01

The timing and extent to which the initial interstellar material was thermally processed provide fundamental constraints for models of the formation and early evolution of the solar protoplanetary disk. We argue that the nonsolar (solar Δ17O ≈ -29‰) and near-terrestrial (Δ17O ≈ 0‰) O-isotopic compositions of the Earth and most extraterrestrial materials (Moon, Mars, asteroids, and comet dust) were established very early by heating of regions of the disk that were modestly enriched (dust/gas ≥ 5-10 times solar) in primordial silicates (Δ17O ≈ -29‰) and water-dominated ice (Δ17O ≈ 24‰) relative to the gas. Such modest enrichments could be achieved by grain growth and settling of dust to the midplane in regions where the levels of turbulence were modest. The episodic heating of the disk associated with FU Orionis outbursts were the likely causes of this early thermal processing of dust. We also estimate that at the time of accretion the CI chondrite and interplanetary dust particle parent bodies were composed of 5-10% of pristine interstellar material. The matrices of all chondrites included roughly similar interstellar fractions. Whether this interstellar material avoided the thermal processing experienced by most dust during FU Orionis outbursts or was accreted by the disk after the outbursts ceased to be important remains to be established.

The Lunar dusty plasmas -levitation and transport.

NASA Astrophysics Data System (ADS)

Atamaniuk, Barbara; Rothkaehl, Hanna

Lunar dust can exhibit unusual behavior -due to electron photoemission via solar-UV radiation the lunar surface represents a complex plasma -"dusty plasma". The dust grains and lunar surface are electrostatically charged by the Moon's interaction with the local plasma environ-ment and the photoemission of electrons due to solar UV and X-rays. This effect causes the like-charged surface and dust particles to repel each other, and creates a near-surface electric field. Lunar dust must be treated as a dusty plasma. Using analytic (kinetic (Vlasov) and magnetohydrodynamic theory ) and numerical modeling we show physical processes related to levitation and transport dusty plasma on the Moon. These dust grains could affect the lunar environment for radio wave and plasma diagnostics and interfere with exploration activities. References: 1. Wilson T.L. (1992), in Analysis of Interplanetary Dust, M. Zolensky et al. AIP Conf.Proc. 310, 33-44 (AIP, NY), 2.Wilson T.L."LUNAR DUST AND DUSTY PLASMA PHYSICS".40th Lunar and Planetary Science Conference (2009), 3. Grün E., et al.(1993),Nature 363, 144. 4. Morfill G. and Grün E.(1979), Planet. Space Sci.. 27, 1269, 1283, 5. Manka R. and Michel F. (1971), Proc. 2nd Lun. Sci. Conf. 2, 1717 (MIT Press, Cambridge). 6. Manka R. et al.(1973), Lun. Sci.-III, 504. 7. Barbara Atamaniuk "Kinetic Description of Localized Plasma Structure in Dusty Plasmas". Czechoslovak Journal of Physics Vol.54 C 2004

A Global, Multi-Waveband Model for the Zodiacal Cloud

NASA Technical Reports Server (NTRS)

Grogan, Keith; Dermott, Stanley F.; Kehoe, Thomas J. J.

2003-01-01

This recently completed three-year project was undertaken by the PI at the University of Florida, NASA Goddard and JPL, and by the Co-I and Collaborator at the University of Florida. The funding was used to support a continuation of research conducted at the University of Florida over the last decade which focuses on the dynamics of dust particles in the interplanetary environment. The main objectives of this proposal were: To produce improved dynamical models of the zodiacal cloud by performing numerical simulations of the orbital evolution of asteroidal and cometary dust particles. To provide visualizations of the results using our visualization software package, SIMUL, simulating the viewing geometries of IRAS and COBE and comparing the model results with archived data. To use the results to provide a more accurate model of the brightness distribution of the zodiacal cloud than existing empirical models. In addition, our dynamical approach can provide insight into fundamental properties of the cloud, including but not limited to the total mass and surface area of dust, the size-frequency distribution of dust, and the relative contributions of asteroidal and cometary material. The model can also be used to provide constraints on trace signals from other sources, such as dust associated with the "Plutinos" , objects captured in the 2:3 resonance with Neptune.

Pristine Stratospheric Collections of Cosmic Dust

NASA Technical Reports Server (NTRS)

Messenger, S.; Keller, L. P.; Nakamura-Messenger, K.; Clemett, S. J.

2012-01-01

Since 1981, NASA has routinely collected interplanetary dust particles (IDPs) in the stratosphere by inertial impact onto silicone oil-coated flat plate collectors deployed on the wings of high-altitude aircraft [1]. The highly viscous oil traps and localizes the particles, which can fragment during collection. Particles are removed from the collectors with a micromanipulator and washed of the oil using organic solvents, typically hexane or xylene. While silicone oil is an efficient collection medium, its use is problematic. All IDPs are initially coated with this material (polydimethylsiloxane, n(CH3)2SiO) and traces of oil may remain after cleaning. The solvent rinse itself is also a concern as it likely removes indigenous organics from the particles. To avoid these issues, we used a polyurethane foam substrate for the oil-free stratospheric collection of IDPs.

Martian Methane From a Cometary Source: A Hypothesis

NASA Technical Reports Server (NTRS)

Fries, M.; Christou, A.; Archer, D.; Conrad, P.; Cooke, W.; Eigenbrode, J.; ten Kate, I. L.; Matney, M.; Niles, P.; Sykes, M.;

Workshop on Evolution of Martian Volatiles. Part 1

NASA Technical Reports Server (NTRS)

Jakosky, B. (Editor); Treiman, A. (Editor)

1996-01-01

This volume contains papers that were presented on February 12-14, 1996 at the Evolution for Martian Volatiles Workshop. Topics in this volume include: returned Martian samples; acidic volatiles and the Mars soil; solar EUV Radiation; the ancient Mars Thermosphere; primitive methane atmospheres on Earth and Mars; the evolution of Martian water; the role of SO2 for the climate history of Mars; impact crater morphology; the formation of the Martian drainage system; atmospheric dust-water ice Interactions; volatiles and volcanos; accretion of interplanetary dust particles; Mars' ionosphere; simulations with the NASA Ames Mars General Circulation Model; modeling the Martian water cycle; the evolution of Martian atmosphere; isotopic composition; solar occultation; magnetic fields; photochemical weathering; NASA's Mars Surveyor Program; iron formations; measurements of Martian atmospheric water vapor; and the thermal evolution Models of Mars.

Are the stratospheric dust particles meteor ablation debris or interplanetary dust?

NASA Technical Reports Server (NTRS)

Blanchard, M. B.; Kyte, F. T.

1978-01-01

Natural and laboratory created fusion crusts and debris from artificial meteor samples were used to develop criteria for recognizing meteor ablation debris in a collection of 5 to 50 micron particles from the stratosphere. These laboratory studies indicate that meteor ablation debris from nickel-iron meteoroids produce spherules containing taenite, wuestite, magnetite, and hematite. These same studies also indicate that ablation debris from chondritic meteoroids produce spheres and fragmentary debris. The spheres may be either silicate rich, containing zoned olivine, magnetite, and glass, or sulfide rich, containing iron oxides (e.g., magnetite, wuestite) and iron sulfides (e.g., pyrrhotite, pentlandite). The fragmentary debris may be either fine-grained aggregates of olivine, magnetite, pyroxene, and occasionally pyrrhotite (derived from the meteorite matrix) or individual olivine and pyroxene grains (derived from meteorite inclusions).

Long-term microparticle flux variability indicated by comparison of Interplanetary Dust Experiment (IDE) timed impacts for LDEF's first year in orbit with impact data for the entire 5.77-year orbital lifetime

NASA Technical Reports Server (NTRS)

Simon, Charles G.; Mulholland, J. Derral; Oliver, John P.; Cooke, William J.; Kassel, Philip C., Jr.

1993-01-01

The electronic sensors of the Interplanetary Dust Experiment (IDE) recorded precise impact times and approximate directions for submicron to approximately 100 micron size particles on all six primary sides of the spacecraft for the first 346 days of the LDEF orbital mission. Previously-reported analyses of the timed impact data have established their spatio-temporal features, including the demonstration that a preponderance of the particles in this regime are orbital debris and that a large fraction of the debris particles are encountered in megameter-size clouds. Short-term fluxes within such clouds can rise several orders of magnitude above the long-term average. These unexpectedly large short-term variations in debris flux raise the question of how representative an indication of the multi-year average flux is given by the nearly one year of timed data. One of the goals of the IDE was to conduct an optical survey of impact sites on detectors that remained active during the entire LDEF mission, to obtain full-mission fluxes. We present here the comparisons and contrasts among the new IDE optical survey impact data, the IDE first-year timed impact data, and impact data from other LDEF micrometeoroid and debris experiments. The following observations are reported: (1) the 5.77 year long-term integrated microparticle impact fluxes recorded by IDE detectors matched the integrated impact fluxes measured by other LDEF investigators for the same period; (2) IDE integrated microparticle impact fluxes varied by factors from 0.5 to 8.3 for LDEF days 1-346, 347-2106 and 1-2106 (5.77 years) on rows 3 (trailing edge, or West), 6 (South side), 12 (North side), and the Earth and Space ends; and (3) IDE integrated microparticle impact fluxes varied less than 3 percent for LDEF days 1-346, 347-2106 and 1-2106 (5.77 years) on row 9 (leading edge, or East). These results give further evidence of the accuracy and internal consistency of the recorded IDE impact data. This leads to the further conclusion that the utility of long-term ratios for impacts on various sides of a stabilized satellite in low Earth orbit (LEO) is extremely limited. These observations and their consequences highlight the need for continuous, real time monitoring of the dynamic microparticle environment in LEO.

Preliminary Examination of the Interstellar Collector of Stardust

NASA Technical Reports Server (NTRS)

Westphal, A. J.; Allen, C.; Bastien, R.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Butterworth, A. L.; Floss, C.; Flynn, G.;

Dust Analyzer Instrument (DANTE) for the detection and elemental analysis of dust particles originating from the inner heliosphere

NASA Astrophysics Data System (ADS)

Sternovsky, Z.; O'brien, L.; Gruen, E.; Horanyi, M.; Malaspina, D.; Moebius, E.; Rocha, J. R. R.

2016-12-01

Nano- to sub-micron-size dust particles generated by the collisional breakup of interplanetary dust particles (IDPs) in the inner solar system can be accelerated away from the Sun and are available for detection and analysis near 1 AU. Beta-meteoroids are sub-micron sized particles for which the radiation pressure dominates over gravity and have already been detected by dedicated dust instrument. Charged nano-sized dust particles are picked up by the expanding solar wind and arrive to 1 AU with high velocity. The recent observations by the WAVE instrument on the two STEREO spacecraft indicated that these particles may exist in large numbers. The Dust Analyzer Instrument (DANTE) is specifically developed to detect and analyze these two populations of dust particles arriving from a direction close to the Sun. DANTE is a linear time-of-flight (ToF) mass spectrometer analyzing the ions generated by the dust impact on a target surface. DANTE is derived from the Cosmic Dust Analyzer instrument operating on Cassini. DANTE has a 300 cm2 target area and a mass resolution of approximately m/dm = 50. The instrument performance has been verified using the dust accelerator facility operating at the University of Colorado. A light trap system, consisting of optical baffles, is designed and optimized in terms of geometry and surface optical properties. A solar wind ion repeller system is included to prevent solar wind from entering the sensor. Both measures facilitate the detection with the instrument pointing close to the Sun's direction. The DANTE measurements will help to understand the sources, sinks and distribution of dust between the Sun and 1 AU, and, when combined with solar wind ion analyzer instrument, they will provide insight on the suspected link between dust particles and pickup ions, and how the massive particles affect the dynamics and energetics of the solar wind.

15N Fractionation in Star-Forming Regions and Solar System Objects

NASA Technical Reports Server (NTRS)

Wirstrom, Eva; Milam, Stefanie; Adande, GIlles; Charnley, Steven; Cordiner, Martin

2015-01-01

A central issue for understanding the formation and evolution of matter in the early Solar System is the relationship between the chemical composition of star-forming interstellar clouds and that of primitive Solar System materials. The pristinemolecular content of comets, interplanetary dust particles and carbonaceous chondrites show significant bulk nitrogen isotopic fractionation relative to the solar value, 14N15N 440. In addition, high spatial resolution measurements in primitive materials locally show even more extreme enhancements of 14N15N 100.

Prebiotic chemistry in space; Proceedings of Symposia B1.4 and F3.3 of the COSPAR Scientific Assembly, 30th, Hamburg, Germany, July 11-21, 1994

NASA Technical Reports Server (NTRS)

1994-01-01

A two-part symposium was held concerning topics in Solar System chemistry. The first part covered the organic chemistry ofsmall bodies of the interplanetray medium. It produced papers on the evolution, spectral properties and composition of organic matter in comets, interplanetary dust and asteroids. The second part covered cryochemistry and exobiology in planetary atmospheres (gas giant planets and their satellites) and in various astronomical ices.

Editorial

NASA Astrophysics Data System (ADS)

Koschny, Detlef; Borovička, Jiří; Janches, Diego; Willliams, Iwan P.

2017-09-01

This Special Issue is the first of two volumes summarizing papers from the Meteoroids 2016 conference, held at ESTEC in the Netherlands from 06 to 10 June 2016. The 'Meteoroids' conference is held every three years and it is the main conference organized by the IAU Commission F1 (Meteors, Meteorites, and Interplanetary Dust). The 2016 conference was the 9th of the series and it brought together over 140 meteor astronomers, both professional and amateurs, who gave a total of 81 presentations and 65 posters of all areas of meteor physics.

Mineralogy of chondritic interplanetary dust particle impact residues from LDEF

NASA Technical Reports Server (NTRS)

Barrett, R. A.; Zolensky, M. E.; Bernhard, R.

1993-01-01

A detailed structural and compositional analysis of several impactor residues was performed utilizing transmission electron microscopy, energy dispersive spectroscopy, and electron diffraction. Residues from the interior of several craters in gold surfaces were removed with a tungsten needle, mounted in EMBED-812 epoxy, and ultramicrotomed. The presence in these residues of equilibrated ferromagnesian minerals, recrystallization textures, glass, and melted metal and sulfide bodies decorating grain boundaries is indicative of varying degrees of shock metamorphism in all impact residues we have characterized.

Remote sensing of dust in the Solar system and beyond using wavelength dependence of polarization

NASA Astrophysics Data System (ADS)

Kolokolova, L.

2011-12-01

For a long time, the main polarimetric tool to study dust in the Solar system has been the dependence of polarization on phase (scattering) angle. Surprisingly, a variety of cosmic dusts (interplanetary and cometary dust, dust on the surfaces of asteroids and in debris disks) possesses a very similar phase dependence of polarization with a negative bowl-shaped part at small phase angles and a positive bell-shaped region with maximum polarization around 95-105 deg. Numerous laboratory and theoretical simulations showed that a polarimetric phase curve of this shape is typical for fluffy materials, e.g., porous, aggregated particles. By contrast, the wavelength dependence of polarization is different for different types of dust. In the visual, polarization decreases with wavelength (negative gradient) for asteroids and interplanetary dust, but usually increases with wavelength (positive gradient) for cometary dust. In debris disks both signs of the spectral gradient of polarization have been found. Moreover, it was found that a cometary positive spectral gradient can change to a negative one as observations move to longer (near-infrared) wavelengths (Kelley et al. AJ, 127, 2398, 2004) and some comets(Kiselev et al. JQSRT, 109, 1384, 2008) have negative gradient even in the visible. The diversity of the spectral dependence of polarization therefore gives us hope that it can be used for characterization of the aggregates that represent different types of cosmic dust. To accomplish this, the physics behind the spectral dependence of polarization need to be revealed. Our recent study shows that the spectral dependence of polarization depends on the strength of electromagnetic interaction between the monomers in aggregates. The strength of the interaction mainly depends on how many monomers the electromagnetic wave covers on the light path equal to one wavelength. Since the electromagnetic interaction depolarizes the light, the more particles a single wavelength covers the smaller is the polarization of the scattered light. Thus, at a given monomer size the polarization decreases as wavelength increases resulting in the negative spectral gradient of polarization. However, this tendency occurs only for rather compact aggregates. For porous particles, an increase of wavelength may not increase the number of the covered monomers. In this case, polarization increases with wavelength as a result of decreasing monomer's size parameter. We performed computer modeling of light scattering by aggregates of different porosity using MSTM (multisphere T-matrix) code by D. Mackowski (see http://eng.auburn.edu/users/dmckwski/scatcodes/). The results show that for each porosity a critical wavelength exists at which the spectral gradient of polarization changes from positive to negative. The electromagnetic interaction is also stronger for more transparent materials which in turn affects the value of the critical wavelength. Thus, measurements of polarization over a broad range of wavelength can be a powerful tool to study the porosity and composition of dust in a variety of cosmic environments, especially when detailed phase dependence of polarization cannot be established (e.g. for TNO and other distant objects).

Dynamics of aspherical dust grains in a cometary atmosphere: I. axially symmetric grains in a spherically symmetric atmosphere

NASA Astrophysics Data System (ADS)

Ivanovski, S. L.; Zakharov, V. V.; Della Corte, V.; Crifo, J.-F.; Rotundi, A.; Fulle, M.

2017-01-01

In-situ measurements of individual dust grain parameters in the immediate vicinity of a cometary nucleus are being carried by the Rosetta spacecraft at comet 67P/Churyumov-Gerasimenko. For the interpretations of these observational data, a model of dust grain motion as realistic as possible is requested. In particular, the results of the Stardust mission and analysis of samples of interplanetary dust have shown that these particles are highly aspherical, which should be taken into account in any credible model. The aim of the present work is to study the dynamics of ellipsoidal shape particles with various aspect ratios introduced in a spherically symmetric expanding gas flow and to reveal the possible differences in dynamics between spherical and aspherical particles. Their translational and rotational motion under influence of the gravity and of the aerodynamic force and torque is numerically integrated in a wide range of physical parameters values including those of comet 67P/Churyumov-Gerasimenko. The main distinctions of the dynamics of spherical and ellipsoidal particles are discussed. The aerodynamic characteristics of the ellipsoidal particles, and examples of their translational and rotational motion in the postulated gas flow are presented.

Carbonaceous Components in the Comet Halley Dust

NASA Technical Reports Server (NTRS)

Fomenkova, M. N.; Chang, S.; Mukhin, L. M.

1994-01-01

Cometary grains containing large amounts of carbon and/or organic matter (CHON) were discovered by in situ measurements of comet Halley dust composition during VEGA and GIOTTO flyby missions. In this paper, we report the classification of these cometary, grains by means of cluster analysis, discuss the resulting compositional groups, and compare them with substances observed or hypothesized in meteorites, interplanetary dust particles, and the interstellar medium. Grains dominated by carbon and/or organic matter (CHON grains) represent approx. 22% of the total population of measured cometary dust particles. They, usually contain a minor abundance of rock-forming elements as well. Grains having organic material are relatively more abundant in the vicinity of the nucleus than in the outer regions of the coma, which suggests decomposition of the organics in the coma environment. The majority of comet Halley organic particles are multicomponent mixtures of carbon phases and organic compounds. Possibly, the cometary CHON grains may be related to kerogen material of an interstellar origin in carbonaceous meteorites. Pure carbon grains, hydrocarbons and polymers of cyanopolyynes, and multi-carbon monoxides are present in cometary dust as compositionally simple and distinctive components among a variety of others. There is no clear evidence of significant presence of pure formaldehyde or HCN polymers in Halley dust particles. The diversity of types of cometary organic compounds is consistent with the inter-stellar dust model of comets and probably reflects differences in composition of precursor dust. Preservation of this heterogeneity among submicron particles suggest the gentle formation of cometary, nucleus by aggregation of interstellar dust in the protosolar nebula without complete mixing or chemical homogenization at the submicron level.

A Secondary Ion Mass Analyzer for Remote Surface Composition Analysis of the Galilean Moons

NASA Technical Reports Server (NTRS)

Krueger, H.; Srama, R.; Johnson, T. V.; Henkel, H.; vonHoerner, H.; Koch, A.; Horanyi, M.; Gruen, E.; Kissel, J.; Krueger, F.

2003-01-01

Galileo in-situ dust measurements have shown that the Galilean moons are surrounded by tenuous dust clouds formed by collisional ejecta from their icy surfaces, kicked up by impacts of interplanetary micrometeoroids. The majority of the ejecta dust particles have been sensed at altitudes below five between 0.5 and 1 micron, just above the detector threshold, indicating a size distribution decreasing towards bigger particles. their parent bodies. They carry information about the properties of the surface from which they have been kicked up. In particular, these grains may carry organic compounds and other chemicals of biological relevance if they exist on the icy Galilean moons. In-situ analysis of the grain composition with a sophisticated dust analyzer instrument flying on a Jupiter Icy Moons Orbiter can provide important information about geochemical and geophysical processes during the evolutionary histories of these moons which are not accessible with other techniques from an orbiter spacecraft. Thus, spacecraft-based in-situ dust measurements can be used as a diagnostic tool for the analysis of the surface composition of the moons. This way, the in-situ measurements turn into a remote sensing technique by using the dust instrument like a telescope for surface investigation. An instrument capable of very high resolution composition analysis of dust particles is the Cometary Secondary Ion Mass Analyzer (COSIMA). The instrument was originally developed for the Comet Rendezvous and Asteroid Flyby (CRAF) mission and has now been built for ESA'S comet orbiter Rosetta. Dust particles are collected on a target and are later located by an optical microscope camera. A pulsed primary indium ion gun partially ionizes the dust grains. The generated secondary ions are accelerated in an electric field and travel through a reflectron-type time-of-flight ion mass spectrometer.

Reexamination of data from the asteroid/meteoroid detector

NASA Technical Reports Server (NTRS)

Soberman, Robert K.; Dubin, Maurice

1990-01-01

A reexamination of the results of the Pioneer 10 and 11 Asteroid Meteoroid Detector, or Sisyphus, was carried out in the light of a recently derived theory characterizing interplanetary matter and the Zodiacal Light (ZL). Sisyphus measured individual meteoroids from reflected sunlight and ZL between meteoroid events. The results were questioned because meteoroid orbits could not be calculated as intended and the ZL as computed from individual meteoroids did not agree with values determined from the ZL mode and from the other ZL sensor on the spacecraft. It is first shown that, independent of any explanation, the measurements are, with high probability, valid and strongly correlated with the ZL. The model which explains the strange behavior of the Sisyphus instrument also resolves the enigma why the three dust experiments on the Pioneer 10 and 11 spacecraft produced extreme disparate results for the distribution and orbits of meteoric particles and the ZL. The theory based primarily on these measurements requires a population in the inner solar system of cold meteoroid material composed mainly of volatile molecules. These meteoroids in orbits of high eccentricity are called cosmoids. They are impulsively disrupted from solar heating, resulting in order of magnitude increases in optical cross section. The dispersed particles, predominantly micron sized, scatter most of the ZL and supply the polarization. The sublimation time in sunlight for micron sized particles of volatile composition opposes the gravitational flux increase expected in approaching the sun. The other two Pioneer 10/11 dust experiments were: the Imaging Photopolarimeter for the ZL, and the Meteoroid Detection Experiment that measured penetration of 25 micron (Pioneer 10) and 50 micron (Pioneer 11) thick walls of pressurized gas cells.

The role of Mab as a source for the μ ring of Uranus

NASA Astrophysics Data System (ADS)

Sfair, R.; Giuliatti Winter, S. M.

2012-07-01

Context. We previously analysed how the solar radiation force combined with the planetary oblateness changes the orbital evolution of a sample of dust particles located at the secondary ring system of Uranus. Both effects combined with the gravitational perturbations of the close satellites lead to the depletion of these dust particles through collisions on the surfaces of these satellites on a timescale of hundreds of years. Aims: In this work we investigate if the impacts of interplanetary dust particles (IDPs) onto Mab's surface can produce sufficient particles to replenish the μ ring population. Methods: We first analysed through numerical simulations the evolution of a sample of particles ejected from the surface of Mab and computed the lifetime of the grains when the effects of the solar radiation pressure and the planetary oblateness are taken into account. Then we estimated the mass production rate due to the impacts of IDPs following a previously established algorithm, and used this value to determine the time necessary to accumulate an amount of particles comparable with the mass of the μ ring. Results: Based on an estimate of the flux of interplanetary particles and on the surface properties of Mab it is expected that the satellite supplies material to the ring at a rate of ~3 g/s. Meanwhile, our numerical model showed that the ejected particles are removed from the system through collisions with the satellite, and the mean lifetime of the grains may vary from 320 to 1500 years, depending on the radius of the particle. Conclusions: The time necessary to accumulate the mass of the μ ring via ejection from Mab is much shorter than the mean lifetime of the particles, and a stationary regime is not reached. If the ring is kept in a steady state, other effects such as the electromagnetic force and/or the existence of additional bodies may play a significant role in the dust balance, but the current lack of information about the environment renders modelling these effects unfeasible.

Survivability of Psychrobacter cryohalolentis K5 Under Simulated Martian Surface Conditions

NASA Technical Reports Server (NTRS)

Smith, David J.; Schuerger, Andrew C.; Davidson, Mark M.; Pacala, Stephen W.; Bakermans, Corien; Onstott, Tullis

2008-01-01

Spacecraft launched to Mars can retain viable terrestrial microorganisms on board that may survive the interplanetary transit. Such biota might compromise the search for life beyond Earth if capable of propagating on Mars. The current study explored the survivability of Psychrobacter cryohalolentis K5, a psychrotolerant microorganism obtained from a Siberian permafrost cryopeg, under simulated martian surface conditions of high ultraviolet irradiation, high desiccation, low temperature, and low atmospheric pressure. First, a desiccation experiment compared the survival of P. cryohalolentis cells embedded, or not embedded, within a medium/salt matrix (MSM) maintained at 25 degrees C for 24 hr within a laminar flow hood. Results indicate that the presence of the MSM enhanced survival of the bacterial cells by 1 to 3 orders of magnitude. Second, tests were conducted in a Mars Simulation Chamber to determine the UV tolerance of the microorganism. No viable vegetative cells of P. cryohalolentis were detected after 8 hr of exposure to Mars-normal conditions of 4.55 W/m(2) UVC irradiation (200-280 nm), -12.5 degrees C, 7.1 mbar, and a Mars gas mix composed of CO2 (95.3%), N2 (2.7%), Ar (1.6%), O2 (0.2%), and H(2)O (0.03%). Third, an experiment was conducted within the Mars chamber in which total atmospheric opacities were simulated at tau = 0.1 (dust-free CO2 atmosphere at 7.1 mbar), 0.5 (normal clear sky with 0.4 = dust opacity and 0.1 = CO2-only opacity), and 3.5 (global dust storm) to determine the survivability of P. cryohalolentis to partially shielded UVC radiation. The survivability of the bacterium increased with the level of UVC attenuation, though population levels still declined several orders of magnitude compared to UVC-absent controls over an 8 hr exposure period.

Survivability of Psychrobacter cryohalolentis K5 Under Simulated Martian Surface Conditions

NASA Astrophysics Data System (ADS)

Smith, David J.; Schuerger, Andrew C.; Davidson, Mark M.; Pacala, Stephen W.; Bakermans, Corien; Onstott, Tullis C.

2009-03-01

Spacecraft launched to Mars can retain viable terrestrial microorganisms on board that may survive the interplanetary transit. Such biota might compromise the search for life beyond Earth if capable of propagating on Mars. The current study explored the survivability of Psychrobacter cryohalolentis K5, a psychrotolerant microorganism obtained from a Siberian permafrost cryopeg, under simulated martian surface conditions of high ultraviolet irradiation, high desiccation, low temperature, and low atmospheric pressure. First, a desiccation experiment compared the survival of P. cryohalolentis cells embedded, or not embedded, within a medium/salt matrix (MSM) maintained at 25°C for 24 h within a laminar flow hood. Results indicate that the presence of the MSM enhanced survival of the bacterial cells by 1 to 3 orders of magnitude. Second, tests were conducted in a Mars Simulation Chamber to determine the UV tolerance of the microorganism. No viable vegetative cells of P. cryohalolentis were detected after 8 h of exposure to Mars-normal conditions of 4.55 W/m2 UVC irradiation (200-280 nm), -12.5°C, 7.1 mbar, and a Mars gas mix composed of CO2 (95.3%), N2 (2.7%), Ar (1.6%), O2 (0.2%), and H2O (0.03%). Third, an experiment was conducted within the Mars chamber in which total atmospheric opacities were simulated at τ = 0.1 (dust-free CO2 atmosphere at 7.1 mbar), 0.5 (normal clear sky with 0.4 = dust opacity and 0.1 = CO2-only opacity), and 3.5 (global dust storm) to determine the survivability of P. cryohalolentis to partially shielded UVC radiation. The survivability of the bacterium increased with the level of UVC attenuation, though population levels still declined several orders of magnitude compared to UVC-absent controls over an 8 h exposure period.

Titanium carbide and titania phases on Antarctic ice particles of probable extraterrrestrial origin

NASA Technical Reports Server (NTRS)

Zolensky, M. E.; Pun, A.; Thomas, K. L.

1989-01-01

Two unique titania-rich particles, found within ancient Antarctic ice have been discovered and characterized, and are believed to be of extraterrestrial origin. Both particles contain abundant submicron-sized crystals of Magneli phases (Ti(n)O(2n-1). In addition, one particle contains a core of TiC. Whereas the Magneli phases would have been stable in the early solar nebula, and so probably formed there, the TiC is more likely to have condensed in the cool, dusty, carbon-rich outer shell of a red giant star. It is suggested that both particles are interplanetary dust particles whose Magneli phases carry a record of the PO2-T conditions of the early solar nebula. It is further suggested that the TiC grain in particle 705 is remnant interstellar dust.

Creation of fully vectorized FORTRAN code for integrating the movement of dust grains in interplanetary environments

NASA Technical Reports Server (NTRS)

Colquitt, Walter

1989-01-01

The main objective is to improve the performance of a specific FORTRAN computer code from the Planetary Sciences Division of NASA/Johnson Space Center when used on a modern vectorizing supercomputer. The code is used to calculate orbits of dust grains that separate from comets and asteroids. This code accounts for influences of the sun and 8 planets (neglecting Pluto), solar wind, and solar light pressure including Poynting-Robertson drag. Calculations allow one to study the motion of these particles as they are influenced by the Earth or one of the other planets. Some of these particles become trapped just beyond the Earth for long periods of time. These integer period resonances vary from 3 orbits of the Earth and 2 orbits of the particles to as high as 14 to 13.

Search for Primitive Matter in the Solar System

NASA Technical Reports Server (NTRS)

Libourel, G.; Michel, P.; Delbo, M.; Ganino, C.; Recio-Blanco, A.; de Laverny, P.; Zolensky, M. E.; Krot, A. N.

2017-01-01

Recent astronomical observations and theoretical modeling led to a consensus regarding the global scenario of the formation of young stellar objects (YSO) from a cold molecular cloud of interstellar dust (organics and minerals) and gas that, in some cases, leads to the formation of a planetary system. In the case of our Solar System, which has already evolved for approximately 4567 Ma, the quest is to access, through the investigation of planets, moons, cometary and asteroidal bodies, meteorites, micrometeorites, and interplanetary dust particles, the primitive material that contains the key information about the early Solar System processes and its evolution. However, laboratory analyses of extraterrestrial samples, astronomical observations and dynamical models of the Solar System evolution have not brought yet any conclusive evidence on the nature and location of primitive matter in the Solar System, preventing a clear understanding of its early stages.

Discovery of Suprathermal Ionospheric Origin Fe+ in and Near Earth's Magnetosphere

NASA Astrophysics Data System (ADS)

Christon, S. P.; Hamilton, D. C.; Plane, J. M. C.; Mitchell, D. G.; Grebowsky, J. M.; Spjeldvik, W. N.; Nylund, S. R.

2017-11-01

Suprathermal (87-212 keV/e) singly charged iron, Fe+, has been discovered in and near Earth's 9-30 RE equatorial magnetosphere using 21 years of Geotail STICS (suprathermal ion composition spectrometer) data. Its detection is enhanced during higher geomagnetic and solar activity levels. Fe+, rare compared to dominant suprathermal solar wind and ionospheric origin heavy ions, might derive from one or all three candidate lower-energy sources: (a) ionospheric outflow of Fe+ escaped from ion layers near 100 km altitude, (b) charge exchange of nominal solar wind iron, Fe+≥7, in Earth's exosphere, or (c) inner source pickup Fe+ carried by the solar wind, likely formed by solar wind Fe interaction with near-Sun interplanetary dust particles. Earth's semipermanent ionospheric Fe+ layers derive from tons of interplanetary dust particles entering Earth's atmosphere daily, and Fe+ scattered from these layers is observed up to 1000 km altitude, likely escaping in strong ionospheric outflows. Using 26% of STICS's magnetosphere-dominated data when possible Fe+2 ions are not masked by other ions, we demonstrate that solar wind Fe charge exchange secondaries are not an obvious Fe+ source. Contemporaneous Earth flyby and cruise data from charge-energy-mass spectrometer on the Cassini spacecraft, a functionally identical instrument, show that inner source pickup Fe+ is likely not important at suprathermal energies. Consequently, we suggest that ionospheric Fe+ constitutes at least a significant portion of Earth's suprathermal Fe+, comparable to the situation at Saturn where suprathermal Fe+ is also likely of ionospheric origin.

The Age of Saturn's Rings Constrained by the Meteoroid Flux Into the System

NASA Astrophysics Data System (ADS)

Kempf, S.; Altobelli, N.; Srama, R.; Cuzzi, J. N.; Estrada, P. R.

2017-12-01

The origin of Saturn's ring is still not known. There is an ongoing argument whether Saturn's ring are rather young or have been formed shortly after Saturn together with its satellites. The water-ice rings contain about 5% rocky material resulting from continuous meteoroid bombardment of the ring material with interplanetary micrometeoroids. Knowledge of the incoming mass flux would allow to estimate the ring's exposure time. Model calculations suggest exposure times of 108 years implying a late ring formation. This scenario is problematic because the tidal disruption of a Mimas-sized moon or of a comet within the planet's Roche zone would lead to a much larger rock content as observed today. Here we report on the measurement of the meteoroid mass flux into the Saturnian system obtained by the charge-sensitive entrance grid system (QP) of the Cosmic Dust Analyser (CDA) on the Cassini spacecraft. Interplanetary dust particles (IDPs) entering Saturn's sphere of gravitational influence are identified through the measurements of their speed vectors. We analyzed the full CDA data set acquired after Cassini's arrival at Saturn in 2004, identified the impact speed vectors of 128 extrinsic micrometeoroids ≥ 2 μm, and determined their orbital elements. On the basis of these measurements we determined the mass flux into the Saturnian system. Our preliminary findings are in support of an old ring. The knowledge of the meteoroids orbital elements allows us for the first time to characterize the meteoroid environment in the outer solar system based on direct measurements.

Physics of interplanetary dust capture via impact into organic polymer foams

NASA Technical Reports Server (NTRS)

Anderson, William W.; Ahrens, Thomas J.

1994-01-01

The physics of hypervelocity impacts into foams is of interest because of the possible application to interplanetary dust particle (IDP) capture by spacecraft. We present a model for the phenomena occurring in such impacts into low-density organic polymer foams. Particles smaller than foam cells behave as if the foam is a series of solid slabs and are fragmented and, at higher velocities, thermally altered. Particles much larger than the foam cells behave as if the foam were a continuum, allowing the use of a continuum mechanics model to describe the effects of drag and ablation. Fragmentation is expected to be a major process, especially for aggregates of small grains. Calculations based on these arguments accurately predict experimental data and, for hypothetical IDPs, indicate that recovery of organic materials will be low for encounter velocities greater than 5 km/s. For an organic particle 100 micrometers in diameter, approx. 35% of the original mass would be collected in an impact at 5 km/s, dropping to approx. 10% at 10 km/s and approx. 0% at 15 km/s. For the same velocities the recovery ratios for troilite (FeS) are approx. 95%, 65%, and 50%, and for olivine (Mg2SiO4) they are approx. 98%, 80%, and 65%, demonstrating that inorganic materials are much more easily collected. The density of the collector material has only a second-order effect, changing the recovered mass by less than 10% of the original mass.

Water and organics in interplanetary dust particles

NASA Astrophysics Data System (ADS)

Bradley, John

Interplanetary dust particles (IDPs) and larger micrometeorites (MMs) impinge on the upper atmosphere where they decelerate at 90 km altitude and settle to the Earths surface. Comets and asteroids are the major sources and the flux, 30,000-40,000 tons/yr, is comparable to the mass of larger meteorites impacting the Earths surface. The sedimentary record suggests that the flux was much higher on the early Earth. The chondritic porous (CP) subset of IDPs together with their larger counterparts, ultracarbonaceous micrometeorites (UCMMs), appear to be unique among known meteoritic materials in that they are composed almost exclusively of anhydrous minerals, some of them contain >> 50% organic carbon by volume as well as the highest abundances of presolar silicate grains including GEMS. D/H and 15N abundances implicate the Oort Cloud or presolar molecular cloud as likely sources of the organic carbon. Prior to atmospheric entry, IDPs and MMs spend 104-105 year lifetimes in solar orbit where their surfaces develop amorphous space weathered rims from exposure to the solar wind (SW). Similar rims are observed on lunar soil grains and on asteroid Itokawa regolith grains. Using valence electron energy-loss spectroscopy (VEELS) we have detected radiolytic water in the rims on IDPs formed by the interaction of solar wind protons with oxygen in silicate minerals. Therefore, IDPs and MMs continuously deliver both water and organics to the earth and other terrestrial planets. The interaction of protons with oxygen-rich minerals to form water is a universal process.

Fullerenes and interplanetary dust at the Permian-Triassic boundary.

PubMed

Poreda, Robert J; Becker, Luann

2003-01-01

We recently presented new evidence that an impact occurred approximately 250 million years ago at the Permian-Triassic boundary (PTB), triggering the most severe mass extinction in the history of life on Earth. We used a new extraterrestrial tracer, fullerene, a third carbon carrier of noble gases besides diamond and graphite. By exploiting the unique properties of this molecule to trap noble gases inside of its caged structure (helium, neon, argon), the origin of the fullerenes can be determined. Here, we present new evidence for fullerenes with extraterrestrial noble gases in the PTB at Graphite Peak, Antarctica, similar to PTB fullerenes from Meishan, China and Sasayama, Japan. In addition, we isolated a (3)He-rich magnetic carrier phase in three fractions from the Graphite Peak section. The noble gases in this magnetic fraction were similar to zero-age deep-sea interplanetary dust particles (IDPs) and some magnetic grains isolated from the Cretaceous-Tertiary boundary. The helium and neon isotopic compositions for both the bulk Graphite Peak sediments and an isolated magnetic fraction from the bulk material are consistent with solar-type gases measured in zero-age deep-sea sediments and point to a common source, namely, the flux of IDPs to the Earth's surface. In this instance, the IDP noble gas signature for the bulk sediment can be uniquely decoupled from fullerene, demonstrating that two separate tracers are present (direct flux of IDPs for (3)He vs. giant impact for fullerene).

Formation of Meteoritic Organic Molecules by Aqueous Alteration of Interstellar Carbonaceous Materials: a Laboratory Model

NASA Astrophysics Data System (ADS)

Saperstein, E.; Arnoult, K. M.; Wdowiak, T. J.; Gerakines, P. A.

2002-09-01

Polycyclic aromatic hydrocarbons (PAHs) have been proposed as a component of interstellar dust. PAHs have also been positively identified in interplanetary dust particles (IDPs) and in carbonaceous meteorites. Many such meteorites show strong evidence for aqueous alteration of their mineral phases, which can be spatially correlated to the presence of organics. This suggests the possibility that PAHs, incorporated into a meteorite parent body, may have been altered along with neighboring minerals and other constituents in the presence of liquid water. We present preliminary results of the alteration of a laboratory analog of interstellar carbonaceous dust, produced by processing naphthalene in a hydrogen plasma, by exposing it to water at elevated temperature (100, 150, and 200 C) and pressure in a sealed container for 24 hours. This is a simulation of pressure capping during the accretion of the parent body. The high temperatures chosen here bring water near its critical point, at which it becomes extremely reactive. One sign of this reactivity is seen in the observed color of the aqueously altered product, changing from golden yellow (original color) to black at 200 C. Comparison of the infrared spectra of the original dust analog with those of the aqueously altered product show an oxidation feature at 1700 cm-1, present in all three products but absent in the dust analog. High performance liquid chromatography (HPLC) of the aqueously altered product, refluxed in tetrahydrafuran, shows a variety of low retention peaks (<600 s), absent in the original dust analog.

The physical and compositional properties of dust: what do we really know?

NASA Astrophysics Data System (ADS)

Jones, A.

Many things in current interstellar dust studies are taken as well understood givens by much of the community. For example, it is widely held that interstellar dust is made up of only three components, i.e., “astronomical silicates”, graphite and polycyclic aromatic hydrocarbons, and that our understanding of these is now complete and sufficient enough to interpret astronomical observations of dust in galaxies. To zeroth order this is a reasonable approximation. However, while these “three pillars” of dust modelling have been useful in advancing our understanding over the last few decades, it is now apparent that they are insufficient to explain the observed evolution of the dust properties from one region to another. Thus, it is time to abandon the “three pillars” approach and to seek more physically-realistic interstellar dust analogues. The analysis of the pre-solar grains extracted from meteorites, interplanetary dust particles and from the Stardust mission, and the interpretation of x-ray scattering and absorption observations, supports the view that our current view of the interstellar dust composition(s) is indeed too naïve. The aim of this review is to point out where our current views are rather secure and, perhaps more importantly, where they are far from secure and we must re-think our ideas. To this aim ten aspects of interstellar dust will be scrutinised and re-evaluated in terms of their validity within the current observational, experimental, modelling and theoretical constraints. It is concluded from this analysis that we really do need to re-assess many of the fundamental assumptions relating to what we think we really do ‘know’ about interstellar dust. In particular, it is clear that unravelling the nature dust evolution in the interstellar medium is perhaps the key to significantly advancing our current understanding of interstellar dust. For example, the dust in the diffuse interstellar medium, molecular clouds, photo-dissociation regions and HII regions is not exactly the same but exhibits important evolution within and between these different regions. An understanding of these evolutionary and regional variations exhibited by dust is now critical.

A study of extended zodiacal structures

NASA Technical Reports Server (NTRS)

Sykes, Mark V.

1990-01-01

Observations of cometary dust trails and zodiacal dust bands, discovered by the Infrared Astronomical Satellite (IRAS) were analyzed in a continuing effort to understand their nature and relationship to comets, asteroids, and processes effecting those bodies. A survey of all trails observed by IRAS has been completed, and analysis of this phenomenon continues. A total of 8 trails have been associated with known short-period comets (Churyumov-Gerasimenko, Encke, Gunn, Kopff, Pons-Winnecke, Schwassmann-Wachmann 1, Tempel 1, and Tempel 2), and a few faint trails have been detected which are not associated with any known comet. It is inferred that all short-period comets may have trails, and that the trails detected were seen as a consequence of observational selection effects. Were IRAS launched today, it would likely observe a largely different set of trails. The Tempel 2 trail exhibits a small but significant excess in color temperature relative to a blackbody at the same heliocentric distance. This excess may be due to the presence of a population of small, low-beta particles deriving from large particles within the trail, or a temperature gradient over the surface of large trail particles. Trails represent the very first stage in the formation and evolution of a meteor stream, and may also be the primary mechanism by which comets contribute to the interplanetary dust complex. A mathematical model of the spatial distribution of orbitally evolved collisional debris was developed which reproduces the zodiacal dust band phenomena and was used in the analysis of dust band observations made by IRAS. This has resulted in the principal zodiacal dust bands being firmly related to the principal Hirayama asteroid families. In addition, evidence for the collisional diffusion of the orbital elements of the dust particles has been found in the case of dust generated in the Eos asteroid family.

Research in space science and technology. [including X-ray astronomy and interplanetary plasma physics

NASA Technical Reports Server (NTRS)

Beckley, L. E.

1977-01-01

Progress in various space flight research programs is reported. Emphasis is placed on X-ray astronomy and interplanetary plasma physics. Topics covered include: infrared astronomy, long base line interferometry, geological spectroscopy, space life science experiments, atmospheric physics, and space based materials and structures research. Analysis of galactic and extra-galactic X-ray data from the Small Astronomy Satellite (SAS-3) and HEAO-A and interplanetary plasma data for Mariner 10, Explorers 47 and 50, and Solrad is discussed.

Does the presence of cosmic dust influence the displacement of the Earth's Magnetopause?

NASA Astrophysics Data System (ADS)

Mann, I.; Hamrin, M.

2012-04-01

In a recent paper Treumann and Baumjohann propose that dust particles in interplanetary space occasionally cause large compressions of the magnetopause that, in the absence of coronal mass ejections, are difficult to explain by other mechanisms (R.A. Treumann and W. Baumjohann, Ann. Geophys. 30, 119-130, 2012). They suggest that enhanced dust number density raises the contribution of the dust component to the solar wind dynamical pressure and hence to the pressure balance that determines the extension of the magnetopause. They quantify the influence of the dust component in terms of a variation of the magnetopause stagnation point distance. As a possible event to trigger the compressions they propose the encounters with meteoroid dust streams along Earth's orbit. We investigate the conditions under which these compressions may occur. The estimate by Treumann and Baumjohann of the magnetopause variation presupposes that the dust particles have reached solar wind speed. Acceleration by electromagnetic forces is efficient in the solar wind for dust particles that have a sufficiently large ratio of surface charge to mass (Mann et al. Plasma Phys. Contr. Fusion, Vol. 52, 124012, 2010). This applies to small dust particles that contribute little to the total dust mass in meteoroid streams. The major fraction of dust particles that reach high speed in the solar wind are nanometer-sized dust particles that form and are accelerated in the inner solar system (Czechowski and Mann, ApJ, Vol. 714, 89, 2010). Observations suggest that the flux of these nanodust particles near 1 AU is highly time-variable (Meyer-Vernet, et al. Solar Physics, Vol. 256, 463, 2009). We estimate a possible variation of the magnetopause stagnation point distance caused by these nanodust fluxes and by the dust associated to meteoroid streams. We conclude that the Earth's encounters with meteoroid dust streams are not likely to strongly influence the magnetopause according to the proposed effect. We further use the expression for the magnetopause stagnation point distance used by Treumann and Baumjohann to investigate the possible influence of time-variable nanoddust fluxes on the magnetopause.

Dust-acoustic waves and stability in the permeating dusty plasma. II. Power-law distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong Jingyu; Du Jiulin; Liu Zhipeng

2012-08-15

The dust-acoustic waves and the stability theory for the permeating dusty plasma with power-law distributions are studied by using nonextensive q-statistics. In two limiting physical cases, when the thermal velocity of the flowing dusty plasma is much larger than, and much smaller than the phase velocity of the waves, we derived the dust-acoustic wave frequency, the instability growth rate, and the instability critical flowing velocity. As compared with the formulae obtained in part I [Gong et al., Phys. Plasmas 19, 043704 (2012)], all formulae of the present cases and the resulting plasma characteristics are q-dependent, and the power-law distribution ofmore » each plasma component of the permeating dusty plasma has a different q-parameter and thus has a different nonextensive effect. Further, we make numerical analyses of an example that a cometary plasma tail is passing through the interplanetary space dusty plasma and we show that these power-law distributions have significant effects on the plasma characteristics of this kind of plasma environment.« less

Seeing the Light (LBNL Science at the Theater)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brunger, Axel; Segalman, Rachel; Westphal, Andrew

2011-09-12

Berkeley Lab's Science at the Theater event "Seeing the Light" took place on Sept 12, 2011, at Berkeley Repertory's Roda Theatre. Learn how the Advanced Light Source is improving medicine, paving the way for clean energy, changing the future of computers, and much more. Featured speakers are Berkeley Lab's Roger Falcone, Rachel Segalman, Andrew Westphal, and Stanford University's Axel Brunger. Rachel Segalman: The future of clean energy technology relies on a better understanding of materials at the nanoscale. Berkeley Lab's Rachel Segalman uses the ALS to conduct this research, which could lead to improved photovoltaics and fuel cells. Axel Brunger:more » Improved treatment for human diseases hinges on understanding molecular-scale processes. Stanford University's Axel Brunger will discuss a new melanoma drug that was developed by a local company, Plexxikon, using the ALS for X-ray data collection. Andrew Westphal: What's comet dust made of? Andrew Westphal of UC Berkeley's Space Sciences Laboratory uses the ALS to study comet dust and interplanetary space dust collected by a NASA spacecraft. Moderated by Roger Falcone, Division Director of the Advanced Light Source« less

IDE spatio-temporal impact fluxes and high time-resolution studies of multi-impact events and long-lived debris clouds

NASA Technical Reports Server (NTRS)

Mulholland, J. Derral; Singer, S. Fred; Oliver, John P.; Weinberg, Jerry L.; Cooke, William J.; Kassel, Philip C.; Wortman, Jim J.; Montague, Nancy L.; Kinard, William H.

1991-01-01

During the first 12 months of the Long Duration Exposure Facility (LDEF) mission, the Interplanetary Dust Experiment (IDE) recorded over 15,000 total impacts on six orthogonal faces with a time resolution on the order of 15 to 20 seconds. When combined with the orbital data and the stabilized configuration of the spacecraft, this permits a detailed analysis of the micro-particulate environment. The functional status of each of the 459 detectors was monitored every 2.4 hours, and post-flight analyses of these data has now permitted an evaluation of the effective active detection area as a function of time, panel by panel and separately for the two sensitivity levels. Thus, total impacts were transformed into areal fluxes, and are presented here for the first time. Also discussed are possible effects of these fluxes on previously announced results: apparent debris events, meteor stream detections, and beta meteoroids in observationally significant numbers.

Transport dynamics calculated under the full Mie scattering theory for micron and submicron lunar ejecta in selenocentric, cislunar, and geocentric space

NASA Technical Reports Server (NTRS)

Hyde, T. W.; Alexander, W. M.

1989-01-01

In 1967, Lunar Explorer 35 was launched from the earth and placed into a stable orbit around the moon. The data from the dust particle experiment on this spacecraft were essentially continuous over a 5-yr period from the time of insertion in lunar orbit. Analysis of this data has been interpreted to show that micron-sized lunar ejecta leave the moon and traverse through selenocentric and cislunar space and obtain either interplanetary/heliocentric orbits or intercept the earth's magnetosphere and move into geocentric orbits. Extensive studies of the orbital trajectories of lunar particles in this size range have now been conducted that include a calculation of the solar radiation force using the full Mie scattering theory. A significant flux of particles with radii less than 0.1 micron are found to intercept the earth's magnetopause surface. This flux is shown to be strongly dependent upon both the particle's density and its index of refraction.

Moon based global field airglow: For Artemis or any common Lunar Lander

NASA Astrophysics Data System (ADS)

Kozlowski, R. W. H.; Sprague, A. L.; Sandel, B. R.; Hunten, D. M.; Broadfoot, A. L.

1994-06-01

An inexpensive, small mass, airglow experiment consisting of a suite of airglow detectors is planned for one or more lunar landers. Solid state detectors measuring light through narrow band filters or concave gratings can integrate emissions from lunar atmospheric constituents and store the information for relay to earth when convenient. The proposed instrument is a simplified version of the Shuttle-borne Arizona Imager-Spectrograph. These zenith and near horizon viewing detectors may allow us to monitor fluctuations in atomic species of oxygen, calcium, sodium, potassium, argon, and neon and OH, if present. This choice of observations would monitor outgassing from the interior (Ar), meteoritic dust flux (Na, K) solar wind sputtering (O, Ca), and outgassing from the surface (implanted Ne, Na, K). A global network could be inexpensively deployed aboard landers carrying a variety of other selenographic instrumentation. Powered by solar cells such a field network will return data applicable to a wide variety of interplanetary medium and solar-lunar interaction problems.

Raman Spectrum of Quenched Carbonaceous Composites

NASA Technical Reports Server (NTRS)

Wada, S.; Hayashi, S.; Miyaoka, H.; Tokunaga, A. T.

1996-01-01

Quenched Carbonaceous Composites (QCC's) are products from the ejecta of a hydrocarbon plasma. Two types of QCC, dark QCC and thermally-altered (heated) filmy QCC, have been shown to have a 220 nm absorption feature similar to that seen in the interstellar extinction curve. We present here Raman spectra of the QCCs and compare them with various carbonaceous materials to better understand the structure QCC. We find that structure of QCC is different from that of graphite and more similar to carbonaceous material found in some interplanetary dust particles and chondritic meteorites.

Commission 22: Meters, Meteorites and Interplanetary Dust

NASA Astrophysics Data System (ADS)

Watanabe, Junichi; Jenniskens, Peter; Spurný, Pavel; Borovička, Jiří; Campbell-Brown, Margaret; Consolmagno, Guy; Jopek, Tadeusz; Vaubaillon, Jeremie; Williams, Iwan P.; Zhu, Jin

2010-05-01

The business meeting of commission 22 was held at the room 5 in the SulAmerica Convention Center in Rio de Janeiro(14:00-15:30). Fifteen people attended at this meeting:J.Borovička, E.Bowell, G.Consolmagno, D.Green, P. Jenniskens, A. Pellinen-Wannberg, R. Rudawska, J. Watanabe, J. Zhu, P. H. A. Hasselmann, F. Ostroviski, D. A. Oszkiewicz, W. Thuillot, P. Mahajani, and A. Sule. This meeting was managed by Junichi Watanabe, the current C22 Vice-President. The summary of the meeting is described.

Spin-State-Dependent Ion-Molecule Chemistry as the Origin of N-15 and D Isotopic Anomalies in Primitive Matter.

NASA Technical Reports Server (NTRS)

Wirstrom, E. S.; Charnley, S. B.; Cordiner, M. A.; Milam, S. N.

2012-01-01

Many meteoritic and interplanetary dust particle (IDP) samples contain bulk enhancements and hotspots rich in N-15. Similarly low C(14)N/C(15)N ratios have been observed in numerous comets, An almost constant enrichment factor in comets from disti'nct formation zones in the nebular disk (i.e. both Jupiter Family and Oort Cloud comets), strongly suggests that this fractionation is primordial and was set in the protsolar cloud core. Deuterium enrichment is observed in both meteorites and IDPs

Mineralogy of dark clasts in primitive versus differentiated meteorites

NASA Technical Reports Server (NTRS)

Zolensky, M. E.; Weisberg, M. K.; Barrett, R. A.; Prinz, M.

1993-01-01

The presence of dark lithic clasts within meteorites can provide information concerning asteroidal regolith processes, the extent of interactions between asteroids, and the relationship between meteorite types, micrometeorites, and interplanetary dust particles. Accordingly, we have been seeking and characterizing dark clasts found within carbonaceous chondrites, unequilibrated ordinary chondrites, howardites, and eucrites. We find that unequilibrated chondrites in this study contain fine-grained, anhydrous unequilibrated inclusions, while the howardites often contain inclusions from geochemically processed, hydrous asteroids (type 1 and 2 carbonaceous chondrites). Eucrites and howardities contain unusual clasts, not easily classified.

The Origin of Organic Matter in the Solar System: Evidence from Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Keller, L. P.; Jacobsen, C.; Wirick, S.

2001-01-01

The origin of the organic matter in interplanetary materials has not been established. A variety of mechanisms have been proposed, with two extreme cases being a Fisher-Tropsch type process operating in the gas phase of the solar nebula or a Miller-Urey type process, which requires interaction with an aqueous fluid, presumably occurring on an asteroid. In the Fisher-Tropsch case, we might expect similar organic matter in hydrated and anhydrous interplanetary materials. However, aqueous alteration is required in the case of the Miller-Urey process, and we would expect to see organic matter preferentially in interplanetary materials that exhibit evidence of aqueous activity, such as the presence of hydrated silicates. The types and abundance of organic matter in meteorites have been used as an indicator of the origin of organic matter in the Solar System. Indigenous complex organic matter, including amino acids, has been found in hydrated carbonaceous chondrite meteorites, such as Murchison. Much lower amounts of complex organic matter, possibly only terrestrial contamination, have been found in anhydrous carbonaceous chondrite meteorites, such as Allende, that contain most of their carbon in elemental form. These results seem to favor production of the bulk of the organic matter in the Solar System by aqueous processing on parent bodies such as asteroids, a Miller-Urey process. However, the hydrated carbonaceous chondrite meteorites have approximately solar abundances of the moderately volatile elements, while all anhydrous carbonaceous chondrite meteorites have significantly lower contents of these moderately volatile elements. Two mechanisms, incomplete condensation or evaporation, both of which involve processing at approx. 1200 C, have been suggested to explain the lower content of the moderately volatile elements in all anhydrous meteorites. Additional information is contained in the original extended abstract.

A Cosmic Dust Sensor Based on an Array of Grid Electrodes

NASA Astrophysics Data System (ADS)

Li, Y. W.; Bugiel, S.; Strack, H.; Srama, R.

2014-04-01

We described a low mass and high sensitivity cosmic dust trajectory sensor using a array of grid segments[1]. the sensor determines the particle velocity vector and the particle mass. An impact target is used for the detection of the impact plasma of high speed particles like interplanetary dust grains or high speed ejecta. Slower particles are measured by three planes of grid electrodes using charge induction. In contrast to conventional Dust Trajectory Sensor based on wire electrodes, grid electrodes a robust and sensitive design with a trajectory resolution of a few degree. Coulomb simulation and laboratory tests were performed in order to verify the instrument design. The signal shapes are used to derive the particle plane intersection points and to derive the exact particle trajectory. The accuracy of the instrument for the incident angle depends on the particle charge, the position of the intersection point and the signal-to-noise of the charge sensitive amplifier (CSA). There are some advantages of this grid-electrodes based design with respect to conventional trajectory sensor using individual wire electrodes: the grid segment electrodes show higher amplitudes (close to 100%induced charge) and the overall number of measurement channels can be reduced. This allows a compact instrument with low power and mass requirements.

A comparative study of the continuum and emission characteristics of comet dust. 1: Are the silicates in Comet Halley and Kohoutek amorphous or crystalline

NASA Technical Reports Server (NTRS)

Nansheng, Zhao; Greenberg, J. Mayo; Hage, J. I.

1989-01-01

A continuum emission was subtracted from the 10 micron emission observed towards comets Halley and Kohoutek. The 10 micron excess emissions were compared with BN absorption and laboratory amorphous silicates. The results show that cometary silicates are predominantly amorphous which is consistent with the interstellar dust model of comets. It is concluded that cometary silicates are predominantly similar to interstellar silicates. For a periodic comet like Comet Halley, it is to be expected that some of the silicate may have been heated enough to convert to crystalline form. But apparently, this is only a small fraction of the total. A comparison of Comet Halley silicates with a combination of the crystalline forms observed in interplanetary dust particles (IPDs) seemed reasonable at first sight (Walker 1988, Brownlee 1988). But, if true, it would imply that the total silicate mass in Comet Halley dust is lower than that given by mass spectrometry data of Kissel and Krueger (1987). They estimated m sub org/m sub sil = 0.5 while using crystalline silicate to produce the 10 micron emission would give m sub org/m sub sil = 5 (Greenberg et al. 1988). This is a factor of 10 too high.

Chemical markers for bacteria in extraterrestrial samples.

PubMed

Fox, Alvin

2002-11-01

Interplanetary missions to collect pristine Martian surface samples for analysis of organic molecules, and to search for evidence of life, are in the planning phases. The only extraterrestrial samples currently on Earth are lunar dust and rocks, brought back by the Apollo (U.S.) and Luna (Soviet Union) missions to the moon, and meteorites. Meteorites are contaminated when they pass through the Earth's atmosphere, and during environmental exposure on Earth. Lunar fines have been stored on Earth for over 30 years under conditions designed to avoid chemical but not microbiological contamination. It has been extremely difficult to draw firm conclusions about the origin of chemicals (including amino acids) in extraterrestrial samples. Of particular concern has been the possibility of bacterial contamination. Recent work using state-of-the-art gas chromatography tandem mass spectrometry (GC-MS/MS) has dramatically lowered the chemical background, allowing a clear demonstration that lunar fines are remarkably different from terrestrial dust in that they generally lack certain chemical markers (muramic acid and 3-hydroxy fatty acids) characteristic of Earth's bacteria. Thus, lunar dust might be used as a negative control, in conjunction with GC-MS/MS analyses, in future analytical studies of lunar dust and meteorites. Such analyses may also be important in studies designed to search for the presence of life on Mars. Copyright 2002 Wiley-Liss, Inc.

Dust in the Solar System - Properties and Origins

NASA Technical Reports Server (NTRS)

Messenger, Scott; Keller, Lindsay; Nakamura-Messenger, Keiko

2013-01-01

Interplanetary dust pervades the inner Solar System, giving rise to a prominent glow above the horizon at sunrise and sunset known as the zodiacal light. This dust derives from the disintegration of comets as they approach the Sun and from collisions among main-belt asteroids. The Earth accretes roughly 4x10(exp 6) kg/year of 1 - 1,000 micron dust particles as they spiral into the Sun under the influence of Poynting-Robertson drag and solar wind drag. Samples of these grains have been collected from deep sea sediments, Antarctic ice and by high-altitude aircraft and balloon flights. Interplanetary dust particles (IDPs) collected in the stratosphere have been classified by their IR spectra into olivine, pyroxene, and hydrated silicate-dominated classes. Most IDPs have bulk major and minor element abundances that are similar to carbonaceous chondrite meteorites. Hydrated silicate-rich IDPs are thought to derive from asteroids based on their mineralogy and low atmospheric entry velocities estimated from peak temperatures reached during atmospheric entry. Anhydrous IDPs are typically aggregates of 0.1 - approx. 1 micron Mg-rich olivine and pyroxene, amorphous silicates (GEMS), Fe, Nisulfides and rare spinel and oxides bound together by carbonaceous material. These IDPs are often argued to derive from comets based on compositional similarities and high atmospheric entry velocities that imply high eccentricity orbits. Infrared spectra obtained from anhydrous IDPs closely match remote IR spectra obtained from comets. The most primitive (anhydrous) IDPs appear to have escaped the parent-body thermal and aqueous alteration that has affected meteorites. These samples thus consist entirely of grains that formed in the ancient solar nebula and pre-solar interstellar and circumstellar environments. Isotopic studies of IDPs have identified silicate stardust grains that formed in the outflows of red giant and asymptotic giant branch stars and supernovae]. These stardust grains include both amorphous and crystalline silicates. The organic matter in these samples also exhibits highly anomalous H, C, and N isotopic compositions that are consistent with formation in low temperature environments at the outermost regions of the solar nebula or presolar cold molecular cloud. The scientific frontiers for these samples include working toward a better understanding of the origins of the solar system amorphous and crystalline grains in IDPs and the very challenging task of determining the chemical composition of sub-micron organic grains. Laboratory studies of ancient and present-day dust in the Solar System thus reveal in exquisite detail the chemistry, mineralogy and isotopic properties of materials that derive from a range of astrophysical environments. These studies are an important complement to astronomical observations that help to place the laboratory observations into broader context.

The Butterflies of Principal Components: A Case of Ultrafine-Grained Polyphase Units

NASA Astrophysics Data System (ADS)

Rietmeijer, F. J. M.

1996-03-01

Dusts in the accretion regions of chondritic interplanetary dust particles [IDPs] consisted of three principal components: carbonaceous units [CUs], carbon-bearing chondritic units [GUs] and carbon-free silicate units [PUs]. Among others, differences among chondritic IDP morphologies and variable bulk C/Si ratios reflect variable mixtures of principal components. The spherical shapes of the initially amorphous principal components remain visible in many chondritic porous IDPs but fusion was documented for CUs, GUs and PUs. The PUs occur as coarse- and ultrafine-grained units that include so called GEMS. Spherical principal components preserved in an IDP as recognisable textural units have unique proporties with important implications for their petrological evolution from pre-accretion processing to protoplanet alteration and dynamic pyrometamorphism. Throughout their lifetime the units behaved as closed-systems without chemical exchange with other units. This behaviour is reflected in their mineralogies while the bulk compositions of principal components define the environments wherein they were formed.

A Southern Hemisphere radar meteor orbit survey

NASA Technical Reports Server (NTRS)

Baggaley, W. Jack; Steel, Duncan I.; Taylor, Andrew D.

1992-01-01

A meteor radar system has been operated on a routine basis near Christchurch, New Zealand, to determine the orbits of Earth-impacting interplanetary dust and meteoroids. The system sensitivity is +13 visual magnitude, corresponding to approximately 100 micron sized meteoroids. With an orbital precision of 2 degrees in angular elements and 10 percent in orbital energy (1/a), the operation yields an average of 1500 orbits daily with a total to date in excess of 10(exp 5). The use of pc's and automated data reduction permit the large orbital data sets we collect to be routinely reduced. Some illustrative examples are presented of the signal formats/processing and the results of data reduction, giving the individual orbital elements and hence the overall distributions. Current studies include the distribution of dust in the inner solar system; the influx of meteoroids associated with near-Earth asteroids; and the orbital structure existing in comet-produced streams.

Modeling of Electromagnetic Scattering by Discrete and Discretely Heterogeneous Random Media by Using Numerically Exact Solutions of the Maxwell Equations

NASA Technical Reports Server (NTRS)

Dlugach, Janna M.; Mishchenko, Michael I.

2017-01-01

In this paper, we discuss some aspects of numerical modeling of electromagnetic scattering by discrete random medium by using numerically exact solutions of the macroscopic Maxwell equations. Typical examples of such media are clouds of interstellar dust, clouds of interplanetary dust in the Solar system, dusty atmospheres of comets, particulate planetary rings, clouds in planetary atmospheres, aerosol particles with numerous inclusions and so on. Our study is based on the results of extensive computations of different characteristics of electromagnetic scattering obtained by using the superposition T-matrix method which represents a direct computer solver of the macroscopic Maxwell equations for an arbitrary multisphere configuration. As a result, in particular, we clarify the range of applicability of the low-density theories of radiative transfer and coherent backscattering as well as of widely used effective-medium approximations.

Carriers of the astronomical 2175 ? extinction feature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, J; Dai, Z; Ernie, R

2004-07-20

The 2175 {angstrom} extinction feature is by far the strongest spectral signature of interstellar dust observed by astronomers. Forty years after its discovery the origin of the feature and the nature of the carrier remain controversial. The feature is enigmatic because although its central wavelength is almost invariant its bandwidth varies strongly from one sightline to another, suggesting multiple carriers or a single carrier with variable properties. Using a monochromated transmission electron microscope and valence electron energy-loss spectroscopy we have detected a 5.7 eV (2175 {angstrom}) feature in submicrometer-sized interstellar grains within interplanetary dust particles (IDPs) collected in the stratosphere.more » The carriers are organic carbon and amorphous silicates that are abundant and closely associated with one another both in IDPs and in the interstellar medium. Multiple carriers rather than a single carrier may explain the invariant central wavelength and variable bandwidth of the astronomical 2175 {angstrom} feature.« less

The Evolution of the Surface of Symmetry of the Interplanetary Dust from 24° to 5° Elongation

NASA Astrophysics Data System (ADS)

Stenborg, Guillermo; Howard, Russell A.

2017-10-01

The white-light STEREO/SECCHI images include light scattered by dust in orbit about the Sun (the F-corona). We analyzed the evolution of the symmetry axis of the F-corona between 2007 and 2012 in the elongation range covered by the STEREO-A/HI-1 instrument (4°-24° elongation) to characterize the plane of symmetry of the zodiacal dust cloud. The symmetry axes both above and below the ecliptic plane were derived separately without assuming any particular functional form. No noticeable time dependence was observed. However, we did find an evolution with elongation of both the inclination I and the ascending node {{{Ω }}}A of the inferred plane of symmetry. Both parameters appeared fairly constant in the outer half of the elongation range studied (I=˜ 3\\buildrel{\\circ}\\over{.} 7,{{{Ω }}}A=˜ 83^\\circ ; values close to those of Venus’s orbit). Then, they start to evolve, becoming I=˜ 6^\\circ (I.e., a trend toward the solar equatorial plane) and {{{Ω }}}A=˜ 57^\\circ at about 5° elongation. This variation indicates that the zodiacal dust cloud exhibits a warped plane of symmetry, with an estimated center of symmetry at about 0.5 {R}⊙ from the Sun’s center on the side of the heliosphere containing Jupiter. We found a marginal difference between the inclination of the axes below and above the ecliptic. This is suggestive of an increased dust density distribution at certain fixed longitudes, which could be explained by the dust deposition of Kreutz Sun-grazing comets. We conjecture that the circumsolar dust is mainly affected by gravitational forces, other forces becoming dominant only where the more rapid changes occur.

Multiple generations of grain aggregation in different environments preceded solar system body formation.

PubMed

Ishii, Hope A; Bradley, John P; Bechtel, Hans A; Brownlee, Donald E; Bustillo, Karen C; Ciston, James; Cuzzi, Jeffrey N; Floss, Christine; Joswiak, David J

2018-06-26

The solar system formed from interstellar dust and gas in a molecular cloud. Astronomical observations show that typical interstellar dust consists of amorphous ( a -) silicate and organic carbon. Bona fide physical samples for laboratory studies would yield unprecedented insight about solar system formation, but they were largely destroyed. The most likely repositories of surviving presolar dust are the least altered extraterrestrial materials, interplanetary dust particles (IDPs) with probable cometary origins. Cometary IDPs contain abundant submicron a- silicate grains called GEMS (glass with embedded metal and sulfides), believed to be carbon-free. Some have detectable isotopically anomalous a- silicate components from other stars, proving they are preserved dust inherited from the interstellar medium. However, it is debated whether the majority of GEMS predate the solar system or formed in the solar nebula by condensation of high-temperature (>1,300 K) gas. Here, we map IDP compositions with single nanometer-scale resolution and find that GEMS contain organic carbon. Mapping reveals two generations of grain aggregation, the key process in growth from dust grains to planetesimals, mediated by carbon. GEMS grains, some with a- silicate subgrains mantled by organic carbon, comprise the earliest generation of aggregates. These aggregates (and other grains) are encapsulated in lower-density organic carbon matrix, indicating a second generation of aggregation. Since this organic carbon thermally decomposes above ∼450 K, GEMS cannot have accreted in the hot solar nebula, and formed, instead, in the cold presolar molecular cloud and/or outer protoplanetary disk. We suggest that GEMS are consistent with surviving interstellar dust, condensed in situ, and cycled through multiple molecular clouds. Copyright © 2018 the Author(s). Published by PNAS.

Comet Dust: The Diversity of "Primitive" Particles and Implications

NASA Technical Reports Server (NTRS)

Wooden, Diane H.; Ishii, Hope A.; Bradley, John P.; Zolensky, Michael E.

2016-01-01

Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive particles has expanded significantly through microscale investigations of cosmic dust samples ( IDP's(Interplanetary Dust Particles) and AMM's (Antarctic Micrometeorites)) and of comet dust samples (Stardust and Rosetta's COSIMA), as well as through remote sensing (spectroscopy and imaging) via Spitzer and via spacecraft encounters with 103P/Hartley 2 and 67P/Churyumov-Gerasimenko. Microscale investigations show that comet dust and cosmic dust are particles of unequilibrated materials, including aggregates of materials unequilibrated at submicron scales. We call unequilibrated materials "primitive" and we deduce they were incorporated into ice-rich (H2O-, CO2-, and CO-ice) parent bodies that remained cold, i.e., into comets, because of the lack of aqueous or thermal alteration since particle aggregation; yet some Stardust olivines suggest mild thermal metamorphism. Primitive particles exhibit a diverse range of: structure and typology; size and size distribution of constituents; concentration and form of carbonaceous and organic matter; D-, N-, and O- isotopic enhancements over solar; Mg-, Fe-contents of the silicate minerals; the compositions and concentrations of sulfides, and of less abundant mineral species such as chondrules, CAIs and carbonates. The uniformity within a group of samples points to: aerodynamic sorting of particles and/or particle constituents; the inclusion of a limited range of oxygen fugacities; the inclusion or exclusion of chondrules; a selection of organics. The properties of primitive particles imply there were disk processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disk present at the time and in the region where the comets formed.

Cosmic dust in the earth's atmosphere.

PubMed

Plane, John M C

2012-10-07

This review discusses the magnitude of the cosmic dust input into the earth's atmosphere, and the resulting impacts from around 100 km to the earth's surface. Zodiacal cloud observations and measurements made with a spaceborne dust detector indicate a daily mass input of interplanetary dust particles ranging from 100 to 300 tonnes, which is in agreement with the accumulation rates of cosmic-enriched elements (Ir, Pt, Os and super-paramagnetic Fe) in polar ice cores and deep-sea sediments. In contrast, measurements in the middle atmosphere - by radar, lidar, high-flying aircraft and satellite remote sensing - indicate that the input is between 5 and 50 tonnes per day. There are two reasons why this huge discrepancy matters. First, if the upper range of estimates is correct, then vertical transport in the middle atmosphere must be considerably faster than generally believed; whereas if the lower range is correct, then our understanding of dust evolution in the solar system, and transport from the middle atmosphere to the surface, will need substantial revision. Second, cosmic dust particles enter the atmosphere at high speeds and undergo significant ablation. The resulting metals injected into the atmosphere are involved in a diverse range of phenomena, including: the formation of layers of metal atoms and ions; the nucleation of noctilucent clouds, which are a sensitive marker of climate change; impacts on stratospheric aerosols and O(3) chemistry, which need to be considered against the background of a cooling stratosphere and geo-engineering plans to increase sulphate aerosol; and fertilization of the ocean with bio-available Fe, which has potential climate feedbacks.

Long-term particle flux variability indicated by comparison of Interplanetary Dust Experiment (IDE) timed impacts for LDEF's first year in orbit with impact data for the entire 5.75-year orbital lifetime

NASA Technical Reports Server (NTRS)

Mulholland, J. Derral; Simon, Charles G.; Cooke, William J.; Oliver, John P.; Misra, V.

1992-01-01

The electronic sensors of the Interplanetary Dust Experiment (IDE) recorded precise impact times and approximate directions for submicron to approximately 100-micron size particles on all six primary sides of the spacecraft for the first 346 days of the Long Duration Exposure Facility (LDEF) orbital mission. Previously-reported analyses of the timed impact data have established their spatio-temporal features, including the demonstration that a preponderance of the particles in this regime are orbital debris and that a large fraction of the debris particles are encountered as megameter-size clouds, some of which persist for long times. Short-term fluxes within such clouds can rise several orders of magnitude above the long-term average. These finding are consistent with the results of the first catastrophic hypervelocity laboratory impacts on a real satellite, recently reported in the press. Analysis continues on the geometric and evolutionary characteristics of these clouds, as well as on the isolation and characterization of the natural micrometeoroid component in the IDE data, but the unexpectedly large short-term variations in debris flux raises the question of how representative an indication of the multi-year average flux is given by the nearly one year of timed data. It has, therefore, always been one of the goals of IDE to conduct an optical survey of the craters on the IDE detectors, to obtain full-mission fluxes for comparisons with the timed data. This work is underway, and the results presently in hand are significant. Optical scanning of the ram and wake (East and West) panels is complete, and it is clear that the first year was in some respects not representative of the subsequent years. The 5.75-year average flux on East panel was 90 percent of the value predicted by the average flux recorded during the first year, while it was only 34 percent on West panel. This suggests that western hemisphere spacecraft launches are a major contributor to the long-term flux and that their contribution is primarily in the smaller end of the size distribution. This conclusion follows from the fact that a closely-spaced series of launch failures (Titan, Delta, Ariane, and Challenger) caused a virtual hiatus in launch activity during a large part of the later years of the LDEF mission. We hope to provide a quantification of the particle size distribution function in this case.

The microbe capture experiment in space: Fluorescence microscopic detection of microbes captured by aerogel

NASA Astrophysics Data System (ADS)

Sugino, Tomohiro; Yokobori, Shin-Ichi; Yang, Yinjie; Kawaguchi, Yuko; Okudaira, Kyoko; Tabata, Makoto; Kawai, Hideyuki; Hasegawa, Sunao; Yamagishi, Akihiko

Microbes have been collected at the altitude up to about 70 km in the sampling experiment done by several groups[1]. We have also collected high altitude microbes, by using an airplane and balloons[2][3][4][5]. We collected new deinococcal strain (Deinococcus aetherius and Deinococ-cus aerius) and several strains of spore-forming bacilli from stratosphere[2][4][5]. However, microbe sampling in space has never been reported. On the other hand, "Panspermia" hy-pothesis, where terrestrial life is originated from outside of Earth, has been proposed[6][7][8][9]. Recent report suggesting existence of the possible microbe fossils in the meteorite of Mars origin opened the serious debate on the possibility of migration of life embedded in meteorites (and cosmic dusts)[10][11]. If we were able to find terrestrial microbes in space, it would suggest that the terrestrial life can travel between astronomical bodies. We proposed a mission "Tanpopo: Astrobiology Exposure and Micrometeoroid Capture Experiments" to examine possible inter-planetary migration of microbes, organic compounds and meteoroids on Japan Experimental Module of the International Space Station (ISS)[12]. Two of six sub themes in this mission are directly related to interplanetary migration of microbes. One is the direct capturing experi-ment of microbes (probably within the particles such as clay) in space by the exposed ultra-low density aerogel. Another is the exposure experiment to examine survivability of the microbes in harsh space environment. They will tell us the possibility of interplanetary migration of microbes (life) from Earth to outside of Earth (or vise versa). In this report, we will report whether aerogel that have been used for the collection of space debris and cosmic dusts can be used for microbe sampling in space. We will discuss how captured particles by aerogel can be detected with DNA-specific fluorescent dye, and how to distinguish microbes from other mate-rials (i.e. aerogel and particles such as clay). The surface of micro-particles captured by aerogel is often vitrified. The non-specific fluorescent light is often observed from vitrified materials. Therefore, we need to distinguish fluorescent light of stained microbes from that of vitrified ma-terials. We are going to use two types of differences (wavelength dependence and attenuation rate of fluorescent) between stained microbes with DNA-specific fluorescent dye and other ma-terials such as clay and aerogel. Fluorescent light of stained microbes shows attenuation faster than that of vitrified materials. Fluorescent light of vitrified materials shows broader range of emission spectra than that of stained microbes. In addition, we simulated the high-speed collision experiment of micro-particles to the aerogel with the two stage light gas gun (ca. 4 km/s). The micro-particles containing pre-stained and dried cells of Deinococcus radiodurans mixed with clay material were used for the collision experiment, and the captured particles were observed with fluorescence microscope. This experiment suggests that the captured microbes can be detected and be distinguished from clay materials. Reference [1] Yang, Y. et al. (2009) Biol. Sci. Space, 23, 151-163. [2] Yang, Y., et al. (2008) Biol. Sci. Space 22:18-25. [3] Yang, Y., et al. (2008) JAXA-RR-08-001: 34-42. [4] Yang, Y., et al. (2009) Internatl. J. Syst. Evol. Bacteriol., 59: 1862-1866. [5] Yang, Y. et al. (2010) Internatl. J. Syst. Evol. Bacteriol. (in press). [6] Arrhenius, S. (1908) Worlds in the Making-the Evolution of the Universe (translation to English by H. Borns) Harper and Brothers Publishers, New York. [7]Crick, F. (1981) Life Itself. Simon Schuster, New York. [8] W.L. Nicholson et al., Microbiol. Mol. Biol. Rev. 64 (2000) 548. [9] G. Horneck et al., Orig. Life Evol. Biosph. 31 (2001) 527. [10] Chyba, C. and C. Sagan (1992) Nature 355: 125-132. [11] Sandford, S. A., et al. (2006) Science 314: 1720-1724. [12] Yamagishi, A., et al. (2008) International Symposium on Space Technology and Science (ISTS) Web Paper Archives. 2008-k-05.

The nature of cometary dust as determined from infrared observations

NASA Technical Reports Server (NTRS)

Swamy, K. S. Krishna; Sandford, Scott A.; Allamandola, Louis J.; Witteborn, Fred C.; Bregman, Jesse D.

1989-01-01

The infrared measurements of comets, the compositional information available from interplanetary dust particles (IDPs), and the recent results of flybys to Comet Halley can help in restricting the nature and composition of cometary dust models (c.f., Proceedings of the 20th ESLAB Symposium on Exploration of Halley's Comet, 1986). Researchers tried to incorporate some of these results into a coherent model to account for the observed cometary infrared emission. The presence of 10 and 3.4 micron features in Comet Halley (c.f. Bregman et al. 1987; Wickramasinghe and Allen 1986) indicated the presence of at least two components in the grain material, namely silicates and some form of amorphous carbon. These two components could reside in separate grains or may be parts of composite particles. Both these cases have been considered (see Krishna Swamy el a. 1988a, 1988b). In the absence of refractive index data for cometary analogs, the authors used the optical constants of olivine-rich lunar material 12009.48 (Perry et al. 1972) for the infrared region and that of alpha:C-H film for amorphous carbon (angus et al. 1986). For the visible region, a value of m = 1.38-0.39i was used for the silicates, and values published by Arakawa et al. (1985) were used for the amorphous carbon. These materials should give a representative behavior of the expected results. The model results were compared to observational data. The strength of the 3.4 micron and 10 micron features relative to the adjacent continuum, as well as the slope of the continuum between 2500 and 1250 cm(exp -1) (4 to 8 microns), were used as criteria for comparison. Model calculations with alpha approx. equals -3.5, and also the size distribution function inferred for Comet Halley, with a mass fraction (X) of silicate to amorphous carbon grains of about 40 to 1 can fit the data. A good match is obtained for the infrared spectra of Comets Halley and West from a 40 to 1 mixture of silicate and amorphous carbon grains with a a(exp -3.5) size distribution function. The results are consistent with compositional constraints provided by interplanetary dust particles (IPDs) and Halley flyby data. The variation of grain temperature with heliocentric distance appears to account for the major changes observed in cometary spectra.

From Stardust to Planetesimals: Contributed Papers

NASA Technical Reports Server (NTRS)

Kress, M. E. (Editor); Tielens, A. G. G. M. (Editor); Pendleton, Y. J. (Editor)

1996-01-01

On June 24 through 26, 1996, a scientific conference entitled From Stardust to Planetesimals was held at the Westin Hotel, Santa Clara, California, as part of the 108th annual meeting of the Astronomical Society of the Pacific. Over the last decade, our understanding of the formation and early evolution of the solar system has advanced considerably due to progress that has been made simultaneously on many fronts. Stardust has been isolated in meteorites and interplanetary dust particles (IDP's), providing us with sample materials which predate the solar system and which offer clues to the processing that has occurred. At the same time, infrared studies have led to a better characterization of the composition of interstellar dust, which is now readily accepted as an important component of the interstellar medium infrared observations have also provided a much better view of the star-formation process and the role of dust therein. Recently, the presence of Kuiper Belt planetesimals has been confirmed and spectroscopy of these rather pristine objects may soon become available. Analysis of spacecraft data from the Comet Halley flybys has yielded a wealth of information on the composition of this comet. These observational advances have changed our understanding of planetesimal processing. The launch of the Infrared Space Observatory, the opening of 10-meter class telescopes, and, in the longer term, the Rosetta mission, promise to continue to broaden and deepen our understanding of the evolution from stardust to planetesimals. For these reasons we considered it timely to organize a meeting focused on the processes that connect stardust and planetesimals. The goal of this meeting was, therefore, to bring together astronomers interested in star- and planet-formation, planetary scientists studying early solar system relics, laboratory scientists studying the processing of analogs, and scientists analyzing meteorites and interplanetary dust particles, grain by grain. As a result of this endeavor, over 200 participants, including 153 scientists from 14 different countries, gathered to discuss the origin and evolution of stardust. We hope that this encounter in Santa Clara will foster an ongoing interchange of information and ideas within this diverse group of scientists. A major aim of this meeting was to produce conference proceedings which reflect the current situation regarding the evolution from stardust to planetesimals.

Comet coma sample return instrument

NASA Technical Reports Server (NTRS)

Albee, A. L.; Brownlee, Don E.; Burnett, Donald S.; Tsou, Peter; Uesugi, K. T.

1994-01-01

The sample collection technology and instrument concept for the Sample of Comet Coma Earth Return Mission (SOCCER) are described. The scientific goals of this Flyby Sample Return are to return to coma dust and volatile samples from a known comet source, which will permit accurate elemental and isotopic measurements for thousands of individual solid particles and volatiles, detailed analysis of the dust structure, morphology, and mineralogy of the intact samples, and identification of the biogenic elements or compounds in the solid and volatile samples. Having these intact samples, morphologic, petrographic, and phase structural features can be determined. Information on dust particle size, shape, and density can be ascertained by analyzing penetration holes and tracks in the capture medium. Time and spatial data of dust capture will provide understanding of the flux dynamics of the coma and the jets. Additional information will include the identification of cosmic ray tracks in the cometary grains, which can provide a particle's process history and perhaps even the age of the comet. The measurements will be made with the same equipment used for studying micrometeorites for decades past; hence, the results can be directly compared without extrapolation or modification. The data will provide a powerful and direct technique for comparing the cometary samples with all known types of meteorites and interplanetary dust. This sample collection system will provide the first sample return from a specifically identified primitive body and will allow, for the first time, a direct method of matching meteoritic materials captured on Earth with known parent bodies.

Dynamics and Distribution of Interplanetary Dust

NASA Astrophysics Data System (ADS)

Ipatov, S. I.; Mather, J. C.

2005-08-01

We integrated the orbital evolution of 12,000 asteroidal, cometary, and trans-Neptunian dust particles, under the gravitational influence of planets, Poynting-Robertson drag, radiation pressure, and solar wind drag (Annals of the New York Academy of Sciences, v. 1017, 66-80, 2004; Advances in Space Research, in press, 2005). The orbital evolution of 30,000 Jupiter-family comets (JFCs) was also integrated (Annals of the New York Academy of Sciences, v. 1017, 46-65, 2004). For asteroidal and cometary particles, the values of the ratio β between the radiation pressure force and the gravitational force varied from <0.0004 to 0.4 (for silicates, such values correspond to particle diameters between >1000 and 1 microns). The considered cometary particles started from comets 2P, 10P, and 39P. The probability of a collision of an asteroidal or cometary dust particle with the Earth during a lifetime of the particle was maximum at diameter about 100 microns; this is in accordance with cratering records. Our different studies of migration of dust particles and small bodies testify that the fraction of cometary dust particles of the overall dust population inside Saturn's orbit is considerable and can be dominant: (1) Some JFCs can reach orbits entirely located inside Jupiter's orbit and remain in such orbits for millions of years. Such former comets could disintegrate during millions of years and produce a lot of mini-comets and dust. (2) The spatial density of migrating trans-Neptunian particles near Jupiter's orbit is smaller by a factor of several than that beyond Saturn's orbit. Only a small fraction of asteroidal particles can migrate outside Jupiter's orbit. Therefore cometary dust particles are needed to explain the observed constant spatial density of dust particles at 3-18 AU from the Sun. (3) Comparison of the velocities of zodiacal dust particles obtained in our runs with the observations of velocities of these particles made by Reynolds et al. (Ap.J., 2004, v. 612, 1206-1213) shows that only asteroidal dust particles cannot explain these observations, and particles produced by high-eccentricity comets (such as Comet Encke) are needed for such explanation. Several our recent papers are presented on astro-ph.

Galactic and zodiacal light surface brightness measurements with the Atmosphere Explorer satellites

NASA Technical Reports Server (NTRS)

Abreu, V. J.; Hays, P. B.; Yee, J. H.

1982-01-01

Galactic and zodiacal light surface maps based on the Atmosphere Explorer-C, -D, and -E satellite data are presented at 7320, 6300, 5577, 5200, and 4278 A. A procedure used to generate these maps, which involves separation of the individual stars and diffuse starlight from the zodiacal light, is described in detail. The maps can be used in atmospheric emission studies to correct for galactic emissions which contaminate satellite as well as ground-based photometric observations. The zodiacal light maps show enhanced features which are important for understanding the nature of interplanetary dust.

The Abundance and Distribution of Presolar Materials in Cluster IDPS

NASA Technical Reports Server (NTRS)

Messenger, Scott; Keller, Lindsay; Nakamura-Messenger, Keiko; Ito, Motoo

2007-01-01

Presolar grains and remnants of interstellar organic compounds occur in a wide range of primitive solar system materials, including meteorites, interplanetary dust particles (IDPs), and comet Wild-2 samples. Among the most abundant presolar phases are silicate stardust grains and molecular cloud material. However, these materials have also been susceptible to destruction and alteration during parent body and nebular processing. In addition to their importance as direct samples of remote and ancient astrophysical environments, presolar materials thus provide a measure of how well different primitive bodies have preserved the original solar system starting materials.

Coordinated Analyses of Mineral-organic Matter Associations in Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Nakamura-Messenger, K.; Herzog, G. F.; Smith, T.; Keller, L. P.; Flynn, G. J.; Khodja, H.; Taylor, S.; Wirick, S.; Messenger, S.

2012-01-01

Little is known about the timing and processes involved in the incorporation of organic matter with inorganic materials in early Solar System bodies. Recently, X-ray absorption near-edge spectroscopy (XANES) studies showed carbon-rich rims surrounding individual mineral grains in anhydrous IDPs [1,2]. These carbonaceous rims are believed to have formed prior to parent body formation and likely served to bond mineral grains during accretion into larger aggregates. We are exploring the nature of these carbonaceous rims through coordinated analyses of their chemistry, mineralogy, spectroscopy and isotopic characteristics. Here we report our preliminary mineralogical observations.

Indigenous Carbonaceous Phases Embedded Within Surface Deposits on Apollo 17 Volcanic Glass Beads

NASA Technical Reports Server (NTRS)

Thomas-Keprta, K. L.; Clemett, S. J.; Ross, D. K.; Le, L.; McKay, D. S.; Gibson, E. K.; Gonzalez, C.

2012-01-01

The assessment of indigenous organic matter in returned lunar samples was one of the primary scientific goals of the Apollo program. Prior studies of Apollo samples have shown the total amount of organic matter to be in the range of approx 50 to 250 ppm. Low concentrations of lunar organics may be a consequence not only of its paucity but also its heterogeneous distribution. Several processes should have contributed to the lunar organic inventory including exogenous carbonaceous accretion from meteoroids and interplanetary dust particles, and endogenous synthesis driven by early planetary volcanism and cosmic and solar radiation.

Organic material: Asteroids, meteorites, and planetary satellites

NASA Technical Reports Server (NTRS)

Cruikshank, Dale P.; Kerridge, John F.

1992-01-01

Telescopic observations in in situ spacecraft investigations over the last two decades have shown that many planetary satellites, asteroids, and comets have surfaces containing very dark material that is either neutral (black) or red in color. Although comets are not the focus of this paper, the possible relationship of comets to asteroids, meteorites, and interplanetary dust is briefly discussed in the context of their dark-matter component. The following topics are discussed with respect to their organic content: carbonaceous chondrites; asteroids; low-albedo planetary satellites; and Pluto, Charon, and Triton. Laboratory studies and a summary are also presented.

Extraterrestrial Materials: The Role of Synchrotron Radiation Analyses in the Study of Our Solar System

ScienceCinema

Sutton, Stephen R. [University of Chicago, Chicago, Illinois, United States

2017-12-09

Sample-return missions and natural collection processes have provided us with a surprisingly extensive collection of matter from Solar System bodies other than the Earth. These collections include samples from the Moon, Mars, asteroids, interplanetary dust, and, recently, from the Sun (solar wind) and a comet. This presentation will describe some of these materials, how they were collected, and what we have learned from them. Synchrotron radiation analyses of these materials are playing an increasingly valuable role in unraveling the histories and properities of the parent Solar System bodies.

Cometary Evolution: Clues on Physical Properties from Chondritic Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.; Mackinnon, Ian D. R.

1989-01-01

The degree of diversity or similarity detected in comets depends primarily on the lifetimes of the individual cometary nuclei at the time of analysis. It is inherent in our understanding of cometary orbital dynamics and the seminal model of comet origins by Oort that cometary evolution is the natural order of events in our Solar System. Thus, predictions of cometary behaviour in terms of bulk physical, mineralogical or chemical parameters should contain an appreciation of temporal variation(s). Previously, Rietmeijer and Mackinnon developed mineralogical bases for the chemical evolution of cometary nuclei primarily with regard to the predominantly silicate fraction of comet nuclei. We suggested that alteration of solids in cometary nuclei should be expected and that indications of likely reactants and products can be derived from judicious comparison with terrestrial diagenetic environments which include hydrocryogenic and low-temperature aqueous alterations. In a further development of this concept, Rietmeijer provides indirect evidence for the formation of sulfides and oxides in comet nuclei. Furthermore, Rietmeijer noted that timescales for hydrocryogenic and low-temperature reactions involving liquid water are probably adequate for relatively mature comets, e.g. P/comet Halley. In this paper, we will address the evolution of comet nuclei physical parameters such as solid particle grain size, porosity and density. In natural environments, chemical evolution (e.g. mineral reactions) is often accompanied by changes in physical properties. These concurrent changes are well-documented in the terrestrial geological literature, especially in studies of sediment diagenesis and we suggest that similar basic principles apply within the upper few meters of active comet nuclei. The database for prediction of comet nuclei physical parameters is, in principle, the same as used for the proposition of chemical evolution. We use detailed mineralogical studies of chondritic interplanetary dust particles (IDPS) as a guide to the likely constitution of mature comets traversing the inner Solar System. While there is, as yet, no direct proof that a specific sub-group or type of chondritic IDP is derived from a specific comet, it is clear that these particles are extraterrestrial in origin and that a certain portion of the interplanetary flux received by the Earth is cometary in origin. Two chondritic porous (CP) MPs, sample numbers W7010A2 and W7029Cl, from the Johnson Space Center Cosmic Dust Collection have been selected for this study of putative cometary physical parameters. This particular type of particle is considered a likely candidate for a cometary origin on the basis of mineralogy, bulk composition and morphology. While many IDPs have been subjected to intensive study over the past decade, we can develop a physical parameter model on only these two CP IDPs because few others have been studied in sufficient detail.

Cometary Evolution: Clues on Physical Properties from Chondritic Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Reitmeijer, Frans J. M.; Mackinnon, Ian D. R.

1997-01-01

The degree of diversity or similarity detected in comets depends primarily on the lifetimes of the individual cometary nuclei at the time of analysis. It is inherent in our understanding of cometary orbital dynamics and the seminal model of comet origins that cometary evolution is the natural order of events in our Solar System. Thus, predictions of cometary behaviour in terms of bulk physical, mineralogical or chemical parameters should contain an appreciation of temporal variation(s). Previously, Rietmeijer and Mackinnon [1987] developed mineralogical bases for the chemical evolution of cometary nuclei primarily with regard to the predominantly silicate fraction of comet nuclei. We suggested that alteration of solids in cometary nuclei should be expected and that indications of likely reactants and products can be derived from judicious comparison with terrestrial diagenetic environments which include hydrocryogenic and low-temperature aqueous alterations. In a further development of this concept, Rietmeijer [1988] provides indirect evidence for the formation of sulfides and oxides in comet nuclei. Furthermore, Rietmeijer [1988] noted that timescales for hydrocryogenic and low-temperature reactions involving liquid water are probably adequate for relatively mature comets, e.g. P/comet Halley. In this paper, we will address the evolution of comet nuclei physical parameters such as solid particle grain size, porosity and density. In natural environments, chemical evolution (e.g. mineral reactions) is often accompanied by changes in physical properties. These concurrent changes are well-documented in the terrestrial geological literature, especially in studies of sediment diagenesis and we suggest that similar basic principles apply within the upper few meters of active comet nuclei. The database for prediction of comet nuclei physical parameters is, in principle, the same as used for the proposition of chemical evolution. We use detailed mineralogical studies of chondritic interplanetary dust particles (IDPS) as a guide to the likely constitution of mature comets traversing the inner Solar System. While there is, as yet, no direct proof that a specific sub-group or type of chondritic IDP is derived from a specific comet, it is clear that these particles are extraterrestrial in origin and that a certain portion of the interplanetary flux received by the Earth is cometary in origin. Two chondritic porous (CP) IDPS, sample numbers W701OA2 and W7029CI, from the Johnson Space Center Cosmic Dust Collection have been selected for this study of putative cometary physical parameters. This particular type of particle is considered a likely candidate for a cometary origin on the basis of mineralogy, bulk composition and morphology. While many IDPs have been subjected to intensive study over the past decade, we can develop a physical parameter model on only these two CP IDPs because few others have been studied in sufficient detail.

Astrophysics with Extraterrestrial Materials

NASA Astrophysics Data System (ADS)

Nittler, Larry R.; Ciesla, Fred

2016-09-01

Extraterrestrial materials, including meteorites, interplanetary dust, and spacecraft-returned asteroidal and cometary samples, provide a record of the starting materials and early evolution of the Solar System. We review how laboratory analyses of these materials provide unique information, complementary to astronomical observations, about a wide variety of stellar, interstellar and protoplanetary processes. Presolar stardust grains retain the isotopic compositions of their stellar sources, mainly asymptotic giant branch stars and Type II supernovae. They serve as direct probes of nucleosynthetic and dust formation processes in stars, galactic chemical evolution, and interstellar dust processing. Extinct radioactivities suggest that the Sun's birth environment was decoupled from average galactic nucleosynthesis for some tens to hundreds of Myr but was enriched in short-lived isotopes from massive stellar winds or explosions shortly before or during formation of the Solar System. Radiometric dating of meteorite components tells us about the timing and duration over which solar nebula solids were assembled into the building blocks of the planets. Components of the most primitive meteoritical materials provide further detailed constraints on the formation, processing, and transport of material and associated timescales in the Sun's protoplanetary disk as well as in other forming planetary systems.

External supply of oxygen to the atmospheres of the giant planets.

PubMed

Feuchtgruber, H; Lellouch, E; de Graauw, T; Bézard, B; Encrenaz, T; Griffin, M

1997-09-11

The atmospheres of the giant planets are reducing, being mainly composed of hydrogen, helium and methane. But the rings and icy satellites that surround these planets, together with the flux of interplanetary dust, could act as important sources of oxygen, which would be delivered to the atmospheres mainly in the form of water ice or silicate dust. Here we report the detection, by infrared spectroscopy, of gaseous H2O in the upper atmospheres of Saturn, Uranus and Neptune. The implied H2O column densities are 1.5 x 10(15), 9 x 10(13) and 3 x 10(14) molecules cm(-2) respectively. CO2 in comparable amounts was also detected in the atmospheres of Saturn and Neptune. These observations can be accounted for by external fluxes of 10(5)-10(7) H2O molecules cm(-2) s(-1) and subsequent chemical processing in the atmospheres. The presence of gaseous water and infalling dust will affect the photochemistry, energy budget and ionospheric properties of these atmospheres. Moreover, our findings may help to constrain the injection rate and possible activity of distant icy objects in the Solar System.

A likely detection of a local interplanetary dust cloud passing near the Earth in the AKARI mid-infrared all-sky map

NASA Astrophysics Data System (ADS)

Ishihara, D.; Kondo, T.; Kaneda, H.; Suzuki, T.; Nakamichi, K.; Takaba, S.; Kobayashi, H.; Masuda, S.; Ootsubo, T.; Pyo, J.; Onaka, T.

2017-07-01

Context. We are creating the AKARI mid-infrared all-sky diffuse maps. Through a foreground removal of the zodiacal emission, we serendipitously detected a bright residual component whose angular size is about 50° × 20° at a wavelength of 9 μm. Aims: We investigate the origin and the physical properties of the residual component. Methods: We measured the surface brightness of the residual component in the AKARI mid-infrared all-sky maps. Results: The residual component was significantly detected only in 2007 January, even though the same region was observed in 2006 July and 2007 July, which shows that it is not due to the Galactic emission. We suggest that this may be a small cloud passing near the Earth. By comparing the observed intensity ratio of I9 μm/I18 μm with the expected intensity ratio assuming thermal equilibrium of dust grains at 1 AU for various dust compositions and sizes, we find that dust grains in the moving cloud are likely to be much smaller than typical grains that produce the bulk of the zodiacal light. Conclusions: Considering the observed date and position, it is likely that it originates in the solar coronal mass ejection (CME) which took place on 2007 January 25.

A 2 MV Van de Graaff accelerator as a tool for planetary and impact physics research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mocker, Anna; Bugiel, Sebastian; Srama, Ralf

Investigating the dynamical and physical properties of cosmic dust can reveal a great deal of information about both the dust and its many sources. Over recent years, several spacecraft (e.g., Cassini, Stardust, Galileo, and Ulysses) have successfully characterised interstellar, interplanetary, and circumplanetary dust using a variety of techniques, including in situ analyses and sample return. Charge, mass, and velocity measurements of the dust are performed either directly (induced charge signals) or indirectly (mass and velocity from impact ionisation signals or crater morphology) and constrain the dynamical parameters of the dust grains. Dust compositional information may be obtained via either time-of-flightmore » mass spectrometry of the impact plasma or direct sample return. The accurate and reliable interpretation of collected spacecraft data requires a comprehensive programme of terrestrial instrument calibration. This process involves accelerating suitable solar system analogue dust particles to hypervelocity speeds in the laboratory, an activity performed at the Max Planck Institut fuer Kernphysik in Heidelberg, Germany. Here, a 2 MV Van de Graaff accelerator electrostatically accelerates charged micron and submicron-sized dust particles to speeds up to 80 km s{sup -1}. Recent advances in dust production and processing have allowed solar system analogue dust particles (silicates and other minerals) to be coated with a thin conductive shell, enabling them to be charged and accelerated. Refinements and upgrades to the beam line instrumentation and electronics now allow for the reliable selection of particles at velocities of 1-80 km s{sup -1} and with diameters of between 0.05 {mu}m and 5 {mu}m. This ability to select particles for subsequent impact studies based on their charges, masses, or velocities is provided by a particle selection unit (PSU). The PSU contains a field programmable gate array, capable of monitoring in real time the particles' speeds and charges, and is controlled remotely by a custom, platform independent, software package. The new control instrumentation and electronics, together with the wide range of accelerable particle types, allow the controlled investigation of hypervelocity impact phenomena across a hitherto unobtainable range of impact parameters.« less

A 2 MV Van de Graaff accelerator as a tool for planetary and impact physics research

NASA Astrophysics Data System (ADS)

Mocker, Anna; Bugiel, Sebastian; Auer, Siegfried; Baust, Günter; Colette, Andrew; Drake, Keith; Fiege, Katherina; Grün, Eberhard; Heckmann, Frieder; Helfert, Stefan; Hillier, Jonathan; Kempf, Sascha; Matt, Günter; Mellert, Tobias; Munsat, Tobin; Otto, Katharina; Postberg, Frank; Röser, Hans-Peter; Shu, Anthony; Sternovsky, Zoltán; Srama, Ralf

2011-09-01

Investigating the dynamical and physical properties of cosmic dust can reveal a great deal of information about both the dust and its many sources. Over recent years, several spacecraft (e.g., Cassini, Stardust, Galileo, and Ulysses) have successfully characterised interstellar, interplanetary, and circumplanetary dust using a variety of techniques, including in situ analyses and sample return. Charge, mass, and velocity measurements of the dust are performed either directly (induced charge signals) or indirectly (mass and velocity from impact ionisation signals or crater morphology) and constrain the dynamical parameters of the dust grains. Dust compositional information may be obtained via either time-of-flight mass spectrometry of the impact plasma or direct sample return. The accurate and reliable interpretation of collected spacecraft data requires a comprehensive programme of terrestrial instrument calibration. This process involves accelerating suitable solar system analogue dust particles to hypervelocity speeds in the laboratory, an activity performed at the Max Planck Institut für Kernphysik in Heidelberg, Germany. Here, a 2 MV Van de Graaff accelerator electrostatically accelerates charged micron and submicron-sized dust particles to speeds up to 80 km s-1. Recent advances in dust production and processing have allowed solar system analogue dust particles (silicates and other minerals) to be coated with a thin conductive shell, enabling them to be charged and accelerated. Refinements and upgrades to the beam line instrumentation and electronics now allow for the reliable selection of particles at velocities of 1-80 km s-1 and with diameters of between 0.05 μm and 5 μm. This ability to select particles for subsequent impact studies based on their charges, masses, or velocities is provided by a particle selection unit (PSU). The PSU contains a field programmable gate array, capable of monitoring in real time the particles' speeds and charges, and is controlled remotely by a custom, platform independent, software package. The new control instrumentation and electronics, together with the wide range of accelerable particle types, allow the controlled investigation of hypervelocity impact phenomena across a hitherto unobtainable range of impact parameters.

Interstellar and Solar System Organic Matter Preserved in Interplanetary Dust

NASA Technical Reports Server (NTRS)

Messenger, Scott; Nakamura-Messenger, Keiko

2015-01-01

Interplanetary dust particles (IDPs) collected in the Earth's stratosphere derive from collisions among asteroids and by the disruption and outgassing of short-period comets. Chondritic porous (CP) IDPs are among the most primitive Solar System materials. CP-IDPs have been linked to cometary parent bodies by their mineralogy, textures, C-content, and dynamical histories. CP-IDPs are fragile, fine-grained (less than um) assemblages of anhydrous amorphous and crystalline silicates, oxides and sulfides bound together by abundant carbonaceous material. Ancient silicate, oxide, and SiC stardust grains exhibiting highly anomalous isotopic compositions are abundant in CP-IDPs, constituting 0.01 - 1 % of the mass of the particles. The organic matter in CP-IDPs is isotopically anomalous, with enrichments in D/H reaching 50x the terrestrial SMOW value and 15N/14N ratios up to 3x terrestrial standard compositions. These anomalies are indicative of low T (10-100 K) mass fractionation in cold molecular cloud or the outermost reaches of the protosolar disk. The organic matter shows distinct morphologies, including sub-um globules, bubbly textures, featureless, and with mineral inclusions. Infrared spectroscopy and mass spectrometry studies of organic matter in IDPs reveals diverse species including aliphatic and aromatic compounds. The organic matter with the highest isotopic anomalies appears to be richer in aliphatic compounds. These materials also bear similarities and differences with primitive, isotopically anomalous organic matter in carbonaceous chondrite meteorites. The diversity of the organic chemistry, morphology, and isotopic properties in IDPs and meteorites reflects variable preservation of interstellar/primordial components and Solar System processing. One unifying feature is the presence of sub-um isotopically anomalous organic globules among all primitive materials, including IDPs, meteorites, and comet Wild-2 samples returned by the Stardust mission.

Volatiles in interplanetary dust particles: A comparison with CI and CM chondrites

NASA Technical Reports Server (NTRS)

Bustin, Roberta

1992-01-01

In an effort to classify and determine the origin of interplanetary dust particles (IDPs), 14 of these particles were studied using a laser microprobe/mass spectrometer. The mass spectra for these particles varied dramatically. Some particles released hydroxide or water which probably originated in hydroxide-bearing minerals or hydrates. Others produced spectra which included a number of hydrocarbons and resembled meteorite spectra. However, none of the individual IDPs gave spectra which could be matched identically with a particular meteorite type such as a CI or CM carbonaceous chondrite. We believe this was due to the fact that 10-20 micron size IDPs are too small to be representative of the parent body. To verify that the diversity was due primarily to the small particle sizes, small grains of approximately the same size range as the IDPs were obtained from two primitive meteorites, Murchison and Orgueil, and these small meteorite particles were treated exactly like the IDPs. Considerable diversity was observed among individual grains, but a composite spectrum of all the grains from one meteorite closely resembled the spectrum obtained from a much larger sample of that meteorite. A composite spectrum of the 14 IDPs also resembled the spectra of the CM and CI meteorites, pointing to a possible link between IDPs and carbonaceous chondrites. This also illustrates that despite the inherent diversity in particles as small as 10-20 micron, conclusions can be drawn about the possible origin and overall composition of such particles by looking not only at results from individual particles but also by including many particles in a study and basing conclusions on some kind of composite data.

Euhedral metallic-Fe-Ni grains in extraterrestrial samples

NASA Technical Reports Server (NTRS)

Rubin, Alan E.

1993-01-01

Metallic Fe-Ni is rare in terrestrial rocks, being largely restricted to serpentinized peridotites and volcanic rocks that assimilated carbonaceous material. In contrast, metallic Fe-Ni is nearly ubiquitous among extraterrestrial samples (i.e., meteorites, lunar rocks, and interplanetary dust particles). Anhedral grains are common. For example, in eucrites and lunar basalts, most of the metallic Fe-Ni occurs interstitially between silicate grains and thus tends to have irregular morphologies. In many porphyritic chondrules, metallic Fe-Ni and troilite form rounded blebs in the mesostasis because their precursors were immiscible droplets. In metamorphosed ordinary chondrites, metallic Fe-Ni and troilite form coarse anhedral grains. Some of the metallic Fe-Ni and troilite grains has also been mobilized and injected into fractures in adjacent silicate grains where local shock-reheating temperatures reached the Fe-FeS eutectic (988 C). In interplanetary dust particles metallic Fe-Ni most commonly occurs along with sulfide as spheroids and fragments. Euhedral metallic Fe-Ni grains are extremely rare. Several conditions must be met before such grains can form: (1) grain growth must occur at free surfaces, restricting euhedral metallic Fe-Ni grains to systems that are igneous or undergoing vapor-deposition; (2) the metal (+/-) sulfide assemblage must have an appropriate bulk composition so that taenite is the liquidus phase in igneous systems or the stable condensate phase in vapor-deposition systems; and (3) metallic Fe-Ni grains must remain underformed during subsequent compaction, thermal metamorphism, and shock. Because of these restrictions, the occurrence of euhedral metallic Fe-Ni grains in an object can potentially provide important petrogenetic information. Despite its rarity, euhedral metallic Fe-Ni occurs in a wide variety of extraterrestrial materials. Some of these materials formed in the solar nebula; others formed on parent body surfaces by meteoroid impacts.

The LBTI Hunt for Observable Signatures of Terrestrial Systems (HOSTS) Survey: a Key NASA Science Program on the Road to Exoplanet Imaging Missions (SPIE Proceedings 2)

NASA Technical Reports Server (NTRS)

Danchi, William C.; Bailey, V.; Defrere, D.; Haniff, C.; Hinz, P.; Kennedy, G.; Mennesson, B.; Millan-Gabet, R.; Rieke, G.; Roberge, Aki;

Characterization of Settled Atmospheric Dust by the DART Experiment

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Jenkins, Phillip P.; Baraona, Cosmo

1999-01-01

The DART ("Dust Accumulation and Removal Test") package is an experiment which will fly as part of the MIP experiment on the Mars-2001 Surveyor Lander. Dust deposition could be a significant problem for photovoltaic array operation for long duration emissions on the surface of Mars. Measurements made by Pathfinder showed 0.3% loss of solar array performance per day due to dust obscuration. The DART experiment is designed to quantify dust deposition from the Mars atmosphere, measure the properties of settled dust, measure the effect of dust deposition on the array performance, and test several methods of mitigating the effect of settled dust on a solar array. Although the purpose of DART (along with its sister experiment, MATE) is to gather information critical to the design of future power systems on the surface of Mars, the dust characterization instrumentation on DART will also provide significant scientific data on the properties of settled atmospheric dust.

"Driverless" Shocks in the Interplanetary Medium

NASA Technical Reports Server (NTRS)

Gopalswamy, N.; Kaiser, M. L.; Lara, A.

1999-01-01

Many interplanetary shocks have been detected without an obvious driver behind them. These shocks have been thought to be either blast waves from solar flares or shocks due to sudden increase in solar wind speed caused by interactions between large scale open and closed field lines of the Sun. We investigated this problem using a set of interplanetary shock detected {\\it in situ} by the Wind space craft and tracing their solar origins using low frequency radio data obtained by the Wind/WAVES experiment. For each of these "driverless shocks" we could find a unique coronal mass ejections (CME) event observed by the SOHO (Solar and Heliospheric Observatory) coronagraphs. We also found that these CMEs were ejected at large angles from the Sun-Earth line. It appears that the "driverless shocks" are actually driver shocks, but the drivers were not intercepted by the spacecraft. We conclude that the interplanetary shocks are much more extended than the driving CMEs.

Cosmic dust synthesis by accretion and coagulation

NASA Technical Reports Server (NTRS)

Praburam, G.; Goree, J.

1995-01-01

The morphology of grains grown by accretion and coagulation is revaled by a new laboratory method of synthesizing cosmic dust analogs. Submicron carbon particles, grown by accretion of carbon atoms from a gas, have a spherical shape with a cauliflower-like surface and an internal micro-structure of radial columns. This shape is probably common for grains grown by accretion at a temperature well below the melting point. Coagulated grains, consisting of spheres that collided to form irregular strings, were also synthesized. Another shape we produced had a bumpy non- spherical morphology, like an interplanetary particle collected in the terrestrial stratosphere. Besides these isolated grains, large spongy aggregates of nanometer-size particles were also found for various experimental conditions. Grains were synthesized using ions to sputter a solid target, producing an atomic vapor at a low temperature. The ions were provided by a plasma, which also provided electrostatic levitation of the grains during their growth. The temporal development of grain growth was studied by extinguishing the plasma after various intervals.

The Origin of the Excess Near-Infrared Diffuse Sky Brightness: Population III Stars or Zodiacal Light?

NASA Technical Reports Server (NTRS)

Dwek, Eli

2006-01-01

The intensity of the diffuse 1 to 5 micron sky emission from which solar system and Galactic foregrounds have been subtracted is in excess of that expected from energy released by galaxies and stars that formed during the z < 5 redshift interval. The spectral signature of this excess near-infrared background light (NIRBL) component is almost identical to that of reflected sunlight from the interplanetary dust cloud, and could therefore be the result of the incomplete subtraction of this foreground emission component from the diffuse sky maps. Alternatively, this emission component could be extragalactic. Its spectral signature is consistent with that of redshifted continuum and recombination line emission from H-II regions formed by the first generation of very massive stars. In this talk I will present the implications of this excess emission for our understanding of the zodiacal dust cloud, the formation rate of Pop III stars, and the TeV gamma-ray opacity to nearby blazars.

Laboratory simulations of atmospheric entry of micrometeoroids: ablation of magnesium

NASA Astrophysics Data System (ADS)

Bones, David; Gomez Martin, Juan Carlos; Diego Carrillo Sanchez, Juan; Dobson, Alexander; Plane, John

2017-04-01

We address the uncertainty in the cosmic dust input into the Earth's atmosphere by simulating the atmospheric entry of micrometeoroids in a custom built chamber, capable of heating particles to 3000 K in 2 s and able to precisely reproduce representative heating profiles. In lieu of interplanetary cosmic dust, we use a range of ground-up recovered meteorites and mineral analogues. We measure the ablation of two metals simultaneously with laser induced fluorescence (LIF). The resulting ablation profiles can be compared with the composition of the remaining, unablated particle, as determined from scanning electron microscopy-energy dispersive x-ray (SEM-EDX) analysis. Building on earlier studies of Na, Fe and Ca, here we present Mg profiles and compare them with results from our chemical ablation model (CABMOD). In general, Mg behaves as predicted, beginning to ablate steadily as one broad ablation peak once temperatures reach 2000 K. In contrast Fe, which should behave similarly to Mg, typically has two ablation peaks due to being present in two distinct phases.

The morphology of cometary dust: Subunit size distributions down to tens of nanometres

NASA Astrophysics Data System (ADS)

Mannel, Thurid; Bentley, Mark; Boakes, Peter; Jeszenszky, Harald; Levasseur-Regourd, Anny-Chantal; Schmied, Roland; Torkar, Klaus

2017-04-01

The Rosetta orbiter carried a dedicated analysis suite for cometary dust. One of the key instruments was MIDAS (Micro-Imaging Dust Analysis System), an atomic force microscope that scanned the surfaces of hundreds of (sub-)micrometre particles in 3D with resolutions down to nanometres. This provided the opportunity to study the morphology of the smallest cometary dust; initial investigation revealed that the particles are agglomerates of smaller subunits [1] with different structural properties [2]. To understand the (surface-) structure of the dust particles and the origin of their smallest building blocks, a number of particles were investigated in detail and the size distribution of their subunits determined [3]. Here we discuss the subunit size distributions ranging from tens of nanometres to a few micrometres. The differences between the subunit size distributions for particles collected pre-perihelion, close to perihelion, and during a huge outburst are examined, as well as the dependence of subunit size on particle size. A case where a particle was fragmented in consecutive scans allows a direct comparison of fragment and subunit size distributions. Finally, the small end of the subunit size distribution is investigated: the smallest determined sizes will be reviewed in the context of other cometary missions, interplanetary dust particles believed to originate from comets, and remote observations. It will be discussed if the smallest subunits can be interpreted as fundamental building blocks of our early Solar System and if their origin was in our protoplanetary disc or the interstellar material. References: [1] M.S. Bentley, R. Schmied, T. Mannel et al., Aggregate dust particles at comet 67P/Chruyumov-Gerasimenko, Nature, 537, 2016. doi:10.1038/nature19091 [2] T. Mannel, M.S. Bentley, R. Schmied et al., Fractal cometary dust - a window into the early Solar system, MNRAS, 462, 2016. doi:10.1093/mnras/stw2898 [3] R. Schmied, T. Mannel, H. Jeszenszky, M.S. Bentley, Properties of cometary dust down to the nanometre scale, poster at the conference 'Comets: A new vision after Rosetta/Philae' in Toulouse, 14-18 November 2016.

Measuring the Dust Flux and Dust Particle Mass Distribution in the Saturn Rings with HRD Dust Instrument on the Cassini Mission

NASA Astrophysics Data System (ADS)

Tuzzolino, A. J.; Economou, T. E.

In July 2004, the Cassini spacecraft will go into the Saturn orbit and start a 4 year intensive investigation of the planet itself, its multiple satellites and its rings with a multinational instrument payload. The High Rate Detectors (HRD) instrument provided by the Laboratory of Astrophysics and Space Research of the University of is part of the German Cosmic Dust Analyzer (CDA) and its main scientific objective is to provide quantitative measurements and mass distributions of dust particles in the rings of Saturn in the 10-11 to 10-4 grams mass range. The HRD instrument consists of two dust detectors -- a 20 and a 200 cm2 polyvinylidene fluoride (PVDF) sensors -- and an electronic box that contains all the analog and digital electronics and in addition provides interface between the HRD and CDA instrument. The CDA stores all the HRD data in its memory and transmits the data to Earth. The HRD weighs 1.7 kg and consumes 1.8 W of power [1]. The HRD instrument was fully calibrated through the entire mass range using two dust particle accelerators at Heidelberg and Munich in Germany. The HRD electronics is very fast and it will provide spatial and time distributions of up to 0.1 second. It can handle rates up to 104 counts/sec expected to be encountered during the Saturn ring crossings without any dead time. The HRD instrument operated successfully during all of the time that it was under power and detected many interplanetary dust particles. Almost all of these particles were close to the lowest mass threshold. References 1 A.J. TUZZOLINO, T.E. ECONOMOU, R.B. MCKIBBEN, J.A. SIMPSON, J.A.M. MCDONNELL, M.J. BURCHELL, B.A.M. VAUGHAN, P. TSOU, M.S. HANNER, B.C. CLARK AND D.E. BROWNLEE. THE DUST FLUX MONITOR INSTRUMENT FOR THE STARDUST MISSION TO COMET WILD-2, J. GEOPHYS. RES., 108, DOI:10.1029/2003JE002091, 2003.

Optimization of the Nano-Dust Analyzer (NDA) for operation under solar UV illumination

NASA Astrophysics Data System (ADS)

O`Brien, L.; Grün, E.; Sternovsky, Z.

2015-12-01

The performance of the Nano-Dust Analyzer (NDA) instrument is analyzed for close pointing to the Sun, finding the optimal field-of-view (FOV), arrangement of internal baffles and measurement requirements. The laboratory version of the NDA instrument was recently developed (O'Brien et al., 2014) for the detection and elemental composition analysis of nano-dust particles. These particles are generated near the Sun by the collisional breakup of interplanetary dust particles (IDP), and delivered to Earth's orbit through interaction with the magnetic field of the expanding solar wind plasma. NDA is operating on the basis of impact ionization of the particle and collecting the generated ions in a time-of-flight fashion. The challenge in the measurement is that nano-dust particles arrive from a direction close to that of the Sun and thus the instrument is exposed to intense ultraviolet (UV) radiation. The performed optical ray-tracing analysis shows that it is possible to suppress the number of UV photons scattering into NDA's ion detector to levels that allow both high signal-to-noise ratio measurements, and long-term instrument operation. Analysis results show that by avoiding direct illumination of the target, the photon flux reaching the detector is reduced by a factor of about 103. Furthermore, by avoiding the target and also implementing a low-reflective coating, as well as an optimized instrument geometry consisting of an internal baffle system and a conical detector housing, the photon flux can be reduced by a factor of 106, bringing it well below the operation requirement. The instrument's FOV is optimized for the detection of nano-dust particles, while excluding the Sun. With the Sun in the FOV, the instrument can operate with reduced sensitivity and for a limited duration. The NDA instrument is suitable for future space missions to provide the unambiguous detection of nano-dust particles, to understand the conditions in the inner heliosphere and its temporal variability, and to constrain the chemical differentiation and processing of IDPs.

Numerical Simulations of Laser-Driven Microflyer Plates

NASA Astrophysics Data System (ADS)

Colvin, Jeffrey D.; Frank, Alan M.; Lee, Ronald S.; Remington, Bruce A.

2000-10-01

Experiments conducted in the US and France have accelerated few-micron-thick foils of aluminum to velocities of 3 - 5 km/s using 25 - 50 J/cm^2 of 1-μm laser light (1,2). These microflyer plates are not too dissimilar in size and velocity from interplanetary dust particles (3). We are performing numerical simulations of these experiments with the 2-D radiation-hydrodynamics code LASNEX (4), incorporating a model for low-fluence electromagnetic wave reflection and absorption in metals, with the objective of determining the physical processes important to optimizing the flyer design. We will discuss our preliminary findings, including the efficacy of a thermal insulation layer and the role played by the substrate on which the flyer is mounted. (1) W.M. Trott, R.E. Setchell, and A.V. Farnsworth, Jr., in Shock Compression of Condensed Matter-1999, ed. M.D. Furnish, L.C. Chhabildas, and R.S. Hixson, AIP, 2000, pp. 1203-06. (2) J. L. Labaste, M. Doucet, and P. Joubert, in Shock Compression of Condensed Matter-1995, ed. S.C. Schmidt and W.C. Tao, AIP, 1996, pp. 1221-24. (3) W.W. Anderson and T.J. Ahrens, J. Geophys. Res. 99, 2063 (1994). (4) G. B. Zimmerman and W. L. Kruer, Comments Plasma Phys. Controlled Fusion 2, 51 (1975).

Galileo dust data from the jovian system: 2000 to 2003

NASA Astrophysics Data System (ADS)

Krüger, H.; Bindschadler, D.; Dermott, S. F.; Graps, A. L.; Grün, E.; Gustafson, B. A.; Hamilton, D. P.; Hanner, M. S.; Horányi, M.; Kissel, J.; Linkert, D.; Linkert, G.; Mann, I.; McDonnell, J. A. M.; Moissl, R.; Morfill, G. E.; Polanskey, C.; Roy, M.; Schwehm, G.; Srama, R.

2010-06-01

The Galileo spacecraft was the first man-made satellite of Jupiter, orbiting the planet between December 1995 and September 2003. The spacecraft was equipped with a highly sensitive dust detector that monitored the jovian dust environment between approximately 2 and 370 RJ (jovian radius RJ=71 492 km). The Galileo dust detector was a twin of the one flying on board the Ulysses spacecraft. This is the tenth in a series of papers dedicated to presenting Galileo and Ulysses dust data. Here we present data from the Galileo dust instrument for the period January 2000 to September 2003 until Galileo was destroyed in a planned impact with Jupiter. The previous Galileo dust data set contains data of 2883 particles detected during Galileo's interplanetary cruise and 12 978 particles detected in the jovian system between 1996 and 1999. In this paper we report on the data of additional 5389 particles measured between 2000 and the end of the mission in 2003. The majority of the 21 250 particles for which the full set of measured impact parameters (impact time, impact direction, charge rise times, charge amplitudes, etc.) was transmitted to Earth were tiny grains (about 10 nm in radius), most of them originating from Jupiter's innermost Galilean moon Io. They were detected throughout the jovian system and the impact rates frequently exceeded 10 min -1. Surprisingly large impact rates up to 100 min -1 occurred in August/September 2000 when Galileo was far away (≈280RJ) from Jupiter, implying dust ejection rates in excess of 100 kg s -1. This peak in dust emission appears to coincide with strong changes in the release of neutral gas from the Io torus. Strong variability in the Io dust flux was measured on timescales of days to weeks, indicating large variations in the dust release from Io or the Io torus or both on such short timescales. Galileo has detected a large number of bigger micron-sized particles mostly in the region between the Galilean moons. A surprisingly large number of such bigger grains was measured in March 2003 within a four-day interval when Galileo was outside Jupiter's magnetosphere at approximately 350 RJ jovicentric distance. Two passages of Jupiter's gossamer rings in 2002 and 2003 provided the first actual comparison of in-situ dust data from a planetary ring with the results inferred from inverting optical images. Strong electronics degradation of the dust instrument due to the harsh radiation environment of Jupiter led to increased calibration uncertainties of the dust data.

Meteoric Material: An Important Component of Planetary Atmospheres

NASA Technical Reports Server (NTRS)

Grebowsky, Joseph M.; Moses, Julianne I.; Pesnell, W. Dean; Vondrak, Richard R. (Technical Monitor)

2001-01-01

Interplanetary dust particles (IDPs) interact with all planetary atmospheres and leave their imprint as perturbations of the background atmospheric chemistry and structure. They lead to layers of metal ions that can become the dominant positively charged species in lower ionospheric regions. Theoretical models and radio occultation measurements provide compelling evidence that such layers exist in all planetary atmospheres. In addition IDP ablation products can affect neutral atmospheric chemistry, particularly at the outer planets where the IDPs supply oxygen compounds like water and carbon dioxide to the upper atmospheres. Aerosol or smoke particles from incomplete ablation or recondensation of ablated IDP vapors may also have a significant impact on atmospheric properties.

A Post-Stardust Mission View of Jupiter Family Comets

NASA Technical Reports Server (NTRS)

Zolensky, M.

2011-01-01

Before the Stardust Mission, many persons (including the mission team) believed that comet nuclei would be geologically boring objects. Most believed that comet nucleus mineralogy would be close or identical to the chondritic interplanetary dust particles (IDPs), or perhaps contain mainly amorphous nebular condensates or that comets might even be composed mainly of preserved presolar material [1]. Amazingly, the results for Comet Wild 2 (a Jupiter class comet) were entirely different. Whether this particular comet will ultimately be shown to be typical or atypical will not be known for a rather long time, so we describe our new view of comets from the rather limited perspective of this single mission.

Radio Emmision during the interaction of two Interplanetary Coronal Mass Ejections

NASA Astrophysics Data System (ADS)

Lara, Alejandro; Niembro, Tatiana; González, Ricardo

2016-07-01

We show that some sporadic radio emission observed by the WIND/WAVES experiment in the decametric/kilometric bands are due to the interaction of two interplanetary Coronal Mass Ejections. We have performed hydrodynamic simulations of the evolution of two consecutive Coronal Mass ejections in the interplanetary medium. With these simulations it is possible to follow the density evolution of the merged structure, and therefore, compute the frequency limits of the possible plasma emission. We study four well documented ICME interaction events, and found radio emission at the time and frequencies predicted by the simulations. This emission may help to anticipate the complexity of the merged region before it reaches one AU.

Elemental analyses of hypervelocity microparticle impact sites on Interplanetary Dust Experiment sensor surfaces

NASA Technical Reports Server (NTRS)

Simon, Charles G.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. A.; Wortman, Jim J.; Brownlee, D. E.

1993-01-01

The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity microparticles (approximately 0.2 to approximately 100 micron diameter) that struck the active sensors with enough energy to break down the 0.4 or 1.0 micron thick SIO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. The high purity Al-SiO2-Si substrates allowed detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) was used to create two-dimensional elemental ion intensity maps of microparticle impact sites on the IDE sensors. The element intensities in the central craters of the impacts were corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results were used to classify the particles' origins as 'manmade,' 'natural,' or 'indeterminate.' The last classification resulted from the presence of too little impactor residue, analytical interference from high background contamination, the lack of information on silicon and aluminum residues, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters of these features. Thus far a total of 79 randomly selected microparticle impact sites from the six primary sides of the LDEF have been analyzed: 36 from tray C-9 (Leading (ram), or East, side), 18 from tray C-3 (Trailing (wake), or West, side), 12 from tray B-12 (North side), 4 from tray D-6 (South side), 3 from tray H-11 (Space end), and 6 from tray G-10 (Earth end). Residue from manmade debris was identified in craters on all trays. (Aluminum oxide particle residues were not detectable on the Al/Si substrates.) These results were consistent with the IDE impact record which showed highly variable long term microparticle impact flux rates on the West, Space and Earth sides of the LDEF which could not be ascribed to astronomical variability of micrometeorite density. The IDE record also showed episodic bursts of microparticle impacts on the East, North, and South sides of the satellite, denoting passage through orbital debris clouds or rings.

Elemental Analyses of Hypervelocity Microparticle Impact Sites on Interplanetary Dust Experiment Sensor Surfaces

NASA Technical Reports Server (NTRS)

Simon, C. G.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. A.; Wortman, J. J.; Brownlee, D. E.

1992-01-01

The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity microparticles (approximately 0.2 to approximately 100 micron diameter) that struck the active sensors with enough energy to breakdown the 0.4 or 1.0 micron thick SiO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. The high purity Al-SiO2-Si substrates allowed detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) was used to create two-dimensional elemental ion intensity maps of microparticle sites on the IDE sensors. The element intensities in the central craters of the impacts were corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results classification resulted from the particles' origins as 'manmade', 'natural', or 'indeterminate'. The last classification resulted from the presence of too little impactor residue, analytical interference from high background contamination, the lack of information on silicon and aluminum residues, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters, of these features. Thus far, a total of 79 randomly selected microparticle impact sites from the six primary sides of the LDEF were analyzed: 36 from tray C-9 (Leading (ram), or east, side), 18 from tray C-3 (Trailing (wake), or west, side), 12 from tray B-12 (north side), 4 from tray D-6 (south side), 3 from tray H-11 (space end), and 6 from tray G-10 (earth end). Residue from manmade debris was identified in craters on all trays (aluminum oxide particle residues were not detectable on the Al/Si substrates). These results were consistent with the IDE impact record which showed highly variable long term microparticle impact flux rates on the west, space, and Earth sides of the LDEF which could not be ascribed to astronomical variability of micrometeorite density. The IDE record also showed episodic bursts of microparticle impacts on the east, north, and south sides of the satellite, denoting passage through orbital debris clouds or rings.

Detecting negative ions on board small satellites

NASA Astrophysics Data System (ADS)

Lepri, S. T.; Raines, J. M.; Gilbert, J. A.; Cutler, J.; Panning, M.; Zurbuchen, T. H.

2017-04-01

Recent measurements near comets, planets, and their satellites have shown that heavy ions, energetic neutral atoms, molecular ions, and charged dust contain a wealth of information about the origin, evolution, and interaction of celestial bodies with their space environment. Using highly sensitive plasma instruments, positively charged heavy ions have been used to trace exospheric and surface composition of comets, planets, and satellites as well as the composition of interplanetary and interstellar dust. While positive ions dominate throughout the heliosphere, negative ions are also produced from surface interactions. In fact, laboratory experiments have shown that oxygen released from rocky surfaces is mostly negatively charged. Negative ions and negatively charged nanograins have been detected with plasma electron analyzers in several different environments (e.g., by Cassini and Rosetta), though more extensive studies have been challenging without instrumentation dedicated to negative ions. We discuss an adaptation of the Fast Imaging Plasma Spectrometer (FIPS) flown on MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) for the measurement of negatively charged particles. MESSENGER/FIPS successfully measured the plasma environment of Mercury from 2011 until 2015, when the mission ended, and has been used to map multiple ion species (H+ through Na+ and beyond) throughout Mercury's space environment. Modifications to the existing instrument design fits within a 3U CubeSat volume and would provide a low mass, low power instrument, ideal for future CubeSat or distributed sensor missions seeking, for the first time, to characterize the contribution of negative particles in the heliospheric plasmas near the planets, moons, comets, and other sources.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jewitt, David; Li Jing, E-mail: jewitt@ucla.ed, E-mail: jli@igpp.ucla.ed

The asteroid (3200) Phaethon is widely recognized as the parent of the Geminid meteoroid stream. However, it has never shown evidence for ongoing mass loss or for any form of comet-like activity that would indicate the continued replenishment of the stream. Following an alert by Battams and Watson, we used NASA's STEREO-A spacecraft to image Phaethon near perihelion, in the period UT 2009 June 17-22, when the heliocentric distance was near 0.14 AU. The resulting photometry shows an unexpected brightening, by a factor of two, starting UT 2009 June 20.2 {+-} 0.2, which we interpret as an impulsive release ofmore » dust particles from Phaethon. If the density is near 2500 kg m{sup -3}, then the emitted dust particles must have a combined mass of {approx}2.5 x 10{sup 8} a{sub 1} kg, where a{sub 1} is the particle radius in millimeters. Assuming a{sub 1} = 1, this is approximately 10{sup -4} of the Geminid stream mass and to replenish the stream in steady state within its estimated {approx}10{sup 3} yr lifetime would require {approx}10 events like the one observed, per orbit. Alternatively, ongoing mass loss may be unrelated to the event which produced the Phaethon-Geminid complex. An impact origin of the dust is highly unlikely. Phaethon is too hot for water ice to survive, rendering the possibility that dust is ejected through gas drag from sublimated ice unlikely. Instead, we suggest that Phaethon is essentially a rock comet, in which the small perihelion distance leads both to the production of dust (through thermal fracture and decomposition cracking of hydrated minerals) and to its ejection into interplanetary space (through radiation pressure sweeping and other effects).« less

Cosmic Ray Exposure Ages of Stony Meteorites: Space Erosion or Yarkovsky?

NASA Technical Reports Server (NTRS)

Rubincam, David Parry

2014-01-01

Space erosion from dust impacts may set upper limits on the cosmic ray exposure (CRE) ages of stony meteorites. A meteoroid orbiting within the asteroid belt is bombarded by both cosmic rays and interplanetary dust particles. Galactic cosmic rays penetrate only the first few meters of the meteoroid; deeper regions are shielded. The dust particle impacts create tiny craters on the meteoroid's surface, wearing it away by space erosion (abrasion) at a particular rate. Hence a particular point inside a meteoroid accumulates cosmic ray products only until that point wears away, limiting CRE ages. The results would apply to other regolith-free surfaces in the solar system as well, so that abrasion may set upper CRE age limits which depend on the dusty environment. Calculations based on N. Divine's dust populations and on micrometeoroid cratering indicate that stony meteoroids in circular ecliptic orbits at 2 AU will record 21Ne CRE ages of approx.176 x 10(exp 6) years if dust masses are in the range 10(exp -21) - 10(exp -3) kg. This is in broad agreement with the maximum observed CRE ages of approx. 100 x 10(exp 6) years for stones. High erosion rates in the inner solar system may limit the CRE ages of Near-Earth Asteroids (NEAs) to approx. 120 x 10(exp 6) years. If abrasion should prove to be approx. 6 times quicker than found here, then space erosion may be responsible for many of the measured CRE ages of main belt stony meteorites. In that case the CRE ages may not measure the drift time to the resonances due to the Yarkovsky effects as in the standard scenario, and that for some reason Yarkovsky is ineffective.

Lunar Dust: Properties and Investigation Techniques

NASA Astrophysics Data System (ADS)

Kuznetsov, I. A.; Zakharov, A. V.; Dolnikov, G. G.; Lyash, A. N.; Afonin, V. V.; Popel, S. I.; Shashkova, I. A.; Borisov, N. D.

2017-12-01

Physical conditions in the near-surface layer of the Moon are overviewed. This medium is formed in the course of the permanent micrometeoroid bombardment of the lunar regolith and due to the exposure of the regolith to solar radiation and high-energy charged particles of solar and galactic origin. During a considerable part of a lunar day (more than 20%), the Moon is passing through the Earth's magnetosphere, where the conditions strongly differ from those in the interplanetary space. The external effects on the lunar regolith form the plasma-dusty medium above the lunar surface, the so-called lunar exosphere, whose characteristic altitude may reach several tens of kilometers. Observations of the near-surface dusty exosphere were carried out with the TV cameras onboard the landers Surveyor 5, 6, and 7 (1967-1968) and with the astrophotometer of Lunokhod-2 (1973). Their results showed that the near-surface layer glows above the sunlit surface of the Moon. This was interpreted as the scattering of solar light by dust particles. Direct detection of particles on the lunar surface was made by the Lunar Ejects and Meteorite (LEAM) instrument deployed by the Apollo 17 astronauts. Recently, the investigations of dust particles were performed by the Lunar Atmosphere and Dust Environment Explorer (LADEE) instrument at an altitude of several tens of kilometers. These observations urged forward the development of theoretical models for the lunar exosphere formation, and these models are being continuously improved. However, to date, many issues related to the dynamics of dust and the near-surface electric fields remain unresolved. Further investigations of the lunar exosphere are planned to be performed onboard the Russian landers Luna-Glob and Luna-Resurs.

Evolution of the Edgeworth-Kuiper Belt and Kuiperoidal Dust

NASA Astrophysics Data System (ADS)

Ozernoy, L. M.; Ipatov, S. I.

Evolution of orbits of Edgeworth-Kuiper belt objects (EKBOs) under the gravitational influence of the giant planets has been studied by a number of authors (e.g., Duncan & Levison; Budd; Ozernoy, Gorkavyi & Taidakova). Here we show that the gravitational interactions of EKBOs can also play a certain role in their orbital evolution. For instance, during the last 4 Gyr as many as several percents of EKBOs could change their semimajor axes by more than 1 AU due to close encounters with other EKBOs. Even small variations in orbital elements of EKBOs caused by their mutual collisions coupled with the mutual gravitational influence can cause large variations in the orbital elements due to the gravitational influence of planets. About 6% of Neptune-crossers can reach the orbit of the Earth, with the average time in Earth-crossing orbits of about 5× 103 yr. The portion of former EKBOs now moving in Earth-crossing orbits can exceed 20% of all Earth-crossers. Evaporation of the volatile material from the EKBOs surfaces, due to mutual EKBO collisions, along with the Solar wind and the heating by the Sun, are the sources of the dust in the outer Solar system. The evolution and structure of the interplanetary dust cloud computed, in some approximations, by Gorkavyi, Ozernoy, Mather, & Taidakova offers a preliminary 3-D physical model of the cloud, which includes three dust components (asteroidal, cometary, and kuiperoidal), which is fairly consistent with the available data of Pioneer and Voyager dust detectors and contribution of the zodiacal light into the COBE/DIRBE data. We acknowledge support of this work by NASA grant NAG5-10776, the Russian Federal Program ``Astronomy'' (section 1.9.4.1), RFBR (01-02-17540), and INTAS (00-240).

Laboratory Analysis of Silicate Stardust Grains of Diverse Stellar Origins

NASA Technical Reports Server (NTRS)

Nguyen, Ann N.; Keller, Lindsay P.; Nakamura-Messenger, Keiko

2016-01-01

Silicate dust is ubiquitous in a multitude of environments across the cosmos, including evolved oxygen-rich stars, interstellar space, protoplanetary disks, comets, and asteroids. The identification of bona fide silicate stardust grains in meteorites, interplanetary dust particles, micrometeorites, and dust returned from comet Wild 2 by the Stardust spacecraft has revolutionized the study of stars, interstellar space, and the history of dust in the Galaxy. These stardust grains have exotic isotopic compositions that are records of nucleosynthetic processes that occurred in the depths of their now extinct parent stars. Moreover, the chemical compositions and mineralogies of silicate stardust are consequences of the physical and chemical nature of the stellar condensation environment, as well as secondary alteration processes that can occur in interstellar space, the solar nebula, and on the asteroid or comet parent body in which they were incorporated. In this talk I will discuss our use of advanced nano-scale instrumentation in the laboratory to conduct coordinated isotopic, chemical, and mineralogical analyses of silicate stardust grains from AGB stars, supernovae, and novae. By analyzing the isotopic compositions of multiple elements in individual grains, we have been able to constrain their stellar sources, explore stellar nucleosynthetic and mixing processes, and Galactic chemical evolution. Through our mineralogical studies, we have found these presolar silicate grains to have wide-ranging chemical and mineral characteristics. This diversity is the result of primary condensation characteristics and in some cases secondary features imparted by alteration in space and in our Solar System. The laboratory analysis of actual samples of stars directly complements astronomical observations and astrophysical models and offers an unprecedented level of detail into the lifecycles of dust in the Galaxy.

Influence of the solar wind/interplanetary medium on Saturnian kilometric radiation

NASA Technical Reports Server (NTRS)

Rucker, Helmut O.; Desch, M. D.

1990-01-01

Previous studies on the periodicities of the Saturnian kilometric radiation (SKR) suggested a considerable solar wind influence on the occurrence of SKR, so it was obvious to investigate the relationship between parameters of the solar wind/interplanetary medium and this Saturnian radio component. Voyager 2 data from the Plasma Science experiment, the Magnetometer experiment and the Planetary Radio Astronomy experiment were used to analyze the external control of SKR. Out of the examined quantities known to be important in controlling magnetospheric processes this investigation yielded a dominance of the solar wind momentum, ram pressure and kinetic energy flux, in stimulating SKR and controlling its activity and emitted energy, and confirmed the results of the Voyager 1 analysis.

Laboratory polarization and permittivity measurements to interpret dust polarimetric observations and in-situ radar studies. Significance for Rosetta mission at 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Levasseur-Regourd, Anny-Chantal; Brouet, Yann; Hadamcik, Edith; Heggy, Essam; Hines, Dean; Lasue, Jérémie; Renard, Jean-Baptiste

2015-08-01

Polarimetric astronomical observations on dust clouds and regolithic surfaces require laboratory simulations on samples to provide information on properties (size distribution, porosity, refractive index) of the scattering media. Similarly, in-situ radar investigations in the solar system require laboratory studies on samples to infer physical properties (e.g. porosity, ice/dust ratio) of sub-surfaces and interiors. Recent developments are illustrated with present studies related to the Rosetta mission, which begun its rendezvous with comet 67P/Churyumov-Gerasimeko (C-G) and landed the Philae module on its nucleus in 2014.We will summarize laboratory simulations with the PROGRA2 suite of instruments that study (in the visible to near IR domain) the polarimetric properties of dust samples in microgravity conditions or on surfaces [1], with emphasis on the interpretation of polarimetric observations of C-G, during its previous perihelion passages from Earth observatories, and currently from HST [2,3]. The presence of large dust particles in the pre-perihelion coma previously inferred from remote observations agrees with Rosetta ground truth [4]. We will also present measurements on the permittivity (in the millimeter to meter domain) of various dust samples, with emphasis on porous samples [5,6]. Results provide constraints on the properties of the subsurface and interior of C-G, as explored by MIRO on Rosetta and CONSERT on Philae.Such studies are relevant for the interpretation of polarimetric observations of other dust clouds (e.g. debris disks, interplanetary dust cloud, clouds in planetary atmospheres) and surfaces (e.g. planets, moons), as well as for those of other radar characterization studies (e.g. Mars, moons, asteroids).[1] Levasseur-Regourd et al. In Polarization of stars and planetary systems, Cambridge UP, in press 2015.[2] Hadamcik et al. A&A 517 2010.[3] Hines and Levasseur-Regourd, PSS submitted 2015.[4] Schulz et al. Nature 518 2015.[5] Heggy et al. 2012, Icarus 221 2012.[6] Brouet et al. A&A submitted 2015.

Evolution of the Earth and Origin of Life: The Role of Gas/Fluid Interactions with Rocks

NASA Technical Reports Server (NTRS)

Freund, Friedemann

2001-01-01

The work under the Cooperative Agreement will be centered on questions of the evolution of Life on the early Earth and possibly on Mars. It is still hotly debated whether the essential organic molecules were delivered to the early Earth from space (by comets, meteorites or interplanetary dust particles) or were generated in situ on Earth. Prior work that has shown that the matrix of igneous minerals is a medium in which progenitors of organic molecules assemble from H2O, C02 and N2 incorporated as minority "impurities" in minerals of igneous rocks during crystallization from H2O/CO2/N2-laden magmas. The underlying processes involve a redox. conversion whereby C, H, and N become chemically reduced, while 0 becomes oxidized to the peroxy state. During Year 02 the work will be divided into three tasks. Task 1: After carboxylic (fatty) acids and N-bearing compounds have been identified, other extractable organic molecules including lipids, oily substances and amino acids will be studied. Dedicated lipid analysis will be combined with gas chromatographic-mass spectroscopic (GCMS) analysis of organic compounds extracted from minerals and rocks. Task 2: Using infrared (IR) spectroscopy, C-H entities that are indicators for the organic progenitors in mineral matrices will be studied. A preliminary heating experiment with MgO single crystals has shown that the C-H entities can be pyrolyzed, causing the IR bands to disappear, but at room temperature the IR bands reappear in a matter of days to weeks. This work will be expanded, both by studying synthetic MgO crystals and olivine crystals from the Earth's upper mantle. The C-H bands will be compared to the published "organic" IR feature of dust in the interstellar medium (ISM) and interplanetary dust particles (IDP). Task 3: A paradox marks the evolution of early Life: Oxygen is highly toxic to primitive life, yet early organisms "learned" to detoxify reactive oxygen species, to utilize oxygen, and even produce it. Why would organisms on the early anaerobic Earth be under evolutionary pressure to evolve defenses against reactive oxygen species? Minerals in igneous rocks are now known to contain peroxy. When such minerals weather, the peroxy hydrolyzes to H2O2. The hypothesis will be tested whether organisms living in intimate contact with rock surfaces are subjected to a constant trickle of H202 and thus under stress to develop strategies to either detoxify the reactive oxygen species or repair the molecular damage that they cause. Understanding these processes is central to the Astrobiology mission. It opens new avenues toward understanding the evolution of early life on Earth, and the potential for aerobic life elsewhere. This Cooperative Agreement also has a strong educational and public outreach component involving high school, undergraduate students, and high school teachers.

The interplanetary exchange of photosynthesis.

PubMed

Cockell, Charles S

2008-02-01

Panspermia, the transfer of organisms from one planet to another, either through interplanetary or interstellar space, remains speculation. However, its potential can be experimentally tested. Conceptually, it is island biogeography on an interplanetary or interstellar scale. Of special interest is the possibility of the transfer of oxygenic photosynthesis between one planet and another, as it can initiate large scale biospheric productivity. Photosynthetic organisms, which must live near the surface of rocks, can be shown experimentally to be subject to destruction during atmospheric transit. Many of them grow as vegetative cells, which are shown experimentally to be susceptible to destruction by shock during impact ejection, although the effectiveness of this dispersal filter can be shown to be mitigated by the characteristics of the cells and their local environment. Collectively these, and other, experiments reveal the particular barriers to the cross-inoculation of photosynthesis. If oxygen biosignatures are eventually found in the atmospheres of extrasolar planets, understanding the potential for the interplanetary exchange of photosynthesis will aid in their interpretation.

A second catalog of gamma ray bursts: 1978 - 1980 localizations from the interplanetary network

NASA Technical Reports Server (NTRS)

Atteia, J. L.; Barat, C.; Hurley, K.; Niel, M.; Vedrenne, G.; Evans, W. D.; Fenimore, E. E.; Klebesadel, R. W.; Laros, J. G.; Cline, T. L.

1985-01-01

Eighty-two gamma ray bursts were detected between 1978 September 14 and 1980 February 13 by the experiments of the interplanetary network (Prognoz 7, Venera 11 and 12 SIGNE experiments, Pioneer Venus Orbiter, International Sun-Earth Explorer 3, Helios 2, and Vela). Sixty-five of these events have been localized to annuli or error boxes by the method of arrival time analysis. The distribution of sources is consistent with isotropy, and there is no statistically convincing evidence for the detection of more than one burst from any source position. The localizations are compared with those of two previous catalogs.

Interactions of Dust Grains with Coronal Mass Ejections and Solar Cycle Variations of the F-Coronal Brightness

NASA Technical Reports Server (NTRS)

Ragot, B. R.; Kahler, S. W.

2003-01-01

The density of interplanetary dust increases sunward to reach its maximum in the F corona, where its scattered white-light emission dominates that of the electron K corona above about 3 Solar Radius. The dust will interact with both the particles and fields of antisunward propagating coronal mass ejections (CMEs). To understand the effects of the CME/dust interactions we consider the dominant forces, with and without CMEs. acting on the dust in the 3-5 Solar Radius region. Dust grain orbits are then computed to compare the drift rates from 5 to 3 Solar Radius. for periods of minimum and maximum solar activity, where a simple CME model is adopted to distinguish between the two periods. The ion-drag force, even in the quiet solar wind, reduces the drift time by a significant factor from its value estimated with the Poynting-Robertson drag force alone. The ion-drag effects of CMEs result in even shorter drift times of the large (greater than or approx. 3 microns) dust grains. hence faster depletion rates and lower dust-pain densities, at solar maxima. If dominated by thermal emission, the near-infrared brightness will thus display solar cycle variations close to the dust plane of symmetry. While trapping the smallest of the grains, the CME magnetic fields also scatter the grains of intermediate size (0.1-3 microns) in latitude. If light scattering by small grains close to the Sun dominates the optical brightness. the scattering by the CME magnetic fields will result in a solar cycle variation of the optical brightness distribution not exceeding 100% at high latitudes, with a higher isotropy reached at solar maxima. A good degree of latitudinal isotropy is already reached at low solar activity since the magnetic fields of the quiet solar wind so close to the Sun are able to scatter the small (less than or approx. 3 microns) grains up to the polar regions in only a few days or less, producing strong perturbations of their trajectories in less than half their orbital periods. Finally, we consider possible observable consequences of individual CME/dust interactions. We show that the dust grains very likely have no observable effect on the dynamics of CMEs. The effect of an individual CME on the dust grains, however, might serve as a forecasting tool for the directions and amplitudes of the magnetic fields within the CME.

Dynamic Dust Accumulation and Dust Removal Observed on the Mars Exploration Rover Magnets

NASA Technical Reports Server (NTRS)

Bertelsen, P.; Bell, J. F., III; Goetz, W.; Gunnlaugsson, H. P.; Herkenhoff, K. E.; Hviid, S. F.; Johnson, J. R.; Kinch, K. M.; Knudsen, J. M.; Madsen, M. B.

2005-01-01

The Mars Exploration Rovers each carry a set of Magnetic Properties Experiments designed to investigate the properties of the airborne dust in the Martian atmosphere. It is a preferred interpretation of previous experiments that the airborne dust in the Martian atmosphere is primarily composed by composite silicate particles containing one or more highly magnetic minerals as a minor constituent. The ultimate goal of the magnetic properties experiments on the Mars Exploration Rover mission is to provide some information/ constraints on whether the dust is formed by volcanic, meteoritic, aqueous, or other processes. The first problem is to identify the magnetic mineral(s) in the airborne dust on Mars. While the overall results of the magnetic properties experiments are presented in, this abstract will focus on dust deposition and dust removal on some of the magnets.

Light scattering by dust particles (PROGRA2 experiment): size and structure effects for transparent and absorbing materials

NASA Astrophysics Data System (ADS)

Hadamcik, E.; Renard, J.-B.; Lasue, J.; Levasseur-Regourd, A. C.

2007-08-01

1- Introduction Cometary and possibly interplanetary dust particles seem to be mainly made of agglomerates of submicron and micron-sized grains. These particles are among the most primitive in our solar system. Regoliths on asteroidal and planetary surfaces seem to be loose materials produced by impinging meteorites on the surface of small bodies. Comparing their physical properties is thus fundamental to understand their evolution. To interpret remote observations of solar light scattered by dust particles and regoliths, it is necessary to use numerical and experimental simulations [1,2,3]. 2- PROGRA2 experiment PROGRA2 instruments are polarimeters; the light sources are two randomly polarized lasers (632.8 nm and 543.5 nm). Levitating particles (in microgravity or lifted by an air-draught) are studied by imaging polarimetry. Details on the instruments can be found in [4,5]. 3- Samples Two kinds of samples are studied: compact particles in the (1-400) micrometer size range and fluffy aggregates in the same size range, made from submicron and micronsized grains. The materials are transparent silica and absorbing carbon. Some deposited particles are huge agglomerates of micron-sized grains produced by random ballistic deposition of single grains [6,7] or produced by evaporation of mixtures in alcohol of fluffy aggregates of submicron-sized grains. Two samples are made of silica spheres coated by a carbonaceous black compound. Cometary analogues are mixtures of silica and amorphous carbon or Mg-Fe silicates mixed with amorphous carbon. 4- Results Phase curves and their main parameters (negative polarization at small phase angles and maximum polarization, Pmax, at 90-100° phase angle) for the different materials will be compared and related to the physical properties. For example, it is well known by numerical simulations and/or by experiments that the maximum polarization decreases when the size (submicrometer range) of the grains increases [2,8,9]. An inverse rule is found for compact grains, larger than the wavelength. Mixtures of fluffy silica and fined grained amorphous carbon or better Mg-Fe silicates with amorphous carbon are excellent cometary particles analogues (as light scattering is concerned) if they are mixed with some compact micron-sized grains [9]. Nevertheless the structure of the aggregates seems to play a major role to obtain the negative branch found on the polarimetric phase curves for comets [10]. 5- Discussion and conclusions The experiments purpose is to help to disentangle the different physical properties of dust particles that can be deduced from remote observations (cometary dust, regoliths). Differences between the main parameters influencing the variations of Pmax and the presence of a negative branch on the polarimetric phase curves for lifted and deposited particles (in huge agglomerates or not) will be discussed. Acknowledgments: Technische Universität Carolo-Wilhelmina, Braunschweig, Deutschland (Pr Blum, Dr Schräpler); University of New Mexico, Albuquerque, USA (Pr Rietmeijer); NASA Goddard Space Flight Center, Maryland, USA (Dr Nuth) References [1] A.C. Levasseur-Regourd, E. Hadamcik, JQSRT 79-80, 903 (2003) [2] J. Lasue, A.C. Levasseur-Regourd, JQSRT 100, 220 (2006) [3] J.-B. Renard et al., ASR 31, 2511 (2003) [4] J.-B. Renard et al., Appl. Opt. 91, 609 (2002) [5] E. Hadamcik et al., JQSRT 106, 74 (2007) [6] J. Blum, R. Schreapler, Phys. Rev Let 93:115031 (2004) [7] J. Blum et al., Astrophys J 652, 1768 (2006) [8] R. West, Appl. Opt. 30, 5216 (1991) [9] E. Hadamcik et al., JQSRT 100, 143 (2006) [10] E. Hadamcik et al., Icarus, in press (2007)

Projectile compositions and modal frequencies on the chemistry of micrometeoroids LDEF experiment

NASA Technical Reports Server (NTRS)

Bernhard, Ronald P.; See, Thomas H.; Hoerz, Friedrich

1993-01-01

The Chemistry of Micrometeoroids Experiment (LDEF instrument A0187-1) exposed witness plates of high-purity gold (greater than 99.99 percent Au) and commercial aluminum (greater than 99 percent Al) with the objective of analyzing the residues of cosmic-dust and orbital-debris particles associated with hypervelocity impact craters. The gold substrates were located approximately 8 deg off LDEF's trailing edge (Bay A03), while the aluminum surfaces resided in Bay A11, approximately 52 deg from LDEF's leading edge. SEM-EDX techniques were employed to analyze the residues associated with 199 impacts on the gold and 415 impacts on the aluminum surfaces. The residues that could be analyzed represent natural or man-made materials. The natural particles dominate at all particle sizes less than 5 micron. It is possible to subdivide both particle populations into subclasses. Chondritic compositions dominate the natural impactors (71 percent), followed by monomineralic, mafic-silicate compositions (26 percent), and by Fe-Ni rich sulfides (approximately 3 percent). Approximately 30 percent of all craters on the gold collectors were caused by man-made debris such as aluminum, paint flakes, and other disintegrated, structural and electronic components. Equations-of-state and associated calculations of shock stresses for typical LDEF impacts into the gold and aluminum substrates suggest that substantial vaporization may have occurred during many of the impacts and is the reason why approximately 50 percent of all craters did not contain sufficient residue to permit analysis by the SEM-EDX technique. After converting the crater diameters into projectile sizes using encounter speeds typical for the trailing-edge and forward-facing (Row 11) directions, and accounting for normalized exposure conditions of the CME collectors, we derived the absolute and relative fluxes of specific projectile classes. The natural impactors encounter all LDEF pointing directions with comparable, modal frequencies suggesting compositional (and dynamic) homogeneity of the interplanetary-dust environment in near-Earth orbit.

Geochemical evidence for a comet shower in the late Eocene

USGS Publications Warehouse

Farley, K.A.; Montanari, A.; Shoemaker, E.M.; Shoemaker, C.S.

1998-01-01

Analyses of pelagic limestones indicate that the flux of extraterrestrial helium-3 to Earth was increased for a 2.5-million year (My) period in the late Eocene. The enhancement began ~1 My before and ended ~1.5 My after the major impact events that produced the large Popigai and Chesapeake Bay craters ~36 million years ago. The correlation between increased concentrations of helium-3, a tracer of fine-grained interplanetary dust, and large impacts indicates that the abundance of Earth-crossing objects and dustiness in the inner solar system were simultaneously but only briefly enhanced. These observations provide evidence for a comet shower triggered by an impulsive perturbation of the Oort cloud.

MultiLaue: A Technique to Extract d-spacings from Laue XRD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gainsforth, Zack; Marcus, Matthew A.; Tamura, Nobumichi

We present that broad spectrum X-ray Diffraction (XRD) is named Laue after Max von Laue, and is the original XRD technique. Today, monochromatic XRD is more common because Bragg's equation allows determination of d-spacings where Laue does not. Laue still remains in use for single crystal systems because it can be used to make very accurate unit cell determinations as well as for strain and orientation mapping. Lastly, a Laue technique which could provide unambiguous determination of lattice spacings, a la Bragg's equation would be a huge leap forward, especially for multiphase samples such as meteorites, interplanetary dust particles andmore » some geological specimens.« less

Deuterium Enrichment of PAHs by VUV Irradiation of Interstellar Ices

NASA Technical Reports Server (NTRS)

Bernstein, Max P.; Sandford, Scott A.; Allamandola, Louis J.; Gillette, J. Seb; Zare, Richard N.; DeVincenzi, Donald (Technical Monitor)

1998-01-01

Laboratory results demonstrate that polycyclic aromatic hydrocarbons (PAHs) rapidly exchange their hydrogen atoms with those of nearby molecules when they are frozen into low-temperature ices and exposed to vacuum ultraviolet radiation. As a result, PAHs quickly become deuterium-enriched when VUV irradiated in D-containing ices. This mechanism has important consequences for several astrophysical issues owing to the ubiquitous nature of PAHs in the interstellar medium. For example, this process may explain the deuterium enrichments found in PAHs in meteorites and interplanetary dust particles. These results also provide general predictions about the molecular siting of the deuterium on aromatic materials in meteorites if this process produced a significant fraction of their D-enrichment.

Prebiotic chemistry in clouds

NASA Technical Reports Server (NTRS)

Oberbeck, Verne R.; Marshall, John; Shen, Thomas

1991-01-01

The chemical evolution hypothesis of Woese (1979), according to which prebiotic reactions occurred rapidly in droplets in giant atmospheric reflux columns was criticized by Scherer (1985). This paper proposes a mechanism for prebiotic chemistry in clouds that answers Scherer's concerns and supports Woese's hypothesis. According to this mechanism, rapid prebiotic chemical evolution was facilitated on the primordial earth by cycles of condensation and evaporation of cloud drops containing clay condensation nuclei and nonvolatile monomers. For example, amino acids supplied by, or synthesized during entry of meteorites, comets, and interplanetary dust, would have been scavenged by cloud drops containing clay condensation nuclei and would be polymerized within cloud systems during cycles of condensation, freezing, melting, and evaporation of cloud drops.

MultiLaue: A Technique to Extract d-spacings from Laue XRD

DOE PAGES

Gainsforth, Zack; Marcus, Matthew A.; Tamura, Nobumichi; ...

2016-07-25

We present that broad spectrum X-ray Diffraction (XRD) is named Laue after Max von Laue, and is the original XRD technique. Today, monochromatic XRD is more common because Bragg's equation allows determination of d-spacings where Laue does not. Laue still remains in use for single crystal systems because it can be used to make very accurate unit cell determinations as well as for strain and orientation mapping. Lastly, a Laue technique which could provide unambiguous determination of lattice spacings, a la Bragg's equation would be a huge leap forward, especially for multiphase samples such as meteorites, interplanetary dust particles andmore » some geological specimens.« less

Some problems in interpretation of the New Horizons observations of Pluto's atmosphere

NASA Astrophysics Data System (ADS)

Krasnopolsky, Vladimir A.

2018-02-01

Here I briefly discuss the following problems related to Pluto's atmosphere: (1) restrictions to LTE in the rotational lines of H2O and HCN above 700 km that affect thermal balance of the atmosphere; (2) contradictions in the estimates of H2O influx from ablation of the interplanetary dust; (3) great difference between the haze volume surface area in the LORRI and MVIC observations and that in the UV solar occultations and the models, including significant corrections to sticking coefficients of C2H2, C2H4, C2H6, and HCN in condensation, and (4) Triton's thermosphere during the Voyager 2 flyby.

Focused Ion Beam Recovery and Analysis of Interplanetary Dust Particles (IDPs) and Stardust Analogues

NASA Technical Reports Server (NTRS)

Graham, G. A.; Bradley, J. P.; Bernas, M.; Stroud, R. M.; Dai, Z. R.; Floss, C.; Stadermann, F. J.; Snead, C. J.; Westphal, A. J.

2004-01-01

Meteoritics research is a major beneficiary of recent developments in analytical instrumentation [1,2]. Integrated studies in which multiple analytical techniques are applied to the same specimen are providing new insight about the nature of IDPs [1]. Such studies are dependent on the ability to prepare specimens that can be analyzed in multiple instruments. Focused ion beam (FIB) microscopy has revolutionized specimen preparation in materials science [3]. Although FIB has successfully been used for a few IDP and meteorite studies [1,4-6], it has yet to be widely utilized in meteoritics. We are using FIB for integrated TEM/NanoSIMS/synchrotron infrared (IR) studies [1].

Search for water and life's building blocks in the Universe: An Introduction

NASA Astrophysics Data System (ADS)

Kwok, Sun

Water and organics are commonly believed to be the essential ingredients for life on Earth. The development of infrared and submillimeter observational techniques has resulted in the detection of water in circumstellar envelopes, interstellar clouds, comets, asteroids, planetary satellites and the Sun. Complex organics have also been found in stellar ejecta, diffuse and molecular clouds, meteorites, interplanetary dust particles, comets and planetary satellites. In this Focus Meeting, we will discuss the origin, distribution, and detection of water and other life's building blocks both inside and outside of the Solar System. The possibility of extraterrestrial organics and water on the origin of life on Earth will also be discussed.

Interactive Soil Dust Aerosol Model in the GISS GCM. Part 1; Sensitivity of the Soil Dust Cycle to Radiative Properties of Soil Dust Aerosols

NASA Technical Reports Server (NTRS)

Perlwitz, Jan; Tegen, Ina; Miller, Ron L.

2000-01-01

The sensitivity of the soil dust aerosol cycle to the radiative forcing by soil dust aerosols is studied. Four experiments with the NASA/GISS atmospheric general circulation model, which includes a soil dust aerosol model, are compared, all using a prescribed climatological sea surface temperature as lower boundary condition. In one experiment, dust is included as dynamic tracer only (without interacting with radiation), whereas dust interacts with radiation in the other simulations. Although the single scattering albedo of dust particles is prescribed to be globally uniform in the experiments with radiatively active dust, a different single scattering albedo is used in those experiments to estimate whether regional variations in dust optical properties, corresponding to variations in mineralogical composition among different source regions, are important for the soil dust cycle and the climate state. On a global scale, the radiative forcing by dust generally causes a reduction in the atmospheric dust load corresponding to a decreased dust source flux. That is, there is a negative feedback in the climate system due to the radiative effect of dust. The dust source flux and its changes were analyzed in more detail for the main dust source regions. This analysis shows that the reduction varies both with the season and with the single scattering albedo of the dust particles. By examining the correlation with the surface wind, it was found that the dust emission from the Saharan/Sahelian source region and from the Arabian peninsula, along with the sensitivity of the emission to the single scattering albedo of dust particles, are related to large scale circulation patterns, in particular to the trade winds during Northern Hemisphere winter and to the Indian monsoon circulation during summer. In the other regions, such relations to the large scale circulation were not found. There, the dependence of dust deflation to radiative forcing by dust particles is probably dominated by physical processes with short time scales. The experiments show that dust radiative forcing can lead to significant changes both in the soil dust cycle and in the climate state. To estimate dust concentration and radiative forcing by dust more accurately, dust size distributions and dust single scattering albedo in the model should be a function of the source region, because dust concentration and climate response to dust radiative forcing are sensitive to dust radiative parameters.

Development of Mercury dust monitor (MDM) using piezo-electric sensor on boad BepiColombo spacecraft

NASA Astrophysics Data System (ADS)

Nogami, K.; Mercury Dust Team

BepiColombo spacecraft K.Nogami(1), S.Sasaki(2), T.Miyachi(3), H.Ohashi(4), M.Fujii(5), H.Shibata(6), T.Iwai(7), A.Fujiwara(8), H.Yano(8), S.Minami(9), S.Takechi(9), T.Ohnishi(9), R.Srama(10) and E.Grün(10) (1) Dokkyo Medical Univ., Japan, (2) National Astronomical Observatory of Japan, Japan, (3) Waseda Univ., Japan, (4) Tokyo Univ. Marine Science and Technology, Japan, (5) FAM Science Co. Ltd., Japan, (6) Kyoto Univ., Japan, (7) Univ. of Tokyo, Japan, (8) ISAS, JAXA, Japan, (9) Osaka City University, Japan, (10) Max Planck Institute for Nuclear Physics, Germany (nogami@dokkyomed.ac.jp / +81-282-87-2116 ) BepiColombo" project is the first large-sized Europe-Japan joint mission to provide the best understanding of Mercury to date. It consists of two individual orbiters: the Mercury Planetary Orbiter (MPO), that will map the planet, and the Mercury Magnetospheric Orbiter (MMO), that will investigate its magnetosphere. It will be launched in 2013. We will have a chance to put the dust monitor (MDM) on the MMO. This project is intended to reveal the dust environment near Mercury. The scientific interests are to investigate the flux and the variations of interplanetary meteoroid complex inside 1 AU. The Mercury dust monitor is a light-weight, heat resistant (˜300°C) piezoelectric ceramic (PZT) which will be installed on the side panel of the BepiColombo MMO spacecraft. Solar radiation near Mercury is ten times greater than near Earth, but the PZT sensor will endure this severe condition. The momentum, crude incoming direction and impact velocity of the cosmic dusts, with masses > 10-15 g are derived from the impact signal from the monitor. This dust monitor is composed of 4 flat PZT plate, 5cm x 5cm and 1mm thick each, and total sensitive area is almost 100 cm2 . The impact signals are processed by a digital circuit with about several 10 MHz A/D converters. From the rise time of the signals, we can know rough speed of the impact particles and also can separate the real impact signals from the noises. The weight of this PZT monitor is about 0.2 kg, and the weight of this circuit, include box and connector is about 0.4 kg and nominal power is less than 3W. Total weight of MDM system will be less than 0.6 kg. The calibration experiments of this system are made using Van de Graaff microparticle accelerators at HIT, Univ. of Tokyo in Japan ( silver or carbon particles, max speed ˜ 10 km/s ), and at MPI-K in Germany ( carbon, iron and silver particles, max speed ˜ 70 km/s ).

Microcrystals and Amorphous Material in Comets and Primitive Meteorites: Keys to Understanding Processes in the Early Solar System

NASA Technical Reports Server (NTRS)

Nuth, J. A.; Brearley, A. J.; Scott, E. R. D.

2004-01-01

Comets, fine-grained matrices of chondrites, and chondritic interplanetary dust particles (IDPs) are each composed of both crystalline and amorphous silicates. The primitive solar nebula, in which comets and asteroids accreted, was formed from the collapsed core of a Giant Molecular Cloud, that, in turn, condensed from materials present in the interstellar medium (ISM). Despite observations that reveal the presence of crystalline magnesium silicate minerals in the shells of very high mass-loss-rate stars [1,2], typical silicate grains in the ISM are most likely to be amorphous, given their relatively long residence time in such a high radiation environment. An upper limit of 3% crystalline grains can be derived from their non-detection in spectra of ISM solids [3]. If the vast majority of grains that enter the primitive solar nebula are amorphous, then the observation of crystalline dust in comets and primitive chondrite matrices indicates the action of specific processes required to transform the amorphous starting materials into the crystals that are observed.

Modeling Nucleation and Grain Growth in the Solar Nebula: Initial Progress Report

NASA Technical Reports Server (NTRS)

Nuth, Joseph A.; Paquette, J. A.; Ferguson, F. T.

2010-01-01

The primitive solar nebula was a violent and chaotic environment where high energy collisions, lightning, shocks and magnetic re-connection events rapidly vaporized some fraction of nebular dust, melted larger particles while leaving the largest grains virtually undisturbed. At the same time, some tiny grains containing very easily disturbed noble gas signatures (e.g., small, pre-solar graphite or SiC particles) never experienced this violence, yet can be found directly adjacent to much larger meteoritic components (chondrules or CAIs) that did. Additional components in the matrix of the most primitive carbonaceous chondrites and in some chondritic porous interplanetary dust particles include tiny nebular condensates, aggregates of condensates and partially annealed aggregates. Grains formed in violent transient events in the solar nebula did not come to equilibrium with their surroundings. To understand the formation and textures of these materials as well as their nebular abundances we must rely on Nucleation Theory and kinetic models of grain growth, coagulation and annealing. Such models have been very uncertain in the past: we will discuss the steps we are taking to increase their reliability.

The role of phosphorus in chemical evolution.

PubMed

Maciá, Enrique

2005-08-01

In this tutorial review we consider the role of phosphorus and its compounds within the context of chemical evolution in galaxies. Following an interdisciplinary approach we first discuss the position of P among the main biogenic elements by considering its relevance in most essential biochemical functions as well as its peculiar chemistry under different physicochemical conditions. Then we review the phosphorus distribution in different cosmic sites, such as terrestrial planets, interplanetary dust particles, cometary dust, planetary atmospheres and the interstellar medium (ISM). In this way we realize that this element is both scarce and ubiquitous in the universe. These features can be related to the complex nucleosynthesis of P nuclide in the cores of massive stars under explosive conditions favouring a wide distribution of this element through the ISM, where it would be ready to react with other available atoms. A general tendency towards more oxidized phosphorus compounds is clearly appreciated as chemical evolution proceeds from circumstellar and ISM materials to protoplanetary and planetary condensed matter phases. To conclude we discuss some possible routes allowing for the incorporation of phosphorus compounds of prebiotic interest during the earlier stages of solar system formation.

Interplanetary dust profile observed on Juno's cruise from Earth to Jupiter

NASA Astrophysics Data System (ADS)

Joergensen, J. L.; Benn, M.; Jørgensen, P. S.; Denver, T.; Jørgensen, F. E.; Connerney, J. E. P.; Andersen, A. C.; Bolton, S. J.; Levin, S.

2017-12-01

Juno was launched August 5th, 2011, and entered the highly-elliptical polar orbit about Jupiter on July 4th, 2016, some 5 years later. Juno's science objectives include the mapping of Jupiter's gravity and magnetic fields and observation of the planet's deep atmosphere, aurora and polar regions. The Juno spacecraft is a large spin-stabilized platform powered by three long solar panel structures, 11 m in length, extending radially outward from the body of the spacecraft with panel normal parallel to the spacecraft spin axis. During almost 5 years in cruise, Juno traversed the inner part of the solar system, from Earth, to a deep space maneuver at 2.2AU, back to 0.8AU for a subsequent rendezvous with Earth for gravity assist, and then out to Jupiter (at 5.4AU at the time of arrival). The solar panels were nearly sun-pointing during the entire cruise phase, with the 60 m2 of solar panel area facing the ram direction (panel normal parallel to the spacecraft velocity vector). Interplanetary Dust Particles (IPDs) impacting Juno's solar panels with typical relative velocities of 20 km/s excavate target mass, some of which will leave the spacecraft at moderate speeds (few m/s) in the form of a few large spallation products. Many of these impact ejecta have been recorded and tracked by one of the autonomous star trackers flown as part of the Juno magnetometer investigation (MAG). Juno MAG instrumentation is accommodated on a boom at the end of one of the solar arrays, and consists of two magnetometer sensor suites each instrumented with two star trackers for accurate attitude determination at the MAG sensors. One of the four star trackers was configured to report such fast moving objects, effectively turning Juno's large solar array area into the largest-aperture IPD detector ever flown - by far. This "detector", by virtue of its prodigious collecting area, is sensitive to the relatively infrequent impacts of particles much larger (at 10's of microns) than those collected in space by dedicated dust detectors. These impactors are those responsible for the zodiacal light. We present the distribution and orbital characteristics of such IDPs as a function of distance from the Sun, and discuss possible sources of origin of these IDPs.

The Preservation of Cometary Organics in Stardust Aerogel

NASA Astrophysics Data System (ADS)

Clemett, Simon; Nakamura-Messenger, Keiko; Sandford, Scott; McKay, David

It has been recognized for many years that the continuous global accretion of organic matter from comets and carbonaceous asteroids, over geological timescales, to the surfaces of both Earth and Mars may have played a significant role in the prebiotic chemical evolution of these planets [1]. The dominant mass fraction of accreted meteoritic material is in the form of interplanetary dust for which the current accretion rate is estimated at ˜ 40±20 Gg·yr-1 [2]. Our understanding of the organic matter present in interplanetary dust is, however, limited by the analytical challenges involved in the molecular analysis of heterogeneous micron sized particles. We have used the technique of ultrafast two-step laser mass spectrometry (µltra-L2 MS) to investigate the nature and distribution of the aromatic organic matter present in individual dust particles from comet P81/Wild 2 collected in aerogel by the STARDUST sample return mission [3]. Complex aromatic hydrocarbons have been detected in cometary particles entrained along multiple aerogel tracks. Although terrestrial contamination from the aerogel remains a concern, a substantial fraction is interpreted as indigenous. The spectral complexity is atypical of carbonaceous and ordinary chondrites. While simple fused ring polycyclic aromatic hydrocarbon (PAHs) such as naphthalene (C10 H8 ), acenaphthalene (C12 H8 ), phenanthrene (C14 H10 ) are present along with their homologous alkylation series (Ar-(CH2 )n -H) there are additionally many prominent odd-mass species present. These are consistent with several interleaved alkylation series of N-containing PAHS (NPAHs) in the form of nitriles (Ar-CN). These species may be related to the 2.3 & 4.6 µm 'XCN' adsorption features observed in the spectra of many young stellar objects and some comets, which is believed to be synthesized by ultraviolet and/or ion bombardment of precometary ices in circumstellar environments. The presence of organo-N species is of particular importance to the organic inventory of the the early Earth since its abiotic synthesis would have been extremely slow due to the difficulty in cleaving the N≡N triple bond in the absence of biology. [1] Anders (1989) Nature 342, 255; [2] Love & Brownlee (1993) Science 262, 550; Clemett et al. MAPS (submited)

Interstellar and Cometary Dust

NASA Technical Reports Server (NTRS)

Mathis, John S.

1997-01-01

'Interstellar dust' forms a continuum of materials with differing properties which I divide into three classes on the basis of observations: (a) diffuse dust, in the low-density interstellar medium; (b) outer-cloud dust, observed in stars close enough to the outer edges of molecular clouds to be observed in the optical and ultraviolet regions of the spectrum, and (c) inner-cloud dust, deep within the cores of molecular clouds, and observed only in the infrared by means of absorption bands of C-H, C=O, 0-H, C(triple bond)N, etc. There is a surprising regularity of the extinction laws between diffuse- and outer-cloud dust. The entire mean extinction law from infrared through the observable ultraviolet spectrum can be characterized by a single parameter. There are real deviations from this mean law, larger than observational uncertainties, but they are much smaller than differences of the mean laws in diffuse- and outer-cloud dust. This fact shows that there are processes which operate over the entire distribution of grain sizes, and which change size distributions extremely efficiently. There is no evidence for mantles on grains in local diffuse and outer-cloud dust. The only published spectra of the star VI Cyg 12, the best candidate for showing mantles, does not show the 3.4 micro-m band which appreciable mantles would produce. Grains are larger in outer-cloud dust than diffuse dust because of coagulation, not accretion of extensive mantles. Core-mantle grains favored by J. M. Greenberg and collaborators, and composite grains of Mathis and Whiffen (1989), are discussed more extensively (naturally, I prefer the latter). The composite grains are fluffy and consist of silicates, amorphous carbon, and some graphite in the same grain. Grains deep within molecular clouds but before any processing within the solar system are presumably formed from the accretion of icy mantles on and within the coagulated outer-cloud grains. They should contain a mineral/carbonaceous matrix, without organic refractory mantles, in between the ices. Unfortunately, they may be significantly processed by chemical processes accompanying the warming (over the 10 K of the dark cloud cores) which occurs in the outer solar system. Evidence of this processing is the chemical anomalies present in interplanetary dust particles collected in the stratosphere, which may be the most primitive materials we have obtained to date. The comet return mission would greatly clarify the situation, and probably provide samples of genuine interstellar grains.

Skylab experiments. Volume 5: Astronomy and space physics. [Skylab observations of galactic radiation, solar energy, and interplanetary composition for high school level education

NASA Technical Reports Server (NTRS)

1973-01-01

The astronomy and space physics investigations conducted in the Skylab program include over 20 experiments in four categories to explore space phenomena that cannot be observed from earth. The categories of space research are as follows: (1) phenomena within the solar system, such as the effect of solar energy on Earth's atmosphere, the composition of interplanetary space, the possibility of an inner planet, and the X-ray radiation from Jupiter, (2) analysis of energetic particles such as cosmic rays and neutrons in the near-earth space, (3) stellar and galactic astronomy, and (4) self-induced environment surrounding the Skylab spacecraft.

Efficiency of Tungsten Dust Collection of Different Types of Dust Particles by Electrostatic Probe

NASA Astrophysics Data System (ADS)

Begrambekov, L. B.; Voityuk, A. N.; Zakharov, A. M.; Bidlevich, O. A.; Vechshev, E. A.; Shigin, P. A.; Vayakis, J.; Walsh, M.

2017-12-01

Formation of dust particles and clusters is observed in almost every modern thermonuclear facility. Accumulation of dust in the next generation thermonuclear installations can dramatically affect the plasma parameters and lead to the accumulation of unacceptably large amounts of tritium. Experiments on collection of dust particles by a model of electrostatic probe developed for collection of metallic dust at ITER are described in the article. Experiments on the generation of tungsten dust consisting of flakes formed during the destruction of tungsten layers formed on the walls of the plasma chamber sputtered from the surface of the tungsten target by plasma ions were conducted. The nature of dust degassing at elevated temperatures and the behavior of dust in an electric field were studied. The results obtained are compared with the results of the experiments with dust consisting of crystal particles of simple geometric shapes. The effectiveness of collection of both types of dust using the model of an electrostatic probe is determined.

Radiation Processing of Polycyclic Aromatic Hydrocarbons (PAHs) in Space: ICEE PoC

NASA Technical Reports Server (NTRS)

Mattioda, Andrew; Cruz-Diaz, Gustavo; Barnhardt, Michael; Ging, Andrew; Schneider, Todd; Vaughn, Jason; Quigley, Emmett; Phillips, Brandon

2017-01-01

Small Polycyclic Aromatic Hydrocarbon molecules or PAHs (<30 carbon atoms) have been identified in comets, meteorites, asteroids, and interplanetary dust particles in our Solar System, while PAHs in the Interstellar Medium (ISM) tend to be much larger, usually between 50 to 100 carbon atoms in size. The cause of the size disparity between PAHs found in the ISM and Solar System as well as their influence on Solar System organics is not yet understood. Two chemical evolutionary paths have been proposed to explain the inventory of solar system organics. In one the prebiotic material was formed from the radiation induced modification of large pre-solar carbon-bearing species (e.g. ISM PAHs). The second path suggests that Solar System prebiotic matter is the result of bottom-up synthesis from small reactive molecules after the Solar System was formed. In this second scenario very few ISM PAHs survived the harsh pre-solar radiation as aromatic structures. ICEE PoC (ICEE Proof of Concept) investigated factors impacting the chemical evolution of large PAHs irradiated under conditions similar to the proto-solar nebula. Likewise ICEE PoC will refine the technical parameters of the proposed ICEE (Institute for Carbon Evolution Experiment) laboratory.

Insight into Primordial Solar System Oxygen Reservoirs from Returned Cometary Samples

NASA Technical Reports Server (NTRS)

Brownlee, D. E.; Messenger, S.

2004-01-01

The recent successful rendezvous of the Stardust spacecraft with comet Wild-2 will be followed by its return of cometary dust to Earth in January 2006. Results from two separate dust impact detectors suggest that the spacecraft collected approximately the nominal fluence of at least 1,000 particles larger than 15 micrometers in size. While constituting only about one microgram total, these samples will be sufficient to answer many outstanding questions about the nature of cometary materials. More than two decades of laboratory studies of stratospherically collected interplanetary dust particles (IDPs) of similar size have established the necessary microparticle handling and analytical techniques necessary to study them. It is likely that some IDPs are in fact derived from comets, although complex orbital histories of individual particles have made these assignments difficult to prove. Analysis of bona fide cometary samples will be essential for answering some fundamental outstanding questions in cosmochemistry, such as (1) the proportion of interstellar and processed materials that comprise comets and (2) whether the Solar System had a O-16-rich reservoir. Abundant silicate stardust grains have recently been discovered in anhydrous IDPs, in far greater abundances (200 5,500 ppm) than those in meteorites (25 ppm). Insight into the more subtle O isotopic variations among chondrites and refractory phases will require significantly higher precision isotopic measurements on micrometer-sized samples than are currently available.

MISR Browse Images: Puerto Rico Dust Experiment (PRiDE)

Atmospheric Science Data Center

2013-04-02

MISR Browse Images: Puerto Rico Dust Experiment (PRiDE) These MISR Browse ... a quick visual overview of the region observed during the Puerto Rico Dust Experiment (PRiDE) field campaign. PRiDE was a study of the ...

Precipitation of low energy electrons at high latitudes: Effects of substorms, interplanetary magnetic field and dipole tilt angle

NASA Technical Reports Server (NTRS)

Burch, J. L.

1972-01-01

Data from the auroral particles experiment on OGO-4 were used to study effects of substorm activity, interplanetary magnetic field latitutde, and dipole tilt angle on high-latitude precipitation of 700 eV electrons. It was found that: (1) The high-latitude zone of 700 eV electron precipitation in late evening and early morning hours moves equatorward by 5 to 10 deg during substorms. (2) The low-latitude boundary of polar cusp electron precipitation at 9 to 15 hours MLT also moves equatorward by several degrees during substorms and, in the absence of significant substorm activity, after a period of southward interplanetary magnetic field. (3) With times containing substorm activity or a southward interplanetary magnetic field eliminated, the low-latitude boundary of polar cusp electron precipitation is found to move by approximately 4 deg over the total yearly range of tilt angles. At maximum winter and summer conditions the invariant latitude of the boundary is shown to shift by approximately -3 deg and +1 deg respectively from its equinox location.

Chemically anomalous, pre-accretionally irradiated grains in interplanetary dust -- interstellar grains?. [Abstract only

NASA Technical Reports Server (NTRS)

Bradley, J. P.

1994-01-01

Ultrafine-grained matrix is a unique and fundamental building block of chondritic porous (CP) interplanetary dust particles. Most IDPs so far determined to be of cometary origin belong to the CP class. The matrix in CP IDPs is not homogeneous but rather a loose mixture of discrete single crystals (e.g., olivine, pyroxene, Fe sulfides) and polyphase grains. The petrographic diversity observed among the polyphase grains suggest that they were formed under variable physiochemical conditions. One particular class of polyphase grains are a dominant component in cometary IDPs. Although their occurrence is well documented, the terminology used to describe them is confused. They have been called many names. Here they are simply called GEMS (Glass with Embedded Metal and Sulfides). The bulk compositions of GEMS are within a factor of 3 chondritic (solar) for all major elements except C. Quantitative thin-film X-ray (EDS) analyses have shown that GEMS are systematically depleted in Mg and Si, enriched in S, Fe, and Ni, and stoichiometrically enriched in O. Electron energy-loss spectroscopy (EELS) suggests that the excess O is present as hydroxyl (-OH) groups. These same chemical 'anomalies' were observed in solar-wind-irradiated amorphous rims on the surfaces of IDPs, suggesting that the compositions of GEMS reflect prior exposure to ionizing radiation. In order to test this hypothesis, a sample of Allende (CV3) matrix was exposed to proton flux. Radiation-damaged amorphous rims on olivine and pyroxene crystals in the Allende sample were found to be depleted in Mg and Ca, enriched in S, Fe, and Ni, and stoichiometrically enriched in O. Thus, the compositions of GEMS are indeed consistent with exposure to ionizing radiation. This study suggests that chemical as well as isotopic anomalies may be used to identify presolar interstellar grains in primitive meteoritic materials.

Exospheres from Asteroids to Planets

NASA Astrophysics Data System (ADS)

Killen, Rosemary M.; Burger, Matthew H.; Farrell, William M.; DREAM2

2016-10-01

The study of exospheres can help us understand the long-term loss of volatiles from planetary bodies due to interactions of planets, satellites, and small bodies with the interplanetary medium (solar wind, meteors, and dust), solar radiation, internal forces including diffusion and outgassing, and surface effects like sticking and chemistry. Recent evidence for water and OH on the moon has spurred interest in processes involving chemistry and sequestration of volatile species at the poles and in voids. In recent years, NASA has sent spacecraft to asteroids including Vesta and Ceres, and ESA sent Rosetta to the asteroids Lutetia and Steins. OSIRIS-REX will return a sample from a primitive asteroid, Bennu, to Earth. It is possible that a Phobos-Deimos flyby will be a precursor to a manned mission to Mars. Exospheric particles are derived from the surface and to some extent from interplanetary dust and meteoroids. By comparing the exospheric compositions before and after major meteor shower events it may be possible to determine the extent to which the exosphere reflects the surface composition. Observation of an escaping exosphere, termed a corona, is challenging. We therefore have embarked on a parametrical study of exospheres as a function of basic controlling parameters such as the mass of the primary object, mass of the exospheric species, heliocentric distance, rotation rate of the primary, composition of the body (asteroid type or icy body). These parameters will be useful for mission planning as well as quick look data to determine the size and location of bodies likely to retain their exospheres and observability of exospheric species. We will also consider the sizes of small clusters that may be gravitationally bound to small bodies such as Phobos. In addition, it is of interest to be able to determine the extent of contamination of the pristine exosphere due to the spacecraft sent to make measurements, and the effect on the measurements of outgassing in the instruments.

Water and organics in interplanetary dust particles

NASA Astrophysics Data System (ADS)

Bradley, John P.

2015-08-01

Interplanetary dust particles (IDPs) and larger micrometeorites (MMs) impinge on the upper atmosphere where they decelerate at ~90 km altitude and settle to the Earth’s surface. Comets and asteroids are the major sources and the flux, 30,000-40,000 tons/yr, is comparable to the mass of larger meteorites impacting the Earth’s surface. The sedimentary record suggests that the flux was much higher on the early Earth. The chondritic porous (CP) subset of IDPs together with their larger counterparts, ultracarbonaceous micrometeorites (UCMMs), appear to be unique among known meteoritic materials in that they are composed almost exclusively of anhydrous minerals, some of them contain >> 50% organic carbon by volume as well as the highest abundances of presolar silicate grains including GEMS. D/H and 15N abundances implicate the Oort Cloud or presolar molecular cloud as likely sources of the organic carbon. Prior to atmospheric entry, IDPs and MMs spend ~104-105 year lifetimes in solar orbit where their surfaces develop amorphous space weathered rims from exposure to the solar wind (SW). Similar rims are observed on lunar soil grains and on asteroid Itokawa regolith grains. Using valence electron energy-loss spectroscopy (VEELS) we have detected radiolytic water in the rims on IDPs formed by the interaction of solar wind protons with oxygen in silicate minerals. Therefore, IDPs and MMs continuously deliver both water and organics to the earth and other terrestrial planets. The interaction of protons with oxygen-rich minerals to form water is a universal process.Affiliations:a University of Hawaii at Manoa, Hawaii Institute of Geophysics and Planetology, 1680 East-West Road, Honolulu, HI 96822, USA.b National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.c Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.d Department of Materials Science & Engineering, University of California, Berkeley, CA 94720, USA.e Advanced Light Source Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.

Extraterrestrial organic matter: a review

NASA Technical Reports Server (NTRS)

Irvine, W. M.

1998-01-01

We review the nature of the widespread organic material present in the Milky Way Galaxy and in the Solar System. Attention is given to the links between these environments and between primitive Solar System objects and the early Earth, indicating the preservation of organic material as an interstellar cloud collapsed to form the Solar System and as the Earth accreted such material from asteroids, comets and interplanetary dust particles. In the interstellar medium of the Milky Way Galaxy more than 100 molecular species, the bulk of them organic, have been securely identified, primarily through spectroscopy at the highest radio frequencies. There is considerable evidence for significantly heavier organic molecules, particularly polycyclic aromatics, although precise identification of individual species has not yet been obtained. The so-called diffuse interstellar bands are probably important in this context. The low temperature kinetics in interstellar clouds leads to very large isotopic fractionation, particularly for hydrogen, and this signature is present in organic components preserved in carbonaceous chondritic meteorites. Outer belt asteroids are the probable parent bodies of the carbonaceous chondrites, which may contain as much as 5% organic material, including a rich variety of amino acids, purines, pyrimidines, and other species of potential prebiotic interest. Richer in volatiles and hence less thermally processed are the comets, whose organic matter is abundant and poorly characterized. Cometary volatiles, observed after sublimation into the coma, include many species also present in the interstellar medium. There is evidence that most of the Earth's volatiles may have been supplied by a 'late' bombardment of comets and carbonaceous meteorites, scattered into the inner Solar System following the formation of the giant planets. How much in the way of intact organic molecules of potential prebiotic interest survived delivery to the Earth has become an increasingly debated topic over the last several years. The principal source for such intact organics was probably accretion of interplanetary dust particles of cometary origin.

Sub-Micrometer Scale Minor Element Mapping in Interplanetary Dust Particles: A Test for Stratospheric Contamination

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Keller, L. P.; Sutton, S. R.

2004-01-01

Combined X-ray microprobe (XRM), energy dispersive x-ray fluorescence using a Transmission Electron Microscope (TEM), and electron microprobe measurements have determined that the average bulk chemical composition of the interplanetary dust particles (IDPs) collected from the Earth s stratosphere is enriched relative to the CI meteorite composition by a factor of 2 to 4 for carbon and for the moderately volatile elements Na, K, P, Mn, Cu, Zn, Ga, Ge, and Se, and enriched to approximately 30 times CI for Br. However, Jessberger et al., who have reported similar bulk enrichments using Proton Induced X-ray Emission (PIXE), attribute the enrichments to contamination by meteor-derived atmospheric aerosols during the several weeks these IDPs reside in the Earth s atmosphere prior to collection. Using scanning Auger spectroscopy, a very sensitive surface analysis technique, Mackinnon and Mogk have observed S contamination on the surface of IDPs, presumably due to the accretion of sulfate aerosols during stratospheric residence. But the S-rich layer they detected was so thin (approximately 100 angstroms thick) that the total amount of S on the surface was too small to significantly perturb the bulk S-content of a chondritic IDP. Stephan et al. provide support for the contamination hypothesis by reporting the enrichment of Br on the edges of the IDPs using Time-of-Flight Secondary-Ion Mass-Spectrometry (TOFSIMS), but TOF-SIMS is notorious for producing false edge-effects, particularly on irregularly-shaped samples like IDPs. Sutton et al. mapped the spatial distribution of Fe, Ni, Zn, Br, and Sr, at the approximately 2 m scale, in four IDPs using element-specific x-ray fluorescence (XRF) computed microtomography. They found the moderately volatile elements Zn and Br, although spatially inhomogeneous, were not concentrated on the surface of any of the IDPs they examined, suggesting that the Zn and the Br enrichments in the IDPs are not due to contamination during stratospheric residence.

Dome C ultracarbonaceous Antarctic micrometeorites. Infrared and Raman fingerprints

NASA Astrophysics Data System (ADS)

Dartois, E.; Engrand, C.; Duprat, J.; Godard, M.; Charon, E.; Delauche, L.; Sandt, C.; Borondics, F.

2018-01-01

Context. UltraCarbonaceous Antarctic MicroMeteorites (UCAMMs) represent a small fraction of interplanetary dust particles reaching the Earth's surface and contain large amounts of an organic component not found elsewhere. They are most probably sampling a contribution from the outer regions of the solar system to the local interplanetary dust particle (IDP) flux. Aims: We characterize UCAMMs composition focusing on the organic matter, and compare the results to the insoluble organic matter (IOM) from primitive meteorites, IDPs, and the Earth. Methods: We acquired synchrotron infrared microspectroscopy (μFTIR) and μRaman spectra of eight UCAMMs from the Concordia/CSNSM collection, as well as N/C atomic ratios determined with an electron microprobe. Results: The spectra are dominated by an organic component with a low aliphatic CH versus aromatic C=C ratio, and a higher nitrogen fraction and lower oxygen fraction compared to carbonaceous chondrites and IDPs. The UCAMMs carbonyl absorption band is in agreement with a ketone or aldehyde functional group. Some of the IR and Raman spectra show a C≡N band corresponding to a nitrile. The absorption band profile from 1400 to 1100 cm-1 is compatible with the presence of C-N bondings in the carbonaceous network, and is spectrally different from that reported in meteorite IOM. We confirm that the silicate-to-carbon content in UCAMMs is well below that reported in IDPs and meteorites. Together with the high nitrogen abundance relative to carbon building the organic matter matrix, the most likely scenario for the formation of UCAMMs occurs via physicochemical mechanisms taking place in a cold nitrogen rich environment, like the surface of icy parent bodies in the outer solar system. The composition of UCAMMs provides an additional hint of the presence of a heliocentric positive gradient in the C/Si and N/C abundance ratios in the solar system protoplanetary disc evolution. Part of the equipment used in this work has been financed by the French INSU-CNRS program "Physique et Chimie du Milieu Interstellaire" (PCMI).

Imaging Interplanetary CMEs at Radio Frequency From Solar Polar Orbit

NASA Astrophysics Data System (ADS)

Wu, Ji; Sun, Weiying; Zheng, Jianhua; Zhang, Cheng; Wang, Chi; Wang, C. B.; Wang, S.

Coronal mass ejections (CMEs) are violent discharges of plasma and magnetic fields from the Sun's corona. They have come to be recognized as the major driver of physical conditions in the Sun-Earth system. Consequently, the detection of CMEs is important for un-derstanding and ultimately predicting space weather conditions. The Solar Polar Orbit Radio Telescope (SPORT) is a proposed mission to observe the propagation of interplanetary CMEs from solar polar orbit. The main payload (radio telescope) on board SPORT will be an in-terferometric imaging radiometer working at the meter wavelength band, which will follow the propagation of interplanetary CMEs from a distance of a few solar radii to near 1 AU from solar polar orbit. The SPORT spacecraft will also be equipped with a set of optical and in situ measurement instruments such as a EUV solar telescope, a solar wind plasma experiment, a solar wind ion composition instrument, an energetic particle detector, a wave detector, a mag-netometer and an interplanetary radio burst tracker. In this paper, we first describe the current shortage of interplanetary CME observations. Next, the scientific motivation and objectives of SPORT are introduced. We discuss the basic specifications of the main radio telescope of SPORT with reference to the radio emission mechanisms and the radio frequency band to be observed. Finally, we discuss the key technologies of the SPORT mission, including the con-ceptual design of the main telescope, the image retrieval algorithm and the solar polar orbit injection. Other payloads and their respective observation objectives are also briefly discussed. Key words: Interplanetary CMEs; Interferometric imaging; Solar polar orbit; Radiometer.

Progress of the Dust Accumulation and Removal Technology Experiment (DART) for the Mars 2001 Lander

NASA Technical Reports Server (NTRS)

Jenkins, Phillip; Landis, Geoffrey A.; Wilt, David; Krasowski, Michael; Greer, Lawrence; Baraona, Cosmo; Scheiman, David

2005-01-01

Dust deposition could be a significant problem for photovoltaic array operation for long duration missions on the surface of Mars. Measurements made by Pathfinder showed 0.3 percent loss of solar array performance per day due to dust obscuration. We have designed an experiment package, "DART", which is part of the Mars ISPP Precursor (MIP) package, to fly on the Mars-2001 Surveyor Lander. This mission, to launch in April 2001, will arrive on Mars in January 2002. The DART experiment is designed to quantify dust deposition from the Mars atmosphere, measure the properties of settled dust, measure the effect of dust deposition on array performance, and test several methods of clearing dust from solar cells.

The gravitational wave experiment

NASA Technical Reports Server (NTRS)

Bertotti, B.; Ambrosini, R.; Asmar, S. W.; Brenkle, J. P.; Comoretto, G.; Giampieri, G.; Less, L.; Messeri, A.; Wahlquist, H. D.

1992-01-01

Since the optimum size of a gravitational wave detector is the wave length, interplanetary dimensions are needed for the mHz band of interest. Doppler tracking of Ulysses will provide the most sensitive attempt to date at the detection of gravitational waves in the low frequency band. The driving noise source is the fluctuations in the refractive index of interplanetary plasma. This dictates the timing of the experiment to be near solar opposition and sets the target accuracy for the fractional frequency change at 3.0 x 10 exp -14 for integration times of the order of 1000 sec. The instrumentation utilized by the experiment is distributed between the radio systems on the spacecraft and the seven participating ground stations of the Deep Space Network and Medicina. Preliminary analysis is available of the measurements taken during the Ulysses first opposition test.

Post-launch data analysis for the cosmic ray isotope experiment ONR-604 in the Combined Release and Radiation Effects Satellite (CRRES)

NASA Technical Reports Server (NTRS)

Simpson, John A.; Garcia-Munoz, Moises

1995-01-01

Research was continued on the origins, acceleration mechanisms, and the propagation modes of the hierarchy of energetic charged particles found in a wide range of astrophysical settings, extending from the cosmic rays arriving from the depth of the galaxy to the energetic particles in the heliosphere and in the near earth environment. In particular this grant has been a vital support in the investigation of the particle radiations in the earth's magnetosphere. The ONR-604 instrument was launched in July 1990 aboard the CRRES spacecraft. The CRRES mission has been a joint program of NASA and the U.S. Air Force Space Test Program which has provided launch support and telemetry coverage. The spacecraft was placed into a low-inclination eccentric orbit with a period of approximately 10 hours, and thus measured charged particle fluxes in both interplanetary space and in the earth's trapped radiation. ONR-604 performed extremely well, both in interplanetary space and in the intense radiation belt environment. We were able to make detailed measurements of interplanetary fluxes and composition into L=4, or for more than 50% of the orbital period. Thus the experiment produced two valuable datasets, one set outside of L=4 for interplanetary studies, and one set inside of L=4 for radiation belt studies. The data returned by the University of Chicago ONR-604 instrument has been the base for 10 papers on magnetospheric and galactic energetic-particle research.

Experimental studies of two-stage centrifugal dust concentrator

NASA Astrophysics Data System (ADS)

Vechkanova, M. V.; Fadin, Yu M.; Ovsyannikov, Yu G.

2018-03-01

The article presents data of experimental results of two-stage centrifugal dust concentrator, describes its design, and shows the development of a method of engineering calculation and laboratory investigations. For the experiments, the authors used quartz, ceramic dust and slag. Experimental dispersion analysis of dust particles was obtained by sedimentation method. To build a mathematical model of the process, dust collection was built using central composite rotatable design of the four factorial experiment. A sequence of experiments was conducted in accordance with the table of random numbers. Conclusion were made.

Electrodynamic Dust Shield for Lunar/ISS Experiment Project

NASA Technical Reports Server (NTRS)

Zeitlin, Nancy; Calle, Carlos; Hogue, Michael; Johansen, Michael; Mackey, Paul

2015-01-01

The Electrostatics and Surface Physics Laboratory at Kennedy Space Center is developing a dust mitigation experiment and testing it on the lunar surface and on the International Space Station (ISS). The Electrodynamic Dust Shield (EDS) clears dust off surfaces and prevents accumulation by using a pattern of electrodes to generate a non-uniform electric field over the surface being protected. The EDS experiment will repel dust off materials such as painted Kapton and glass to demonstrate applications for thermal radiators, camera lenses, solar panels, and other hardware and equipment.

Microgravity combustion of dust clouds: Quenching distance measurements

NASA Technical Reports Server (NTRS)

Goroshin, S.; Kleine, H.; Lee, J. H. S.; Frost, D.

1995-01-01

The current level of physical understanding of dust combustion phenomena is still in a rudimentary state compared with the understanding of gas combustion processes. The reason for such a lack of fundamental understanding is partially based on the complexity of multiphase combustion and the enormous diversity of chemical-physical properties of heterogeneous combustible mixtures but is largely due to difficulties in the experimental investigation of dust combustion. The influence of gravity on a dust suspension is the main reason. First of all, when particulates (either solid particles or liquid droplets) with a characteristic size of the order of tens of microns are suspended, they rapidly settle in the gravitational field. To maintain a particulate suspension for a time duration adequate to carry out combustion experiments invariably requires continuous convection of particulates at or in excess of the gravitational settling velocity. Of necessity, this makes the experiments turbulent in character and makes it impossible to study laminar dust flames. For particle sizes of the order of microns a stable laminar dust flow can be maintained only for relatively small dust concentrations (e.g., for low fuel equivalence ratios) at normal gravity conditions. High dust loading leads to gravitational instability of the dust cloud and to the formation of recirculation cells in a dust suspension in a confined volume, or to the rapid sedimentation of the dense dust cloud as a whole in an unconfined volume. In addition, many important solid fuels such as low volatile coal, carbon, and boron have low laminar flame speeds (of the order of several centimeters per second). Gravitational convection that occurs in combustion products due to the buoyancy forces disrupts low speed dust flames and, therefore, makes observation of such flames at normal gravity impossible. The only way to carry out 'clean' fundamental experiments in dust combustion over a wide range of dust cloud parameters is in a gravity-free environment. Access to the microgravity environment provided by the use of large-scale drop towers, parabolic flights of aircraft and rockets, and shuttle and space station orbits has permitted now to proceed with a systematic program of dust combustion microgravity research. For example, the NASA-Lewis drop tower and a Lear jet parabolic flight aircraft were used by Ross et al. and by Berlad and Tangirala for experiments with Iycopodium/air mixtures. The Japan Microgravity Center drop shaft (JAMIC) where a microgravity condition of 10(exp -4) g for 10 s is available, was recently used by Kobayashi, Niioka et al. for measuring flame propagation velocities in polymethyl methacrylate dust/air suspensions. Microgravity dust combustion experiments were started at McGill University in the early 90's under the sponsorship of the Canadian Space Agency. Several generations of dust combustion platforms permitting dust combustion microgravity experiments to be carried out on board a parabolic flight aircraft (KC-135, NASA) have been designed and tested. The experimental data and experience gained from this research allowed us to design and build in a current phase of this program the microgravity apparatus for the visual observation of freely propagating constant pressure laminar dust flames. Quenching distances in aluminum dust suspensions have been measured in a wide range of dust cloud parameters in ground-based experiments and in recent microgravity experiments (KC-135 parabolic flights, Houston, February 1995).

Interplanetary charged particle models (1974). [and the effects of cosmic exposure upon spacecraft and spacecraft components

NASA Technical Reports Server (NTRS)

Divine, N.

1975-01-01

The design of space vehicles for operation in interplanetary space is given, based on descriptions of solar wind, solar particle events, and galactic cosmic rays. A state-of-the-art review is presented and design criteria are developed from experiment findings aboard interplanetary and high-altitude earth-orbiting spacecraft. Solar cells were found to be particularly sensitive. Solar protons may also impact the reliability of electric propulsion systems and spacecraft surfaces, as well as causing interference, detector saturation, and spurious signals. Galactic cosmic-ray impact can lead to similar electronic failure and interference and may register in photographic films and other emulsions. It was concluded that solar wind electron measurements might result from differential charging when shadowed portions of the spacecraft acquired a negative charge from electron impact.

University of California electron and X-ray experiments on ISEE-3

NASA Technical Reports Server (NTRS)

Anderson, K. A.

1981-01-01

The history of the University of California solar and interplanetary electron experiment and the solar X-ray experiment is outlined, and the two instruments used are described. The roles of personnel are mentioned and the data analysis projects completed or begun are summarized. A bibliography is included.

Suprathermal ion detector results from Apollo missions.

NASA Technical Reports Server (NTRS)

Freeman, J. W., Jr.

1972-01-01

This paper reviews briefly the knowledge of the ion environment of the moon as obtained from the Apollo Lunar Surface Experiments Package, Suprathermal Ion Detector Experiment. Topics to be discussed include: an interplanetary shock as seen from the lunar surface; bow shock and magnetosheath ions; magnetotail plasma seen during a magnetic disturbance; suprathermal ions seen during passage of the sunset and sunrise terminators; and ions associated with neutral gas clouds in the vicinity of the moon, and in particular the low energy mono-energetic spectrum of these ions. It is believed that these low energy spectra and some terminator ions can be explained by ion acceleration by the interplanetary electric field. This paper serves as catalog to references to these and other related phenomena.

Electron microscopic observations of hydrogen implantation in ilmenites

NASA Technical Reports Server (NTRS)

Blanford, G. E.

1983-01-01

Hydrogen ion beams were found to form submicrometer, bumpy textures on the surface of ilmenite grains. From this effect, it is believed that similar bumpy textures seen on lunar ilmenite, pyroxene, and olivine grains are likely to be caused by solar wind irradiation. As a consequence, the concentration of bumpy textured grains may be a useful index of surface maturity for lunar soils. An attempt was made to search for grains with these bumpy textures in interplanetary dust and lunar and meteoritic regolith breccias in order to obtain information about the duration of their exposure to the solar wind. Solar wind irradiation was simulated on natural, terrestrial ilmenite. Hydrogen ion beams were directed at small grains and polished sections which were then examined by electron microscopy.

Deep-sea spherules from Pacific clay - Mass distribution and influx rate. [extraterrestrial origins from optical and electron microscopy

NASA Technical Reports Server (NTRS)

Murrell, M. T.; Davis, P. A., Jr.; Nishiizumi, K.; Millard, H. T., Jr.

1980-01-01

From 411 kg of Pacific clay, 22 mg of stony spherules and 50 mg of iron spherules larger than 150 microns were concentrated. The extraterrestrial origin of these particles was evaluated with the aid of optical and electron microscopy and atomic absorption elemental analysis. An expression for the integral number of stony particles from this sediment in the mass range 20-300 micrograms was derived. The world-wide influx rate of stony particles in the mass range which survive atmospheric heating and ocean sediment storage is calculated to be 90 tons/yr. The relative contributions of ablation debris vs fused interplanetary dust to the influx of stony spherules is discussed, but no conclusions could be made.

Spectrum of 100-kyr glacial cycle: Orbital inclination, not eccentricity

PubMed Central

Muller, Richard A.; MacDonald, Gordon J.

1997-01-01

Spectral analysis of climate data shows a strong narrow peak with period ≈100 kyr, attributed by the Milankovitch theory to changes in the eccentricity of the earth’s orbit. The narrowness of the peak does suggest an astronomical origin; however the shape of the peak is incompatible with both linear and nonlinear models that attribute the cycle to eccentricity or (equivalently) to the envelope of the precession. In contrast, the orbital inclination parameter gives a good match to both the spectrum and bispectrum of the climate data. Extraterrestrial accretion from meteoroids or interplanetary dust is proposed as a mechanism that could link inclination to climate, and experimental tests are described that could prove or disprove this hypothesis. PMID:11607741

Organics Captured from Comet Wild 2 by the Stardust Spacecraft

NASA Technical Reports Server (NTRS)

Sandford, Scott A.; Aleon, Jerome; Araki, Tohru; Bajt, Sasa; Baratta, Giuseppe A.; Borg, Janet; Brucato, John R.; Burchell, Mark J.; Busemann, Henner; Butterworth, Anna;

Side Group Addition to the PAH Coronene by UV Photolysis in Cosmic Ice Analogs

NASA Technical Reports Server (NTRS)

Bernstein, Max P.; Elsila, Jamie E.; Dworkin, Jason P.; Sandford, Scott A.; Allamandola, Louis J.; Zare, Richard N.; DeVincenzi, D. (Technical Monitor)

2002-01-01

Ultraviolet photolysis of various ice mixtures at low temperature and pressure caused the addition of amino (-NH2), methyl (-CH3), methoxy (-OCH3), and cyano (-CN) functional groups to the polycyclic aromatic hydrocarbon (PAH) coronene (C22H12). The implications of these results for interstellar and meteoritic chemistry are discussed. Previously only simple PAH photo-oxidation had been reported. This work represents the first experimental evidence that ice photochemistry may have contributed to aromatics bearing carbon and nitrogen containing side groups that are detected in primitive meteorites and interplanetary dust particles. Furthermore, these results suggest a wider range of modified PAHs should be expected in interstellar lees and materials predating solar system formation.

Interplanetary particles and fields, November 22 - December 6, 1977: Helios, Voyager, and IMP observations between 0.6 AU and 1.6 AU

NASA Technical Reports Server (NTRS)

Burlaga, L. F.; Lepping, R. P.; Weber, R.; Armstrong, T.; Goodrich, C.; Sullivan, J.; Gurnett, D.; Kellogg, P.; Keppler, E.; Mariani, F.

1979-01-01

The principal interplanetary events observed are described and analyzed. Three flow systems were observed: (1) a corotating stream and a stream interface associated with a coronal hole; (2) a shock wave and an energetic particle event associated with a 2-B flare; and (3) an isolated shock wave of uncertain origin. Data from 28 experiments and 6 spacecraft provide measurements of solar wind plasma, magnetic fields, plasma waves, radio waves, energetic electrons, and low energy protons.

Plasma wave phenomena at interplanetary shocks observed by the Ulysses URAP experiment. [Unified Radio and Plasma Waves

NASA Technical Reports Server (NTRS)

Lengyel-Frey, D.; Macdowall, R. J.; Stone, R. G.; Hoang, S.; Pantellini, F.; Harvey, C.; Mangeney, A.; Kellogg, P.; Thiessen, J.; Canu, P.

1992-01-01

We present Ulysses URAP observations of plasma waves at seven interplanetary shocks detected between approximately 1 and 3 AU. The URAP data allows ready correlation of wave phenomena from .1 Hz to 1 MHz. Wave phenomena observed in the shock vicinity include abrupt changes in the quasi-thermal noise continuum, Langmuir wave activity, ion acoustic noise, whistler waves and low frequency electrostatic waves. We focus on the forward/reverse shock pair of May 27, 1991 to demonstrate the characteristics of the URAP data.

Migration of tungsten dust in tokamaks: role of dust-wall collisions

NASA Astrophysics Data System (ADS)

Ratynskaia, S.; Vignitchouk, L.; Tolias, P.; Bykov, I.; Bergsåker, H.; Litnovsky, A.; den Harder, N.; Lazzaro, E.

2013-12-01

The modelling of a controlled tungsten dust injection experiment in TEXTOR by the dust dynamics code MIGRAINe is reported. The code, in addition to the standard dust-plasma interaction processes, also encompasses major mechanical aspects of dust-surface collisions. The use of analytical expressions for the restitution coefficients as functions of the dust radius and impact velocity allows us to account for the sticking and rebound phenomena that define which parts of the dust size distribution can migrate efficiently. The experiment provided unambiguous evidence of long-distance dust migration; artificially introduced tungsten dust particles were collected 120° toroidally away from the injection point, but also a selectivity in the permissible size of transported grains was observed. The main experimental results are reproduced by modelling.

Electrodynamic Dust Shields on the International Space Station: Exposure to the Space Environment

NASA Technical Reports Server (NTRS)

Calle, C. I.; Hogue, M. D.; Johansen, M. R.; Yim, H.; Delaune, P. B.; Clements, J. S.

2012-01-01

Electrodynamic Dust Shields (EDS) have been in development at NASA as a dust mitigation method for lunar and Martian missions. An active dust mitigation strategy. such as that provided by the EDS, that can remove dust from surfaces, is of crucial importance to the planetary exploration program. We report on the development of a night experiment to fully ex pose four EDS panels to the space environment. This flight experiment is part of the Materials International Space Station experiment X(MISSE-X). an external platform on the International Space Station that will expose materials to the space environment.

Laboratory simulations of thermal annealing in proto-planetary discs - II. Crystallization of enstatite from amorphous thin films

NASA Astrophysics Data System (ADS)

Droeger, J.; Burchard, M.; Lattard, D.

2011-12-01

Amorphous silicates of olivine and pyroxene composition are thought to be common constituents of circumstellar, interstellar, and interplanetary dust. In proto-planetary discs amorphous dust crystallize essentially as a result of thermal annealing. The present project aims at deciphering the kinetics of crystallization pyroxene in proto-planetary dust on the basis of experiments on amorphous thin films. The thin films are deposited on Si-wafers (111) by pulsed laser deposition (PLD). The thin films are completely amorphous, chemically homogeneous (on the MgSiO3 composition) and with a continuous and flat surface. They are subsequently annealed for 1 to 216 h at 1073K and 1098K in a vertical quench furnace and drop-quenched on a copper block. To monitor the progress of crystallization, the samples are characterized by AFM and SEM imaging and IR spectroscopy. After short annealing durations (1 to 12 h) AFM and SE imaging reveal small shallow polygonal features (diameter 0.5-1 μm; height 2-3 nm) evenly distributed at the otherwise flat surface of the thin films. These shallow features are no longer visible after about 3 h at 1098 K, resp. >12 h at 1073 K. Meanwhile, two further types of features appear small protruding pyramids and slightly depressed spherolites. The orders of appearance of these features depend on temperature, but both persist and steadily grow with increasing annealing duration. Their sizes can reach about 12 μm. From TEM investigations on annealed thin films on the Mg2SiO4 composition we know that these features represent crystalline sites, which can be surrounded by a still amorphous matrix (Oehm et al. 2010). A quantitative evaluation of the size of the features will give insights on the progress of crystallization. IR spectra of the unprocessed thin films show only broad bands. In contrast, bands characteristic of crystalline enstatite are clearly recognizable in annealed samples, e.g. after 12 h at 1078 K. Small bands can also be assigned to crystalline forsterite. Compared to the findings of Murata et al. (2009), our preliminary results point to smaller crystallization rates of enstatite from amorphous precursors.

2014–2015 MULTIPLE OUTBURSTS OF 15P/FINLAY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishiguro, Masateru; Kwon, Yuna Grace; Kim, Yoonyoung

Multiple outbursts of a Jupiter-family comet (JFC), 15P/Finlay, occurred from late 2014 to early 2015. We conducted an observation of the comet after the first outburst and subsequently witnessed another outburst on 2015 January 15.6–15.7. The gas, consisting mostly of C{sub 2} and CN, and dust particles expanded at speeds of 1110 ± 180 m s{sup −1} and 570 ± 40 m s{sup −1} at a heliocentric distance of 1.0 au. We estimated the maximum ratio of solar radiation pressure with respect to the solar gravity β {sub max} = 1.6 ± 0.2, which is consistent with porous dust particles composed of silicates and organics. We found thatmore » 10{sup 8}–10{sup 9} kg of dust particles (assumed to be 0.3 μ m–1 mm) were ejected through each outburst. Although the total mass is three orders of magnitude smaller than that of the 17P/Holmes event observed in 2007, the kinetic energy per unit mass (10{sup 4} J kg{sup −1}) is equivalent to the estimated values of 17P/Holmes and 332P/2010 V1 (Ikeya–Murakami), suggesting that the outbursts were caused by a similar physical mechanism. From a survey of cometary outbursts on the basis of voluntary reports, we conjecture that 15P/Finlay-class outbursts occur >1.5 times annually and inject dust particles from JFCs and Encke-type comets into interplanetary space at a rate of ∼10 kg s{sup −1} or more.« less

Formation of Glass with Embedded Metal and Sulfides from Shock-accelerated Crystalline Dust in Superbubbles

NASA Astrophysics Data System (ADS)

Westphal, A. J.; Bradley, J. P.

2004-12-01

Interplanetary dust particles (IDPs) contain enigmatic submicron components called GEMS (glass with embedded metal and sulfides). The compositions and structures of GEMS indicate that they have been processed by exposure to ionizing radiation, but details of the actual irradiation environment(s) have remained elusive. Here we propose a mechanism and astrophysical site for GEMS formation that explains for the first time the following key properties of GEMS: they are stoichiometrically enriched in oxygen and systematically depleted in S, Mg, Ca, and Fe (relative to solar abundances); most have normal (solar) oxygen isotopic compositions; they exhibit a strikingly narrow size distribution (0.1-0.5 μm diameter); and some of them contain ``relict'' crystals within their silicate glass matrices. We show that the compositions, size distribution, and survival of relict crystals are inconsistent with amorphization by particles accelerated by diffusive shock acceleration. Instead, we propose that GEMS are formed from crystalline grains that condense in stellar outflows from massive stars in OB associations, are accelerated in encounters with frequent supernova shocks inside the associated superbubble (SB), and are implanted with atoms from the hot gas in the SB interior. We thus reverse the usual roles of target and projectile. Rather than being bombarded at rest by energetic ions, grains are accelerated and bombarded by a nearly monovelocity beam of atoms as viewed in their rest frame. Meyer, Drury, and Ellison have proposed that Galactic cosmic rays (GCRs) originate from ions sputtered from such accelerated dust grains. We suggest that GEMS are surviving members of a population of fast grains that constitute the long-sought source material for GCRs. Thus, representatives of the GCR source material may have been awaiting discovery in cosmic dust labs for the last 30 yr.

The possible interplanetary transfer of microbes: assessing the viability of Deinococcus spp. under the ISS Environmental conditions for performing exposure experiments of microbes in the Tanpopo mission.

PubMed

Kawaguchi, Yuko; Yang, Yinjie; Kawashiri, Narutoshi; Shiraishi, Keisuke; Takasu, Masako; Narumi, Issay; Satoh, Katsuya; Hashimoto, Hirofumi; Nakagawa, Kazumichi; Tanigawa, Yoshiaki; Momoki, Yoh-Hei; Tanabe, Maiko; Sugino, Tomohiro; Takahashi, Yuta; Shimizu, Yasuyuki; Yoshida, Satoshi; Kobayashi, Kensei; Yokobori, Shin-Ichi; Yamagishi, Akihiko

2013-10-01

To investigate the possible interplanetary transfer of life, numerous exposure experiments have been carried out on various microbes in space since the 1960s. In the Tanpopo mission, we have proposed to carry out experiments on capture and space exposure of microbes at the Exposure Facility of the Japanese Experimental Module of the International Space Station (ISS). Microbial candidates for the exposure experiments in space include Deinococcus spp.: Deinococcus radiodurans, D. aerius and D. aetherius. In this paper, we have examined the survivability of Deinococcus spp. under the environmental conditions in ISS in orbit (i.e., long exposure to heavy-ion beams, temperature cycles, vacuum and UV irradiation). A One-year dose of heavy-ion beam irradiation did not affect the viability of Deinococcus spp. within the detection limit. Vacuum (10(-1) Pa) also had little effect on the cell viability. Experiments to test the effects of changes in temperature from 80 °C to -80 °C in 90 min (± 80 °C/90 min cycle) or from 60 °C to -60 °C in 90 min (± 60 °C/90 min cycle) on cell viability revealed that the survival rate decreased severely by the ± 80 °C/90 min temperature cycle. Exposure of various thicknesses of deinococcal cell aggregates to UV radiation (172 nm and 254 nm, respectively) revealed that a few hundred micrometer thick aggregate of deinococcal cells would be able to withstand the solar UV radiation on ISS for 1 year. We concluded that aggregated deinococcal cells will survive the yearlong exposure experiments. We propose that microbial cells can aggregate as an ark for the interplanetary transfer of microbes, and we named it 'massapanspermia'.

Type II solar radio bursts, interplanetary shocks, and energetic particle events

NASA Technical Reports Server (NTRS)

Cane, H. V.; Stone, R. G.

1984-01-01

Using the ISEE-3 radio astronomy experiment data 37 interplanetary (IP) type II bursts have been identified in the period September 1978 to December 1981. These events and the associated phenomena are listed. The events are preceded by intense, soft X ray events with long decay times (LDEs) and type II and/or type IV bursts at meter wavelengths. The meter wavelength type II bursts are usually intense and exhibit herringbone structure. The extension of the herringbone structure into the kilometer wavelength range results in the occurrence of a shock accelerated (SA) event. The majority of the interplanetary type II bursts are associated with energetic particle events. These results support other studies awhich indicate that energetic solar particles detected at 1 A.U. are generated by shock acceleration. From a preliminary analysis of the available data there appears to be a high correlation with white light coronal transients.

Type 2 radio bursts, interplanetary shocks and energetic particle events

NASA Technical Reports Server (NTRS)

Cane, H. V.; Stone, R. G.

1982-01-01

Using the ISEE-3 radio astronomy experiment data 37 interplanetary (IP) type II bursts have been identified in the period September 1978 to December 1981. These events and the associated phenomena are listed. The events are preceded by intense, soft X ray events with long decay times (LDEs) and type II and/or type IV bursts at meter wavelengths. The meter wavelength type II bursts are usually intense and exhibit herringbone structure. The extension of the herringbone structure into the kilometer wavelength range results in the occurrence of a shock accelerated (SA) event. The majority of the interplanetary type II bursts are associated with energetic particle events. These results support other studies which indicate that energetic solar particles detected at 1 A.U. are generated by shock acceleration. From a preliminary analysis of the available data there appears to be a high correlation with white light coronal transients.

Ultraviolet Irradiation of Pyrimidine in Interstellar Ice Analogs: Formation and Photo-Stability of Nucleobases

NASA Technical Reports Server (NTRS)

Nuevo, Michel; Milam, Stefanie N.; Sandford, Scott A.; Elsila, Jamie E.; Dworkin, Jason P.

2010-01-01

Astrochemistry laboratory experiments recently showed that molecules of prebiotic interest can potentially form in space, as supported by the detection of amino acids in organic residues formed by the UV photolysis of ices simulating interstellar and cometary environments (H2O, CO, CO2, CH3OH, NH3, etc.). Although the presence of amino acids in the interstellar medium (ISM) is still under debate, experiments and the detection of amino acids in meteorites both support a scenario in which prebiotic molecules could be of extraterrestrial origin, before they are delivered to planets by comets, asteroids, and interplanetary dust particles. Nucleobases, the informational subunits of DNA and RNA, have also been detected in meteorites, although they have not yet been observed in the ISM. Thus, these molecules constitute another family of prebiotic compounds that can possibly form via abiotical processes in astrophysical environments. Nucleobases are nitrogen-bearing cyclic aromatic species with various functional groups attached, which are divided into two classes: pyrimidines (uracil, cytosine, and thymine) and purines (adenine and guanine). In this work, we study how UV irradiation affects pyrimidine mixed in interstellar ice analogs (H2O, NH3, CH3OH). In particular, we show that the UV irradiation of H2O:pyrimidine mixtures leads to the production of oxidized compounds including uracil, and show that both uracil and cytosine are formed upon irradiation of H2O:NH3:pyrimidine mixtures. We also study the photostability of pyrimidine and its photoproducts formed during these experiments.

Dust particles interaction with plasma jet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ticos, C. M.; Jepu, I.; Lungu, C. P.

2009-11-10

The flow of plasma and particularly the flow of ions play an important role in dusty plasmas. Here we present some instances in laboratory experiments where the ion flow is essential in establishing dust dynamics in strongly or weakly coupled dust particles. The formation of ion wake potential and its effect on the dynamics of dust crystals, or the ion drag force exerted on micron size dust grains are some of the phenomena observed in the presented experiments.

Experiments to trap dust particles by a wire simulating an electron beam

NASA Astrophysics Data System (ADS)

Saeki, Hiroshi; Momose, Takashi; Ishimaru, Hajime

1991-11-01

Motion of trapped dust particles has been previously analyzed using high-energy bremsstrahlung data obtained during dust trapping in the TRISTAN accumulation ring. Because it is difficult to observe the actual motions of dust particles trapped in an electron beam due to the strong synchrotron light background, we carried out experiments to trap sample dust particles with a Cu wire simulating an electron beam. A negative potential was slowly applied to the wire using a high voltage dc power supply. Motions of dust particles trapped by the wire were recorded with a video camera system. In an experiment using a Cu wire (1.5 mm in diameter) with no magnetic field, the charged dust particle made vertical oscillation about the wire. In another experiment using the same wire but with a vertical magnetic field (0.135 T) simulating a bending magnetic field, both vertical and horizontal oscillating motions perpendicular to the wire were observed. Furthermore, it was found that the dust particle moved in the longitudinal direction of the wire in the bending magnetic field. Therefore, it is expected that charged dust particles trapped by the electric field of the electron beam oscillate vertically where there is no magnetic field in the TRISTAN accumulation ring. It is also expected that trapped dust particles where there is a bending magnetic field oscillate horizontally and vertically as the particle drifts in a longitudinal direction along the ring.

The MAGO experiment for dust environment monitoring on the Martian surface

NASA Astrophysics Data System (ADS)

Palumbo, P.; Battaglia, R.; Brucato, J. R.; Colangeli, L.; della Corte, V.; Esposito, F.; Ferrini, G.; Mazzotta Epifani, E.; Mennella, V.; Palomba, E.; Panizza, A.; Rotundi, A.

2004-01-01

Among the main directions identified for future Martian exploration, the study of the properties of dust dispersed in the atmosphere, its cycle and the impact on climate are considered of primary relevance. Dust storms, dust devils and the dust ``cycle'' have been identified and studied by past remote and in situ experiments, but little quantitative information is available on these processes, so far. The airborne dust contributes to the determination of the dynamic and thermodynamic evolution of the atmosphere, including the large-scale circulation processes and its impact on the climate of Mars. Moreover, aeolian erosion, redistribution of dust on the surface and weathering processes are mostly known only qualitatively. In order to improve our knowledge of the airborne dust evolution and other atmospheric processes, it is mandatory to measure the amount, mass-size distribution and dynamical properties of solid particles in the Martian atmosphere as a function of time. In this context, there is clearly a need for the implementation of experiments dedicated to study directly atmospheric dust. The Martian atmospheric grain observer (MAGO) experiment is aimed at providing direct quantitative measurements of mass and size distributions of dust particles, a goal that has never been fully achieved so far. The instrument design combines three types of sensors to monitor in situ the dust mass flux (micro balance system, MBS) and single grain properties (grain detection system, GDS+impact sensor, IS). Technical solutions and science capabilities are discussed in this paper.

Small Particles Intact Capture Experiment (SPICE)

NASA Technical Reports Server (NTRS)

Nishioka, Ken-Ji; Carle, G. C.; Bunch, T. E.; Mendez, David J.; Ryder, J. T.

1994-01-01

The Small Particles Intact Capture Experiment (SPICE) will develop technologies and engineering techniques necessary to capture nearly intact, uncontaminated cosmic and interplanetary dust particles (IDP's). Successful capture of such particles will benefit the exobiology and planetary science communities by providing particulate samples that may have survived unaltered since the formation of the solar system. Characterization of these particles may contribute fundamental data to our knowledge of how these particles could have formed into our planet Earth and, perhaps, contributed to the beginnings of life. The term 'uncontaminated' means that captured cosmic and IDP particles are free of organic contamination from the capture process and the term 'nearly intact capture' means that their chemical and elemental components are not materially altered during capture. The key to capturing cosmic and IDP particles that are organic-contamination free and nearly intact is the capture medium. Initial screening of capture media included organic foams, multiple thin foil layers, and aerogel (a silica gel); but, with the exception of aerogel, the requirements of no contamination or nearly intact capture were not met. To ensure no contamination of particles in the capture process, high-purity aerogel was chosen. High-purity aerogel results in high clarity (visual clearness), a useful quality in detection and recovery of embedded captured particles from the aerogel. P. Tsou at the Jet Propulsion Laboratory (JPL) originally described the use of aerogel for this purpose and reported laboratory test results. He has flown aerogel as a 'GAS-can Lid' payload on STS-47 and is evaluating the results. The Timeband Capture Cell Experiment (TICCE), a Eureca 1 experiment, is also flying aerogel and is scheduled for recovery in late April.

Results of studies on long-term exposition of dormant forms of various organisms in outer space environment

NASA Astrophysics Data System (ADS)

Novikova, Nataliya; Gusev, Oleg; Sugimoto, Manabu; Deshevaya, Elena; Levinskikh, Margarita; Sychev, Vladimir; Okuda, Takashi; Orlov, Oleg; Alekseev, Victor; Poddubko, Svetlana; Polikarpov, Nikolay

The planetary quarantine is one of the key problems of deep space exploration. Risks of the possible transfer of biological objects across interplanetary space should be necessarily assessed during space exploration. The risks associated with a possible transfer of biological objects and primarily microorganisms in interplanetary space is a priority for space studies We can assume, that on the exterior side of both unmanned and manned space stations there can be millions of microbial cells, many of which are in spore forms, the stability of which towards the unfavorable factors is extremely high. However, direct evidence to support this assumption, obtained only in recent years. “Biorisk” is an apparatus designed for conduction of space experiments focused on long-term exposition of latent stages of different forms of organism on the outer side of Russian Segment of International Space Station was developed and used in SSC RF - Institute for Biomedical Problems RAS. The purpose of this experiment is to determine the principle capability of preservation of life capacity in test-cultures of microorganisms during long-term exposure (comparable with the term of interplanetary flight) in space. The first experiment was performed using spores of bacteria (Bacillus) and fungi (Penicillium, Aspergillus and Cladosporium) housed in 3 boxes that were exposed to outer space for 7, 12 or 18 months. It was for the first time demonstrated that bacterial and fungal spores could survive an exposure to outer space during the time period comparable with the duration of a return mission to Mars. Moreover, the microbial strains proved viable and highly active. The second experiment was expanded by flying, in addition to the above spores, dormant forms of higher plants, insects, lower crustaceans and vertebrates. The 31-month experiment showed that, in spite of harsher than in the first study temperatures, some specimens remained viable and capable of further multiplication. In summary, our experiments provided evidence that not only bacterial and fungal spores but also dormant forms of organisms that reached higher levels of evolutionary development had the capability to survive a long-term exposure to outer space. This observation suggests that they can be transferred on outer walls of space platforms during interplanetary missions. Our findings are of scientific interest as well as of importance for the development of planetary quarantine concepts related to future space flight.

COSIMA-Rosetta calibration for in situ characterization of 67P/Churyumov-Gerasimenko cometary inorganic compounds

NASA Astrophysics Data System (ADS)

Krüger, Harald; Stephan, Thomas; Engrand, Cécile; Briois, Christelle; Siljeström, Sandra; Merouane, Sihane; Baklouti, Donia; Fischer, Henning; Fray, Nicolas; Hornung, Klaus; Lehto, Harry; Orthous-Daunay, Francois-Régis; Rynö, Jouni; Schulz, Rita; Silén, Johan; Thirkell, Laurent; Trieloff, Mario; Hilchenbach, Martin

2015-11-01

COmetary Secondary Ion Mass Analyzer (COSIMA) is a time-of-flight secondary ion mass spectrometry (TOF-SIMS) instrument on board the Rosetta space mission. COSIMA has been designed to measure the composition of cometary dust particles. It has a mass resolution m/Δm of 1400 at mass 100 u, thus enabling the discrimination of inorganic mass peaks from organic ones in the mass spectra. We have evaluated the identification capabilities of the reference model of COSIMA for inorganic compounds using a suite of terrestrial minerals that are relevant for cometary science. Ground calibration demonstrated that the performances of the flight model were similar to that of the reference model. The list of minerals used in this study was chosen based on the mineralogy of meteorites, interplanetary dust particles and Stardust samples. It contains anhydrous and hydrous ferromagnesian silicates, refractory silicates and oxides (present in meteoritic Ca-Al-rich inclusions), carbonates, and Fe-Ni sulfides. From the analyses of these minerals, we have calculated relative sensitivity factors for a suite of major and minor elements in order to provide a basis for element quantification for the possible identification of major mineral classes present in the cometary particles.

Does Comet WILD-2 contain Gems?

NASA Technical Reports Server (NTRS)

Chi, M.; Ishii, H.; Dai, Z. R.; Toppani, A.; Joswiak, D. J.; Leroux, H.; Zolensky, M.; Keller, L. P.; Browning, N. D.

2007-01-01

It is expected that Comet Wild-2 dust should resemble anhydrous carbon-rich, chondritic porous (CP) interplanetary dust particles (IDPs) collected in the stratosphere because some CP IDPs are suspected to be from comets. The rarity of carbonaceous grains and presolar silicates, as well as the presence of high-temperature inner solar nebula minerals in the Wild-2 sample (e.g. osbornite and melilite), appear incompatible with most CP IDPs. However, it is premature to draw firm conclusions about the mineralogy of comet Wild-2 because only approx. 1% of the sample has been examined. The most abundant silicates in CP IDPs are GEMS (glass with embedded metal and sulfides). Nonsolar O isotopic compositions confirm that at least some GEMS in IDPs are presolar amorphous silicates. The presence or absence of GEMS in the Wild-2 sample is important because it addresses, (a) the relationship between CP IDPs and comets, and (b) the hypothesis that other GEMS in IDPs formed in the solar nebula. Here we show that most of the GEMSlike materials so far identified in Stardust aerogel were likely impact generated during collection. At the nanometer scale, they are compositionally and crystallographically distinct from GEMS in IDPs.

Search for water and life's building blocks in the universe: A summary

NASA Astrophysics Data System (ADS)

Ehrenfreund, Pascale; Kwok, Sun; Bergin, Edwin

2015-08-01

Water and organic compounds are essential ingredients for life on Earth and possibly elsewhere. In gaseous form water acts as a coolant that allows interstellar gas clouds to collapse to form stars, whereas water ice covers small dust particles that agglomerate to form planetesimals and planets. The variety of organic compounds identified in interstellar and circumstellar regions reflects complex reaction schemes in the gaseous and icy/solid state. Interstellar volatiles and refractory materials were processed and radially mixed within the protostellar disk from which our solar system formed. But the dynamic solar nebula was also a source for new materials and the search for water and life’s building blocks on terrestrial planets, most of the outer-solar-system satellites as well as small solar system bodies reveals exciting new findings. The analysis of small bodies and their fragments, meteorites and interplanetary dust particles, sheds lights onto the extraterrestrial delivery process of prebiotic molecules to young planets and the pathways to life’s origin on Earth and possibly elsewhere. We summarize the results of invited and contributed papers of this Focus Meeting which will allow us to better assess the habitability of objects in our solar system and provide constraints for exoplanets.

Self-assembling amphiphilic molecules: Synthesis in simulated interstellar/precometary ices

PubMed Central

Dworkin, Jason P.; Deamer, David W.; Sandford, Scott A.; Allamandola, Louis J.

2001-01-01

Interstellar gas and dust constitute the primary material from which the solar system formed. Near the end of the hot early phase of star and planet formation, volatile, less refractory materials were transported into the inner solar system as comets and interplanetary dust particles. Once the inner planets had sufficiently cooled, late accretionary infall seeded them with complex organic compounds [Oró, J. (1961) Nature (London) 190, 389–390; Delsemme, A. H. (1984) Origins Life 14, 51–60; Anders, E. (1989) Nature (London) 342, 255–257; Chyba, C. F. & Sagan, C. (1992) Nature (London) 355, 125–131]. Delivery of such extraterrestrial compounds may have contributed to the organic inventory necessary for the origin of life. Interstellar ices, the building blocks of comets, tie up a large fraction of the biogenic elements available in molecular clouds. In our efforts to understand their synthesis, chemical composition, and physical properties, we report here that a complex mixture of molecules is produced by UV photolysis of realistic, interstellar ice analogs, and that some of the components have properties relevant to the origin of life, including the ability to self-assemble into vesicular structures. PMID:11158552

Particle Lifting Processes in Dust Devils

NASA Astrophysics Data System (ADS)

Neakrase, L. D. V.; Balme, M. R.; Esposito, F.; Kelling, T.; Klose, M.; Kok, J. F.; Marticorena, B.; Merrison, J.; Patel, M.; Wurm, G.

2016-11-01

Particle lifting in dust devils on both Earth and Mars has been studied from many different perspectives, including how dust devils could influence the dust cycles of both planets. Here we review our current understanding of particle entrainment by dust devils by examining results from field observations on Earth and Mars, laboratory experiments (at terrestrial ambient and Mars-analog conditions), and analytical modeling. By combining insights obtained from these three methodologies, we provide a detailed overview on interactions between particle lifting processes due to mechanical, thermal, electrodynamical and pressure effects, and how these processes apply to dust devils on Earth and Mars. Experiments and observations have shown dust devils to be effective lifters of dust given the proper conditions on Earth and Mars. However, dust devil studies have yet to determine the individual roles of each of the component processes acting at any given time in dust devils.

The Deep Impact Network Experiment Operations Center Monitor and Control System

NASA Technical Reports Server (NTRS)

Wang, Shin-Ywan (Cindy); Torgerson, J. Leigh; Schoolcraft, Joshua; Brenman, Yan

2009-01-01

The Interplanetary Overlay Network (ION) software at JPL is an implementation of Delay/Disruption Tolerant Networking (DTN) which has been proposed as an interplanetary protocol to support space communication. The JPL Deep Impact Network (DINET) is a technology development experiment intended to increase the technical readiness of the JPL implemented ION suite. The DINET Experiment Operations Center (EOC) developed by JPL's Protocol Technology Lab (PTL) was critical in accomplishing the experiment. EOC, containing all end nodes of simulated spaces and one administrative node, exercised publish and subscribe functions for payload data among all end nodes to verify the effectiveness of data exchange over ION protocol stacks. A Monitor and Control System was created and installed on the administrative node as a multi-tiered internet-based Web application to support the Deep Impact Network Experiment by allowing monitoring and analysis of the data delivery and statistics from ION. This Monitor and Control System includes the capability of receiving protocol status messages, classifying and storing status messages into a database from the ION simulation network, and providing web interfaces for viewing the live results in addition to interactive database queries.

Far travelers: The exploring machines

NASA Technical Reports Server (NTRS)

Nicks, O. W.

1985-01-01

During the first two decades of space activities, unmanned spacecraft played a vital role in the initial exploration of the Moon and the planets. The spacecraft employed emerging technologies to provide extensions of man in the close-up viewing and measurement of the environment and features of Earth's interplanetary neighbors. An account of early experiences in the development and use of interplanetary vehicles is presented. Specific lunar and planetary missions (e.g., Ranger, Mariner, and Viking) are discussed. In addition, incidents highlighting the evolution of significant technologies are presented, based on personal views of people intimately involved in the efforts.

Aeolian Erosion on Mars - a New Threshold for Saltation

NASA Astrophysics Data System (ADS)

Teiser, J.; Musiolik, G.; Kruss, M.; Demirci, T.; Schrinski, B.; Daerden, F.; Smith, M. D.; Neary, L.; Wurm, G.

2017-12-01

The Martian atmosphere shows a large variety of dust activity, ranging from local dust devils to global dust storms. Also, sand motion has been observed in form of moving dunes. The dust entrainment into the Martian atmosphere is not well understood due to the small atmospheric pressure of only a few mbar. Laboratory experiments on Earth and numerical models were developed to understand these processes leading to dust lifting and saltation. Experiments so far suggested that large wind velocities are needed to reach the threshold shear velocity and to entrain dust into the atmosphere. In global circulation models this threshold shear velocity is typically reduced artificially to reproduce the observed dust activity. Although preceding experiments were designed to simulate Martian conditions, no experiment so far could scale all parameters to Martian conditions, as either the atmospheric or the gravitational conditions were not scaled. In this work, a first experimental study of saltation under Martian conditions is presented. Martian gravity is reached by a centrifuge on a parabolic flight, while pressure (6 mbar) and atmospheric composition (95% CO2, 5% air) are adjusted to Martian levels. A sample of JSC 1A (grain sizes from 10 - 100 µm) was used to simulate Martian regolith. The experiments showed that the reduced gravity (0.38 g) not only affects the weight of the dust particles, but also influences the packing density within the soil and therefore also the cohesive forces. The measured threshold shear velocity of 0.82 m/s is significantly lower than the measured value for 1 g in ground experiments (1.01 m/s). Feeding the measured value into a Global Circulation Model showed that no artificial reduction of the threshold shear velocity might be needed to reproduce the global dust distribution in the Martian atmosphere.

Proof of concept demonstration of novel technologies for lunar spacesuit dust mitigation

NASA Astrophysics Data System (ADS)

Manyapu, Kavya K.; De Leon, Pablo; Peltz, Leora; Gaier, James R.; Waters, Deborah

2017-08-01

A recent report by NASA identified dust/particulate mitigation techniques as a highly relevant study for future long-term planetary exploration missions (NASA, 2015). The deleterious effects of lunar dust on spacesuits discovered during the Apollo missions has compelled NASA to identify dust mitigation as a critical path for potential future lunar, asteroid and Mars missions. The complexity of spacesuit design has however constrained integrating existing dust cleaning technologies, formerly demonstrated on rigid surfaces, into the spacesuit system. Accordingly, this research is investigating novel methods to integrate dust mitigation technologies for use on spacesuits. We examine utilizing a novel combination of active and passive technologies integrated into the spacesuit outerlayer to alleviate dust contamination. Leveraging two specific technologies, the Electrodynamics Dust Shield (EDS) active technology and Work Function Matching Coating (WFM) passive technology, developed by NASA for rigid surfaces, we apply new high performance materials such as the Carbon Nanotube (CNT) flexible fibers to develop a spacesuit-integrated dust cleaning system. Through experiments conducted using JSC-1A lunar dust simulant on coupons made of spacesuit outerlayer material, feasibility of integrating the proposed dust cleaning system and its performance were assessed. Results from these preliminary experiments show that the integrated dust cleaning system is capable of removing 80-95% of dust from the spacesuit material demonstrating proof of concept. This paper describes the techniques and results from the experiments. Future challenges of implementing the proposed approach into fight suits are identified.

Establishing a molecular relationship between chondritic and cometary organic solids

PubMed Central

Cody, George D.; Heying, Emily; Alexander, Conel M. O.; Nittler, Larry R.; Kilcoyne, A. L. David; Sandford, Scott A.

2011-01-01

Multidimensional solid-state NMR spectroscopy is used to refine the identification and abundance determination of functional groups in insoluble organic matter (IOM) isolated from a carbonaceous chondrite (Murchison, CM2). It is shown that IOM is composed primarily of highly substituted single ring aromatics, substituted furan/pyran moieties, highly branched oxygenated aliphatics, and carbonyl groups. A pathway for producing an IOM-like molecular structure through formaldehyde polymerization is proposed and tested experimentally. Solid-state 13C NMR analysis of aqueously altered formaldehyde polymer reveals considerable similarity with chondritic IOM. Carbon X-ray absorption near edge structure spectroscopy of formaldehyde polymer reveals the presence of similar functional groups across certain Comet 81P/Wild 2 organic solids, interplanetary dust particles, and primitive IOM. Variation in functional group concentration amongst these extraterrestrial materials is understood to be a result of various degrees of processing in the parent bodies, in space, during atmospheric entry, etc. These results support the hypothesis that chondritic IOM and cometary refractory organic solids are related chemically and likely were derived from formaldehyde polymer. The fine-scale morphology of formaldehyde polymer produced in the experiment reveals abundant nanospherules that are similar in size and shape to organic nanoglobules that are ubiquitous in primitive chondrites. PMID:21464292

Synchrotron X-Ray Diffraction Studies of Olivine from Comet Wild 2

NASA Technical Reports Server (NTRS)

2008-01-01

We have analyzed a collection of the Comet Wild 2 coma grains returned by the NASA Stardust Mission, using micro-area Laue diffraction equipment. The purpose of the diffraction experiment is to permit the structure refinement of olivine including site occupancies. In addition to the intrinsic importance of the olivine structures for revealing the thermal history of Wild 2 materials, we wish to test reports that olivine recovered after hypervelocity capture in silica aerogel has undergone a basic structural change due to capture heating [1]. The diffraction equipment placed at beam line BL- 4B1 of PF, KEK was developed with a micropinhole and an imaging plate (Fuji Co. Ltd.) using the Laue method combined with polychromatic X-ray of synchrotron radiation operated at energy of 2.5 GeV. The incident beam is limited to 1.6 m in diameter by a micropinhole set just upstream of the sample [2, 3]. It is essential to apply a microbeam to obtain diffracted intensities with high signal to noise ratios. This equipment has been successfully applied to various extraterrestrial materials, including meteorites and interplanetary dust particles [4]. The Laue pattern of the sample C2067,1,111,4 (Fig. 1) was successfully taken on an imaging plate after a 120 minute exposure (Fig. 2).

Astromaterials Research Office (KR) Overview

NASA Technical Reports Server (NTRS)

Draper, David S.

2014-01-01

The fundamental goal of our research is to understand the origin and evolution of the solar system, particularly the terrestrial, "rocky" bodies. Our research involves analysis of, and experiments on, astromaterials in order to understand their nature, sources, and processes of formation. Our state-of-the-art analytical laboratories include four electron microbeam laboratories for mineral analysis, four spectroscopy laboratories for chemical and mineralogical analysis, and four mass spectrometry laboratories for isotopic analysis. Other facilities include the experimental impact laboratory and both 1-atm gas mixing and high-pressure experimental petrology laboratories. Recent research has emphasized a diverse range of topics, including: Study of the solar system's primitive materials, such as carbonaceous chondrites and interplanetary dust; Study of early solar system chronology using short-lived radioisotopes and early nebular processes through detailed geochemical and isotopic characterizations; Study of large-scale planetary differentiation and evolution via siderophile and incompatible trace element partitioning, magma ocean crystallization simulations, and isotopic systematics; Study of the petrogenesis of Martian meteorites through petrographic, isotopic, chemical, and experimental melting and crystallization studies; Interpretation of remote sensing data, especially from current robotic lunar and Mars missions, and study of terrestrial analog materials; Study of the role of organic geochemical processes in the evolution of astromaterials and the extent to which they constrain the potential for habitability and the origin of life.

Microbial Isolates from the Upper Atmosphere Support Panspermia Hypothesis

NASA Astrophysics Data System (ADS)

Yang, Yinjie; Yokobori, Shin-Ichi; Yamagishi, Akihiko

Terrestrial microbes may be transported into the upper atmosphere via various means. Due to the environmental similarity of the upper atmosphere to outer space, knowledge of microbes in the upper atmosphere would be valuable for assessing the chances and limits of microbial transfer from the earth to extraterrestrial bodies (i.e., Panspermia of terrestrial microbes). We collected air dust samples in the upper troposphere and the stratosphere over Japan by using aircrafts or balloons. Microbial isolates from the samples were endospore-forming species (Bacillus, Paenibacillus, Streptomyces) and non-spore-forming Deinococci. Besides the evidence of microbial presence in the upper atmosphere, we show the possible presence of terrestrial microbes in space by extrapolated height-dependent distribution of microbes. High resistance to radiation and desiccation was common for our upper-atmospheric isolates and likely the most important feature enabled their survival in the environment of elevated radiation and desiccation. In this regard, Panspermia of viable Deinococci and endospores would be more likely than other terrestrial microbes. Specifically, the Deinococcus isolates exhibited extreme resistance to radiation (several times higher than bacterial endospores), the principle threat for microbial survival during interplanetary transfer. Based on detailed characterization of the Deinococcus isolates, we proposed two new species Deinococcus aerius sp. nov. and Deinococcus aetherius sp. nov., which are now candidate microbes for exposure experiment in space.

Lunar and Planetary Surface Dynamics and Early History

NASA Technical Reports Server (NTRS)

2003-01-01

This document, submitted as part of this proposal renewal represents the Final Report required by NASA for Grant NAGS-9442. It should be emphasized that, while this work statement in the original proposal outlined anticipated directions of our research, the specific activities we carried out during this period differed slightly from those proposed, capitalizing on new unexpected results and new advances in analytical capability. The thrust of all the work we completed were completely within the stated research goals of the proposal and significantly advanced our knowledge of planetary processes and our understanding of the early solar system. The following summary outlines our achievements in the different areas of research. These include: A) Early solar system processes and time scales using I-Xe chronometry; B) The Active Capture of Volatiles: A new mechanism for the capture of heavy noble gases, possible implications for phase Q and planetary heavy noble gases; C) Separation of Xe-L from Xe-H: Physically selective experiments; D) Abundances of Presolar grains; E) Studies of Neon and Helium from single interstellar SiC and graphite grains; F) Pre-compaction exposure of meteoritic grains and chondrules; G) Geochemically Measured Half-Lives: Double beta-decay of Te and Ba isotopes; H) Noble gases in stratospheric interplanetary dust particles; I) New Analytical Instrument.

Surface materials on unusual planetary object Chiron

NASA Technical Reports Server (NTRS)

Hartmann, W. K.; Cruikshank, D. P.; Degewij, J.; Capps, R. W.

1981-01-01

JHK near-infrared colorimetry of the surface of the planetary object 2060 Chiron has yielded colors consistent with those of outer solar system asteroids, which have: (1) albedos of only a few percent, (2) C-, RD-, or DM-type spectra, and (3) no known H2O ice absorption features. The colors are also in keeping with theoretical colors for certain size distributions of dirty ice grains. Along with VJHK colorimetric data, results suggest that the spectrally dominant surface is probably dark, carbonaceous-like silicate dust with a possible, microscale admixture of ice grains. It is concluded that, if Chiron has the low albedo common to such materials on known interplanetary bodies, its diameter may lie in the 310-400 km range and therefore place it among the eight largest asteroids.

Nebular and Interstellar Materials in a Giant Cluster IDP of Probable Cometary Origin

NASA Technical Reports Server (NTRS)

Messenger, S.; Brownlee, D. E.; Joswiak, D. J.; Nguyen, A. N.

2015-01-01

Comets contain a complex mixture of materials with presolar and Solar System origins. Chondritic porous interplanetary dust particles (CP-IDPs) are associated with comets by their fragile nature, unequilibrated anhydrous mineralogy and high abundances of circumstellar grains and isotopically anomalous organic materials. Comet 81P/Wild 2 samples returned by the Stardust spacecraft contain presolar materials as well as refractory 16O-rich Ca-Al-rich inclusion- (CAI), chondrule-, and AOA-like materials. We are conducting coordinated chemical, mineralogical, and isotopic studies of a giant cluster CP-IDP (U2-20-GCA) to determine the proportions of inner Solar System and interstellar materials. We previously found that this IDP contains abundant presolar silicates (approx. 1,800 ppm) and 15N-rich hotspots [6].

Densities of 5-15 micron interplanetary dust particles

NASA Technical Reports Server (NTRS)

Love, S. G.; Joswiak, D. J.; Brownlee, D. E.

1993-01-01

We have measured the densities of about 100 5-15 micron stratospheric IDPs. Great care was taken to minimize selection bias in the sample population. Masses were determined using an absolute x-ray analysis technique with a transmission electron microscope, and volumes were found using scanning electron microscope imagery. Unmelted chondritic particles have densities between 0.5 and 6.0 g/cc. Roughly half of the particles have densities below 2 g/cc, indicating appreciable porosity, but porosities greater than about 70 percent are rare. IDPs with densities above 3.5 g/cc usually contain large sulfide grains. We find no evidence of bimodality in the unmelted particle density distribution. Chondritic spherules (melted particles) have densities near 3.5 g/cc, consistent with previous results for deep sea spherules.

Deep-sea spherules from Pacific clay: mass distribution and influx rate

USGS Publications Warehouse

Murrell, M.T.; Davis, P.A.; Nishiizumi, K.; Millard, H.T.

1980-01-01

From 411 kg of Pacific clay, 22 mg of stony spherules and 50 mg of iron spherules larger than 150 ??m were concentrated. The extraterrestrial origin of these particles was evaluated with the aid of both optical and electron microscopy as well as atomic absorption elemental analysis. The integral number (N) of stony particles from this sediment in the mass (M) range 20-300 ??g is given by N( > M(g)) = 5.13 ?? 10-6 ?? M-1.65. The world-wide influx rate of stony particles in the mass range which survive atmospheric heating and ocean sediment storage is calculated to be 90 tons/yr. The relative contributions of ablation debris vs fused interplanetary dust to the influx of stony spherules is discussed, but as yet the question remains unanswered. ?? 1980.

Observation of Dust Particle Gyromotion in a Magnetized Dusty Plasma

NASA Astrophysics Data System (ADS)

Compton, C. S.; Amatucci, W. E.; Gatling, G.; Tejero, E.

2008-11-01

In dusty plasma research, gyromotion of the dust has been difficult to observe experimentally. Previous experiments by Amatucci et al. have shown gyromotion of a single dust particle [1]. This early work was performed with alumina dust that had a size distribution and non-uniformly shaped particles. In the current experiment, evidence of spherical, monodispersed, dust particles exhibiting gyromotion has been observed. Silica particles 0.97 micrometers in diameter are suspended in a DC glow discharge argon plasma. The experiment is performed in the Naval Research Laboratory's DUsty PLasma EXperiment (DUPLEX Jr.). DUPLEX is a 61-cm tall by 46-cm diameter acrylic chamber allowing full 360 degree optical access for diagnostics. The neutral pressure for the experiment is 230 mTorr with a 275 V bias between the circular electrodes. The electrodes have a separation of 4 cm. A strong magnetic field is created by 2 pairs of neodymium iron boride magnets placed above and below the anode and cathode respectively. The resulting field is 1.4 kG. The dust particles are illuminated with a 25 mW, 672 nm laser. Images are captured using an intensified CCD camera and a consumer digital video cassette recorder. Recent evidence of gyromotion of spherical, monodispersed, dust particles will be presented. [1] Amatucci, W.E., et al., Phys. Plasmas, 11, 2097 (2004)

Mate and Dart: An Instrument Package for Characterizing Solar Energy and Atmospheric Dust on Mars

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Jenkins, Phillip; Scheiman, David; Baraona, Cosmo

2000-01-01

The MATE (Mars Array Technology Experiment) and DART (Dust Accumulation and Removal Test) instruments were developed to fly as part of the Mars ISPP Precursor (MIP) experiment on the (now postponed) Mars-2001 Surveyor Lander. MATE characterizes the solar energy reaching the surface of Mars, and measures the performance and degradation of solar cells under Martian conditions. DART characterizes the dust environment of Mars, measures the effect of settled dust on solar arrays, and investigates methods to mitigate power loss due to dust accumulation.

Studies on Charge Variation and Waves in Dusty Plasmas

NASA Astrophysics Data System (ADS)

Kausik, Siddhartha Sankar

Plasma and dust grains are both ubiquitous ingredients of the universe. The interplay between them has opened up a new and fascinating research domain, that of dusty plasmas, which contain macroscopic particles of solid matter besides the usual plasma constituents. The research in dusty plasmas received a major boost in the early eighties with Voyager spacecraft observation on the formation of Saturn rings. Dusty plasmas are defined as partially or fully-ionized gases that contain micron-sized particles of electrically charged solid material, either dielectric or conducting. The physics of dusty plasmas has recently been studied intensively because of its importance for a number of applications in space and laboratory plasmas. This thesis presents the experimental studies on charge variation and waves in dusty plasmas. The experimental observations are carried out in two different experimental devices. Three different sets of experiments are carried out in two different experimental devices. Three different sets of experiments are carried out to study the dust charge variation in a filament discharge argon plasma. The dust grains used in these experiments are grains of silver. In another get of experiment, dust acoustic waves are studied in a de glow discharge argon plasma. Alumina dust grains are sprinkled in this experiment. The diagnostic tools used in these experiments are Langmuir probe and Faraday cup. The instruments used in these experiments are electrometer, He-Ne laser and charge coupled device (CCD) camera. Langmuir probe is used to measure plasma parameters, while Faraday cup and electrometer are used to measure very low current (~pA) carried by a collimated dust beam. He-Ne laser illuminates the dust grains and CCD camera is used to capture the images of dust acoustic waves. Silver dust grains are produced in the dust chamber by gas-evaporation technique. Due to differential pressure maintained between the dust and plasma chambers, the dust grains move upward in the form of a collimated beam. Argon plasma is produced in an experimental setup consisting of a dust chamber, a plasma chamber and a diagnostic chamber (also called deflection chamber) by striking a discharge between incandescent tungsten filaments and the magnetic cage, which is grounded. Plasma thus produced is confined by a full line cusped magnetic field confinement system consisting of a cylindrically shaped cage made up of stainless steel channels filled up with cube shaped having 1.2 kG field strength at its surface.

Dust That's Worth Keeping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hazi, A

2006-01-25

Images taken of interstellar space often display a colorful canvas of portions of the electromagnetic spectrum. Dispersed throughout the images are interstellar clouds of dust and gas--remnants ejected from stars and supernovae over billions and billions of years. For more than 40 years, astronomers have observed that interstellar dust exhibits a consistent effect at a spectral wavelength of 2,175 angstroms, the equivalent of 5.7 electronvolts in energy on the electromagnetic spectrum. At this wavelength, light from stars is absorbed by dust in the interstellar medium, blocking the stars light from reaching Earth. The 2,175-angstrom feature, which looks like a bumpmore » on spectra, is the strongest ultraviolet-visible light spectral signature of interstellar dust and is visible along nearly every observational line of sight. Scientists have sought to solve the mystery of what causes the 2,175-angstrom feature by reproducing the effect in the laboratory. They speculated a number of possibilities, including fullerenes (buckyballs), nanodiamonds, and even interstellar organisms. However, none of these materials fits the data for the unique spectral feature. Limitations in the energy and spatial resolution achievable with electron microscopes and ion microprobes--the two main instruments used to study samples of dust--have also prevented scientists from finding the answer. A collaborative effort led by Livermore physicist John Bradley and funded by the National Aeronautics and Space Administration (NASA) has used a new-generation transmission electron microscope (TEM) and nanoscale ion microprobe to unlock the mystery. The Livermore group includes physicists Zu Rong Dai, Ian Hutcheon, Peter Weber, and Sasa Bajt and postdoctoral researchers Hope Ishii, Giles Graham, and Julie Smith. They collaborated with the University of California at Davis (UCD), Lawrence Berkeley National Laboratory, Washington University's Laboratory for Space Sciences in St. Louis, and NASA's Ames Research Center for their discovery. The team analyzed micrometer-size interplanetary dust particles (IDPs), each about one-tenth the diameter of a human hair. Within the particles, they found carriers of the 2,175-angstrom feature: organic carbon mixed with amorphous silicates (glass with embedded metals and sulfides, GEMS), two of the most common materials in interstellar space. Ishii says, ''Organic carbon and amorphous silicates are abundant in interstellar dust clouds, and abundant carriers are needed to account for the frequent astronomical observation of the 2,175-angstrom feature. It makes sense that this ubiquitous feature would come from common materials in interstellar space''. The group's results increase scientific understanding of the starting materials for the formation of the Sun, solar system, and life on Earth.« less

Dust That's Worth Keeping

NASA Technical Reports Server (NTRS)

Hazi, A.

2006-01-01

Images taken of interstellar space often display a colorful canvas of portions of the electromagnetic spectrum. Dispersed throughout the images are interstellar clouds of dust and gas--remnants ejected from stars and supernovae over billions and billions of years. For more than 40 years, astronomers have observed that interstellar dust exhibits a consistent effect at a spectral wavelength of 2,175 angstroms, the equivalent of 5.7 electronvolts in energy on the electromagnetic spectrum. At this wavelength, light from stars is absorbed by dust in the interstellar medium, blocking the stars light from reaching Earth. The 2,175-angstrom feature, which looks like a bump on spectra, is the strongest ultraviolet-visible light spectral signature of interstellar dust and is visible along nearly every observational line of sight. Scientists have sought to solve the mystery of what causes the 2,175-angstrom feature by reproducing the effect in the laboratory. They speculated a number of possibilities, including fullerenes (buckyballs), nanodiamonds, and even interstellar organisms. However, none of these materials fits the data for the unique spectral feature. Limitations in the energy and spatial resolution achievable with electron microscopes and ion microprobes--the two main instruments used to study samples of dust--have also prevented scientists from finding the answer. A collaborative effort led by Livermore physicist John Bradley and funded by the National Aeronautics and Space Administration (NASA) has used a new-generation transmission electron microscope (TEM) and nanoscale ion microprobe to unlock the mystery. The Livermore group includes physicists Zu Rong Dai, Ian Hutcheon, Peter Weber, and Sasa Bajt and postdoctoral researchers Hope Ishii, Giles Graham, and Julie Smith. They collaborated with the University of California at Davis (UCD), Lawrence Berkeley National Laboratory, Washington University's Laboratory for Space Sciences in St. Louis, and NASA's Ames Research Center for their discovery. The team analyzed micrometer-size interplanetary dust particles (IDPs), each about one-tenth the diameter of a human hair. Within the particles, they found carriers of the 2,175-angstrom feature: organic carbon mixed with amorphous silicates (glass with embedded metals and sulfides, GEMS), two of the most common materials in interstellar space. Ishii says, 'Organic carbon and amorphous silicates are abundant in interstellar dust clouds, and abundant carriers are needed to account for the frequent astronomical observation of the 2,175-angstrom feature. It makes sense that this ubiquitous feature would come from common materials in interstellar space'. The group's results increase scientific understanding of the starting materials for the formation of the Sun, solar system, and life on Earth.

The New Horizons and Hubble Space Telescope search for rings, dust, and debris in the Pluto-Charon system

NASA Astrophysics Data System (ADS)

Lauer, Tod R.; Throop, Henry B.; Showalter, Mark R.; Weaver, Harold A.; Stern, S. Alan; Spencer, John R.; Buie, Marc W.; Hamilton, Douglas P.; Porter, Simon B.; Verbiscer, Anne J.; Young, Leslie A.; Olkin, Cathy B.; Ennico, Kimberly; New Horizons Science Team

2018-02-01

We conducted an extensive search for dust or debris rings in the Pluto-Charon system before, during, and after the New Horizons encounter in July 2015. Methodologies included attempting to detect features by back-scattered light during the approach to Pluto (phase angle α ∼ 15°), in situ detection of impacting particles, a search for stellar occultations near the time of closest approach, and by forward-scattered light imaging during departure (α ∼ 165°). An extensive search using the Hubble Space Telescope (HST) prior to the encounter also contributed to the final ring limits. No rings, debris, or dust features were observed, but our new detection limits provide a substantially improved picture of the environment throughout the Pluto-Charon system. Searches for rings in back-scattered light covered the range 35,000-250,000 km from the system barycenter, a zone that starts interior to the orbit of Styx, the innermost minor satellite, and extends out to four times the orbital radius of Hydra, the outermost known satellite. We obtained our firmest limits using data from the New Horizons LORRI camera in the inner half of this region. Our limits on the normal I/F of an unseen ring depends on the radial scale of the rings: 2 ×10-8 (3σ) for 1500 km wide rings, 1 ×10-8 for 6000 km rings, and 7 ×10-9 for 12,000 km rings. Beyond ∼ 100, 000 km from Pluto, HST observations limit normal I/F to ∼ 8 ×10-8 . Searches for dust features from forward-scattered light extended from the surface of Pluto to the Pluto-Charon Hill sphere (rHill = 6.4 ×106 km). No evidence for rings or dust clouds was detected to normal I/F limits of ∼ 8.9 ×10-7 on ∼ 104 km scales. Four stellar occulation observations also probed the space interior to Hydra, but again no dust or debris was detected. The Student Dust Counter detected one particle impact 3.6 × 106 km from Pluto, but this is consistent with the interplanetary space environment established during the cruise of New Horizons. Elsewhere in the solar system, small moons commonly share their orbits with faint dust rings. Our results support recent dynamical studies suggesting that small grains are quickly lost from the Pluto-Charon system due to solar radiation pressure, whereas larger particles are orbitally unstable due to ongoing perturbations by the known moons.

Solar Wind Characteristics from SOHO-Sun-Ulysses Quadrature Observations

NASA Technical Reports Server (NTRS)

Poletto, Giannina; Suess, Steve T.; Six, N. Frank (Technical Monitor)

2002-01-01

Over the past few years, we have been running SOHO (Solar and Heliospheric Observatory)-Sun-Ulysses quadrature campaigns, aimed at comparing the plasma properties at coronal altitudes with plasma properties at interplanetary distances. Coronal plasma has been observed by SOHO experiments: mainly, we used LASCO (Large Angle and Spectrometric Coronagraph Experiment) data to understand the overall coronal configuration at the time of quadratures and analyzed SUMER (Solar Ultraviolet Measurements of Emitted Radiation), CDS (Coronal Diagnostic Spectrometer) and UVCS (Ultraviolet Coronagraph Spectrometer) data to derive its physical characteristics. At interplanetary distances, SWICS (Solar Wind Ion Composition Spectrometer) and SWOOPS (Solar Wind Observation over the Poles of the Sun) aboard Ulysses provided us with interplanetary plasma data. Here we report on results from some of the campaigns. We notice that, depending on the geometry of the quadrature, i.e. on whether the radial to Ulysses traverses the corona at high or low latitudes, we are able to study different kinds of solar wind. In particular, a comparison between low-latitude and high-latitude wind, allowed us to provide evidence for differences in the acceleration of polar, fast plasma and equatorial, slow plasma: the latter occurring at higher levels and through a more extended region than fast wind. These properties are shared by both the proton and heavy ions outflows. Quadrature observations may provide useful information also on coronal vs. in situ elemental composition. To this end, we analyzed spectra taken in the corona, at altitudes ranging between approx. 1.02 and 2.2 solar radii, and derived the abundances of a number of ions, including oxygen and iron. Values of the O/Fe ratio, at coronal levels, have been compared with measurements of this ratio made by SWICS at interplanetary distances. Our results are compared with previous findings and predictions from modeling efforts.

Student Dust Counter I : Science Objectives

NASA Astrophysics Data System (ADS)

Mitchell, C.; Bryant, C.; Bunch, N.; Chanthawanich, T.; Colgan, M.; Fernandez, A.; Grogan, B.; Holland, G.; Krauss, C.; Krauss, E.; Krauss, O.; Neeland, M.; Horanyi, M.

2003-12-01

The New Horizons mission to Pluto and the Kuiper Belt is scheduled for launch in January 2006. As part of the Education and Public Outreach activity of the mission, undergraduate and graduate students at the Laboratory for Atmospheric and Space Physics, University of Colorado, are building a space experiment: the Student Dust Counter (SDC). This talk will summarize the scientific goals of this experiment. An accompanying poster describes the technical details of SDC. The primary goal of SDC is to map the dust distribution in the Solar System from 1 to 50 AU. It will greatly enhance our knowledge of dust production and transport in the outer Solar System by providing more sensitive observations than earlier experiments past Saturn, and the first in situ dust observations beyond 18 AU.

Electrodynamic Dust Shield for Solar Panels on Mars

NASA Technical Reports Server (NTRS)

Calle, C. I.; Buhler, C. R.; Mantovani, J. G.; Clements S.; Chen, A.; Mazumder, M. K.; Biris, A. S.; Nowicki, A. W.

2004-01-01

The Materials Adherence Experiment on the Mars Pathfinder mission measured an obscuration of the solar arrays due to dust deposition at a rate of about 0.2 8% per day. It was estimated that settling dust may cause degradation in performance of a solar panel of between 22% and 89% over the course of two years [1, 2]. These results were obtained without the presence of a global dust storm. Several types of adherence forces keep dust particles attached to surfaces. The most widely discussed adherence force is the electrostatic force. Laboratory experiments [3] as well as indirect evidence from the Wheel Abrasion Experiment on Pathfinder [4] indicate that it is very likely that the particles suspended in the Martian atmosphere are electrostatically charged.

The Suborbital Particle Aggregation and Collision Experiment (SPACE): studying the collision behavior of submillimeter-sized dust aggregates on the suborbital rocket flight REXUS 12.

PubMed

Brisset, Julie; Heißelmann, Daniel; Kothe, Stefan; Weidling, René; Blum, Jürgen

2013-09-01

The Suborbital Particle Aggregation and Collision Experiment (SPACE) is a novel approach to study the collision properties of submillimeter-sized, highly porous dust aggregates. The experiment was designed, built, and carried out to increase our knowledge about the processes dominating the first phase of planet formation. During this phase, the growth of planetary precursors occurs by agglomeration of micrometer-sized dust grains into aggregates of at least millimeters to centimeters in size. However, the formation of larger bodies from the so-formed building blocks is not yet fully understood. Recent numerical models on dust growth lack a particular support by experimental studies in the size range of submillimeters, because these particles are predicted to collide at very gentle relative velocities of below 1 cm/s that can only be achieved in a reduced-gravity environment. The SPACE experiment investigates the collision behavior of an ensemble of silicate-dust aggregates inside several evacuated glass containers which are being agitated by a shaker to induce the desired collisions at chosen velocities. The dust aggregates are being observed by a high-speed camera, allowing for the determination of the collision properties of the protoplanetary dust analog material. The data obtained from the suborbital flight with the REXUS (Rocket Experiments for University Students) 12 rocket will be directly implemented into a state-of-the-art dust growth and collision model.

Scientific activity program for 1989

NASA Astrophysics Data System (ADS)

1989-04-01

The current research projects are summarized. The research is grouped into four main directions: infrared astronomy, interplanetary media, cosmic rays and gravitational fields. The projects include instruments for the Infrared Space Observatory (ISO) satellite, problems of star formation and star evolution, Tethered Satellite System (TSS) experiment, Opera experiment, propagation of cosmic rays in the ionosphere, design of a solar neutron detector, and gravitational wave antennas experiments.

Investigation of dust transport on the lunar surface in laboratory plasmas

NASA Astrophysics Data System (ADS)

Wang, X.; Horanyi, M.; Robertson, S. H.

2009-12-01

There has been much evidence indicating dust levitation and transport on or near the lunar surface. Dust mobilization is likely to be caused by electrostatic forces acting on small lunar dust particles that are charged by UV radiation and solar wind plasma. To learn about the basic physical process, we investigated the dynamics of dust grains on a conducting surface in laboratory plasmas. The first experiment was conducted with a dust pile (JSC-Mars-1) sitting on a negatively biased surface in plasma. The dust pile spread and formed a diffusing dust ring. Dust hopping was confirmed by noticing grains on protruding surfaces. The electrostatic potential distributions measured above the dust pile show an outward pointing electrostatic force and a non-monotonic sheath above the dust pile, indicating a localized upward electrostatic force responsible for lifting dust off the surface. The second experiment was conducted with a dust pile sitting on an electrically floating conducting surface in plasma with an electron beam. Potential measurements show a horizontal electric field at the dust/surface boundary and an enhanced vertical electric field in the sheath above the dust pile when the electron beam current is set to be comparable to the Bohm ion current. Secondary electrons emitted from the surfaces play an important role in this case.

Status of the Dust Accumulation and Removal Technology Experiment for the Mars 2001 Surveyor Lander

NASA Technical Reports Server (NTRS)

Jenkins, P. P.; Landis, G. L.; Krasowski, M. J.; Greer, L. C. , III; Lekki, J.; Baraona, C. R.; Scheiman, D. A.; Wilt, D. M.

1999-01-01

The Dust Accumulation and Removal Technology (DART) experiment is designed to quantify the nature of dust settling out of the Martian atmosphere. DART is part of the Mars in-situ propellant precursor (MIP) experiment which is a payload on the Mars 2001 Surveyor Lander. At the time of this writing, high fidelity development hardware has been integrated in to the MIP experiment and completed Mars environment testing. Additional information is contained in the original extended abstract.

Magnetospheric access of solar particles and the configuration of the distant geomagnetic field, volume 1. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Evans, L. C.

1972-01-01

The access of 1.2 to 40 MeV protons and 0.4 to 1.0 MeV electrons from interplanetary space to the polar cap regions was investigated with an experiment on board a low altitude, polar-orbiting satellite (0G0 4). A total of 333 quiet time observations of the electron polar cap boundary give a mapping of the boundary between open and closed geomagnetic field lines. Observations of events associated with co-rotating regions of enhanced proton flux in interplanetary space were used to establish the characteristics of the 1.2 to 40 MeV proton access windows. The results were compared to particle access predictions of the distant geomagnetic tail configurations. The role played by interplanetary anisotropies in the observation of persistent polar cap features is discussed. Special emphasis is given to the problem of nonadiabatic particle entry through regions where the magnetic field is changing direction.

Population characteristics of submicrometer-sized craters on regolith particles from asteroid Itokawa

NASA Astrophysics Data System (ADS)

Matsumoto, Toru; Hasegawa, S.; Nakao, S.; Sakai, M.; Yurimoto, H.

2018-03-01

We investigated impact crater structures on regolith particles from asteroid Itokawa using scanning electron microscopy. We observed the surfaces of 51 Itokawa particles, ranging from 15 μm to 240 μm in size. Craters with average diameters ranging from 10 nm to 2.8 μm were identified on 13 Itokawa particles larger than 80 μm. We examined the abundance, spatial distribution, and morphology of approximately 900 craters on six Itokawa particles. Craters with sizes in excess of 200 nm are widely dispersed, with spatial densities from 2.6 μm2 to 4.5 μm2; a fraction of the craters was locally concentrated with a density of 0.1 μm2. The fractal dimension of the cumulative crater diameters ranges from 1.3 to 2.3. Craters of several tens of nanometers in diameter exhibit pit and surrounding rim structures. Craters of more than 100 nm in diameter commonly have melted residue at their bottom. These morphologies are similar to those of submicrometer-sized craters on lunar regolith. We estimated the impactor flux on Itokawa regolith-forming craters, assuming that the craters were accumulated during direct exposure to the space environment for 102 to 104 yr. The range of impactor flux onto Itokawa particles is estimated to be at least one order of magnitude higher than the interplanetary dust flux and comparable to the secondary impact flux on the Moon. This indicates that secondary ejecta impacts are probably the dominant cratering process in the submicrometer range on Itokawa regolith particles, as well as on the lunar surface. We demonstrate that secondary submicrometer craters can be produced anywhere in centimeter- to meter-sized depressions on Itokawa's surface through primary interplanetary dust impacts. If the surface unevenness on centimeter to meter scales is a significant factor determining the abundance of submicrometer secondary cratering, the secondary impact flux could be independent of the overall shapes or sizes of celestial bodies, and the secondary impact flux could have similar values on Itokawa and the Moon.

KSC-2013-3906

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities. CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities.

Assessment of State-of-the-Art Dust Emission Scheme in GEOS

NASA Technical Reports Server (NTRS)

Darmenov, Anton; Liu, Xiaohong; Prigent, Catherine

2017-01-01

The GEOS modeling system has been extended with state of the art parameterization of dust emissions based on the vertical flux formulation described in Kok et al 2014. The new dust scheme was coupled with the GOCART and MAM aerosol models. In the present study we compare dust emissions, aerosol optical depth (AOD) and radiative fluxes from GEOS experiments with the standard and new dust emissions. AOD from the model experiments are also compared with AERONET and satellite based data. Based on this comparative analysis we concluded that the new parameterization improves the GEOS capability to model dust aerosols originating from African sources, however it lead to overestimation of dust emissions from Asian and Arabian sources. Further regional tuning of key parameters controlling the threshold friction velocity may be required in order to achieve more definitive and uniform improvement in the dust modeling skill.

Ignition of Combustible Dust Clouds by Strong Capacitive Electric Sparks of Short Discharge Times

NASA Astrophysics Data System (ADS)

Eckhoff, Rolf K.

2017-10-01

It has been known for more than half a century that the discharge times of capacitive electric sparks can influence the minimum ignition energies of dust clouds substantially. Experiments by various workers have shown that net electric-spark energies for igniting explosive dust clouds in air were reduced by a factor of the order of 100 when spark discharge times were increased from a few μs to 0.1-1 ms. Experiments have also shown that the disturbance of the dust cloud by the shock/blast wave emitted by "short" spark discharges is a likely reason for this. The disturbance increases with increasing spark energy. In this paper a hitherto unpublished comprehensive study of this problem is presented. The work was performed about 50 years ago, using sparks of comparatively high energies (strong sparks). Lycopodium was used as test dust. The experiments were conducted in a brass vessel of 1 L volume. A transient dust cloud was generated in the vessel by a blast of compressed air. Synchronization of appearance of dust cloud and spark discharge was obtained by breaking the spark gap down by the dust cloud itself. This may in fact also be one possible synchronization mechanism in accidental industrial dust explosions initiated by electrostatic sparks. The experimental results for various spark energies were expressed as the probability of ignition, based on 100 replicate experiments, as a function of the nominal dust concentration. All probabilities obtained were 0%

Investigation of the Interplanetary Transfer of Microbes in the Tanpopo Mission at the Exposed Facility of the International Space Station.

PubMed

Kawaguchi, Yuko; Yokobori, Shin-Ichi; Hashimoto, Hirofumi; Yano, Hajime; Tabata, Makoto; Kawai, Hideyuki; Yamagishi, Akihiko

2016-05-01

The Tanpopo mission will address fundamental questions on the origin of terrestrial life. The main goal is to test the panspermia hypothesis. Panspermia is a long-standing hypothesis suggesting the interplanetary transport of microbes. Another goal is to test the possible origin of organic compounds carried from space by micrometeorites before the terrestrial origin of life. To investigate the panspermia hypothesis and the possible space origin of organic compounds, we performed space experiments at the Exposed Facility (EF) of the Japanese Experiment Module (JEM) of the International Space Station (ISS). The mission was named Tanpopo, which in Japanese means dandelion. We capture any orbiting microparticles, such as micrometeorites, space debris, and terrestrial particles carrying microbes as bioaerosols, by using blocks of silica aerogel. We also test the survival of microbial species and organic compounds in the space environment for up to 3 years. The goal of this review is to introduce an overview of the Tanpopo mission with particular emphasis on the investigation of the interplanetary transfer of microbes. The Exposed Experiment Handrail Attachment Mechanism with aluminum Capture Panels (CPs) and Exposure Panels (EPs) was exposed on the EF-JEM on May 26, 2015. The first CPs and EPs will be returned to the ground in mid-2016. Possible escape of terrestrial microbes from Earth to space will be evaluated by investigating the upper limit of terrestrial microbes by the capture experiment. Possible mechanisms for transfer of microbes over the stratosphere and an investigation of the effect of the microbial cell-aggregate size on survivability in space will also be discussed. Panspermia-Astrobiology-Low-Earth orbit. Astrobiology 16, 363-376.

KSC-2013-3908

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. -- Dust particles scatter during an experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The fabricated material is designed to mimic the dust on the lunar surface. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities. CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities.

KSC-2013-3907

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. -- Dust particles are readied for an experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The fabricated material is designed to mimic the dust on the lunar surface. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities. CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities.

Dust Transport from Enceladus to the moons of Saturn

NASA Astrophysics Data System (ADS)

Juhasz, A.; Hsu, H. W.; Kempf, S.; Horanyi, M.

2016-12-01

Saturn's vast E-ring engulfs the satellites Mimas, Enceladus, Tethys, Dione, and Rea, reaching even beyond Titan, while its inner edge is adjacent with the outskirts of the A-ring. The E-ring is comprised of characteristically micron and submicron sized particles, originating mainly from the active plumes of Enceladus, and possibly the other moons as well due to their continual bombardment by interplanetary dust particles. The dynamics of the E-ring grains can be surprising as in addition to the gravity of Saturn and its moons, their motion is governed by radiation pressure, plasma drag, and electromagnetic forces as they collect charges interacting with the magnetospheric plasma environment of Saturn. Due to sputtering, their mass is diminishing and, hence, their charge-to-mass ratio is increasing in time. A "young" gravitationally dominated micron-sized particle will "mature" into a nanometer-sized grain whose motion resembles that of a heavy ion. Simultaneously with their mass loss, the dust particles are pushed outwards by plasma drag. Time to time, their evolving orbits intersect the orbits of the Saturnian moons and the E-ring particles can be deposited onto their surfaces, possibly altering their makeup and spectral properties. Using the Cassini magnetospheric observations, we have followed the orbital evolution of E-ring particles, through their entire life, starting at Enceladus, ending in: a) a collision with the A-ring or any of the satellites; or b) losing all their mass due to sputtering; or c) leave the magnetosphere of Saturn. This presentation will focus on the deposition rates and maps of E-ring particles to the surfaces of the moons.

Telecommunications in cometary environments

NASA Technical Reports Server (NTRS)

Flock, W. L.

1981-01-01

Propagation effects on telecommunications in a cometary environment include those due to dust, the inhomogeneous plasma of the coma and tail, and ionization generated by impact of neutral molecules and dust on the spacecraft. Attenuation caused by dust particles is estimated to be on the order of 10 to the minus 5th power dB for the Halley Intercept Mission. Ionization generated by impact on the spacecraft is estimated to result in an electron content of 10 to the 12th power to 10 to the 13th power el/sq meters (3 eV electrons) along the telecommunications path. An estimate of the electron content due to Comet Halley itself is 10 to the 16th power to 10 to the 17th power el/sq meters, compared to a content of 10 to the 16th power to 10 to the 18th power el/sq meters for the Earth's ionosphere and 10 to the 17th power to 10 to the 18th power el/sq meters for the interplanetary medium. The electron content of the plasma near Comet Halley will cause excess range delay, and a Doppler shift of the signal from the spacecraft will occur in propagation to the rate of change of the path electron content. It is recommended that S and X down-link frequencies by employed to monitor the path electron content and amplitude scintillation and spectral broadening of the received signals. These measurements will provide a quantitative base of knowledge that will be valuable for radio science and telecommunications system design purposes.

Nanoflow Separation of Amino Acids for the Analysis of Cosmic Dust

NASA Technical Reports Server (NTRS)

Martin, M. P.; Glavin, D. P.; Dworkin, Jason P.

2008-01-01

The delivery of amino acids to the early Earth by interplanetary dust particles, comets, and carbonaceous meteorites could have been a significant source of the early Earth's prebiotic organic inventory. Amino acids are central to modern terrestrial biochemistry as major components of proteins and enzymes and were probably vital in the origin of life. A variety of amino acids have been detected in the CM carbonaceous meteorite Murchison, many of which are exceptionally rare in the terrestrial biosphere including a-aminoisobutyric acid (AIB) and isovaline. AIB has also been detected in a small percentage of Antarctic micrometeorite grains believed to be related to the CM meteorites We report on progress in optimizing a nanoflow liquid chromatography separation system with dual detection via laser-induced-fluorescence time of flight mass spectrometry (nLC-LIF/ToF-MS) for the analysis of o-phthaldialdehydelN-acetyl-L-cysteine (OPA/NAC) labeled amino acids in cosmic dust grains. The very low flow rates (<3 micro-L/min) of nLC over analytical LC (>0.1 ml/min) combined with <2 micron column bead sizes has the potential to produce efficient analyte ionizations andchromatograms with very sharp peaks; both increase sensitivity. The combination of the selectivity (only primary amines are derivatized), sensitivity (>4 orders of magnitude lower than traditional GC-MS techniques), and specificity (compounds identities are determined by both retention time and exact mass) makes this a compelling technique. However, the development of an analytical method to achieve separation of compounds as structurally similar as amino acid monomers and produce the sharp peaks required for maximum sensitivity is challenging.

Measurements of Photoelectric Yield and Physical Properties of Individual Lunar Dust Grains

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Tankosic, D.; Craven, P. D.; Spann, J. F.; LeClair, A.; West, F. A.; Taylor, L.; Hoover, R.

2005-01-01

Micron size dust grains levitated and transported on the lunar surface constitute a major problem for the robotic and human habitat missions for the Moon. It is well known since the Apollo missions that the lunar surface is covered with a thick layer of micron/sub-micron size dust grains. Transient dust clouds over the lunar horizon were observed by experiments during the Apollo 17 mission. Theoretical models suggest that the dust grains on the lunar surface are charged by the solar UV radiation as well as the solar wind. Even without any physical activity, the dust grains are levitated by electrostatic fields and transported away from the surface in the near vacuum environment of the Moon. The current dust charging and the levitation models, however, do not fully explain the observed phenomena. Since the abundance of dust on the Moon's surface with its observed adhesive characteristics is believed to have a severe impact on the human habitat and the lifetime and operations of a variety of equipment, it is necessary to investigate the phenomena and the charging properties of the lunar dust in order to develop appropriate mitigating strategies. We will present results of some recent laboratory experiments on individual micro/sub-micron size dust grains levitated in electrodynamic balance in simulated space environments. The experiments involve photoelectric emission measurements of individual micron size lunar dust grains illuminated with UV radiation in the 120-160 nm wavelength range. The photoelectric yields are required to determine the charging properties of lunar dust illuminated by solar UV radiation. We will present some recent results of laboratory measurement of the photoelectric yields and the physical properties of individual micron size dust grains from the Apollo and Luna-24 sample returns as well as the JSC-1 lunar simulants.

The impacts of the dust radiative effect on vegetation growth in the Sahel

NASA Astrophysics Data System (ADS)

Evans, S. M.; Shevliakova, E.; Malyshev, S.; Ginoux, P. A.

2017-12-01

Many studies have been conducted on the effects of dust on rainfall in the Sahel, and generally show that African dust weakens the West African Monsoon, drying the region. This drying is often assumed to reduce vegetation cover for the region, providing a positive feedback with dust emission. There are, however, other competing effects of dust that are also important to plant growth, including a reduction in surface temperature, a reduction in downwelling solar radiation, and an increase in the diffuse fraction of that solar radiation. Using the NOAA/GFDL CM3 model coupled to the dynamic vegetation model LM3, we demonstrate that the combined effect of all these processes is to decrease the vegetation coverage and productivity of the Sahel and West Africa. We accomplish this by comparing experiments with radiatively active dust to experiments with radiatively invisible dust. We find that in modern conditions, the dust radiative effect reduces the net primary productivity of West Africa and the Sahel by up to 30% locally, and when summed over the region accounts for a difference of approximately 0.4 GtC per year. Experiments where the vegetation experiences preindustrial rather than modern CO2 levels show that without carbon fertilization, this loss of productivity would be approximately 10% stronger. In contrast, during preindustrial conditions the vegetation response is less than half as strong, despite the dust induced rainfall and temperature anomalies being similar. We interpret this as the vegetation being less susceptible to drought in a less evaporative climate. These changes in vegetation create the possibility of a dust-vegetation feedback loop whose strength varies with the mean state of the climate, and which may grow stronger in the future.