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Sample records for planetary geochemical cycles

  1. DETECTING PLANETARY GEOCHEMICAL CYCLES ON EXOPLANETS: ATMOSPHERIC SIGNATURES AND THE CASE OF SO{sub 2}

    SciTech Connect

    Kaltenegger, L.; Sasselov, D.

    2010-01-10

    We study the spectrum of a planetary atmosphere to derive detectable features in low resolution of different global geochemical cycles on exoplanets-using the sulfur cycle as our example. We derive low-resolution detectable features for first generation space- and ground-based telescopes as a first step in comparative planetology. We assume that the surfaces and atmospheres of terrestrial exoplanets (Earth-like and super-Earths) will most often be dominated by a specific geochemical cycle. Here we concentrate on the sulfur cycle driven by outgassing of SO{sub 2} and H{sub 2}S followed by their transformation to other sulfur-bearing species, which is clearly distinguishable from the carbon cycle, which is driven by outgassing of CO{sub 2}. Due to increased volcanism, the sulfur cycle is potentially the dominant global geochemical cycle on dry super-Earths with active tectonics. We calculate planetary emission, reflection, and transmission spectrum from 0.4 mum to 40 mum with high and low resolution to assess detectable features using current and Archean Earth models with varying SO{sub 2} and H{sub 2}S concentrations to explore reducing and oxidizing habitable environments on rocky planets. We find specific spectral signatures that are observable with low resolution in a planetary atmosphere with high SO{sub 2} and H{sub 2}S concentration. Therefore, first generation space- and ground-based telescopes can test our understanding of geochemical cycles on rocky planets and potentially distinguish planetary environments dominated by the carbon and sulfur cycles.

  2. Geochemical cycles of atmospheric gases

    NASA Technical Reports Server (NTRS)

    Walker, J. C. G.; Drever, J. I.

    1988-01-01

    The processes that control the atmosphere and atmospheric changes are reviewed. The geochemical cycles of water vapor, nitrogen, carbon dioxide, oxygen, and minor atmospheric constituents are examined. Changes in atmospheric chemistry with time are discussed using evidence from the rock record and analysis of the present atmosphere. The role of biological evolution in the history of the atmosphere and projected changes in the future atmosphere are considered.

  3. Coal weathering and the geochemical carbon cycle

    SciTech Connect

    Chang, S.; Berner, R.A.

    1999-10-01

    The weathering rate of sedimentary organic matter in the continental surficial environment is poorly constrained despite its importance to the geochemical carbon cycle. During this weathering, complete oxidation to carbon dioxide is normally assumed, but there is little proof that this actually occurs. Knowledge of the rate and mechanisms of sedimentary organic matter weathering is important because it is one of the major controls on atmospheric oxygen level through geologic time. The authors have determined the aqueous oxidation rates of pyrite-free bituminous coal at 24 and 50 C by using a dual-cell flow-through method. Coal was used as an example of sedimentary organic matter because of the difficulty in obtaining pyrite-free kerogen for laboratory study. The aqueous oxidation rate obtained in the present study for air-saturated water (270 {micro}M O{sub 2}) was found to be on the order of 2 x 10{sup {minus}12} mol O{sub 2}/m{sup 2}/s at 25 C, which is fast compared to other geologic processes such as tectonic uplift and exposure through erosion. The reaction order with respect to oxygen level is 0.5 on a several thousand hour time scale for both 24 and 50 C experiments. Activation energies, determined under 24 and 50 C conditions, were {approx}40 kJ/mol O{sub 2} indicating that the oxidation reaction is surface reaction controlled. The oxygen consumption rate obtained in this study is two to three orders of magnitude smaller than that for pyrite oxidation in water, but still rapid on a geologic time scale. Aqueous coal oxidation results in the formation of dissolved CO{sub 2}, dissolved organic carbon (DOC), and solid oxidation products, which are all quantitatively significant reaction products.

  4. Combined Gamma-Ray Spectrometer and Pulsed Neutron Generator System for In-Situ Planetary Geochemical Analysis

    SciTech Connect

    Starr, R. D.; Evans, L. G.; Parsons, A. M.; Akkurt, Hatice; Floyd, H.; Wraight, P.; Ziegler, W.; Schweitzer, J.

    2007-01-01

    A combined pulsed neutron/gamma-ray system can be used on planetary surfaces to provide valuable geochemical analysis of surface materials to depths of {approx}1 m. We describe experimental results that demonstrate the capabilities of such a system.

  5. Geochemical Cycling of Iodine Species in Soils

    SciTech Connect

    Hu, Q; Moran, J E; Blackwood, V

    2007-08-23

    Iodine is an important element in studies of environmental protection and human health, global-scale hydrologic processes and nuclear nonproliferation. Biogeochemical cycling of iodine in soils is complex, because iodine occurs in multiple oxidation states and as inorganic and organic species that may be hydrophilic, atmophilic, and biophilic. In this study, we applied new analytical techniques to study the content and speciation of stable iodine in representative surface soils, and sorption and transport behavior of iodine species (iodide, iodate, and 4-iodoaniline) in sediments collected at numerous nuclear facilities in the United States, where anthropogenic {sup 129}I from prior nuclear fuel processing activities poses an environmental risk. The surface soil samples were chosen for their geographic locations (e.g., near the ocean or nuclear facilities) and for their differing physico-chemical characteristics (organic matter, texture, etc). Extracted solutions were analyzed by IC and ICP-MS methods to determine iodine concentrations and to examine iodine speciation (iodide, iodate, and organic iodine). In natural soils, iodine is mostly (nearly 90% of total iodine) present as organic species, while inorganic iodine becomes important (up to 50%) only in sediments with low organic matter. Results from laboratory column studies, aimed at examining transport of different iodine species, showed much greater retardation of 4-iodoaniline than iodide or iodate. Careful attention must be given to potential interconversion among species when interpreting the biogeochemical behavior of iodine in the environment. In addition to speciation, input concentration and residence time effects will influence the biogeochemical cycling of anthropogenic 129I deposited on surface soils.

  6. A carbonate-silicate aqueous geochemical cycle model for Mars

    NASA Astrophysics Data System (ADS)

    Schaefer, M. W.; Leidecker, H.

    1992-12-01

    A model for the carbonate-silicate geochemical cycle of an early, wet Mars is under development. The results of this study will be used to constrain models of the geochemical history of Mars and the likely mineralogy of its present surface. Although Mars today is a cold, dry planet, it may once have been much warmer and wetter. Values of total outgassed CO2 from several to about 10 bars are consistent with present knowledge (Pollack et al. 1987), and this amount of CO2 implies an amount of water outgassed at least equal to an equivalent depth of 500-1000 meters (Carr 1986). Pollack et al. (1987), in addition, estimate that a thick CO2 atmosphere may have existed for an extended period of time, perhaps as long as a billion years. The greenhouse effect of such an atmosphere would permit the presence of liquid water on the surface, most likely in the form of a shallow sea in the lowest regions of the planet, such as the northern plains (Schaefer 1990). The treatment of geochemical cycles as complex kinetic chemical reactions has been undertaken for terrestrial systems in recent years with much success (Lasaga 1980, 1981; Berner et al. 1983; Lasaga et al. 1985). Although the Martian system is vastly less well understood, and hence less well-constrained, it is also a much simpler system, due to the lack of biogenic reactions that make the terrestrial system so complex. It should be possible, therefore, to use the same techniques to model the Martian system as have been used for terrestrial systems, and to produce useful results. A diagram of the carbonate-silicate cycle for Mars (simplified from the terrestrial system) is given.

  7. Distinguishing Solar Cycle Effects in Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    Aplin, K. L.; Harrison, R. G.

    2008-12-01

    As solar radiation decreases with distance from the Sun, other sources of energy, such as ionization from galactic cosmic rays (GCR), assume a greater relative importance than at the terrestrial planets. Charged particle effects could therefore be more relevant to the formation of clouds and haze at the outer planets. The long-term solar modulation of Neptune's albedo is thought to be caused by either ion-induced nucleation of cloud-forming particles, or ultraviolet (UV) radiation effects on the colour of the clouds. On the basis of the 11 year solar cycle, the statistical evidence was slightly in favour of the UV mechanism, however distinguishing unambiguously between the two mechanisms will require more than the solar cycle variation alone. A 1.68 year quasi-periodicity, uniquely present at some times from heliospheric modulation of GCR, has previously been used to discriminate between solar UV and GCR effects in terrestrial data. The cosmic ray proton monitor data from both the Voyager spacecraft show this 1.68 year modulation during the 1980s when the spacecraft were close to the outer planets, indicating the possibility for applying a similar technique as far out as Neptune.

  8. Early Evolution of Earth's Geochemical Cycle and Biosphere: Implications for Mars Exobiology

    NASA Technical Reports Server (NTRS)

    DesMarais, David J.; Chang, Sherwood (Technical Monitor)

    1997-01-01

    Carbon (C) has played multiple key roles for life and its environment. C has formed organics, greenhouse gases, aquatic pH buffers, redox buffers, and magmatic constituents affecting plutonism and volcanism. These roles interacted across a network of reservoirs and processes known as the biogeochemical C cycle. Changes in the cycle over geologic time were driven by increasing solar luminosity, declining planetary heat flow, and continental and biological evolution. The early Archean C cycle was dominated by hydrothermal alteration of crustal rocks and by thermal emanations of CO2 and reduced species (eg., H2, Fe(2+) and sulfides). Bioorganic synthesis was achieved by nonphotosynthetic CO2-fixing bacteria (chemoautotrophs) and, possibly, bacteria (organotrophs) utilizing any available nonbiological organic C. Responding both to abundant solar energy and to a longterm decline in thermal sources of chemical energy and reducing power, the blaspheme first developed anoxygenic photosynthesis, then, ultimately, oxygenic photosynthesis. O2-photosynthesis played a central role in transforming the ancient environment and blaspheme to the modem world. The geochemical C cycles of early Earth and Mars were quite similar. The principal differences between the modem C cycles of these planets arose during the later evolution of their heat flows, crusts, atmospheres and, perhaps, their blasphemes.

  9. Geochemical Evidence of Cryptic Sulfur Cycling in Salt Marsh Sediments

    NASA Astrophysics Data System (ADS)

    Mills, J. V.; Antler, G.; Turchyn, A. V.

    2014-12-01

    In modern marine and marginal marine sediments, bacterial sulfate reduction dominates the subsurface oxidation of organic carbon due to the abundance of sulfate in many surface environments. While bacterial sulfate reduction may control anaerobic organic carbon oxidation, there is increasing evidence that iron redox chemistry may be intimately linked to sulfur redox chemistry in the anoxic subsurface, with iron species acting as catalysts or electron shuttles for the microbial use of sulfur, and vice versa. We use stable isotope and geochemical techniques to explore the coupling of the iron and sulfur cycles in salt marsh sediments in North Norfolk, UK. Unique among previously studied environments, these sediments contain high concentrations of both sulfate (20-40mM) and ferrous iron (1-3mM). High ferrous iron concentrations require extended regions of bacterial iron reduction. Within these zones of iron reduction we would predict no sulfate reduction, and lack of change in sulfur isotopes and no loss of sulfate suggest that there is no net sulfate reduction in this zone. However, coincident with the increase in ferrous iron concentrations, the δ18Osulfate exhibits significant increases of up to 5‰. The decoupling of the sulfur and oxygen isotopes of sulfate is suggestive of a cryptic sulfur cycle in which sulfate is reduced to an intermediate valence state sulfur species and subsequently reoxidized to sulfate; this cycle must by quasi-quantitative to produce the suite of geochemical observations. We further explore the nature of this cycling through a series of batch reactor incubation experiments. When sediments are incubated in 18O-enriched water, significant shifts (>15‰) in the δ18Osulfate are observed with no corresponding shift in sulfur isotopes. This provides direct evidence that microbial assemblages in these salt marsh sediments facilitate a cryptic cycling of sulfur, potentially mediated by iron species in the zone of iron reduction. We contrast

  10. Examining Volcanic Terrains Using In Situ Geochemical Technologies; Implications for Planetary Field Geology

    NASA Technical Reports Server (NTRS)

    Young, K. E.; Bleacher, J. E.; Evans, C. A.; Rogers, A. D.; Ito, G.; Arzoumanian, Z.; Gendreau, K.

    2015-01-01

    Regardless of the target destination for the next manned planetary mission, the crew will require technology with which to select samples for return to Earth. The six Apollo lunar surface missions crews had only the tools to enable them to physically pick samples up off the surface or from a boulder and store those samples for return to the Lunar Module and eventually to Earth. Sample characterization was dependent upon visual inspection and relied upon their extensive geology training. In the four decades since Apollo however, great advances have been made in traditionally laboratory-based instrument technologies that enable miniaturization to a field-portable configuration. The implications of these advancements extend past traditional terrestrial field geology and into planetary surface exploration. With tools that will allow for real-time geochemical analysis, an astronaut can better develop a series of working hypotheses that are testable during surface science operations. One such technology is x-ray fluorescence (XRF). Traditionally used in a laboratory configuration, these instruments have now been developed and marketed commercially in a field-portable mode. We examine this technology in the context of geologic sample analysis and discuss current and future plans for instrument deployment. We also discuss the development of the Chromatic Mineral Identification and Surface Texture (CMIST) instrument at the NASA Goddard Space Flight Center (GSFC). Testing is taking place in conjunction with the RIS4E (Remote, In Situ, and Synchrotron Studies for Science and Exploration) SSERVI (Solar System Exploration and Research Virtual Institute) team activities, including field testing at Kilauea Volcano, HI..

  11. Planetary geochemical investigations using Raman and laser-induced breakdown spectroscopy.

    PubMed

    Clegg, Samuel M; Wiens, Roger; Misra, Anupam K; Sharma, Shiv K; Lambert, James; Bender, Steven; Newell, Raymond; Nowak-Lovato, Kristy; Smrekar, Sue; Dyar, M Darby; Maurice, Sylvestre

    2014-01-01

    An integrated Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS) instrument is a valuable geoanalytical tool for future planetary missions to Mars, Venus, and elsewhere. The ChemCam instrument operating on the Mars Curiosity rover includes a remote LIBS instrument. An integrated Raman-LIBS spectrometer (RLS) based on the ChemCam architecture could be used as a reconnaissance tool for other contact instruments as well as a primary science instrument capable of quantitative mineralogical and geochemical analyses. Replacing one of the ChemCam spectrometers with a miniature transmission spectrometer enables a Raman spectroscopy mineralogical analysis to be performed, complementing the LIBS chemical analysis while retaining an overall architecture resembling ChemCam. A prototype transmission spectrometer was used to record Raman spectra under both Martian and Venus conditions. Two different high-pressure and high-temperature cells were used to collect the Raman and LIBS spectra to simulate surface conditions on Venus. The resulting LIBS spectra were used to generate a limited partial least squares Venus calibration model for the major elements. These experiments demonstrate the utility and feasibility of a combined RLS instrument. PMID:25226246

  12. Effects of the Seasonal Cycle on Superrotation in Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    Mitchell, Jonathan L.; Vallis, Geoffrey K.; Potter, Samuel F.

    2014-05-01

    The dynamics of dry atmospheric general circulation model simulations forced by seasonally varying Newtonian relaxation are explored over a wide range of two control parameters and are compared with the large-scale circulation of Earth, Mars, and Titan in their relevant parameter regimes. Of the parameters that govern the behavior of the system, the thermal Rossby number (Ro) has previously been found to be important in governing the spontaneous transition from an Earth-like climatology of winds to a superrotating one with prograde equatorial winds, in the absence of a seasonal cycle. This case is somewhat unrealistic as it applies only if the planet has zero obliquity or if surface thermal inertia is very large. While Venus has nearly vanishing obliquity, Earth, Mars, and Titan (Saturn) all have obliquities of ~25° and varying degrees of seasonality due to their differing thermal inertias and orbital periods. Motivated by this, we introduce a time-dependent Newtonian cooling to drive a seasonal cycle using idealized model forcing, and we define a second control parameter that mimics non-dimensional thermal inertia of planetary surfaces. We then perform and analyze simulations across the parameter range bracketed by Earth-like and Titan-like regimes, assess the impact on the spontaneous transition to superrotation, and compare Earth, Mars, and Titan to the model simulations in the relevant parameter regime. We find that a large seasonal cycle (small thermal inertia) prevents model atmospheres with large thermal Rossby numbers from developing superrotation by the influences of (1) cross-equatorial momentum advection by the Hadley circulation and (2) hemispherically asymmetric zonal-mean zonal winds that suppress instabilities leading to equatorial momentum convergence. We also demonstrate that baroclinic instabilities must be sufficiently weak to allow superrotation to develop. In the relevant parameter regimes, our seasonal model simulations compare favorably to

  13. Effects of the seasonal cycle on superrotation in planetary atmospheres

    SciTech Connect

    Mitchell, Jonathan L.; Vallis, Geoffrey K.; Potter, Samuel F.

    2014-05-20

    The dynamics of dry atmospheric general circulation model simulations forced by seasonally varying Newtonian relaxation are explored over a wide range of two control parameters and are compared with the large-scale circulation of Earth, Mars, and Titan in their relevant parameter regimes. Of the parameters that govern the behavior of the system, the thermal Rossby number (Ro) has previously been found to be important in governing the spontaneous transition from an Earth-like climatology of winds to a superrotating one with prograde equatorial winds, in the absence of a seasonal cycle. This case is somewhat unrealistic as it applies only if the planet has zero obliquity or if surface thermal inertia is very large. While Venus has nearly vanishing obliquity, Earth, Mars, and Titan (Saturn) all have obliquities of ∼25° and varying degrees of seasonality due to their differing thermal inertias and orbital periods. Motivated by this, we introduce a time-dependent Newtonian cooling to drive a seasonal cycle using idealized model forcing, and we define a second control parameter that mimics non-dimensional thermal inertia of planetary surfaces. We then perform and analyze simulations across the parameter range bracketed by Earth-like and Titan-like regimes, assess the impact on the spontaneous transition to superrotation, and compare Earth, Mars, and Titan to the model simulations in the relevant parameter regime. We find that a large seasonal cycle (small thermal inertia) prevents model atmospheres with large thermal Rossby numbers from developing superrotation by the influences of (1) cross-equatorial momentum advection by the Hadley circulation and (2) hemispherically asymmetric zonal-mean zonal winds that suppress instabilities leading to equatorial momentum convergence. We also demonstrate that baroclinic instabilities must be sufficiently weak to allow superrotation to develop. In the relevant parameter regimes, our seasonal model simulations compare favorably to

  14. Long-term climate change and the geochemical cycle of carbon

    NASA Technical Reports Server (NTRS)

    Marshall, Hal G.; Walker, James C. G.; Kuhn, William R.

    1988-01-01

    The response of the coupled climate-geochemical system to changes in paleography is examined in terms of the biogeochemical carbon cycle. The simple, zonally averaged energy balance climate model combined with a geochemical carbon cycle model, which was developed to study climate changes, is described. The effects of latitudinal distributions of the continents on the carbon cycle are investigated, and the global silicate weathering rate as a function of latitude is measured. It is observed that a concentration of land area at high altitudes results in a high CO2 partial pressure and a high global average temperature, and for land at low latitudes a cold globe and ice are detected. It is noted that the CO2 greenhouse feedback effect is potentially strong and has a stabilizing effect on the climate system.

  15. How life affects the geochemical cycle of carbon

    NASA Technical Reports Server (NTRS)

    Walker, James C. G.

    1992-01-01

    Developing a quantitative understanding of the biogeochemical cycles of carbon as they have worked throughout Earth history on various time scales, how they have been affected by biological evolution, and how changes in the carbon content of ocean and atmosphere may have affected climate and the evolution of life are the goals of the research. Theoretical simulations were developed that can be tuned to reproduce such data as exist and, once tuned, can be used to predict properties that have not yet been observed. This is an ongoing process, in which models and results are refined as new data and interpretations become available and as understanding of the global system improves. Results of the research are described in several papers which were published or submitted for publication. These papers are summarized. Future research plans are presented.

  16. The interglacial-glacial cycle and geochemical evolution of Canadian and Fennoscandian Shield groundwaters

    NASA Astrophysics Data System (ADS)

    Stotler, R. L.; Frape, S. K.; Ruskeeniemi, T.; Pitkänen, P.; Blowes, D. W.

    2012-01-01

    Results from cryogenic column experiments are compared with the geochemical data collected in the Canadian and Fennoscandian Shields over the past 25 years to investigate the relative influence of the glacial-interglacial cycle; specifically, the impact of continental glaciers, permafrost, and methane hydrate, on the evolution of groundwater from crystalline shield environments. Several different geochemical indicators of freezing processes (either glacial or permafrost-related) were utilized: comparisons of Na/Cl and Br/Cl ratios, δ 18O and δ 2H values, and δ 18O values and Cl - concentration. During freezing, fluids with different dominant cations follow distinctly different linear trends when Na/Cl and Br/Cl ratios are compared. Significantly, none of the freezing trends follows the trend hypothesized by Herut et al. (1990) for the evolution of seawater chemistry during freezing. Intrusion of glacial meltwater and in situ freezing (i.e., permafrost formation) result in a similar end-member when comparing δ 18O values and Cl - concentration. The geochemical influence of a freezing process on fresh, brackish, and some saline fluids was identified at some, but not all Canadian Shield sites, regardless of site location with respect to modern-day permafrost. Appreciably, physical and geochemical data do not support the formation of brines through any freezing process in the Canadian and Fennoscandian Shields, as hypothesized by Starinsky and Katz (2003). Rather, on all diagnostic freezing plots, brines are an end-member, indicating a different evolutionary pathway. Significant depletions in 18O with respect to modern precipitation, an indication of either glacial meltwater or a freezing process, were identified at depths of up to 1 km at some sites in the Canadian Shield, and to shallower depths in the Fennoscandian Shield. The potential of this fluid to reach such depths could be attributable to artificial gradients and mixing, glacial recharge, permafrost or

  17. A hybrid model of the CO2 geochemical cycle and its application to large impact events

    NASA Technical Reports Server (NTRS)

    Kasting, J. F.; Pollack, J. B.; Toon, O. B.; Richardson, S. M.

    1986-01-01

    The effects of a large asteriod or comet impact on modern and ancient marine biospheres are analyzed. A hybrid model of the carbonate-silicate geochemical cycle, which is capable of calculating the concentrations of carbon dioxide in the atmosphere, ocean, and sedimentary rocks, is described. The differences between the Keir and Berger (1983) model and the hybrid model are discussed. Equilibrium solutions are derived for the preindustrial atmosphere/ocean system and for a system similar to that of the late Cretaceous Period. The model data reveal that globl darkening caused by a stratospheric dust veil could destroy the existing phytoplankton within a period of several weeks or months, nd the dissolution of atmospheric NO(x) compounds would lower the pH of ocean surface waters and release CO2 into the atmosphere. It is noted that the surface temperatures could be increased by several degrees and surface oceans would be uninhabitable for calcaerous organisms for approximately 20 years.

  18. Community Structure of Methane-Cycling Archaea in Different Geochemical Zones in Aarhus Bay, Denmark

    NASA Astrophysics Data System (ADS)

    Chen, X.; Lever, M. A.; Saunders, A. M.; Jørgensen, B. B.

    2014-12-01

    Methanogenesis and anaerobic oxidation of methane are dominant processes regulating methane cycle in the deep biosphere in marine environments, both of which are executed by microbes. The diversity of methane-cycling archaea has been intensively studied by exploring 16S ribosomal RNA gene and alpha subunit of methyl coenzyme M reductase gene (mcrA). In marine sediments, methanogens and methane-oxidizing archaea are mainly found in methane zone (MZ) and in sulfate-methane transition zone (SMTZ), respectively. However, methane-cycling archaea are also present in zones other than their usual residing geochemical zones. Next generation sequencing of mcrA genes from 5 gravity cores shows that both methanogens and methane-oxidizing archaeal group - ANME-1 are ubiquitous in all biogeochemical zones in Aarhus Bay. We will further discuss below questions: which methanogens and methanotrophs are present and active in the presence of sulfate, and which are restricted in SMTZ or MZ? How do activity and pathway of methanogenesis / methanotrophy change with depth and substrate availability?

  19. Planetary Biology and Microbial Ecology: Molecular Ecology and the Global Nitrogen cycle

    NASA Technical Reports Server (NTRS)

    Nealson, Molly Stone (Editor); Nealson, Kenneth H. (Editor)

    1993-01-01

    This report summarizes the results of the Planetary Biology and Molecular Ecology's summer 1991 program, which was held at the Marine Biological Laboratory in Woods Hole, Massachusetts. The purpose of the interdisciplinary PBME program is to integrate, via lectures and laboratory work, the contributions of university and NASA scientists and student interns. The goals of the 1991 program were to examine several aspects of the biogeochemistry of the nitrogen cycle and to teach the application of modern methods of molecular genetics to field studies of organisms. Descriptions of the laboratory projects and protocols and abstracts and references of the lectures are presented.

  20. Geothermal Systems in Yellowstone National Park are Excellent Model Environments for Linking Microbial Processes and Geochemical Cycling

    NASA Astrophysics Data System (ADS)

    Inskeep, W. P.; Jay, Z.

    2008-12-01

    Geothermal systems in Yellowstone National Park (YNP) are geochemically diverse, span pH values from approximately 2 to 10, and generally contain a plethora of reduced constituents that may serve as electron donors for chemotrophic microorganisms. One of our long-term goals has been to determine linkages between geochemical processes and the distribution of microbial populations in high-temperature environments, where geochemical conditions often constrain microbial community diversity. Although geochemical characteristics vary greatly across the world's largest geothermal basin, there exist key geochemical attributes that are likely most important for defining patterns in microbial distribution. For example, excellent model systems exist in YNP, where the predominant geochemical and microbial processes are focused on either S species and or Fe-oxidation-reduction. In such cases, we hypothesize that genetic diversity and functional gene content will link directly with habitat parameters. Several cases studies will be presented where pilot metagenomic data (random shotgun sequencing of environmental DNA) was used to identify key functional attributes and confirm that specific patterns of microbial distribution are indeed reflected in other gene loci besides the 16S rRNA gene. These model systems are excellent candidates for elucidating definitive linkages between S, As, and or Fe cycling, genomics and microbial regulation.

  1. Parallel geochemical and metagenomic datasets reveal biogeochemical cycling in a hot spring ecosystem

    NASA Astrophysics Data System (ADS)

    Meyer-Dombard, D. R.; Swingley, W.; Raymond, J.; Shock, E.

    2012-12-01

    Environmental sequence data (2,321 16S rRNA clones and 470 megabases of "metagenome" sequence) were produced from biofilms at five sites in the outflow of "Bison Pool" (BP), an alkaline hot spring in the Lower Geyser Basin of Yellowstone National Park. The outflow of BP is characterized by decreasing temperature, increasing pH, increasing dissolved oxygen, decreasing total sulfide, and changing availability of biological nutrients. Microbial life along a 22 m gradient at BP transitions from a 92°C chemotrophic streamer biofilm community in the source pool to a 56°C phototrophic mat community. Coordinated analysis of the BP Environmental Genome and a complementary contextual geochemical dataset of ~75 parameters has revealed biogeochemical cycling and metabolic and microbial community shifts within a hot spring ecosystem (1). In the BP outflow, genes diagnostic for sulfide oxidation, attributed to Aquificales in the chemosynthetic zone and Deinococcus-Thermus at the photosynthetic fringe, decrease in total number downstream. Geochemical data indicate that biological sulfide oxidation, an energy-yielding process in BP, occurs over this same range. While the genetic capacity for sulfate reduction in Thermoproteales at high temperature was found, inorganic sulfate reduction is only minimally energy-yielding at BP suggesting limited activity of these genes. Presence of apr, sat, and dsr genes in the photosynthetic mats may indicate sulfate reduction in micro-niches at depth within the biofilms, perhaps in response to increased availability of organic solutes. Carbon fixation tactics shift downstream in BP as well, as evidenced by the presence of genes associated with specific pathways and carbon isotope ratios. Capacity for the rTCA cycle, attributed to Aquificales and Thermoproteales, and the acetyl co-A pathway are found throughout BP, but are most prevalent in highest temperature sites. At lower temperature sites, fewer total carbon fixation genes were observed

  2. A geomorphic-geochemical framework for quantifying the cycling of sediment-associated contaminants in fluvial systems

    NASA Astrophysics Data System (ADS)

    Byrne, Patrick; Lopez-Tarazon, Jose; Williams, Richard

    2016-04-01

    Recent high-profile contamination events linked to extreme floods have underlined the persistent environmental risk posed by legacy metals stored in fluvial systems worldwide. While we understand that the fate of sediment-associated metals is largely determined by the dynamics of the fluvial transport system, we still lack a process-based understanding of the spatial and temporal mechanisms that affect the physical and geochemical transfer of metals through catchments. This interdisciplinary project will exploit advances in geomorphic and geochemical analyses to develop a methodological approach and conceptual framework to answer key questions related to the dynamics and timescales of metal cycling in fluvial systems. The approach will be tested in two reaches of the mining-impacted Afon Twymyn, Wales. The main objectives are: (i) quantify the physical transport of sediment and metals over a range of river flows and model sediment pathways; (ii) establish the geochemical mobility and speciation of sediment-associated metals and how this is modified through the sediment pathways. To achieve these objectives a geomorphic-geochemical combined methodology will be applied. It includes: (i) Aerial imagery that will be acquired from UAV surveys pre- and post-high flows and transformed into high-resolution DEMs using Structure-from-Motion; (ii) suspended sediment flux will be estimated indirectly by field calibration with a logging turbidimeter; (iii) 2D hydraulic and sediment transport model (Delft3D) will be used to quantify the transport of sediment and associated metals and to map the source, pathway and sink of contaminated sediment; (iv) soil and sediment samples (including suspended sediment) will be collected pre- and post-high flows for geochemical (concentration, speciation) and mineralogical (XRD, SEM) analyses; (v) finally, a geochemical model (Geochemists Workbench) will be developed to generate hypotheses that explain observed geochemical change as a function

  3. Chemical footprint: a methodological framework for bridging life cycle assessment and planetary boundaries for chemical pollution.

    PubMed

    Sala, Serenella; Goralczyk, Malgorzata

    2013-10-01

    The development and use of footprint methodologies for environmental assessment are increasingly important for both the scientific and political communities. Starting from the ecological footprint, developed at the beginning of the 1990s, several other footprints were defined, e.g., carbon and water footprint. These footprints-even though based on a different meaning of "footprint"-integrate life cycle thinking, and focus on some challenging environmental impacts including resource consumption, CO2 emission leading to climate change, and water consumption. However, they usually neglect relevant sources of impacts, as those related to the production and use of chemicals. This article presents and discusses the need and relevance of developing a methodology for assessing the chemical footprint, coupling a life cycle-based approach with methodologies developed in other contexts, such as ERA and sustainability science. Furthermore, different concepts underpin existing footprint and this could be the case also of chemical footprint. At least 2 different approaches and steps to chemical footprint could be envisaged, applicable at the micro- as well as at the meso- and macroscale. The first step (step 1) is related to the account of chemicals use and emissions along the life cycle of a product, sector, or entire economy, to assess potential impacts on ecosystems and human health. The second step (step 2) aims at assessing to which extent actual emission of chemicals harm the ecosystems above their capability to recover (carrying capacity of the system). The latter step might contribute to the wide discussion on planetary boundaries for chemical pollution: the thresholds that should not be surpassed to guarantee a sustainable use of chemicals from an environmental safety perspective. The definition of what the planetary boundaries for chemical pollution are and how the boundaries should be identified is an on-going scientific challenge for ecotoxicology and ecology. In

  4. Linking the climatic and geochemical controls on global soil carbon cycling

    NASA Astrophysics Data System (ADS)

    Doetterl, Sebastian; Stevens, Antoine; Six, Johan; Merckx, Roel; Van Oost, Kristof; Casanova Pinto, Manuel; Casanova-Katny, Angélica; Muñoz, Cristina; Boudin, Mathieu; Zagal Venegas, Erick; Boeckx, Pascal

    2015-04-01

    Climatic and geochemical parameters are regarded as the primary controls for soil organic carbon (SOC) storage and turnover. However, due to the difference in scale between climate and geochemical-related soil research, the interaction of these key factors for SOC dynamics have rarely been assessed. Across a large geochemical and climatic transect in similar biomes in Chile and the Antarctic Peninsula we show how abiotic geochemical soil features describing soil mineralogy and weathering pose a direct control on SOC stocks, concentration and turnover and are central to explaining soil C dynamics at larger scales. Precipitation and temperature had an only indirect control by regulating geochemistry. Soils with high SOC content have low specific potential CO2 respiration rates, but a large fraction of SOC that is stabilized via organo-mineral interactions. The opposite was observed for soils with low SOC content. The observed differences for topsoil SOC stocks along this transect of similar biomes but differing geo-climatic site conditions are of the same magnitude as differences observed for topsoil SOC stocks across all major global biomes. Using precipitation and a set of abiotic geochemical parameters describing soil mineralogy and weathering status led to predictions of high accuracy (R2 0.53-0.94) for different C response variables. Partial correlation analyses revealed that the strength of the correlation between climatic predictors and SOC response variables decreased by 51 - 83% when controlling for geochemical predictors. In contrast, controlling for climatic variables did not result in a strong decrease in the strength of the correlations of between most geochemical variables and SOC response variables. In summary, geochemical parameters describing soil mineralogy and weathering were found to be essential for accurate predictions of SOC stocks and potential CO2 respiration, while climatic factors were of minor importance as a direct control, but are

  5. SEDIMENT GEOCHEMICAL MODEL

    EPA Science Inventory

    Until recently, sediment geochemical models (diagenetic models) have been only able to explain sedimentary flux and concentration profiles for a few simplified geochemical cycles (e.g., nitrogen, carbon and sulfur). However with advances in numerical methods, increased accuracy ...

  6. Synchronized Helicity Oscillations: A Link Between Planetary Tides and the Solar Cycle?

    NASA Astrophysics Data System (ADS)

    Stefani, F.; Giesecke, A.; Weber, N.; Weier, T.

    2016-09-01

    Recent years have seen an increased interest in the question of whether the gravitational action of planets could have an influence on the solar dynamo. Without discussing the observational validity of the claimed correlations, we examine which possible physical mechanism might link the weak planetary forces with solar dynamo action. We focus on the helicity oscillations that were recently found in simulations of the current-driven, kink-type Tayler instability, which is characterized by an m=1 azimuthal dependence. We show how these helicity oscillations may be resonantly excited by some m=2 perturbations that reflect a tidal oscillation. Specifically, we speculate that the tidal oscillation of 11.07 years induced by the Venus-Earth-Jupiter system may lead to a 1:1 resonant excitation of the oscillation of the α-effect. Finally, we recover a 22.14-year cycle of the solar dynamo in the framework of a reduced zero-dimensional α- Ω dynamo model.

  7. Geochemical and hydrodynamic controls on arsenic and trace metal cycling in a seasonally stratified US sub-tropical reservoir

    SciTech Connect

    Brandenberger, Jill M.; Louchouarn, Patrick; Herbert, Bruce; Tissot, Philippe

    2004-10-01

    The phase distribution of trace metals and oxyanions was investigated within a South Texas watershed hosting a high density of surface uranium mine pits and tailings. The objectives of the study were to evaluate the potential impact of these old uranium mining sites on the watershed with particular emphasis on spatial and temporal changes in water quality of a reservoir that serves as the major source of freshwater to a population of {approx} 350,000 people in the region. A livestock pond, bordered by uranium mine tailings, was used as a model case-study site to evaluate the cycling of uranium mine-derived oxyanions under changing redox conditions. Although the pond showed seasonal thermal and chemical stratification, geochemical cycling of metals was limited to Co and Pb, which seemed to be mostly associated with redox cycling of Mn mineral phases, and U, which suggested reductive precipitation in the ponds hypolimnion. Uranium levels, however, were too low to support strong inputs from th e tailings into the water column of the pond. The strong relations observed between particulate Cr, Cs, V and Fe suggest that these metals are associated with a stable particulate phase (probably allochthonous aluminosilicates) enriched in unreactive iron. This observation is supported by a parallel relationship in sediments collected across a broad range of sediment depositional processed (and histories) in the basin. Arsenic, though selectively enriched in the ponds water column, remained stable and mostly in solution throughout the depth of the profile and showed no sign of geochemical cycling or interaction with Fe-rich particles. We found no evidence of anthropogenic impacts of U mines beyond the purely local scale. Arsenic does decrease in concentration downstream of uranium mining sites but its presence within the Nueces drainage basin is related to interactions between surface and ground waters with uranium-rich geological formations rather than long-scale transport of

  8. Evidence for Milankovitch periodicities in Cenomanian-Turonian lithologic and geochemical cycles, Western Interior U.S.A.

    SciTech Connect

    Sageman, B.B.; Rich, J.; Birchfield, G.E.; Arthur, M.A.; Dean, W.E.

    1997-03-01

    The limestone/marlstone bedding couplets of the Bridge Creek Limestone Member, Cenomanian-Turonian Greenhorn Formation, were analyzed by applying spectral techniques to high-resolution lithologic and geochemical data from a core. The results suggest that the Bridge Creek contains a complex record of orbital cyclicity. The dominant signal appears to be obliquity, but signals corresponding to precession and eccentricity were also observed. The development of the bedding couplets is interpreted to have resulted from a combination of factors, including insolation-controlled changes in higher-latitude precipitation leading to dilution/redox cycles, and in lower-latitude evaporation, leading to changes in surface water conditions and productivity cycles in the calcareous plankton. The data interpreted to reflect redox cycles appear to be more strongly influenced by obliquity, and show a weak precessional signal. In contrast, trends in the carbonate record show the opposite response. The complex bedding pattern observed in the Bridge Creek Limestone is interpreted to result from the competing influences of different orbital cycles expressed through different pathways of the depositional system, and was also affected by changes in sedimentation rates related to relative sea level fluctuations, aperiodic dilution by volcanic ash, and changes in organic-matter production and redox conditions related to a global oceanic anoxic event. These factors complicate cycle analysis in the lower part of the member but leave a relatively undisturbed record in the upper Bridge Creek Limestone.

  9. Evidence for Milankovitch periodicities in Cenomanian-Turonian lithologic and geochemical cycles, western interior U.S.A.

    USGS Publications Warehouse

    Sageman, B.B.; Rich, J.; Arthur, M.A.; Birchfield, G.E.; Dean, W.E.

    1997-01-01

    The limestone/marlstone bedding couplets of the Bridge Creek Limestone Member, Cenomanian-Turonian Greenhorn Formation, were analyzed by applying spectral techniques to high-resolution lithologic and geochemical data from a core. The results suggest that the Bridge Creek contains a complex record of orbital cyclicity. The dominant signal appears to be obliquity, but signals corresponding to precession and eccentricity were also observed. The development of the bedding couplets is interpreted to have resulted from a combination of factors, including insolation-controlled changes in higher-latitude precipitation leading to dilution/redox cycles, and in lower-latitude evaporation, leading to changes in surface water conditions and productivity cycles in the calcareous plankton. The data interpreted to reflect redox cycles appear to be more strongly influenced by obliquity, and show a weak precessional signal. In contrast, trends in the carbonate record show the opposite response. The complex bedding pattern observed in the Bridge Creek Limestone is interpreted to result from the competing influences of different orbital cycles expressed through different pathways of the depositional system, and was also affected by changes in sedimentation rates related to relative sea level fluctuations, aperiodic dilution by volcanic ash, and changes in organic-matter production and redox conditions related to a global "oceanic anoxic event". These factors complicate cycle analysis in the lower part of the member but leave a relatively undisturbed record in the upper Bridge Creek Limestone. Copyright ?? 1997, SEPM (Society for Sedimentary Geology).

  10. The geochemical cycling of trace elements in a biogenic meromictic lake

    USGS Publications Warehouse

    Balistrieri, L.S.; Murray, J.W.; Paul, B.

    1994-01-01

    The geochemical processes affecting the behavior and speciation of As, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn in Hall Lake, Washington, USA, are assessed by examining dissolved and acid soluble particulate profiles of the elements and utilizing results from thermodynamic calculations. The water column of this meromictic lake is highly stratified and contains distinctive oxic, suboxic, and anoxic layers. Changes in the redox state of the water column with depth affect the distribution of all the elements studied. Most noticeable are increases in dissolved Co, Cr, Fe, Mn, Ni, Pb, and Zn concentrations across the oxic-suboxic boundary, increases in dissolved As, Co, Cr, Fe, Mn, and V concentrations with depth in the anoxic layer, significant decreases in dissolved Cu, Ni, Pb, and Zn concentrations in the anoxic region below the sulfide maximum, and large increases in acid soluble particulate concentrations of As, Cr, Cu, Fe, Mo, Ni, Pb, V, and Zn in the anoxic zone below the sulfide maximum. Thermodynamic calculations for the anoxic region indicate that all redox sensitive elements exist in their reduced forms, the primary dissolved forms of Cu, Ni, Pb, and Zn are metal sulfide solution complexes, and solid sulfide phases of Cu, Fe, Mo, and Pb are supersaturated. Calculations using a vertical diffusion and reaction model indicate that the oxidation rate constant for Mn(II) in Hall Lake is estimated to be 0.006 d-1 and is at the lower end of the range of microbial oxidation rates observed in other natural systems. The main geochemical processes influencing the distribution and speciation of trace elements in Hall Lake appear to be transformations of dissolved elements between their oxidation states (As, Cr, Cu, Fe, Mn, V), cocycling of trace elements with Mn and Fe (As, Co, Cr, Cu, Mo, Ni, Pb, V, Zn), formation of soluble metal sulfide complexes (Co, Cu, Ni, Pb, Zn), sorption (As, Co, Cr, Ni, V), and precipitation (Cu, Fe, Mn, Mo, Pb, Zn). ?? 1994.

  11. Beyond Vmax and Km: How details of enzyme function influence geochemical cycles

    NASA Astrophysics Data System (ADS)

    Steen, A. D.

    2015-12-01

    Enzymes catalyze the vast majority of chemical reactions relevant to geomicrobiology. Studies of the activities of enzymes in environmental systems often report Vmax (the maximum possible rate of reaction; often proportional to the concentration of enzymes in the system) and sometimes Km (a measure of the affinity between enzymes and their substrates). However, enzyme studies - particularly those related to enzymes involved in organic carbon oxidation - are often limited to only those parameters, and a relatively limited and mixed set of enzymes. Here I will discuss some novel methods to assay and characterize the specific sets of enzymes that may be important to the carbon cycle in aquatic environments. First, kinetic experiments revealed the collective properties of the complex mixtures of extracellular peptidases that occur where microbial communities are diverse. Crystal structures combined with biochemical characterization of specific enzymes can yield more detailed information about key steps in organic carbon transformations. These new techniques have the potential to provide mechanistic grounding to geomicrobiological models.

  12. Do Two Deep Drill Holes Into the Upper Ocean Crust Quantify the Hydrothermal Contribution to Global Geochemical Cycles?

    NASA Astrophysics Data System (ADS)

    Teagle, D. A. H.; Alt, J.; Coggon, R. M.; Harris, M.; Smith-Duque, C. E.; Rehkamper, M.

    2014-12-01

    Vigorous circulation of seawater at the ocean ridges is required to cool and crystallize magma to form new ocean crust. Axial and ridge flank hydrothermal fluid circulation is accompanied by seawater-basalt exchanges over a spectrum of temperatures that buffer the chemistry of seawater, provide unique microbial niches, alter the chemistry and mineralogy of the ocean crust, and through subduction return surface-derived geochemical tracers to the interior of our planet. In many models of axial and ridge flank hydrothermal circulation, most fluid-rock interaction occurs in the upper oceanic crust. Hence inventories of seawater exchange should be captured by relatively shallow (<2 km) boreholes. However, after 45+ years of ocean drilling we have just two deep drill holes that sample the lava and dike layers of intact upper oceanic crust. DSDP Hole 504B on 6.9 Ma ocean crust produced at the intermediate spreading rate Costa Rica Rift penetrates 1836 m into basement through a complete sequence of lavas to near the base of the sheeted dike complex. In isolation, Hole 504B became the 'reference section' for upper oceanic crust from which hydrothermal contributions to global geochemical cycles were determined. The recent drilling of Hole 1256D in 15 Ma superfast spreading rate Pacific crust penetrated through the complete volcanic and sheeted dike layers into the underlying gabbroic rocks in intact ocean crust for the first time. These boreholes are complemented by observations from seafloor tectonic windows, fracture zones, and ophiolites, but these are imperfect analogs. Although Holes 504B and 1256D formed at different spreading rates, crust from both sites is expected to conform to textbook Penrose-type layering, albeit with different thicknesses of lavas and dikes. However, what was not anticipated was the contrasting distribution and nature of elemental and isotopic hydrothermal exchanges. Differences reflect the influence of local crustal structure, such as lava

  13. Impact of anaerobic oxidation of methane on the geochemical cycle of redox-sensitive elements at cold-seep sites of the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Hu, Yu; Feng, Dong; Liang, Qianyong; Xia, Zhen; Chen, Linying; Chen, Duofu

    2015-12-01

    Cold hydrocarbon seepage is a frequently observed phenomenon along continental margins worldwide. However, little is known about the impact of seeping fluids on the geochemical cycle of redox-sensitive elements. Pore waters from four gravity cores (D-8, D-5, D-7, and D-F) collected from cold-seep sites of the northern South China Sea were analyzed for SO42-, Mg2+, Ca2+, Sr2+, dissolved inorganic carbon (DIC), δ13CDIC, dissolved Fe, Mn, and trace elements (e.g. Mo, U). The sulfate concentration-depth profiles, δ13CDIC values and (ΔDIC+ΔCa2++ΔMg2+)/ΔSO42- ratios suggest that organoclastic sulfate reduction (OSR) is the dominant process in D-8 core. Besides OSR, anaerobic oxidation of methane (AOM) is partially responsible for depletion of sulfate at D-5 and D-7 cores. The sulfate consumption at D-F core is predominantly caused by AOM. The depth of sulfate-methane interface (SMI) and methane diffusive flux of D-F core are calculated to be ~7 m and 0.035 mol m-2 yr-1, respectively. The relatively shallow SMI and high methane flux at D-F core suggest the activity of gas seepage in this region. The concentrations of dissolved uranium (U) were inferred to decrease significantly within the iron reduction zone. It seems that AOM has limited influence on the U geochemical cycling. In contrast, a good correlation between the consumption of sulfate and the removal of molybdenum (Mo) suggests that AOM has a significantly influence on the geochemical cycle of Mo at cold seeps. Accordingly, cold seep environments may serve as an important potential sink in the marine geochemical cycle of Mo.

  14. Solar cycle influence on troposphere and middle atmosphere via ozone layer in the presence of planetary waves: Simulation with ARM

    NASA Astrophysics Data System (ADS)

    Krivolutsky, A. A.; Cherepanova, L. A.; Dement'eva, A. V.

    2015-10-01

    Global circulation model of the Troposphere-Middle Atmosphere-Lower Thermosphere ARM (Atmospheric Research Model) is used to simulate the thermal and wind response to solar cycle-induced UV variations. ARM covers altitudes from 1 to 135 km and has corresponding spatial resolution: 1 km in altitude; 11.25° in longitude; 5° in latitude. Internal Gravity Waves parameterization and planetary waves (PWs) structure on the basis of observations are determined at the lower boundary of the model. Changes in UV radiation, which is absorbed by ozone and molecular oxygen, are introduced into the model to find the corresponding global wind and temperature response. Stationary PWs with zonal wave numbers 1-3 are included at lower boundary in model runs. The simulations show that atmospheric response to solar cycle has a visible nonzonal character with the amplitude of about 5 K in the troposphere for the winter season. The effect is rather smaller for summer due to the trapping PWs at lower altitudes. So, in accordance with the results of simulations, the link between the solar UV variability and the middle and low atmosphere strongly depends on the ozone and PWs activity.

  15. Barotropic interaction between planetary- and synoptic-scale waves during the life cycles of blockings

    NASA Astrophysics Data System (ADS)

    Luo, Dehai; Li, Jianping

    2000-12-01

    In this paper, in an equivalent barotropic framework a new forced nonlinear Schroedinger equation is proposed to examine the interaction between the planetary-scale waves and the localized synoptic-scale eddies upstream. With the help of the perturbed inverse scattering transform method, nonlinear parameter equations can be derived to describe the evolution of the dipole soliton amplitude, frequency, group velocity and phase under the forcing of localized synoptic-scale eddies. The numerical solutions of these equations predict that in the interaction between the weak dipole soliton (weak incipient dipole anomaly) and the synoptic-scale eddies, only when the high-frequency eddies themselves have a moderate parameter match they can near resonantly enhance a quasi-stationary large-amplitude split flow. The instantaneous total streamfunction field (the sum of background westerly wind, envelope Rossby soliton and synoptic-scale waves) is found to be very similar to the observed Berggren-type blocking on the weather map(Berggren et al. 1949). The role of synoptic-scale eddies is to increase the amplitude of large-scale dipole anomaly flow, and to decrease its group velocity, phase velocity and zonal wavenumber so that the dipole anomaly system can be amplified and transferred from dispersive system to very weak dispersive one. This may explain why and how the synoptic-scale eddies can reinforce and maintain vortex pair block. Furthermore, it is clearly found that during the prevalence of the vortex pair block the synoptic-scale eddies are split into two branches around the vortex pair block due to the feedback of amplified dipole block.

  16. Analysis of Co-spatial UV-Optical STIS Spectra of Seven Planetary Nebulae From HST Cycle 19 GO 12600

    NASA Astrophysics Data System (ADS)

    Miller, Timothy R.; Henry, Richard B. C.; Dufour, Reginald J.; Kwitter, Karen B.; Shaw, Richard A.; Balick, Bruce; Corradi, Romano

    2016-01-01

    We present an analysis of seven spatially resolved planetary nebulae (PNe), NGC 2440, NGC 3242, NGC 5315, NGC 5882, NGC 7662, IC 2165, and IC 3568, from observations in the Cycle 19 program GO 12600 using HST STIS. These seven observations cover the wavelength range 1150-10,270 Å with 0.2 and 0.5 arcsec wide slits, and are co-spatial to within 0.1 arcsec along a 25 arcsec length across each nebula. The wavelength and spatial coverage enabled a detailed study of physical conditions and abundances from UV and optical line emissions (compared to only optical lines) for these seven PNe. The first UV lines of interest are those of carbon. The resolved lines of C III] 1906.68 and 1908.73 yielded a direct measurement of the density within the volume occupied by doubly-ionized carbon and other similar co-spatial ions as well as contributed to an accurate measurement of the carbon abundance. Each PN spectrum was divided into smaller spatial regions or segments in order to assess inferred density variations among the regions along the entire slit. There is a clear difference in the inferred density for several regions of each PNe. Variations in electron temperature and chemical abundances were also probed and shown to be completely homogeneous within the errors. Lastly, these nebulae were modeled in detail with the photoionization code CLOUDY. This modeling constrained the central star parameters of temperature and luminosity and tested the effects different density profiles have on these parameters. We gratefully acknowledge generous support from NASA through grants related to the Cycle 19 program GO 12600, as well as from the University of Oklahoma.

  17. How Subduction Settings can Affect Planetary Nitrogen Cycle: An Experimental Insight

    NASA Astrophysics Data System (ADS)

    Cedeno, D. G.; Conceicao, R. V.; Wilbert de Souza, M. R.; Carniel, L. C.; Schmitz Quinteiro, R. V.

    2015-12-01

    Nitrogen is one of the main building blocks of life on Earth and its elemental cycle is deeply connected with organic matter and the biological system. It is known that nitrogen can be stored in mantellic phases (such as clinopyroxenes) or in metallic alloys under high pressures, meaning that Earth's mantle, and even the core, could be efficient nitrogen reservoirs. Probably, nitrogen is present in these deep Earth systems since the formation of our planet. Nevertheless, it is possible that superficial nitrogen can be reintroduced in the mantle through tectonic processes along Earth history. This is reinforced by d15N values in inclusions in diamonds and other deep mantle phases. We believe that subduction zones are efficient enough to transport nitrogen from surface to mantle. Clay minerals with high charge exchange capacity (CEC) are good candidates to convey nitrogen in subduction zones, especially when we take into account the similarities between K+ and NH4+. To simulate the high-pressure high-temperature conditions found in subduction zones, we performed a series of experiments with montmorillonite clay mineral undergone to high pressure and high temperature produced by a hydraulic press coupled with toroidal chambers, in pressures ranging from 2.5 to 7.7 GPa and temperatures up to 700oC. We used ex situ XRD analysis to accompany the main montmorillonite structural changes and FTIR analysis to determine quantitatively the presence of nitrogen. So far, our results show that the main structural transition in montmorillonite happens at ~350oC at room pressure and ~450oC at 2.5 and 4.0 GPa and consists in the transformation of an open clay structure to a closed mica structure (tobelite). FTIR data show the presence of nitrogen in all the analysed experiments. With the data obtained, we can presume that clay minerals carried in subduction zones can successfully transport nitrogen and other volatiles to the mantle. However, only cold subduction systems have the

  18. Comments on the BLAG model - The carbonate-silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 million years

    NASA Technical Reports Server (NTRS)

    Kasting, J. F.

    1984-01-01

    A self-consistent method of determining initial conditions for the model presented by Berner, Lasaga, and Garrels (1983) (henceforth, the BLAG model) is derived, based on the assumption that the CO2 geochemical cycle was in steady state at t = -100 m.y. (million years). This initialization procedure leads to a dissolved magnesium concentration higher than that calculated by Berner, Lasaga, and Garrels and to a low ratio of dissolved calcium to bicarbonate prior to 60 m.y. ago. The latter prediction conflicts with the geologic record of evaporite deposits, which requires that this ratio remain greater than 0.5. The contradiction is probably caused by oversimplifications in the BLAG model, such as the neglect of the cycles of organic carbon and sulfur.

  19. Comments on the BLAG model: the carbonate-silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 million years

    NASA Technical Reports Server (NTRS)

    Kasting, J. F.

    1984-01-01

    A self-consistent method of determining initial conditions for the model presented by Berner, Lasaga, and Garrels (1983) (henceforth, the BLAG model) is derived, based on the assumption that the CO2 geochemical cycle was in steady state at t = -100 my (million years). This initialization procedure leads to a dissolved magnesium concentration higher than that calculated by Berner, Lasaga, and Garrels and to a low ratio of dissolved calcium to bicarbonate prior to 60 my ago. The latter prediction conflicts with the geologic record of evaporite deposits, which requires that this ratio remain greater than 0.5. The contradiction is probably caused by oversimplifications in the BLAG model, such as the neglect of the cycles of organic carbon and sulfur.

  20. Microbial Iron Cycling in Acidic Geothermal Springs of Yellowstone National Park: Integrating Molecular Surveys, Geochemical Processes, and Isolation of Novel Fe-Active Microorganisms

    PubMed Central

    Kozubal, Mark A.; Macur, Richard E.; Jay, Zackary J.; Beam, Jacob P.; Malfatti, Stephanie A.; Tringe, Susannah G.; Kocar, Benjamin D.; Borch, Thomas; Inskeep, William P.

    2012-01-01

    Geochemical, molecular, and physiological analyses of microbial isolates were combined to study the geomicrobiology of acidic iron oxide mats in Yellowstone National Park. Nineteen sampling locations from 11 geothermal springs were studied ranging in temperature from 53 to 88°C and pH 2.4 to 3.6. All iron oxide mats exhibited high diversity of crenarchaeal sequences from the Sulfolobales, Thermoproteales, and Desulfurococcales. The predominant Sulfolobales sequences were highly similar to Metallosphaera yellowstonensis str. MK1, previously isolated from one of these sites. Other groups of archaea were consistently associated with different types of iron oxide mats, including undescribed members of the phyla Thaumarchaeota and Euryarchaeota. Bacterial sequences were dominated by relatives of Hydrogenobaculum spp. above 65–70°C, but increased in diversity below 60°C. Cultivation of relevant iron-oxidizing and iron-reducing microbial isolates included Sulfolobus str. MK3, Sulfobacillus str. MK2, Acidicaldus str. MK6, and a new candidate genus in the Sulfolobales referred to as Sulfolobales str. MK5. Strains MK3 and MK5 are capable of oxidizing ferrous iron autotrophically, while strain MK2 oxidizes iron mixotrophically. Similar rates of iron oxidation were measured for M. yellowstonensis str. MK1 and Sulfolobales str. MK5. Biomineralized phases of ferric iron varied among cultures and field sites, and included ferric oxyhydroxides, K-jarosite, goethite, hematite, and scorodite depending on geochemical conditions. Strains MK5 and MK6 are capable of reducing ferric iron under anaerobic conditions with complex carbon sources. The combination of geochemical and molecular data as well as physiological observations of isolates suggests that the community structure of acidic Fe mats is linked with Fe cycling across temperatures ranging from 53 to 88°C. PMID:22470372

  1. Microbial iron cycling in acidic geothermal springs of yellowstone national park: integrating molecular surveys, geochemical processes, and isolation of novel fe-active microorganisms.

    PubMed

    Kozubal, Mark A; Macur, Richard E; Jay, Zackary J; Beam, Jacob P; Malfatti, Stephanie A; Tringe, Susannah G; Kocar, Benjamin D; Borch, Thomas; Inskeep, William P

    2012-01-01

    Geochemical, molecular, and physiological analyses of microbial isolates were combined to study the geomicrobiology of acidic iron oxide mats in Yellowstone National Park. Nineteen sampling locations from 11 geothermal springs were studied ranging in temperature from 53 to 88°C and pH 2.4 to 3.6. All iron oxide mats exhibited high diversity of crenarchaeal sequences from the Sulfolobales, Thermoproteales, and Desulfurococcales. The predominant Sulfolobales sequences were highly similar to Metallosphaera yellowstonensis str. MK1, previously isolated from one of these sites. Other groups of archaea were consistently associated with different types of iron oxide mats, including undescribed members of the phyla Thaumarchaeota and Euryarchaeota. Bacterial sequences were dominated by relatives of Hydrogenobaculum spp. above 65-70°C, but increased in diversity below 60°C. Cultivation of relevant iron-oxidizing and iron-reducing microbial isolates included Sulfolobus str. MK3, Sulfobacillus str. MK2, Acidicaldus str. MK6, and a new candidate genus in the Sulfolobales referred to as Sulfolobales str. MK5. Strains MK3 and MK5 are capable of oxidizing ferrous iron autotrophically, while strain MK2 oxidizes iron mixotrophically. Similar rates of iron oxidation were measured for M. yellowstonensis str. MK1 and Sulfolobales str. MK5. Biomineralized phases of ferric iron varied among cultures and field sites, and included ferric oxyhydroxides, K-jarosite, goethite, hematite, and scorodite depending on geochemical conditions. Strains MK5 and MK6 are capable of reducing ferric iron under anaerobic conditions with complex carbon sources. The combination of geochemical and molecular data as well as physiological observations of isolates suggests that the community structure of acidic Fe mats is linked with Fe cycling across temperatures ranging from 53 to 88°C. PMID:22470372

  2. Application of isotopic and geochemical tools for the evaluation of nitrogen cycling in an agricultural basin, the Fucino Plain, Central Italy

    NASA Astrophysics Data System (ADS)

    Petitta, Marco; Fracchiolla, Domenico; Aravena, Ramon; Barbieri, Maurizio

    2009-06-01

    SummaryGeochemical and isotope data collected in the agricultural area of Fucino Plain, Central Italy provided information about the relationship between the nitrate cycle and agricultural practices and seasonal changes in hydrology, in particular concerning the interaction between groundwater and surface water. The nitrate cycle of the alluvial aquifer of the Plain has been summarized in a seasonal-dependent conceptual model, where the shallow alluvial aquifer plays a fundamental role contributing to contamination of irrigation channels during periods of no manure application. Based on isotopic fingerprinting, chemical characterization and agricultural practices, the main nitrate source involved in the nitrate cycle in the study area is manure that is applied during the fall and winter periods. A nitrogen contribution from the deep alluvial-lacustrine aquifer was also documented in this study. The isotope data also showed the occurrence of denitrification occurring in nitrate pools in the shallow aquifer, which is characterized by low-permeability layers. The nitrate pool in the shallow aquifer is related to infiltration after the application of manure. The isotope and concentration data showed that the increase of nitrate in the irrigation channels under non-runoff conditions is controlled by seepage from the shallow aquifer. The cycle ends with a new application of manure, generating considerable increases of "fresh" nitrate concentration in the channels. The historical trend of decreasing water table conditions and increasing nitrate content in the shallow aquifer threatens the deep aquifer, used for drinking purposes, since heavy pumping can induce the transport of nitrate from the shallow aquifer toward the capture zone of the deep wells.

  3. Geochemical cycles in sediments deposited on the slopes of the Guaymas and Carmen Basins of the Gulf of California over the last 180 years

    USGS Publications Warehouse

    Dean, W.; Pride, C.; Thunell, R.

    2004-01-01

    Sediments deposited on the slopes of the Guaymas and Carmen Basins in the central Gulf of California were recovered in two box cores. Q-mode factor analyses identified detrital-clastic, carbonate, and redox associations in the elemental composition of these sediments. The detrital-clastic fraction appears to contain two source components, a more mafic component presumably derived from the Sierra Madre Occidental along the west coast of Mexico, and a more felsic component most likely derived from sedimentary rocks (mostly sandstones) of the Colorado Plateau and delivered by the Colorado River. The sediments also contain significant siliceous biogenic components and minor calcareous biogenic components, but those components were not quantified in this study. Redox associations were identified in both cores based on relatively high concentrations of molybdenum, which is indicative of deposition under conditions of sulfate reduction. Decreases in concentrations of molybdenum in younger sediments suggest that the bottom waters of the Gulf have became more oxygenated over the last 100 years. Many geochemical components in both box cores exhibit distinct cyclicity with periodicities of 10-20 years. The most striking are 20-year cycles in the more mafic components (e.g., titanium), particularly in sediments deposited during the 19th century. In that century, the titanium cycles are in very good agreement with warm phases of the Pacific Decadal Oscillation, implying that at times of greater influx of titanium-rich volcanic debris, there were more El Nin??os and higher winter precipitation. The cycles are interpreted as due to greater and lesser riverine influx of volcanic rock debris from the Sierra Madre. There is also spectral evidence for periodicities of 4-8 and 8-16 years, suggesting that the delivery of detrital-clastic material is responding to some multiannual (ENSO?) forcing.

  4. Planetary rings

    SciTech Connect

    Greenberg, R.; Brahic, A.

    1984-01-01

    Among the topics discussed are the development history of planetary ring research, the view of planetary rings in astronomy and cosmology over the period 1600-1900, the characteristics of the ring systems of Saturn and Uranus, the ethereal rings of Jupiter and Saturn, dust-magnetosphere interactions, the effects of radiation forces on dust particles, the collisional interactions and physical nature of ring particles, transport effects due to particle erosion mechanisms, and collision-induced transport processes in planetary rings. Also discussed are planetary ring waves, ring particle dynamics in resonances, the dynamics of narrow rings, the origin and evolution of planetary rings, the solar nebula and planetary disk, future studies of the planetary rings by space probes, ground-based observatories and earth-orbiting satellites, and unsolved problems in planetary ring dynamics.

  5. Understanding past climatic and hydrological variability in the Mediterranean from Lake Prespa sediment isotope and geochemical record over the Last Glacial cycle

    NASA Astrophysics Data System (ADS)

    Leng, Melanie J.; Wagner, Bernd; Boehm, Anne; Panagiotopoulos, Konstantinos; Vane, Christopher H.; Snelling, Andrea; Haidon, Cheryl; Woodley, Ewan; Vogel, Hendrik; Zanchetta, Gianni; Baneschi, Ilaria

    2013-04-01

    Here we present stable isotope and geochemical data from Lake Prespa (Macedonia/Albania border) over the Last Glacial cycle (Marine Isotope Stages 5-1) and discuss past lake hydrology and climate (TIC, oxygen and carbon isotopes), as well as responses to climate of terrestrial and aquatic vegetation (TOC, Rock Eval pyrolysis, carbon isotopes, pollen). The Lake Prespa sediments broadly fall into 5 zones based on their sedimentology, geochemistry, palynology and the existing chronology. The Glacial sediments suggest low supply of carbon to the lake, but high summer productivity; intermittent siderite layers suggest that although the lake was likely to have mixed regularly leading to enhanced oxidation of organic matter, there must have been within sediment reducing conditions and methanogenesis. MIS 5 and 1 sediments suggest much more productivity, higher rates of organic material preservation possibly due to more limited mixing with longer periods of oxygen-depleted bottom waters. We also calculated lakewater δ18O from siderite (authigenic/Glacial) and calcite (endogenic/Holocene) and show much lower lakewater δ18O values in the Glacial when compared to the Holocene, suggesting the lake was less evaporative in the Glacial, probably as a consequence of cooler summers and longer winter ice cover. In the Holocene the oxygen isotope data suggests general humidity, with just 2 marked arid phases, features observed in other Eastern and Central Mediterranean lakes.

  6. The effects of diagenesis and dolomitization on Ca and Mg isotopes in marine platform carbonates: Implications for the geochemical cycles of Ca and Mg

    NASA Astrophysics Data System (ADS)

    Fantle, Matthew S.; Higgins, John

    2014-10-01

    The Ca, Mg, O, and C isotopic and trace elemental compositions of marine limestones and dolostones from ODP Site 1196A, which range in depth (∼58 to 627 mbsf) and in depositional age (∼5 and 23 Ma), are presented. The objectives of the study are to explore the potential for non-traditional isotope systems to fingerprint diagenesis, to quantify the extent to which geochemical proxies are altered during diagenesis, and to investigate the importance of diagenesis within the global Ca and Mg geochemical cycles. The data suggest that Ca, which has a relatively high solid to fluid mass ratio, can be isotopically altered during diagenesis. In addition, the alteration of Ca correlates with the alteration of Mg in such a way that both can serve as useful tools for deciphering diagenesis in ancient rocks. Bulk carbonate δ44Ca values vary between 0.60 and 1.31‰ (SRM-915a scale); the average limestone δ44Ca is 0.97 ± 0.24‰ (1SD), identical within error to the average dolostone (1.03 ± 0.15 1SD ‰). Magnesium isotopic compositions (δ26Mg, DSM-3 scale) range between -2.59‰ and -3.91‰, and limestones (-3.60 ± 0.25‰) and dolostones (-2.68 ± 0.07‰) are isotopically distinct. Carbon isotopic compositions (δ13C, PDB scale) vary between 0.86‰ and 2.47‰, with average limestone (1.96 ± 0.31‰) marginally offset relative to average dolostone (1.68 ± 0.57‰). The oxygen isotopic compositions (δ18O, PDB scale) of limestones (-1.22 ± 0.94‰) are substantially lower than the dolostones measured (2.72 ± 1.07‰). The isotopic data from 1196A suggest distinct and coherent trends in isotopic and elemental compositions that are interpreted in terms of diagenetic trajectories. Numerical modeling supports the contention that such trends can be interpreted as diagenetic, and suggests that the appropriate distribution coefficient (KMg) associated with limestone diagenesis is ∼1 to 5 × 10-3, distinctly lower than those values (>0.015) reported in laboratory

  7. Speciation of C-O-H volatiles in reduced magmas applicable to early terrestrial and planetary deep volatile cycles

    NASA Astrophysics Data System (ADS)

    Armstrong, Lora; Hirschmann, Marc

    2014-05-01

    The speciation and solubility of C-O-H volatiles in reduced magmas are of great importance for volatile behavior in the early Earth and other planets determining partitioning between Earth's earliest atmospheres, mantle, and cores, as well as influencing volcanogenic degassing on reduced planetary bodies such as Mars and the Moon. In mafic and ultramafic magmas, C is soluble chiefly as carbonate under oxidizing conditions, but when fO2 is below that required for graphite (or diamond) saturation, carbonate solubility diminishes severely. This has left the question as to what, if any, species may host dissolved C in magmas under reducing conditions. Initial results suggested that the principle species may be CH4 (Mysen et al. 2009), but experiments at well-defined thermodynamic conditions have shown that CH4 solubility is very small except under conditions of very high H2 fugacity (Ardia et al. 2012). More recent experiments (Wetzel et al. 2013; Stanley et al. 2014) have identified Fe-carbonyl-like species as possibly the most stable. To clarify the relative stability of these species, we have conducted additional high pressure experiments at 1.2 GPa and 1400°C with graphite-saturated martian and terrestrial (MORB) basalt compositions, over a range of oxygen fugacities, paying careful attention to the availability of H2O. FTIR and Raman analyses reveal a range of distinct species that predominate as a function of fO2 and availability of H2O. At comparatively oxidizing conditions, carbonate is the most abundant species but within 1 log unit of iron wustite (IW), carbonyl-like species predominate, provided that conditions are comparatively dry. At yet more reducing conditions, carbonyl is absent and instead N-H associated species (perhaps amides?) are more important. Methane is observed only when quenched glasses have appreciable H2O (approaching ~ 1 wt.%). In all cases, solubilities are small when conditions are reduced, with <100 ppm C at IW or below.

  8. Groundwater ecosystem resilience to organic contaminations: microbial and geochemical dynamics throughout the 5-year life cycle of a surrogate ethanol blend fuel plume.

    PubMed

    Ma, Jie; Nossa, Carlos W; Alvarez, Pedro J J

    2015-09-01

    The capacity of groundwater ecosystem to recover from contamination by organic chemicals is a vital concern for environmental scientists. A pilot-scale aquifer system was used to investigate the long-term dynamics of contaminants, groundwater geochemistry, and microbial community structure (by 16S rRNA gene pyrosequencing and quantitative real-time PCR) throughout the 5-year life cycle of a surrogate ethanol blend fuel plume (10% ethanol + 50 mg/L benzene + 50 mg/L toluene). Two-year continuous ethanol-blended release significantly changed the groundwater geochemistry (resulted in anaerobic, low pH, and organotrophic conditions) and increased bacterial and archaeal populations by 82- and 314-fold respectively. Various anaerobic heterotrophs (fermenters, acetogens, methanogens, and hydrocarbon degraders) were enriched. Two years after the release was shut off, all contaminants and their degradation byproducts disappeared and groundwater geochemistry completely restored to the pre-release states (aerobic, neutral pH, and oligotrophic). Bacterial and archaeal populations declined by 18- and 45-fold respectively (relative to the time of shut off). Microbial community structure reverted towards the pre-release states and alpha diversity indices rebounded, suggesting the resilience of microbial community to ethanol blend releases. We also found shifts from O2-sensitive methanogens (e.g., Methanobacterium) to methanogens that are not so sensitive to O2 (e.g., Methanosarcina and Methanocella), which is likely to contribute to the persistence of methanogens and methane generation following the source removal. Overall, the rapid disappearance of contaminants and their metabolites, rebound of geochemical footprints, and resilience of microbial community unequivocally document the natural capacity of groundwater ecosystem to attenuate and recover from a large volume of catastrophic spill of ethanol-based biofuel. PMID:25996759

  9. The HARPS search for southern extra-solar planets. XXX. Planetary systems around stars with solar-like magnetic cycles and short-term activity variation

    NASA Astrophysics Data System (ADS)

    Dumusque, X.; Lovis, C.; Ségransan, D.; Mayor, M.; Udry, S.; Benz, W.; Bouchy, F.; Lo Curto, G.; Mordasini, C.; Pepe, F.; Queloz, D.; Santos, N. C.; Naef, D.

    2011-11-01

    We present the discovery of four new long-period planets within the HARPS high-precision sample: HD 137388b (Msini = 0.22 MJ), HD 204941b (Msini = 0.27 MJ), HD 7199b (Msini = 0.29 MJ), HD 7449b (Msini = 1.04 MJ). A long-period companion, probably a second planet, is also found orbiting HD 7449. Planets around HD 137388, HD 204941, and HD 7199 have rather low eccentricities (less than 0.4) relative to the 0.82 eccentricity of HD 7449b. All these planets were discovered even though their hosting stars have clear signs of activity. Solar-like magnetic cycles, characterized by long-term activity variations, can be seen for HD 137388, HD 204941 and HD 7199, whereas the measurements of HD 7449 reveal a short-term activity variation, most probably induced by magnetic features on the stellar surface. We confirm that magnetic cycles induce a long-term radial velocity variation and propose a method to reduce considerably the associated noise. The procedure consists of fitting the activity index and applying the same solution to the radial velocities because a linear correlation between the activity index and the radial velocity is found. Tested on HD 137388, HD 204941, and HD 7199, this correction reduces considerably the stellar noise induced by magnetic cycles and allows us to derive precisely the orbital parameters of planetary companions. Based on observations made with the HARPS instrument on the ESO 3.6-m telescope at La Silla Observatory (Chile), under programme IDs 072.C-0488 and 183.C-0972.Radial velocities (Tables 4-7) are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/535/A55

  10. Biological and geochemical controls on diel dissolved inorganic carbon cycling in a low-order agricultural stream: Implications for reach scales and beyond

    USGS Publications Warehouse

    Tobias, C.; Böhlke, J.K.

    2011-01-01

    Movement of dissolved inorganic carbon (DIC) through the hydrologic cycle is an important component of global carbon budgets, but there is considerable uncertainty about the controls of DIC transmission from landscapes to streams, and through river networks to the oceans. In this study, diel measurements of DIC, ??13C-DIC, dissolved oxygen (O2), ??18O-O2, alkalinity, pH, and other parameters were used to assess the relative magnitudes of biological and geochemical controls on DIC cycling and flux in a nutrient-rich, net autotrophic stream. Rates of photosynthesis (P), respiration (R), groundwater discharge, air-water exchange of CO2, and carbonate precipitation/dissolution were quantified through a time-stepping chemical/isotope (12C and 13C, 16O and 18O) mass balance model. Groundwater was the major source of DIC to the stream. Primary production and carbonate precipitation were equally important sinks for DIC removed from the water column. The stream was always super-saturated with respect to carbonate minerals, but carbonate precipitation occurred mainly during the day when P increased pH. We estimated more than half (possibly 90%) of the carbonate precipitated during the day was retained in the reach under steady baseflow conditions. The amount of DIC removed from the overlying water through carbonate precipitation was similar to the amount of DIC generated from R. Air-water exchange of CO2 was always from the stream to the atmosphere, but was the smallest component of the DIC budget. Overall, the in-stream DIC reactions reduced the amount of CO2 evasion and the downstream flux of groundwater-derived DIC by about half relative to a hypothetical scenario with groundwater discharge only. Other streams with similar characteristics are widely distributed in the major river basins of North America. Data from USGS water quality monitoring networks from the 1960s to the 1990s indicated that 40% of 652 stream monitoring stations in the contiguous USA were at or above

  11. Biological and geochemical controls on diel dissolved inorganic carbon cycling in a low-order agricultural stream: implications for reach scales and beyond

    USGS Publications Warehouse

    Bohlke, Johnkarl F.; Tobias, Craig

    2011-01-01

    Movement of dissolved inorganic carbon (DIC) through the hydrologic cycle is an important component of global carbon budgets, but there is considerable uncertainty about the controls of DIC transmission from landscapes to streams, and through river networks to the oceans. In this study, diel measurements of DIC, d13C-DIC, dissolved oxygen (O2), d18O-O2, alkalinity, pH, and other parameters were used to assess the relative magnitudes of biological and geochemical controls on DIC cycling and flux in a nutrient-rich, net autotrophic stream. Rates of photosynthesis (P), respiration (R), groundwater discharge, air–water exchange of CO2, and carbonate precipitation/dissolution were quantified through a time-stepping chemical/isotope (12C and 13C, 16O and 18O) mass balance model. Groundwater was the major source of DIC to the stream. Primary production and carbonate precipitation were equally important sinks for DIC removed from the water column. The stream was always super-saturated with respect to carbonate minerals, but carbonate precipitation occurred mainly during the day when P increased pH. We estimated more than half (possibly 90%) of the carbonate precipitated during the day was retained in the reach under steady baseflow conditions. The amount of DIC removed from the overlying water through carbonate precipitation was similar to the amount of DIC generated from R. Air–water exchange of CO2 was always from the stream to the atmosphere, but was the smallest component of the DIC budget. Overall, the in-stream DIC reactions reduced the amount of CO2 evasion and the downstream flux of groundwater-derived DIC by about half relative to a hypothetical scenario with groundwater discharge only. Other streams with similar characteristics are widely distributed in the major river basins of North America. Data from USGS water quality monitoring networks from the 1960s to the 1990s indicated that 40% of 652 stream monitoring stations in the contiguous USA were at or above

  12. Planetary Radar

    NASA Technical Reports Server (NTRS)

    Neish, Catherine D.; Carter, Lynn M.

    2015-01-01

    This chapter describes the principles of planetary radar, and the primary scientific discoveries that have been made using this technique. The chapter starts by describing the different types of radar systems and how they are used to acquire images and accurate topography of planetary surfaces and probe their subsurface structure. It then explains how these products can be used to understand the properties of the target being investigated. Several examples of discoveries made with planetary radar are then summarized, covering solar system objects from Mercury to Saturn. Finally, opportunities for future discoveries in planetary radar are outlined and discussed.

  13. A bibliography of planetary geology principal investigators and their associates, 1976-1978

    NASA Technical Reports Server (NTRS)

    1978-01-01

    This bibliography cites publications submitted by 484 principal investigators and their associates who were supported through NASA's Office of Space Sciences Planetary Geology Program. Subject classifications include: solar system formation, comets, and asteroids; planetary satellites, planetary interiors, geological and geochemical constraints on planetary evolution; impact crater studies, volcanism, eolian studies, fluvian studies, Mars geological mapping; Mercury geological mapping; planetary cartography; and instrument development and techniques. An author/editor index is provided.

  14. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry

    2014-03-01

    Preface: a personal view of planetary rings; 1. Introduction: the allure of the ringed planets; 2. Studies of planetary rings 1610-2013; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Uranus' rings and moons; 13. Neptune's partial rings; 14. Jupiter's ring-moon system after Galileo and New Horizons; 15. Ring photometry; 16. Dusty rings; 17. Concluding remarks; Afterword; Glossary; References; Index.

  15. Planetary Magnetism

    NASA Technical Reports Server (NTRS)

    Connerney, J. E. P.

    2007-01-01

    The chapter on Planetary Magnetism by Connerney describes the magnetic fields of the planets, from Mercury to Neptune, including the large satellites (Moon, Ganymede) that have or once had active dynamos. The chapter describes the spacecraft missions and observations that, along with select remote observations, form the basis of our knowledge of planetary magnetic fields. Connerney describes the methods of analysis used to characterize planetary magnetic fields, and the models used to represent the main field (due to dynamo action in the planet's interior) and/or remnant magnetic fields locked in the planet's crust, where appropriate. These observations provide valuable insights into dynamo generation of magnetic fields, the structure and composition of planetary interiors, and the evolution of planets.

  16. Planetary Interiors

    NASA Technical Reports Server (NTRS)

    Banerdt, W. Bruce; Abercrombie, Rachel; Keddie, Susan; Mizutani, Hitoshi; Nagihara, Seiichi; Nakamura, Yosio; Pike, W. Thomas

    1996-01-01

    This report identifies two main themes to guide planetary science in the next two decades: understanding planetary origins, and understanding the constitution and fundamental processes of the planets themselves. Within the latter theme, four specific goals related to interior measurements addressing the theme. These are: (1) Understanding the internal structure and dynamics of at least one solid body, other than the Earth or Moon, that is actively convecting, (2) Determine the characteristics of the magnetic fields of Mercury and the outer planets to provide insight into the generation of planetary magnetic fields, (3) Specify the nature and sources of stress that are responsible for the global tectonics of Mars, Venus, and several icy satellites of the outer planets, and (4) Advance significantly our understanding of crust-mantle structure for all the solid planets. These goals can be addressed almost exclusively by measurements made on the surfaces of planetary bodies.

  17. Inland aquatic resources and biogeochemical cycles

    SciTech Connect

    Melack, J.M.

    1984-08-01

    The biosphere is the entire planetary system that includes, sustains and is influenced by life. The central issue of the science of the biosphere is the extent to which the Earth's surface, atmosphere and hydrosphere is the result of biological rather than abiotic processes. Space science and technology accelerates the understanding of global biological processes by providing repetive synoptic observations on large spatial scales once the relationships between the processes and the remotely sensed quantities are established. Especially promising applications of space technology are the measurement of biological productivity and portions of geochemical cycles in aquatic ecosystems and the evaluation and management of the quality of freshwater resources.

  18. Planetary magnetism

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1980-01-01

    Planetary spacecraft have now probed the magnetic fields of all the terrestrial planets, the moon, Jupiter, and Saturn. These measurements reveal that dynamos are active in at least four of the planets, Mercury, the earth, Jupiter, and Saturn but that Venus and Mars appear to have at most only very weak planetary magnetic fields. The moon may have once possessed an internal dynamo, for the surface rocks are magnetized. The large satellites of the outer solar system are candidates for dynamo action in addition to the large planets themselves. Of these satellites the one most likely to generate its own internal magnetic field is Io.

  19. Planetary astronomy

    NASA Technical Reports Server (NTRS)

    Morrison, David; Hunten, Donald; Ahearn, Michael F.; Belton, Michael J. S.; Black, David; Brown, Robert A.; Brown, Robert Hamilton; Cochran, Anita L.; Cruikshank, Dale P.; Depater, Imke

    1991-01-01

    The authors profile the field of astronomy, identify some of the key scientific questions that can be addressed during the decade of the 1990's, and recommend several facilities that are critically important for answering these questions. Scientific opportunities for the 1990' are discussed. Areas discussed include protoplanetary disks, an inventory of the solar system, primitive material in the solar system, the dynamics of planetary atmospheres, planetary rings and ring dynamics, the composition and structure of the atmospheres of giant planets, the volcanoes of IO, and the mineralogy of the Martian surface. Critical technology developments, proposed projects and facilities, and recommendations for research and facilities are discussed.

  20. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry W.

    2011-07-01

    Preface; 1. Introduction: the allure of ringed planets; 2. Studies of planetary rings 1610-2004; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-Body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Neptune's partial rings; 13. Jupiter's ring-moon system after Galileo; 14. Ring photometry; 15. Dusty rings; 16. Cassini observations; 17. Summary: the big questions; Glossary; References; Index.

  1. Planetary quarantine

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The overall objective is to identify those areas of future missions which will be impacted by planetary quarantine (PQ) constraints. The objective of the phase being described was to develop an approach for using decision theory in performing a PQ analysis for a Mariner Jupiter Uranus Mission and to compare it with the traditional approach used for other missions.

  2. Planetary Rings

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  3. Planetary radar

    NASA Technical Reports Server (NTRS)

    Taylor, R. M.

    1980-01-01

    The radar astronomy activities supported by the Deep Space Network during June, July, and August 1980 are reported. The planetary bodies observed were Venus, Mercury, and the asteroid Toro. Data were obtained at both S and X band, and the observations were considered successful.

  4. Planetary Geomorphology.

    ERIC Educational Resources Information Center

    Baker, Victor R.

    1984-01-01

    Discusses various topics related to planetary geomorphology, including: research techniques; such geomorphic processes as impact, volcanic, degradational, eolian, and hillslope/mass movement processes; and channels and valleys. Indicates that the subject should be taught as a series of scientific questions rather than scientific results of…

  5. Planetary quarantine

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Developed methodologies and procedures for the reduction of microbial burden on an assembled spacecraft at the time of encapsulation or terminal sterilization are reported. This technology is required for reducing excessive microbial burden on spacecraft components for the purposes of either decreasing planetary contamination probabilities for an orbiter or minimizing the duration of a sterilization process for a lander.

  6. Multiscale comparative spectral analysis of satellite total solar irradiance measurements from 2003 to 2013 reveals a planetary modulation of solar activity and its nonlinear dependence on the 11 yr solar cycle

    NASA Astrophysics Data System (ADS)

    Scafetta, N.; Willson, R. C.

    2013-11-01

    Herein we adopt a multiscale dynamical spectral analysis technique to compare and study the dynamical evolution of the harmonic components of the overlapping ACRIMSAT/ACRIM3 (Active Cavity Radiometer Irradiance Monitor Satellite/Active Cavity Radiometer Irradiance Monitor 3), SOHO/VIRGO (Solar and Heliopheric Observatory/Variability of solar Irradiance and Gravity Oscillations), and SORCE/TIM (Solar Radiation and Climate Experiment/Total Irradiance Monitor) total solar irradiance (TSI) records during 2003.15 to 2013.16 in solar cycles 23 and 24. The three TSI time series present highly correlated patterns. Significant power spectral peaks are common to these records and are observed at the following periods: ~ 0.070 yr, ~ 0.097 yr, ~ 0.20 yr, ~ 0.25 yr, ~ 0.30-0.34 yr, and ~ 0.39 yr. Less certain spectral peaks occur at about 0.55 yr, 0.60-0.65 yr and 0.7-0.9 yr. Four main frequency periods at ~ 4.8 days (~ 0.068 yr), ~ 27.3 days (~ 0.075 yr), at ~ 34-35 days (~ 0.093-0.096 yr), and ~ 36-38 days (~ 0.099-0.104 yr) characterize the solar rotation cycle. The amplitude of these oscillations, in particular of those with periods larger than 0.5 yr, appears to be modulated by the ~ 11 yr solar cycle. Similar harmonics have been found in other solar indices. The observed periodicities are found highly coherent with the spring, orbital and synodic periods of Mercury, Venus, Earth and Jupiter. We conclude that solar activity is likely modulated by planetary gravitational and electromagnetic forces acting on the Sun. The strength of the Sun's response to planetary forcing depends nonlinearly on the state of internal solar dynamics; planetary-Sun coupling effects are enhanced during solar activity maxima and attenuated during minima.

  7. Planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the North Atlantic

    NASA Technical Reports Server (NTRS)

    Smith, Phillip J.

    1995-01-01

    The formation of a blocking anticyclone over the North Atlantic has been examined over its entire life-CyCle using the Zwack-Okossi (Z-O) equation as the diagnostic tool. This blocking anticyclone occurred in late October and early November of 1985. The data used were provided by the NASA Goddard Laboratory for Atmospheres on a global 2.O degree latitude by 2.5 degree longitudinal grid. The horizontal distribution of the atmospheric forcing mechanisms that were important to 500 mb block formation, maintenance and decay were examined. A scale-partitioned form of the Z-O equation was then used to examine the relative importance of forcing on the planetary and synoptic scales, and their interactions. As seen in previous studies, the results presented here show that upper tropospheric anticyclonic vorticity advection was the most important contributor to block formation and maintenance. However, adiabatic warming, and vorticity tilting were also important at various times during the block lifetime. In association with precursor surface cyclogenesis, the 300 mb jet streak in the downstream (upstream) from a long-wave trough (ridge) amplified significantly. This strengthening of the jet streak enhanced the anti-cyclonic vorticity advection field that aided the amplification of a 500 mb short-wave ridge. Tile partitioned height tendency results demonstrate that the interactions between the planetary and sn,noptic-scale through vorticity advection was the most important contributor to block formation. Planetary-scale, synoptic-scale. and their interactions contributed weakly to the maintenance of the blocking anticyclone with the advection of synoptic-scale vorticity by the planetary-scale flow playing a more important role. Planetary-scale decay ofthe long-wave ridge contributed to the demise of this blocking event.

  8. Planetary Society

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Carl Sagan, Bruce Murray and Louis Friedman founded the non-profit Planetary Society in 1979 to advance the exploration of the solar system and to continue the search for extraterrestrial life. The Society has its headquarters in Pasadena, California, but is international in scope, with 100 000 members worldwide, making it the largest space interest group in the world. The Society funds a var...

  9. Planetary quarantine

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Those areas of future missions which will be impacted by planetary quarantine (PQ) constraints were identified. The specific objectives for this reporting period were (1) to perform an analysis of the effects of PQ on an outer planet atmospheric probe, and (2) to prepare a quantitative illustration of spacecraft microbial reduction resulting from exposure to space environments. The Jupiter Orbiter Probe mission was used as a model for both of these efforts.

  10. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Gordon, M. K.; Araki, S.; Black, G. J.; Bosh, A. S.; Brahic, A.; Brooks, S. M.; Charnoz, S.; Colwell, J. E.; Cuzzi, J. N.; Dones, L.; Durisen, R. H.; Esposito, L. W.; Ferrari, C.; Festou, M.; French, R. G.; Giuliatti-Winter, S. M.; Graps, A. L.; Hamilton, D. P.; Horanyi, M.; Karjalainen, R. M.; Krivov, A. V.; Krueger, H.; Larson, S. M.; Levison, H. F.; Lewis, M. C.; Lissauer, J. J.; Murray, C. D.; Namouni, F.; Nicholson, P. D.; Olkin, C. B.; Poulet, F.; Rappaport, N. J.; Salo, H. J.; Schmidt, J.; Showalter, M. R.; Spahn, F.; Spilker, L. J.; Srama, R.; Stewart, G. R.; Yanamandra-Fisher, P.

    2002-08-01

    The past two decades have witnessed dramatic changes in our view and understanding of planetary rings. We now know that each of the giant planets in the Solar System possesses a complex and unique ring system. Recent studies have identified complex gravitational interactions between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto, or collisions between, parent bodies. Yet, as far as we have come, our understanding is far from complete. The fundamental questions confronting ring scientists at the beginning of the twenty-first century are those regarding the origin, age and evolution of the various ring systems, in the broadest context. Understanding the origin and age requires us to know the current ring properties, and to understand the dominant evolutionary processes and how they influence ring properties. Here we discuss a prioritized list of the key questions, the answers to which would provide the greatest improvement in our understanding of planetary rings. We then outline the initiatives, missions, and other supporting activities needed to address those questions, and recommend priorities for the coming decade in planetary ring science.

  11. Planetary engineering

    NASA Astrophysics Data System (ADS)

    Pollack, James B.; Sagan, Carl

    Assuming commercial fusion power, heavy lift vehicles and major advances in genetic engineering, the authors survey possible late-21st century methods of working major transformations in planetary environments. Much more Earthlike climates may be produced on Mars by generating low freezing point greenhouse gases from indigenous materials; on Venus by biological conversion of CO2 to graphite, by canceling the greenhouse effect with high-altitude absorbing fine particles, or by a sunshield at the first Lagrangian point; and on Titan by greenhouses and/or fusion warming. However, in our present state of ignorance we cannot guarantee a stable endstate or exclude unanticipated climatic feedbacks or other unintended consequences. Moreover, as the authors illustrate by several examples, many conceivable modes of planetary engineering are so wasteful of scarce solar system resources and so destructive of important scientific information as to raise profound ethical issues, even if they were economically feasible, which they are not. Global warming on Earth may lead to calls for mitigation by planetary engineering, e.g., emplacement and replenishment of anti-greenhouse layers at high altitudes, or sunshields in space. But here especially we must be concerned about precision, stability, and inadvertent side-effects. The safest and most cost-effective means of countering global warming - beyond, e.g., improved energy efficiency, CFC bans and alternative energy sources - is the continuing reforestation of approximately 2 times 107 sq km of the Earth's surface. This can be accomplished with present technology and probably at the least cost.

  12. Planetary engineering

    NASA Technical Reports Server (NTRS)

    Pollack, James B.; Sagan, Carl

    1991-01-01

    Assuming commercial fusion power, heavy lift vehicles and major advances in genetic engineering, the authors survey possible late-21st century methods of working major transformations in planetary environments. Much more Earthlike climates may be produced on Mars by generating low freezing point greenhouse gases from indigenous materials; on Venus by biological conversion of CO2 to graphite, by canceling the greenhouse effect with high-altitude absorbing fine particles, or by a sunshield at the first Lagrangian point; and on Titan by greenhouses and/or fusion warming. However, in our present state of ignorance we cannot guarantee a stable endstate or exclude unanticipated climatic feedbacks or other unintended consequences. Moreover, as the authors illustrate by several examples, many conceivable modes of planetary engineering are so wasteful of scarce solar system resources and so destructive of important scientific information as to raise profound ethical issues, even if they were economically feasible, which they are not. Global warming on Earth may lead to calls for mitigation by planetary engineering, e.g., emplacement and replenishment of anti-greenhouse layers at high altitudes, or sunshields in space. But here especially we must be concerned about precision, stability, and inadvertent side-effects. The safest and most cost-effective means of countering global warming - beyond, e.g., improved energy efficiency, CFC bans and alternative energy sources - is the continuing reforestation of approximately 2 times 107 sq km of the Earth's surface. This can be accomplished with present technology and probably at the least cost.

  13. Global geochemical problems

    NASA Technical Reports Server (NTRS)

    Harriss, R. C.

    1980-01-01

    Application of remote sensing techniques to the solution of geochemical problems is considered with emphasis on the 'carbon-cycle'. The problem of carbon dioxide sinks and the areal extent of coral reefs are treated. In order to assess the problems cited it is suggested that remote sensing techniques be utilized to: (1)monitor globally the carbonate and bicarbonate concentrations in surface waters of the world ocean; (2)monitor the freshwater and oceanic biomass and associated dissolved organic carbon; (3) inventory the coral reef areas and types and the associated oceanographic climatic conditions; and (4)measure the heavy metal fluxes from forested and vegetated areas, from volcanos, from different types of crustal rocks, from soils, and from sea surfaces.

  14. Abundance patterns in planetary nebulae

    NASA Astrophysics Data System (ADS)

    Henry, Richard B. C.

    1990-06-01

    Abundances of He, N, O, and Ne have been uniformly calculated for 192 planetary nebulas residing in the Galactic disk and halo, the LMC, the SMC, and M31. Direct correlations appear to exist for type I as well as non-type I objects for the following pairs of parameters: N/O-He/H, N/O-N/H, and Ne/H-O/H. Separately, type I planetaries show a weak anticorrelation between N/O and O/H, while non-type I's exhibit direct correlations between N/H and O/H and between N/O and O/H. From these patterns, it is inferred that non-type I's synthesize N via the CN cycle. Type I planetaries, on the other hand, manufacture N at least partially via the ON cycle, destroying O in the process. Neither type appears to synthesize O or Ne.

  15. Planetary atlases

    NASA Technical Reports Server (NTRS)

    Batson, R. M.; Inge, J. L.; Morgan, H. F.

    1991-01-01

    Two kinds of planetary map atlases are in production. Atlases of the first kind contain reduced-scale versions of maps in hard-bound books with dimensions of 11 x 14 inches. These new atlases are intended to: (1) provide concise but comprehensive references to the geography of the planets needed by planetary scientists and others; and (2) allow inexpensive access to the planetary map dataset without requiring acquisition and examination of tens or hundreds of full-size map sheets. Two such atlases have been published and a third is in press. Work was begun of an Atlas of the Satellite of the Outer Planets. The second kind of atlas is a popular or semi-technical version designed for commercial publication and distribution. The first edition, The Atlas of the Solar System, is nearly ready for publication. New funding and contracting constraints now make it unlikely that the atlas can be published in the format originally planned. Currently, the possibility of publishing the maps through the U.S. Geological Survey as a series of folios in the I-map series is being explored. The maps are global views of each solid-surface body of the Solar System. Each map shows airbrushed relief, albedo, and, where available, topography. A set of simplified geologic maps is also included. All of the maps are on equal-area projections. Scales are 1:40,000,000 for the Earth and Venus; 1:2,000,000 for the Saturnian satellites Mimas and Enceladus and the Uranian satellite Miranda; 1:100,000 for the Martian satellites, Phobos and Deimos; and 1:10,000,000 for all other bodies.

  16. Planetary Dynamos

    NASA Technical Reports Server (NTRS)

    Busse, F. H.

    1985-01-01

    The MAGSAT-program has added significantly to our knowledge of planetary magnetism. The accuracy of observations has been improved such that a reliable extrapolation of the magnetic field to the core surface is now much more feasible than it has been before, and the prospect of further MAGSAT missions raises the expectation that the time dependence of the geomagnetic field will be known with similar accuracy in the future. In the research support it has been attempted to develop dynamo theory with these applications in mind.

  17. Planetary astronomy

    NASA Technical Reports Server (NTRS)

    Smith, Harlan J.

    1991-01-01

    Lunar-based astronomy offers major prospects for solar system research in the coming century. In addition to active advocacy of both ground-based and Lunar-based astronomy, a workshop on the value of asteroids as a resource for man is being organized. The following subject areas are also covered: (1) astrophysics from the Moon (composition and structure of planetary atmospheres); (2) a decade of cost-reduction in Very Large Telescopes (the SST as prototype of special-purpose telescopes); and (3) a plan for development of lunar astronomy.

  18. Planetary Volcanism

    NASA Technical Reports Server (NTRS)

    Antonenko, I.; Head, J. W.; Pieters, C. W.

    1998-01-01

    The final report consists of 10 journal articles concerning Planetary Volcanism. The articles discuss the following topics: (1) lunar stratigraphy; (2) cryptomare thickness measurements; (3) spherical harmonic spectra; (4) late stage activity of volcanoes on Venus; (5) stresses and calderas on Mars; (6) magma reservoir failure; (7) lunar mare basalt volcanism; (8) impact and volcanic glasses in the 79001/2 Core; (9) geology of the lunar regional dark mantle deposits; and (10) factors controlling the depths and sizes of magma reservoirs in Martian volcanoes.

  19. Planetary magnetospheres

    NASA Technical Reports Server (NTRS)

    Stern, D. P.; Ness, N. F.

    1981-01-01

    A concise overview is presented of our understanding of planetary magnetospheres (and in particular, of that of the Earth), as of the end of 1981. Emphasis is placed on processes of astrophysical interest, e.g., on particle acceleration, collision-free shocks, particle motion, parallel electric fields, magnetic merging, substorms, and large scale plasma flows. The general morphology and topology of the Earth's magnetosphere are discussed, and important results are given about the magnetospheres of Jupiter, Saturn and Mercury, including those derived from the Voyager 1 and 2 missions and those related to Jupiter's satellite Io. About 160 references are cited, including many reviews from which additional details can be obtained.

  20. Planetary Habitability

    NASA Technical Reports Server (NTRS)

    Kasting, James F.

    1997-01-01

    This grant was entitled 'Planetary Habitability' and the work performed under it related to elucidating the conditions that lead to habitable, i.e. Earth-like, planets. Below are listed publications for the past two and a half years that came out of this work. The main thrusts of the research involved: (1) showing under what conditions atmospheric O2 and O3 can be considered as evidence for life on a planet's surface; (2) determining whether CH4 may have played a role in warming early Mars; (3) studying the effect of varying UV levels on Earth-like planets around different types of stars to see whether this would pose a threat to habitability; and (4) studying the effect of chaotic obliquity variations on planetary climates and determining whether planets that experienced such variations might still be habitable. Several of these topics involve ongoing research that has been carried out under a new grant number, but which continues to be funded by NASA's Exobiology program.

  1. Planetary Astronomy

    NASA Technical Reports Server (NTRS)

    Stern, S. Alan

    1998-01-01

    This 1-year project was an augmentation grant to my NASA Planetary Astronomy grant. With the awarded funding, we accomplished the following tasks: (1) Conducted two NVK imaging runs in conjunction with the ILAW (International Lunar Atmosphere Week) Observing Campaigns in 1995 and 1997. In the first run, we obtained repeated imaging sequences of lunar Na D-line emission to better quantify the temporal variations detected in earlier runs. In the second run we obtained extremely high resolution (R=960.000) Na line profiles using the 4m AAT in Australia. These data are being analyzed under our new 3-year Planetary Astronomy grant. (2) Reduced, analyzed, and published our March 1995 spectroscopic dataset to detect (or set stringent upper limits on) Rb. Cs, Mg. Al. Fe, Ba, Ba. OH, and several other species. These results were reported in a talk at the LPSC and in two papers: (1) A Spectroscopic Survey of Metallic Abundances in the Lunar Atmosphere. and (2) A Search for Magnesium in the Lunar Atmosphere. Both reprints are attached. Wrote up an extensive, invited Reviews of Geophysics review article on advances in the study of the lunar atmosphere. This 70-page article, which is expected to appear in print in 1999, is also attached.

  2. Geochemical ecosystem engineering by the mud shrimp Upogebia pugettensis (Crustacea: Thalassinidae) in Yaquina Bay, Oregon: density-dependent effects on organic matter remineralization and nutrient cycling

    EPA Science Inventory

    We investigated the effect of the thalassinid mud shrimp Upogebia pugettensis on organic matter and nutrient cycling on Idaho Flat, an intertidal flat in the Yaquina River estuary, Oregon. Field studies were conducted to measure carbon and nitrogen remineralization rates and bent...

  3. Advanced planetary analyses. [for planetary mission planning

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The results are summarized of research accomplished during this period concerning planetary mission planning are summarized. The tasks reported include the cost estimations research, planetary missions handbook, and advanced planning activities.

  4. Planetary magnetism

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1981-01-01

    A synoptic view of early and recent data on the planetary magnetism of Mercury, Venus, the moon, Mars, Jupiter, and Saturn is presented. The data on Mercury from Mariner 10 are synthesized with various other sources, while data for Venus obtained from 120 orbits of Pioneer Venus give the upper limit of the magnetic dipole. Explorer 35 Lunar Orbiter data provided the first evidence of lunar magnetization, but it was the Apollo subsatellite data that measured accurately the magnetic dipole of the moon. A complete magnetic survey of Mars is still needed, and only some preliminary data are given on the magnetic dipole of the planet. Figures on the magnetic dipoles of Jupiter and Saturn are also suggested. It is concluded that if the magnetic field data are to be used to infer the interior properties of the planets, good measures of the multiple harmonics in the field are needed, which may be obtained only through low altitude polar orbits.

  5. Planetary Surface Instruments Workshop

    NASA Technical Reports Server (NTRS)

    Meyer, Charles (Editor); Treiman, Allan H. (Editor); Kostiuk, Theodor (Editor)

    1996-01-01

    This report on planetary surface investigations and planetary landers covers: (1) the precise chemical analysis of solids; (2) isotopes and evolved gas analyses; (3) planetary interiors; planetary atmospheres from within as measured by landers; (4) mineralogical examination of extraterrestrial bodies; (5) regoliths; and (6) field geology/processes.

  6. Planetary nomenclature

    NASA Technical Reports Server (NTRS)

    Strobell, M. E.; Masursky, Harold

    1987-01-01

    In fiscal 1986, names were chosen for prominent features on the five previously known Uranian satellites and for features on the largest of the 10 satellites discovered by Voyager 2. The names of the five large satellites are taken mostly from Shakespeare, and most are spirits; therefore, Shakespearean and spirit themes were used to choose names for topographic features on the satellites. Crater names and most other feature names on Miranda, Oberon, and Titania are from Shakespeare; features on Ariel are named for bright spirits and those on Umbriel for dark, all taken from universal mythology. Preliminary coordinates for these features are derived from shaded relief maps of the satellites to be published in 1987. Orbital elements have been established for the 10 new satellites, and a paper describing this work is in progress; satellite positions are under review by Commission 16 of the IAU. The moon 1985 U1 is informally designated Puck. The nine small satellites discovered in 1986 are to be named for Shakespearean heroines; these names are to be listed in the 1987 edition of the Annual Gazetteer of Planetary Nomenclature.

  7. Planetary Seismology

    NASA Technical Reports Server (NTRS)

    Weber, Renee C.

    2015-01-01

    Of the many geophysical means that can be used to probe a planet's interior, seismology remains the most direct. In addition to Earth, seismometers have been installed on Venus, Mars, and the Moon. Given that the seismic data gathered on the Moon (now over 40 years ago) revolutionized our understanding of the Moon and are still being used today to produce new insight into the state of the lunar interior, it is no wonder that many future missions, both real and conceptual, plan to take seismometers to other planets. To best facilitate the return of high-quality data from these instruments, as well as to further our understanding of the dynamic processes that modify a planet's interior, various modeling approaches are used to quantify parameters such as the amount and distribution of seismicity, tidal deformation, and seismic structure of the terrestrial planets. In addition, recent advances in wavefield modeling have permitted a renewed look at seismic energy transmission and the effects of attenuation and scattering, as well as the presence and effect of a core, on recorded seismograms. In this talk I will discuss some of these methods and review the history of planetary seismology.

  8. Planetary nebulae

    NASA Astrophysics Data System (ADS)

    Gieseking, F.

    1983-02-01

    The first planetary nebula (PN) was discovered by Darquier in 1779. In 1981, a compilation of galactic PN listed a total of 1455 objects. Outside the Milky Way Galaxy, PN are currently known in the Magellanic Clouds and in several members of the local group of galaxies. The PN have a rich emission-line spectrum, which makes it possible to recognize them at large distances. A central stellar object can be observed within the nebula. In 1927, spectral lines at 4959 A and 5007 A emitted by the PN could finally be identified as 'forbidden lines' of O(++). The life expectancy of a PN, estimated on the basis of the observed expansion rate, is only about 30,000 years. The PN have a number of interesting characteristics which are partly related to the high effective temperature and luminosity of the central stars, the presence of a particle system under extreme physical conditions, and the stellar material provided by the PN for the interstellar medium. Attention is given to the determination of the distance of PN, the Shklovsky distances, and two mysterious aspects related to the spectrum

  9. Significant achievements in the Planetary Geology Program. [geologic processes, comparative planetology, and solar system evolution

    NASA Technical Reports Server (NTRS)

    Head, J. W. (Editor)

    1978-01-01

    Developments reported at a meeting of principal investigators for NASA's planetology geology program are summarized. Topics covered include: constraints on solar system formation; asteriods, comets, and satellites; constraints on planetary interiors; volatiles and regoliths; instrument development techniques; planetary cartography; geological and geochemical constraints on planetary evolution; fluvial processes and channel formation; volcanic processes; Eolian processes; radar studies of planetary surfaces; cratering as a process, landform, and dating method; and the Tharsis region of Mars. Activities at a planetary geology field conference on Eolian processes are reported and techniques recommended for the presentation and analysis of crater size-frequency data are included.

  10. Laboratory simulation of organic geochemical processes.

    NASA Technical Reports Server (NTRS)

    Eglinton, G.

    1972-01-01

    Discussion of laboratory simulations that are important to organic geochemistry in that they provide direct evidence relating to geochemical cycles involving carbon. Reviewed processes and experiments include reactions occurring in the geosphere, particularly, short-term diagenesis of biolipids and organochlorine pesticides in estuarine muds, as well as maturation of organic matter in ancient sediments.

  11. Mechanisms and Geochemical Models of Core Formation

    NASA Astrophysics Data System (ADS)

    David Rubie; Seth Andrew Jacobson

    2016-03-01

    The formation of the Earth's core is a consequence of planetary accretion and processes in the Earth's interior. The mechanical process of planetary differentiation is likely to occur in large, if not global, magma oceans created by the collisions of planetary embryos. Metal-silicate segregation in magma oceans occurs rapidly and efficiently unlike grain scale percolation according to laboratory experiments and calculations. Geochemical models of the core formation process as planetary accretion proceeds are becoming increasingly realistic. Single stage and continuous core formation models have evolved into multi-stage models that are couple to the output of dynamical models of the giant impact phase of planet formation. The models that are most successful in matching the chemical composition of the Earth's mantle, based on experimentally-derived element partition coefficients, show that the temperature and pressure of metal-silicate equilibration must increase as a function of time and mass accreted and so must the oxygen fugacity of the equilibrating material. The latter can occur if silicon partitions into the core and through the late delivery of oxidized material. Coupled dynamical accretion and multi-stage core formation models predict the evolving mantle and core compositions of all the terrestrial planets simultaneously and also place strong constraints on the bulk compositions and oxidation states of primitive bodies in the protoplanetary disk.

  12. Planetary Moon Cycler Trajectories

    NASA Technical Reports Server (NTRS)

    Russell, Ryan P.; Strange, Nathan J.

    2007-01-01

    Free-return cycler trajectories repeatedly shuttle a spacecraft between two bodies using little or no fuel. Here, the cycler architecture is proposed as a complementary and alternative method for designing planetary moon tours. Previously applied enumerative cycler search and optimization techniques are generalized and specifically implemented in the Jovian and Saturnian moon systems. In addition, the algorithms are tested for general use to find non-Earth heliocentric cyclers. Overall, hundreds of ideal model ballistic cycler geometries are found and several representative cases are documented and discussed. Many of the ideal model solutions are found to remain ballistic in a zero radius sphere of influence patched conic ephemeris model, and preliminary work in a high-fidelity fully integrated model demonstrates near-ballistic cycles for several example cases.

  13. Advances in planetary geology

    NASA Technical Reports Server (NTRS)

    Woronow, A. (Editor)

    1981-01-01

    This second issue in a new series intended to serve the planetary geology community with a form for quick and thorough communications includes (1) a catalog of terrestrial craterform structures for northern Europe; (2) abstracts of results of the Planetary Geology Program, and (3) a list of the photographic holdings of regional planetary image facilities.

  14. Molecular geomicrobiology: genes and geochemical cycling

    NASA Astrophysics Data System (ADS)

    Macalady, Jennifer; Banfield, Jillian F.

    2003-04-01

    Core geosciences concepts are being fundamentally revised as the result of breakthroughs in geomicrobiology. Revolutionary discoveries have resulted from increased effort devoted to study of microorganisms in the context of their environments. Much recent progress has been made possible by genetic data, particularly those that allow the description of microbial populations in situ. New gene and genome sequences are elucidating previously unexpected or unexplained interactions between microorganisms and Earth materials, with implications for key geological phenomena such as the formation of ore deposits and the regulation of global climate and surface oxidation state. Genetic data have also led to extensive revision of our understanding of the pace and mechanisms by which evolution occurs. Yet, the field of molecular geomicrobiology remains in its infancy. In the foreseeable future, merging of modern biogeochemistry with molecularly resolved ecological studies will inspire the development of integrated models for the processes that shape the Earth.

  15. Planetary Evolution, Habitability and Life

    NASA Astrophysics Data System (ADS)

    Tilman, Spohn; Breuer, Doris; de Vera, Jean-Pierre; Jaumann, Ralf; Kuehrt, Ekkehard; Möhlmann, Diedrich; Rauer, Heike; Richter, Lutz

    A Helmholtz Alliance has been established to study the interactions between life and the evo-lution of planets. The approach goes beyond current studies in Earth-System Sciences by including the entire planet from the atmosphere to the deep interior, going beyond Earth to include other Earth-like planets such as Mars and Venus and satellites in the solar system where ecosystems may exist underneath thick ice shells,considering other solar systems. The approach includes studies of the importance of plate tectonics and other tectonic regimes such as single plate tectonics for the development and for sustaining life and asks the question: If life can adapt to a planet, can a planet adapt to life? Can life be seen as a geological process and if so, can life shape the conditions on a planet such that life can flourish? The vision goes beyond the solar system by including the challenges that life would face in other solar systems. The Alliance uses theoretical modelling of feedback cycles and coupled planetary atmosphere and interior processes. These models are based on the results of remote sensing of planetary surfaces and atmospheres, laboratory studies on (meteorite) samples from other planets and on studies of life under extreme conditions. The Alliance uses its unique capabilities in remote sensing and in-situ exploration to prepare for empirical studies of the parameters affecting habitability. The Alliance aims to establish a network infrastructure in Germany to enable the most ad-vanced research in planetary evolution studies by including life as a planetary process. Finding extraterrestrial life is a task of fundamental importance to mankind, and its fulfilment will be philosophically profound. Evaluating the interactions between planetary evolution and life will help to put the evolution of our home planet (even anthropogenic effects) into perspective.

  16. Advanced planetary studies

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Results of planetary advanced studies and planning support provided by Science Applications, Inc. staff members to Earth and Planetary Exploration Division, OSSA/NASA, for the period 1 February 1981 to 30 April 1982 are summarized. The scope of analyses includes cost estimation, planetary missions performance, solar system exploration committee support, Mars program planning, Galilean satellite mission concepts, and advanced propulsion data base. The work covers 80 man-months of research. Study reports and related publications are included in a bibliography section.

  17. The planetary data system

    NASA Technical Reports Server (NTRS)

    Lee, Steven W.

    1991-01-01

    Nasa has sponsored the development of the Planetary Data System (PDS) in order to preserve the scientific returns from past and future planeary missions and to make those data readily accessible in a well-documented form. The PDS encompasses all planetary data, but also provides a distributed, discipline-oriented architecture to best serve the needs of the diverse planetary sciences user-community. It is the intention of the PDS to ease and promote the analysis of planetary data through the development and application of data and documentation standards, basic analysis tools, and technology.

  18. Planetary geosciences, 1988

    NASA Technical Reports Server (NTRS)

    Zuber, Maria T. (Editor); Plescia, Jeff L. (Editor); James, Odette B. (Editor); Macpherson, Glenn (Editor)

    1989-01-01

    Research topics within the NASA Planetary Geosciences Program are presented. Activity in the fields of planetary geology, geophysics, materials, and geochemistry is covered. The investigator's current research efforts, the importance of that work in understanding a particular planetary geoscience problem, the context of that research, and the broader planetary geoscience effort is described. As an example, theoretical modelling of the stability of water ice within the Martian regolith, the applicability of that work to understanding Martian volatiles in general, and the geologic history of Mars is discussed.

  19. Planetary atmospheres. [reviewing recent research

    NASA Technical Reports Server (NTRS)

    Leovy, Conway

    1987-01-01

    Observations and theoretical models of planetary atmospheres published during the period 1983-1986 are reviewed, including Vega and Voyager data and results from ground-based remote sensing. Consideration is given to water-vapor and sulfur-compound distributions, electrical phenomena, and dynamics in the Venus atmosphere; dust storms, water cycles, and water and ice erosion on Mars; the compositions, temperature profiles, and dynamics of the Jovian and Saturnian atmospheres; chemical processes and zonal winds on Titan; and the radiation budgets and chemical compositions of the outer planets.

  20. Geobiochemistry: Placing Biochemistry in Its Geochemical Context

    NASA Astrophysics Data System (ADS)

    Shock, E.; Boyer, G. M.; Canovas, P. A., III; Prasad, A.; Dick, J. M.

    2014-12-01

    Goals of geobiochemistry include simultaneously evaluating the relative stabilities of microbial cells and minerals, and predicting how the composition of biomolecules can change in response to the progress of geochemical reactions. Recent developments in theoretical geochemistry make it possible to predict standard thermodynamic properties of proteins, nucleotides, lipids, and many metabolites including the constituents of the citric acid cycle, at all temperatures and pressures where life is known to occur, and beyond. Combining these predictions with constraints from geochemical data makes it possible to assess the relative stabilities of biomolecules. Resulting independent predictions of the environmental occurrence of homologous proteins and lipid side-chains can be compared with observations from metagenomic and metalipidomic data to quantify geochemical driving forces that shape the composition of biomolecules. In addition, the energetic costs of generating biomolecules from within a diverse range of habitable environments can be evaluated in terms of prevailing geochemical variables. Comparisons of geochemical bioenergetic calculations across habitats leads to the generalization that the availability of H2 determines the cost of autotrophic biosynthesis relative to the aquatic environment external to microbial cells, and that pH, temperature, pressure, and availability of C, N, P, and S are typically secondary. Increasingly reduced conditions, which are determined by reactions of water with mineral surfaces and mineral assemblages, allow many biosynthetic reactions to shift from costing energy to releasing energy. Protein and lipid synthesis, as well as the reverse citric acid cycle, become energy-releasing processes under these conditions. The resulting energy balances that determine habitability contrast dramatically with assumptions derived from oxic surface conditions, such as those where human biochemistry operates.

  1. Advances in Planetary Geology

    NASA Technical Reports Server (NTRS)

    Woronow, A. (Editor)

    1982-01-01

    Advances in Planetary Geology is a new series intended to serve the planetary geology community with a form for quick and thorough communications. There are no set lists of acceptable topics or formats, and submitted manuscripts will not undergo a formal review. All submissions should be in a camera ready form, preferably spaced, and submitted to the editor.

  2. Advanced planetary studies

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Results of planetary advanced studies and planning support are summarized. The scope of analyses includes cost estimation research, planetary mission performance, penetrator advanced studies, Mercury mission transport requirements, definition of super solar electric propulsion/solar sail mission discriminators, and advanced planning activities.

  3. Planetary Exploration in ESA

    NASA Technical Reports Server (NTRS)

    Schwehm, Gerhard H.

    2005-01-01

    A viewgraph presentation on planetary exploration in the European Space Agency is shown. The topics include: 1) History of the Solar System Material; 2) ROSETTA: The Comet Mission; 3) A New Name For The Lander: PHILAE; 4) The Rosetta Mission; 5) Lander: Design Characteristics; 6) SMART-1 Mission; 7) MARS Express VENUS Express; 8) Planetary Exploration in ESA The Future.

  4. Mathematical optimization of matter distribution for a planetary system configuration

    NASA Astrophysics Data System (ADS)

    Morozov, Yegor; Bukhtoyarov, Mikhail

    2016-07-01

    Planetary formation is mostly a random process. When the humanity reaches the point when it can transform planetary systems for the purpose of interstellar life expansion, the optimal distribution of matter in a planetary system will determine its population and expansive potential. Maximization of the planetary system carrying capacity and its potential for the interstellar life expansion depends on planetary sizes, orbits, rotation, chemical composition and other vital parameters. The distribution of planetesimals to achieve maximal carrying capacity of the planets during their life cycle, and maximal potential to inhabit other planetary systems must be calculated comprehensively. Moving much material from one planetary system to another is uneconomic because of the high amounts of energy and time required. Terraforming of the particular planets before the whole planetary system is configured might drastically decrease the potential habitability the whole system. Thus a planetary system is the basic unit for calculations to sustain maximal overall population and expand further. The mathematical model of optimization of matter distribution for a planetary system configuration includes the input observed parameters: the map of material orbiting in the planetary system with specified orbits, masses, sizes, and the chemical compound for each, and the optimized output parameters. The optimized output parameters are sizes, masses, the number of planets, their chemical compound, and masses of the satellites required to make tidal forces. Also the magnetic fields and planetary rotations are crucial, but they will be considered in further versions of this model. The optimization criteria is the maximal carrying capacity plus maximal expansive potential of the planetary system. The maximal carrying capacity means the availability of essential life ingredients on the planetary surface, and the maximal expansive potential means availability of uranium and metals to build

  5. Life cycles of transient planetary waves

    NASA Technical Reports Server (NTRS)

    Nathan, Terrence

    1993-01-01

    In recent years there has been an increasing effort devoted to understanding the physical and dynamical processes that govern the global-scale circulation of the atmosphere. This effort has been motivated, in part, from: (1) a wealth of new satellite data; (2) an urgent need to assess the potential impact of chlorofluorocarbons on our climate; (3) an inadequate understanding of the interactions between the troposphere and stratosphere and the role that such interactions play in short and long-term climate variability; and (4) the realization that addressing changes in our global climate requires understanding the interactions among various components of the earth system. The research currently being carried out represents an effort to address some of these issues by carrying out studies that combine radiation, ozone, seasonal thermal forcing and dynamics. Satellite and ground-based data that is already available is being used to construct basic states for our analytical and numerical models. Significant accomplishments from 1991-1992 are presented and include the following: ozone-dynamics interaction; (2) periodic local forcing and low frequency variability; and (3) steady forcing and low frequency variability.

  6. PLANETARY METABOLISM: UNDERSTANDING THE CARBON CYCLE

    EPA Science Inventory

    Biological systems are intimately involved in the transfers of energy and materials around our planet, affecting the geochemistry and other physical properties of the atmosphere, the land surface, ant the oceans and their sediments. ossil-fuel combustion, land use, and other huma...

  7. Planetary Data Definition

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Planetary data include all of those data which have resulted from measurements made by the instruments carried aboard planetary exploration spacecraft, and (for our purposes) exclude observations of Moon and Earth. The working, planetary data base is envisioned to contain not only these data, but also a wide range of supporting measurements such as calibration files, navigation parameters, spacecraft engineering states, and the various Earth-based and laboratory measurements which provide the planetary research scientist with historical and comparative data. No convention exists across the disciplines of the planetary community for defining or naming the various levels through which data pass in the progression from a sensed impulse at the spacecraft to a reduced, calibrated, and/or analyzed element in a planetary data set. Terms such as EDR (experiment data record), RDR (reduced data record), and SEDR (supplementary experiment data record) imply different meanings depending on the data set under consideration. The development of standard terminology for the general levels of planetary data is necessary.

  8. Planetary data definition

    NASA Astrophysics Data System (ADS)

    1984-10-01

    Planetary data include all of those data which have resulted from measurements made by the instruments carried aboard planetary exploration spacecraft, and (for our purposes) exclude observations of Moon and Earth. The working, planetary data base is envisioned to contain not only these data, but also a wide range of supporting measurements such as calibration files, navigation parameters, spacecraft engineering states, and the various Earth-based and laboratory measurements which provide the planetary research scientist with historical and comparative data. No convention exists across the disciplines of the planetary community for defining or naming the various levels through which data pass in the progression from a sensed impulse at the spacecraft to a reduced, calibrated, and/or analyzed element in a planetary data set. Terms such as EDR (experiment data record), RDR (reduced data record), and SEDR (supplementary experiment data record) imply different meanings depending on the data set under consideration. The development of standard terminology for the general levels of planetary data is necessary.

  9. Geochemical modeling: a review

    SciTech Connect

    Jenne, E.A.

    1981-06-01

    Two general families of geochemical models presently exist. The ion speciation-solubility group of geochemical models contain submodels to first calculate a distribution of aqueous species and to secondly test the hypothesis that the water is near equilibrium with particular solid phases. These models may or may not calculate the adsorption of dissolved constituents and simulate the dissolution and precipitation (mass transfer) of solid phases. Another family of geochemical models, the reaction path models, simulates the stepwise precipitation of solid phases as a result of reacting specified amounts of water and rock. Reaction path models first perform an aqueous speciation of the dissolved constituents of the water, test solubility hypotheses, then perform the reaction path modeling. Certain improvements in the present versions of these models would enhance their value and usefulness to applications in nuclear-waste isolation, etc. Mass-transfer calculations of limited extent are certainly within the capabilities of state-of-the-art models. However, the reaction path models require an expansion of their thermodynamic data bases and systematic validation before they are generally accepted.

  10. Planetary Geophysics and Tectonics

    NASA Technical Reports Server (NTRS)

    Zuber, Maria

    2005-01-01

    The broad objective of this work is to improve understanding of the internal structures and thermal and stress histories of the solid planets by combining results from analytical and computational modeling, and geophysical data analysis of gravity, topography and tectonic surface structures. During the past year we performed two quite independent studies in the attempt to explain the Mariner 10 magnetic observations of Mercury. In the first we revisited the possibility of crustal remanence by studying the conditions under which one could break symmetry inherent in Runcorn's model of a uniformly magnetized shell to produce a remanent signal with a dipolar form. In the second we applied a thin shell dynamo model to evaluate the range of intensity/structure for which such a planetary configuration can produce a dipole field consistent with Mariner 10 results. In the next full proposal cycle we will: (1) develop numerical and analytical and models of thin shell dynamos to address the possible nature of Mercury s present-day magnetic field and the demise of Mars magnetic field; (2) study the effect of degree-1 mantle convection on a core dynamo as relevant to the early magnetic field of Mars; (3) develop models of how the deep mantles of terrestrial planets are perturbed by large impacts and address the consequences for mantle evolution; (4) study the structure, compensation, state of stress, and viscous relaxation of lunar basins, and address implications for the Moon s state of stress and thermal history by modeling and gravity/topography analysis; and (5) use a three-dimensional viscous relaxation model for a planet with generalized vertical viscosity distribution to study the degree-two components of the Moon's topography and gravity fields to constrain the primordial stress state and spatial heterogeneity of the crust and mantle.

  11. Seeking a geochemical identifier for authigenic carbonate

    PubMed Central

    Zhao, Ming-Yu; Zheng, Yong-Fei; Zhao, Yan-Yan

    2016-01-01

    Authigenic carbonate was recently invoked as a third major global carbon sink in addition to primary marine carbonate and organic carbon. Distinguishing the two carbonate sinks is fundamental to our understanding of Earth's carbon cycle and its role in regulating the evolution of atmospheric oxygen. Here, using microscale geochemical measurements of carbonates in Early Triassic strata, we show that the growth of authigenic carbonate follows a different trajectory from primary marine carbonate in a cross-plot of uranium concentration and carbon isotope composition. Thus, a combination of the two geochemical variables is able to distinguish between the two carbonate sinks. The temporal distribution of authigenic carbonates in the Early Triassic strata suggests that the increase in the extent of carbonate authigenesis acted as a negative feedback to the elevated atmospheric CO2 concentration. PMID:26947562

  12. Seeking a geochemical identifier for authigenic carbonate

    NASA Astrophysics Data System (ADS)

    Zhao, Ming-Yu; Zheng, Yong-Fei; Zhao, Yan-Yan

    2016-03-01

    Authigenic carbonate was recently invoked as a third major global carbon sink in addition to primary marine carbonate and organic carbon. Distinguishing the two carbonate sinks is fundamental to our understanding of Earth's carbon cycle and its role in regulating the evolution of atmospheric oxygen. Here, using microscale geochemical measurements of carbonates in Early Triassic strata, we show that the growth of authigenic carbonate follows a different trajectory from primary marine carbonate in a cross-plot of uranium concentration and carbon isotope composition. Thus, a combination of the two geochemical variables is able to distinguish between the two carbonate sinks. The temporal distribution of authigenic carbonates in the Early Triassic strata suggests that the increase in the extent of carbonate authigenesis acted as a negative feedback to the elevated atmospheric CO2 concentration.

  13. Seeking a geochemical identifier for authigenic carbonate.

    PubMed

    Zhao, Ming-Yu; Zheng, Yong-Fei; Zhao, Yan-Yan

    2016-01-01

    Authigenic carbonate was recently invoked as a third major global carbon sink in addition to primary marine carbonate and organic carbon. Distinguishing the two carbonate sinks is fundamental to our understanding of Earth's carbon cycle and its role in regulating the evolution of atmospheric oxygen. Here, using microscale geochemical measurements of carbonates in Early Triassic strata, we show that the growth of authigenic carbonate follows a different trajectory from primary marine carbonate in a cross-plot of uranium concentration and carbon isotope composition. Thus, a combination of the two geochemical variables is able to distinguish between the two carbonate sinks. The temporal distribution of authigenic carbonates in the Early Triassic strata suggests that the increase in the extent of carbonate authigenesis acted as a negative feedback to the elevated atmospheric CO2 concentration. PMID:26947562

  14. Lunar & Planetary Science Conference.

    ERIC Educational Resources Information Center

    Warner, Jeffrey L.; And Others

    1982-01-01

    Summaries of different topics discussed at the Lunar and Planetary Science Conference are presented to provide updated information to nonplanetologists. Some topics include Venus, isotopes, chondrites, creation science, cosmic dust, cratering, moons and rings, igneous rocks, and lunar soil. (DC)

  15. Physics of planetary ionospheres

    NASA Technical Reports Server (NTRS)

    Bauer, S. J.

    1973-01-01

    The fundamental physical and chemical processes in an idealized planetary ionosphere are considered as a general abstraction, with actual planetary ionospheres representing special cases. After describing the structure of the neutral atmospheres (the barosphere, the thermosphere, and the exosphere) and noting the principal ionizing radiations responsible for the formation of planetary ionospheres, a detailed study is made of the thermal structure of these ionospheres and of the chemical processes and plasma-transport processes occurring in them. The features of equilibrium and realistic models of planetary ionospheres are discussed, and an attempt is made to determine the extent of these ionospheres. Considering the ionosphere as a plasma, a plasma kinetic approach is developed for determining the effects of interactions between individual particles and waves in this plasma. The use of remote-sensing radio techniques and direct measurement or in situ techniques is discussed. Finally, the observed properties of the ionospheres of the Earth, Mars, Venus, and Jupiter are reviewed.

  16. Lunar & Planetary Science, 11.

    ERIC Educational Resources Information Center

    Geotimes, 1980

    1980-01-01

    Presents a summary of each paper presented at the Lunar and Planetary Science Conference at the Johnson Space Center, Houston in March 1980. Topics relate to Venus, Jupiter, Mars, asteroids, meteorites, regoliths, achondrites, remote sensing, and cratering studies. (SA)

  17. The Planetary Project

    NASA Astrophysics Data System (ADS)

    Pataki, Louis P.

    2016-06-01

    This poster presentation presents the Planetary Project, a multi-week simulated research experience for college non-science majors. Students work in research teams of three to investigate the properties of a fictitious planetary system (the “Planetary System”) created each semester by the instructor. The students write team and individual papers in which they use the available data to draw conclusions about planets, other objects or general properties of the Planetary System and in which they compare, contrast and explain the similarities between the objects in the Planetary System and comparable objects in the Solar System.Data about the orbital and physical properties of the planets in the Planetary System are released at the start of the project. Each week the teams request data from a changing pool of available data. For example, in week one pictures of the planets are available. Each team picks one planet and the data (pictures) on that planet are released only to that team. Different data are available in subsequent weeks. Occasionally a news release to all groups reports an unusual occurrence - e.g. the appearance of a comet.Each student acts as principal author for one of the group paper which must contain a description of the week’s data, conclusions derived from that data about the Planetary System and a comparison with the Solar System. Each students writes a final, individual paper on a topic of their choice dealing with the Planetary System in which they follow the same data, conclusion, comparison format. Students “publish” their papers on a class-only restricted website and present their discoveries in class talks. Data are released to all on the website as the related papers are “published.” Additional papers commenting on the published work and released data are encouraged.The successes and problems of the method are presented.

  18. The search for signs of life on exoplanets at the interface of chemistry and planetary science.

    PubMed

    Seager, Sara; Bains, William

    2015-03-01

    The discovery of thousands of exoplanets in the last two decades that are so different from planets in our own solar system challenges many areas of traditional planetary science. However, ideas for how to detect signs of life in this mélange of planetary possibilities have lagged, and only in the last few years has modeling how signs of life might appear on genuinely alien worlds begun in earnest. Recent results have shown that the exciting frontier for biosignature gas ideas is not in the study of biology itself, which is inevitably rooted in Earth's geochemical and evolutionary specifics, but in the interface of chemistry and planetary physics. PMID:26601153

  19. Planetary life: why and how?

    NASA Astrophysics Data System (ADS)

    Pratt, Andy; Kerr, William

    2012-07-01

    Understanding life in an astrobiological context requires that we understand why and how life emerged on earth. We report on the elaboration and preliminary testing of our recent model for the origin of life (Pratt, 2011). This model identifies key components, including availability of chemicals and geochemical energy sources, required for the emergence of planetary life. The model is based on the theory (Russell and Kanik, 2010) that life emerged as a mechanism for the dissipation of the intrinsic geochemical energy gradient of the planet. It proposes that life is founded on an ongoing chemical energy flux that can be harnessed more efficiently by autocatalytic networks of reactions than by direct chemical processes. Feedback and selection mechanisms are required to foster the apparently irreducible complexity found in cells. We posit that selective solubilisation in a hydrothermal flow system was a key mechanism that underpinned the emergence of life. Amongst other things, earthly cells are dependent on a combination of organic molecules, iron (for electron-transfer and catalysis) and phosphate (e.g. for digital information). Soluble aqueous systems that include all these components are constrained by precipitation chemistry (de Zwart et al., 2004). We propose that in situ abiological carbon fixation produced organic molecules that, in turn, led to more active carbon fixation catalysts and hence more efficient reduction of carbon oxides. By encapsulating free iron ions, these organic molecules also facilitated the solubilisation of phosphate species which thereby became integrated within this expanding autocatalytic network. We have evaluated the competitive solubility of phosphate species in the presence of iron and organic moieties to test this theory and provide evidence that this could act as positive feedback loop for a form of prebiological evolution that underpinned the emergence of complex cells. References, Pratt, A. J. (2011) Prebiological Evolution and

  20. Non-planetary Science from Planetary Missions

    NASA Astrophysics Data System (ADS)

    Elvis, M.; Rabe, K.; Daniels, K.

    2015-12-01

    Planetary science is naturally focussed on the issues of the origin and history of solar systems, especially our own. The implications of an early turbulent history of our solar system reach into many areas including the origin of Earth's oceans, of ores in the Earth's crust and possibly the seeding of life. There are however other areas of science that stand to be developed greatly by planetary missions, primarily to small solar system bodies. The physics of granular materials has been well-studied in Earth's gravity, but lacks a general theory. Because of the compacting effects of gravity, some experiments desired for testing these theories remain impossible on Earth. Studying the behavior of a micro-gravity rubble pile -- such as many asteroids are believed to be -- could provide a new route towards exploring general principles of granular physics. These same studies would also prove valuable for planning missions to sample these same bodies, as techniques for anchoring and deep sampling are difficult to plan in the absence of such knowledge. In materials physics, first-principles total-energy calculations for compounds of a given stoichiometry have identified metastable, or even stable, structures distinct from known structures obtained by synthesis under laboratory conditions. The conditions in the proto-planetary nebula, in the slowly cooling cores of planetesimals, and in the high speed collisions of planetesimals and their derivatives, are all conditions that cannot be achieved in the laboratory. Large samples from comets and asteroids offer the chance to find crystals with these as-yet unobserved structures as well as more exotic materials. Some of these could have unusual properties important for materials science. Meteorites give us a glimpse of these exotic materials, several dozen of which are known that are unique to meteorites. But samples retrieved directly from small bodies in space will not have been affected by atmospheric entry, warmth or

  1. Planetary mass function and planetary systems

    NASA Astrophysics Data System (ADS)

    Dominik, M.

    2011-02-01

    With planets orbiting stars, a planetary mass function should not be seen as a low-mass extension of the stellar mass function, but a proper formalism needs to take care of the fact that the statistical properties of planet populations are linked to the properties of their respective host stars. This can be accounted for by describing planet populations by means of a differential planetary mass-radius-orbit function, which together with the fraction of stars with given properties that are orbited by planets and the stellar mass function allows the derivation of all statistics for any considered sample. These fundamental functions provide a framework for comparing statistics that result from different observing techniques and campaigns which all have their very specific selection procedures and detection efficiencies. Moreover, recent results both from gravitational microlensing campaigns and radial-velocity surveys of stars indicate that planets tend to cluster in systems rather than being the lonely child of their respective parent star. While planetary multiplicity in an observed system becomes obvious with the detection of several planets, its quantitative assessment however comes with the challenge to exclude the presence of further planets. Current exoplanet samples begin to give us first hints at the population statistics, whereas pictures of planet parameter space in its full complexity call for samples that are 2-4 orders of magnitude larger. In order to derive meaningful statistics, however, planet detection campaigns need to be designed in such a way that well-defined fully deterministic target selection, monitoring and detection criteria are applied. The probabilistic nature of gravitational microlensing makes this technique an illustrative example of all the encountered challenges and uncertainties.

  2. Detectability of extrasolar planetary transits

    NASA Technical Reports Server (NTRS)

    Borucki, W. J.; Scargle, J. D.; Hudson, H. S.

    1985-01-01

    Precise stellar photometry can be used to detect other planetary systems. However, the intrinsic variability of stellar luminosity imposes a fundamental limit on the sensitivity of this method. Based on recent precise solar observations made from the Solar Maximum Mission satellite, it appears that the detection of earth-sized planets will be marginal during periods of high stellar activity. However, with a suitable photometer larger planets should be readily detectable even in the presence of stellar activity equal to that of the sun at the peak of its sunspot cycle. The high precision, multiple-star photometric system required to detect planets in other stellar systems could be used to monitor flares, starspots, and global oscillations.

  3. Nebular UV Absorption Lines in Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Dinerstein, Harriet

    We propose to continue our Cycle 1 program of studying the Lyman and Werner bands of H_2, seen in absorption against the UV continua of planetary nebula central stars, which arise within neutral-molecular envelopes surrounding the ionized gas. These are the pump lines for a fluorescent cascade of near-infrared emission lines which are observed in many planetary nebulae. By observing the UV lines we can probe the chemical and thermal structure of the envelopes, as well as measure molecular column densities and clarify the excitation processes for the infrared lines. In Cycle 1 we were granted time for three targets, one of which was successfully observed shortly before submission of this proposal. Although the data were not yet available for examination, similar target observed by the project team revealed a rich set of H_2 circumstellar absorption features, demonstrating the feasibility of our program. FUSE spectra also include absorption features from atomic species such as O I and C II, which give rise to important far-infrared fine-structure cooling lines that likewise have been observed from planetary nebulae. In Cycle 2, we add as a secondary goal a search for nebular components of the O VI 032, 1038 AA absorption lines, which trace the presence of hot shocked gas, in nebulae with anomalously strong optical recombination lines of ions of oxygen and nitrogen. This will test a plausible hypothesis for the origin of this anomaly.

  4. Planetary noble gases

    NASA Technical Reports Server (NTRS)

    Zahnle, Kevin

    1993-01-01

    An overview of the history and current status of research on planetary noble gases is presented. The discovery that neon and argon are vastly more abundant on Venus than on earth points to the solar wind rather than condensation as the fundamental process for placing noble gases in the atmospheres of the terrestrial planets; however, solar wind implantation may not be able to fully reproduce the observed gradient, nor does it obviously account for similar planetary Ne/Ar ratios and dissimilar planetary Ar/Kr ratios. More recent studies have emphasized escape rather than accretion. Hydrodynamic escape, which is fractionating, readily accounts for the difference between atmospheric neon and isotopically light mantle neon. Atmospheric cratering, which is nearly nonfractionating, can account for the extreme scarcity of nonradiogenic noble gases (and other volatiles) on Mars.

  5. Principles of Planetary Climate

    NASA Astrophysics Data System (ADS)

    Pierrehumbert, Raymond T.

    2010-12-01

    This book introduces the reader to all the basic physical building blocks of climate needed to understand the present and past climate of Earth, the climates of Solar System planets, and the climates of extrasolar planets. These building blocks include thermodynamics, infrared radiative transfer, scattering, surface heat transfer and various processes governing the evolution of atmospheric composition. Nearly four hundred problems are supplied to help consolidate the reader's understanding, and to lead the reader towards original research on planetary climate. This textbook is invaluable for advanced undergraduate or beginning graduate students in atmospheric science, Earth and planetary science, astrobiology, and physics. It also provides a superb reference text for researchers in these subjects, and is very suitable for academic researchers trained in physics or chemistry who wish to rapidly gain enough background to participate in the excitement of the new research opportunities opening in planetary climate.

  6. Extrasolar planetary systems.

    NASA Technical Reports Server (NTRS)

    Huang, S.-S.

    1973-01-01

    The terms 'planet' and 'planet-like objects' are defined. The observational search for extrasolar planetary systems is described, as performable by earthbound optical telescopes, by space probes, by long baseline radio interferometry, and finally by inference from the reception of signals sent by intelligent beings in other worlds. It is shown that any planetary system must be preceded by a rotating disk of gas and dust around a central mass. A brief review of the theories of the formation of the solar system is given, along with a proposed scheme for classification of these theories. The evidence for magnetic activity in the early stages of stellar evolution is presented. The magnetic braking theories of solar and stellar rotation are discussed, and an estimate is made for the frequency of occurrence of planetary systems in the universe.

  7. Airships for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony

    2004-01-01

    The feasibility of utilizing an airship for planetary atmospheric exploration was assessed. The environmental conditions of the planets and moons within our solar system were evaluated to determine their applicability for airship flight. A station-keeping mission of 50 days in length was used as the baseline mission. Airship sizing was performed utilizing both solar power and isotope power to meet the baseline mission goal at the selected planetary location. The results show that an isotope-powered airship is feasible within the lower atmosphere of Venus and Saturn s moon Titan.

  8. Geochemical Speciation Mass Transfer

    SciTech Connect

    1985-12-01

    PHREEQC is designed to model geochemical reactions. Based on an ion association aqueous model, PHREEQC can calculate pH, redox potential, and mass transfer as a function of reaction progress. It can be used to describe geochemical processes for both far-field and near-field performance assessment and to evaluate data acquisition needs and test data. It can also calculate the composition of solutions in equilibrium with multiple phases. The data base, including elements, aqueous species, and mineral phases, is independent of the program and is completely user-definable. PHREEQC requires thermodynamic data for each solid, gaseous, or dissolved chemical species being modeled. The two data bases, PREPHR and DEQPAK7, supplied with PHREEQC are for testing purposes only and should not be applied to real problems without first being carefully examined. The conceptual model embodied in PHREEQC is the ion-association model of Pearson and Noronha. In this model a set of mass action equations are established for each ion pair (and controlling solid phases when making mass transfer calculations) along with a set of mass balance equations for each element considered. These sets of equations are coupled using activity coefficient values for each aqueous species and solved using a continued fraction approach for the mass balances combined with a modified Newton-Raphson technique for all other equations. The activity coefficient expressions in PHREEQC include the extended Debye-Huckel, WATEQ Debye-Huckel, and Davies equations from the original United States Geological Survey version of the program. The auxiliary preprocessor program PHTL, which is derived from EQTL, converts EQ3/6 thermodynamic data to PHREEQC format so that the two programs can be compared. PHREEQC can be used to determine solubility limits on the radionuclides present in the waste form. These solubility constraints may be input to the WAPPA leach model.

  9. Geochemical Speciation Mass Transfer

    Energy Science and Technology Software Center (ESTSC)

    1985-12-01

    PHREEQC is designed to model geochemical reactions. Based on an ion association aqueous model, PHREEQC can calculate pH, redox potential, and mass transfer as a function of reaction progress. It can be used to describe geochemical processes for both far-field and near-field performance assessment and to evaluate data acquisition needs and test data. It can also calculate the composition of solutions in equilibrium with multiple phases. The data base, including elements, aqueous species, and mineralmore » phases, is independent of the program and is completely user-definable. PHREEQC requires thermodynamic data for each solid, gaseous, or dissolved chemical species being modeled. The two data bases, PREPHR and DEQPAK7, supplied with PHREEQC are for testing purposes only and should not be applied to real problems without first being carefully examined. The conceptual model embodied in PHREEQC is the ion-association model of Pearson and Noronha. In this model a set of mass action equations are established for each ion pair (and controlling solid phases when making mass transfer calculations) along with a set of mass balance equations for each element considered. These sets of equations are coupled using activity coefficient values for each aqueous species and solved using a continued fraction approach for the mass balances combined with a modified Newton-Raphson technique for all other equations. The activity coefficient expressions in PHREEQC include the extended Debye-Huckel, WATEQ Debye-Huckel, and Davies equations from the original United States Geological Survey version of the program. The auxiliary preprocessor program PHTL, which is derived from EQTL, converts EQ3/6 thermodynamic data to PHREEQC format so that the two programs can be compared. PHREEQC can be used to determine solubility limits on the radionuclides present in the waste form. These solubility constraints may be input to the WAPPA leach model.« less

  10. ESA Missions Planetary Protection Status

    NASA Astrophysics Data System (ADS)

    Kminek, Gerhard

    2016-07-01

    This presentation will report the planetary protection status of ESA flight projects with planetary protection requirements. It will cover Rosetta, Mars Express, ExoMars 2016, ExoMars 2018, JUICE, Solar Orbiter, and Bepi Colombo.

  11. Conference on Planetary Volatiles

    NASA Technical Reports Server (NTRS)

    Hrametz, K.; Kofler, L.

    1982-01-01

    Initial and present volatile inventories and distributions in the Earth, other planets, meteorites, and comets; observational evidence on the time history of volatile transfer among reservoirs; and volatiles in planetary bodies, their mechanisms of transport, and their relation to thermal, chemical, geological and biological evolution were addressed.

  12. Planetary quarantine computer applications

    NASA Technical Reports Server (NTRS)

    Rafenstein, M.

    1973-01-01

    The computer programs are identified pertaining to planetary quarantine activities within the Project Engineering Division, both at the Air Force Eastern Test Range and on site at the Jet Propulsion Laboratory. A brief description of each program and program inputs are given and typical program outputs are shown.

  13. Advances in planetary geology

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A wide variety of topics on planetary geology are presented. Subjects include stratigraphy and geomorphology of Copernicus, the Mamers valle region, and other selected regions of Mars and the Moon. Crater density and distribution are discussed for Callisto and the lunar surface. Spectroscopic analysis is described for Europa and Ganymede.

  14. Asteroidal and planetary analysis

    NASA Technical Reports Server (NTRS)

    Hartmann, W. K.

    1975-01-01

    Photometric, spectrophotometric, and radiometric investigations of asteroids and planets are reported. Profiles of the planetary disk were used to study the physical structure of the Uranus atmosphere, and thermal and photographic properties of Saturn rings were theoretically modelled. Ground-based Mars observations were made for long-term comparison with Mariner 9 results.

  15. Advanced planetary studies

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Eleven study tasks are described and key results are discussed for the following: advanced planning activity; cost estimation research; planetary missions performance handbooks-revisions; multiple discipline science assessment; asteroid workshop; galilean lander mission strategies; asteroid exploration study; ion drive transport capabilities; Mars strategy study; Venus surface sample return; and ion drive/solar sail assessment study.

  16. Planetary Radar Astronomy

    NASA Technical Reports Server (NTRS)

    Ostro, Steven J.

    1993-01-01

    Radar is a powerful technique that has furnished otherwise unavailable information about solar system bodies for three decades. The advantages of radar in planetary astronomy result from: (1) the observer's control of all the attributes of the coherent signal used to illuminate the target, especially the wave form's time/frequency modulation and polarization; (2) the ability of radar to resolve objects spatially via measurements of the distribution of echo power in time delay and Doppler frequency; (3) the pronounced degree to which delay-Doppler measurements constrain orbits and spin vectors; and (4) centimeter-to-meter wavelengths, which easily penetrate optically opaque planetary clouds and cometary comae, permit investigation of near-surface macrostructure and bulk density, and are sensitive to high concentrations of metal or, in certain situations, ice. Planetary radar astronomy has primarily involved observations with Earth-based radar telescopes, but also includes some experiments with a spaceborne transmitter or receiver. In addition to providing a wealth of information about the geological and dynamical properties of asteroids, comets, the inner planets, and natural satellites, radar experiments have established the scale of the solar system, have contributed significantly to the accuracy of planetary ephemerides, and have helped to constrain theories of gravitation. This review outlines radar astronomical techniques and describes principal observational results.

  17. Conference on Planetary Volatiles

    NASA Technical Reports Server (NTRS)

    Pepin, R. O. (Compiler); Oconnell, R. (Compiler)

    1982-01-01

    Initial and present volatile inventories and distributions in the Earth, other planets, meteorites, and comets; observational evidence on the time history of volatile transfer among reservoirs; and volatiles in planetary bodies, their mechanisms of transport, and their relation to thermal, chemical, geological and biological evolution are addressed.

  18. Lunar and Planetary Science XXXV

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The 35th Lunar and Planetary Science Conference covered topics on Mars, planetary origins, planetary analog studies, education,chondrite studies, and meteorite composition. Over 1000 reports were presented at the conference in over 100 sessions. Each session, and presentations,was processed separately for the database.

  19. Environmental Applications of Geochemical Modeling

    NASA Astrophysics Data System (ADS)

    Zhu, Chen; Anderson, Greg

    2002-05-01

    This book discusses the application of geochemical models to environmental practice and studies, through the use of numerous case studies of real-world environmental problems, such as acid mine drainage, pit lake chemistry, nuclear waste disposal, and landfill leachates. In each example the authors clearly define the environmental threat in question; explain how geochemical modeling may help solve the problem posed; and advise the reader how to prepare input files for geochemical modeling codes and interpret the results in terms of meeting regulatory requirements.

  20. Planetary science: A lunar perspective

    NASA Technical Reports Server (NTRS)

    Taylor, S. R.

    1982-01-01

    An interpretative synthesis of current knowledge on the moon and the terrestrial planets is presented, emphasizing the impact of recent lunar research (using Apollo data and samples) on theories of planetary morphology and evolution. Chapters are included on the exploration of the solar system; geology and stratigraphy; meteorite impacts, craters, and multiring basins; planetary surfaces; planetary crusts; basaltic volcanism; planetary interiors; the chemical composition of the planets; the origin and evolution of the moon and planets; and the significance of lunar and planetary exploration. Photographs, drawings, graphs, tables of quantitative data, and a glossary are provided.

  1. Geochemical Evidence for a Terrestrial Magma Ocean

    NASA Technical Reports Server (NTRS)

    Agee, Carl B.

    1999-01-01

    The aftermath of phase separation and crystal-liquid fractionation in a magma ocean should leave a planet geochemically differentiated. Subsequent convective and other mixing processes may operate over time to obscure geochemical evidence of magma ocean differentiation. On the other hand, core formation is probably the most permanent, irreversible part of planetary differentiation. Hence the geochemical traces of core separation should be the most distinct remnants left behind in the mantle and crust, In the case of the Earth, core formation apparently coincided with a magma ocean that extended to a depth of approximately 1000 km. Evidence for this is found in high pressure element partitioning behavior of Ni and Co between liquid silicate and liquid iron alloy, and with the Ni-Co ratio and the abundance of Ni and Co in the Earth's upper mantle. A terrestrial magma ocean with a depth of 1000 km will solidify from the bottom up and first crystallize in the perovskite stability field. The largest effect of perovskite fractionation on major element distribution is to decrease the Si-Mg ratio in the silicate liquid and increase the Si-Mg ratio in the crystalline cumulate. Therefore, if a magma ocean with perovskite fractionation existed, then one could expect to observe an upper mantle with a lower than chondritic Si-Mg ratio. This is indeed observed in modern upper mantle peridotites. Although more experimental work is needed to fully understand the high-pressure behavior of trace element partitioning, it is likely that Hf is more compatible than Lu in perovskite-silicate liquid pairs. Thus, perovskite fractionation produces a molten mantle with a higher than chondritic Lu-Hf ratio. Arndt and Blichert-Toft measured Hf isotope compositions of Barberton komatiites that seem to require a source region with a long-lived, high Lu-Hf ratio. It is plausible that that these Barberton komatiites were generated within the majorite stability field by remelting a perovskite

  2. Planetary evolution and habitability

    NASA Astrophysics Data System (ADS)

    Spohn, T.

    2008-09-01

    Planetary habitability is usually thought to require water on (or near) the surface, a magnetic field to protect life against cosmic radiation, and transport mechanisms for nutrients. A magnetic field also serves to protect an existing atmosphere against erosion by the solar wind and thus helps to stabilize the presence of water and habitability. Magnetic fields are generated in the cores of the terrestrial planets and thus habitability is linked to the evolution of the interior. Moreover, the interior is a potential source and sink for water and CO2 and may interact with the surface and atmosphere reservoirs through volcanic activity and recycling. On the Earth, water is stabilized by complex interactions between the atmosphere, the biosphere, the oceans, the crust, and the deep interior. On geological timescales, the anorganic CO2 cycle is most important. The most efficient known mechanism for recycling is plate tectonics. Plate tectonics is known to operate, at present, only on the Earth, although Mars may have had a phase of plate tectonics as may have Venus. Single-plate tectonics associated with stagnant lid convection can transfer water and CO2 from the interior but a simple recycling mechanism is lacking for this tectonic style. Stagnant lid convection will evolve to thicken the lid and increasingly frustrate volcanic activity and degassing. (This can keep the interior from running completely dry.) Plate tectonics supports the generation of magnetic fields by effectively cooling the deep interior. In addition, plate tectonics rejuvenates nutrients on the surface and generates granitic cratons. For Venus it is likely that a present-day magnetic field would require plate tectonics to operate. The chemistry of the Martian core likely precludes the growth of an inner core and thus a present-day dynamo. An early field is possible for both planets even with stagnant lid convection but the dynamos will have operated less than about a billion years on Mars and a

  3. The role of biology in planetary evolution: cyanobacterial primary production in low-oxygen Proterozoic oceans.

    PubMed

    Hamilton, Trinity L; Bryant, Donald A; Macalady, Jennifer L

    2016-02-01

    Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well-preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and membrane-derived hydrocarbon molecules that are still challenging to interpret. However, it is clear from the sulfur isotope record and other geochemical proxies that the production of oxygen or oxidizing power radically changed Earth's surface and atmosphere during the Proterozoic Eon, pushing it away from the more reducing conditions prevalent during the Archean. In addition to ancient rocks, our reconstruction of Earth's redox evolution is informed by our knowledge of biogeochemical cycles catalysed by extant biota. The emergence of oxygenic photosynthesis in ancient cyanobacteria represents one of the most impressive microbial innovations in Earth's history, and oxygenic photosynthesis is the largest source of O2 in the atmosphere today. Thus the study of microbial metabolisms and evolution provides an important link between extant biota and the clues from the geologic record. Here, we consider the physiology of cyanobacteria (the only microorganisms capable of oxygenic photosynthesis), their co-occurrence with anoxygenic phototrophs in a variety of environments and their persistence in low-oxygen environments, including in water columns as well as mats, throughout much of Earth's history. We examine insights gained from both the rock record and cyanobacteria presently living in early Earth analogue ecosystems and synthesize current knowledge of these ancient microbial mediators in planetary redox evolution. Our analysis supports the hypothesis that anoxygenic photosynthesis

  4. Robot Manipulator Technologies for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Das, H.; Bao, X.; Bar-Cohen, Y.; Bonitz, R.; Lindemann, R.; Maimone, M.; Nesnas, I.; Voorhees, C.

    1999-01-01

    NASA exploration missions to Mars, initiated by the Mars Pathfinder mission in July 1997, will continue over the next decade. The missions require challenging innovations in robot design and improvements in autonomy to meet ambitious objectives under tight budget and time constraints. The authors are developing design tools, component technologies and capabilities to address these needs for manipulation with robots for planetary exploration. The specific developments are: 1) a software analysis tool to reduce robot design iteration cycles and optimize on design solutions, 2) new piezoelectric ultrasonic motors (USM) for light-weight and high torque actuation in planetary environments, 3) use of advanced materials and structures for strong and light-weight robot arms and 4) intelligent camera-image coordinated autonomous control of robot arms for instrument placement and sample acquisition from a rover vehicle.

  5. Planetary tides during the Maunder Sunspot Minimum

    NASA Technical Reports Server (NTRS)

    Smythe, C. M.; Eddy, J. A.

    1977-01-01

    In order to test the tidal theory of sunspots, sun-centered planetary conjunctions and tidal potentials are reconstructed for the period of the Maunder Minimum (1645 to 1715). These are found to be effectively indistinguishable from patterns of conjunctions and power spectra of tidal potential in the modern era of a well-established 11-yr sunspot cycle. The pattern of planetary tidal forces during the Maunder Minimum is then reconstructed to investigate the possibility that multiple-planet forces were somehow fortuituously cancelled at that time; i.e., the positions of the slower moving planets in the late 17th and early 18th centuries were such that conjunctions and tidal potentials were reduced in number and force. Calculations of daily positions for Mercury, Venus, earth, and Jupiter as well as daily values of the tidal potential for the period from 1450 to 2000 indicate no striking dissimilarities between the time of the Maunder Minimum and any other period considered.

  6. Forming different planetary systems

    NASA Astrophysics Data System (ADS)

    Zhou, Ji-Lin; Xie, Ji-Wei; Liu, Hui-Gen; Zhang, Hui; Sun, Yi-Sui

    2012-08-01

    With the increasing number of detected exoplanet samples, the statistical properties of planetary systems have become much clearer. In this review, we summarize the major statistical results that have been revealed mainly by radial velocity and transiting observations, and try to interpret them within the scope of the classical core-accretion scenario of planet formation, especially in the formation of different orbital architectures for planetary systems around main sequence stars. Based on the different possible formation routes for different planet systems, we tentatively classify them into three major catalogs: hot Jupiter systems, standard systems and distant giant planet systems. The standard system can be further categorized into three sub-types under different circumstances: solar-like systems, hot Super-Earth systems, and subgiant planet systems. We also review the theory of planet detection and formation in binary systems as well as planets in star clusters.

  7. Survival of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Ward, William R.

    1996-06-01

    Recent low frequency results from attempts to detect Jupiter-sized planets around nearby stars have raised a question as to whether such objects are all that common. In the over 200 stars observed so far, the yield has been 3%. And, the close orbit (0.05 AU) of the nearly Jupiter-sized object around Peg 51 places the object in an environment where the current paradigm of planetary formation would not predict planets to form at all. Other newly discovered candidates, such a Vir 70 and HR3522, also have suspiciously small semi-major axes for gas giants. Of course, the low yield may be strongly influenced by selection effects since massive planets close to their primaries are more easily detected. Nevertheless, given the results to date, it is natural to wonder whether a planetary system like ours is such a natural outgrowth of a circumplantary disk. In particular, could there be forces absent from the existing paradigm that tend to destroy a planetary system once formed? We point out that strong gravitational interactions (i.e., disk tides) between a newly formed protoplanet and its precursor disk give rise to a net torque that drains angular momentum from the protoplanet's orbit. As a result, protoplanetary objects suffer orbital decay as the disk attempts to destroy the very system it spawns. Strong interaction (type I) leads to gap formation and co-evolution with the disk; weak inter- action (type II) leads to drift relative to the disk and in some cases, a much more rapid decay. Survival of a planetary system may be a comparatively uncommon outcome. Newly discovered planets such as Peg 51b may be evidence of such large-scale orbit migration due to disk tidal torques (i.e., Lin et al., 1996).

  8. Planetary seismology and interiors

    NASA Technical Reports Server (NTRS)

    Toksoz, M. N.

    1979-01-01

    This report briefly summarizes knowledge gained in the area of planetary seismology in the period 1969-1979. Attention is given to the seismic instruments, the seismic environment (noise, characteristics of seismic wave propagation, etc.), and the seismicity of the moon and Mars as determined by the Apollo missions and Viking Lander experiments, respectively. The models of internal structures of the terrestrial planets are discussed, with the earth used for reference.

  9. NASA Planetary Rover Program

    NASA Technical Reports Server (NTRS)

    Lavery, David; Bedard, Roger J., Jr.

    1991-01-01

    The NASA Planetary Rover Project was initiated in 1989. The emphasis of the work to date has been on development of autonomous navigation technology within the context of a high mobility wheeled vehicle at the JPL and an innovative legged locomotion concept at Carnegie Mellon University. The status and accomplishments of these two efforts are discussed. First, however, background information is given on the three rover types required for the Space Exploration Initiative (SEI) whose objective is a manned mission to Mars.

  10. Galactic planetary science.

    PubMed

    Tinetti, Giovanna

    2014-04-28

    Planetary science beyond the boundaries of our Solar System is today in its infancy. Until a couple of decades ago, the detailed investigation of the planetary properties was restricted to objects orbiting inside the Kuiper Belt. Today, we cannot ignore that the number of known planets has increased by two orders of magnitude nor that these planets resemble anything but the objects present in our own Solar System. Whether this fact is the result of a selection bias induced by the kind of techniques used to discover new planets--mainly radial velocity and transit--or simply the proof that the Solar System is a rarity in the Milky Way, we do not know yet. What is clear, though, is that the Solar System has failed to be the paradigm not only in our Galaxy but even 'just' in the solar neighbourhood. This finding, although unsettling, forces us to reconsider our knowledge of planets under a different light and perhaps question a few of the theoretical pillars on which we base our current 'understanding'. The next decade will be critical to advance in what we should perhaps call Galactic planetary science. In this paper, I review highlights and pitfalls of our current knowledge of this topic and elaborate on how this knowledge might arguably evolve in the next decade. More critically, I identify what should be the mandatory scientific and technical steps to be taken in this fascinating journey of remote exploration of planets in our Galaxy. PMID:24664916

  11. Planetary System Physics

    NASA Technical Reports Server (NTRS)

    Peale, S. J.

    2002-01-01

    Contents include a summary of publications followed by their abstracts titeled: 1. On microlensing rates and optical depth toward the Galactic center. 2. Newly discovered brown dwarfs not seen in microlensing timescale frequency distribution? 3. Origin and evolution of the natural satellites. 4. Probing the structure of the galaxy with microlensing. 5. Tides, Encyclopedia of Astronomy and Astrophysics. 6. The Puzzle of the Titan-Hyperion 4:3 Orbital Resonance. 7. On the Validity of the Coagulation Equation and the Nature of Runaway Growth. 8. Making Hyperion. 9. The MESSENGER mission to Mercury: Scientific objectives and implementation. 10. A Survey of Numerical Solutions to the Coagulation. 11. Probability of detecting a planetary companion during a microlensing event. 12. Dynamics and origin of the 2:l orbital resonances of the GJ876 planets. 13. Planetary Interior Structure Revealed by Spin Dynamics. 14. A primordial origin of the Laplace relation among the Galilean Satellites. 15. A procedure for determining the nature of Mercury's core. 16. Secular evolution of hierarchical planetary systems. 17. Tidally induced volcanism. 18. Extrasolar planets and mean motion resonances. 19. Comparison of a ground-based microlensing search for planets with a search from space.

  12. Galactic planetary science

    PubMed Central

    Tinetti, Giovanna

    2014-01-01

    Planetary science beyond the boundaries of our Solar System is today in its infancy. Until a couple of decades ago, the detailed investigation of the planetary properties was restricted to objects orbiting inside the Kuiper Belt. Today, we cannot ignore that the number of known planets has increased by two orders of magnitude nor that these planets resemble anything but the objects present in our own Solar System. Whether this fact is the result of a selection bias induced by the kind of techniques used to discover new planets—mainly radial velocity and transit—or simply the proof that the Solar System is a rarity in the Milky Way, we do not know yet. What is clear, though, is that the Solar System has failed to be the paradigm not only in our Galaxy but even ‘just’ in the solar neighbourhood. This finding, although unsettling, forces us to reconsider our knowledge of planets under a different light and perhaps question a few of the theoretical pillars on which we base our current ‘understanding’. The next decade will be critical to advance in what we should perhaps call Galactic planetary science. In this paper, I review highlights and pitfalls of our current knowledge of this topic and elaborate on how this knowledge might arguably evolve in the next decade. More critically, I identify what should be the mandatory scientific and technical steps to be taken in this fascinating journey of remote exploration of planets in our Galaxy. PMID:24664916

  13. Planetary polarization nephelometer

    NASA Astrophysics Data System (ADS)

    Banfield, D.; Dissly, R.; Mishchenko, M.; Muñoz, O.; Roos-Serote, M.; Stam, D.; Volten, H.

    2004-02-01

    We have proposed to develop a polarization nephelometer for use on future planetary descent probes. It will measure both the scattered intensity and polarization phase functions of the aerosols it encounters descending through an atmosphere. These measurements will be taken at two wavelengths separated by about an octave, with one light source near 500nm and another near 1μm. Adding polarization measurements to the intensity phase functions greatly increases our ability to constrain the size distribution, shape and chemical composition of the sampled particles. There remain important questions about these parameters of the aerosols on Venus, the giant planets and Titan that can only be addressed with a nephelometer like ours. The NRC Planetary Sciences Decadal Survey has identified probe missions to Venus and Jupiter as a priority. On both of these missions, our proposed instrument would be an excellent candidate for flight. We also expect that future probe missions to Saturn, Uranus, Neptune or Titan would employ our instrument. It could also find use in Earth in situ aerosol studies. We will use a technique to simultaneously measure intensity and polarization phase functions that uses polarization modulation of a light source. This technique has been implemented in laboratory settings, but not with considerations to the environment on a planetary descent probe. We have proposed to design and build a flexible breadboard nephelometer to test the components and concepts of our approach. We would then test the device against well defined aerosols, ensuring that it accurately measures their expected intensity and polarization phase functions. With the knowledge gained in this flexible design, we would then design and build a breadboard polarization nephelometer more suited to integration on a planetary descent probe. To include traceability in the technical requirements of our device, we would also conduct an Observing System Simulation Experiment. In this study, we

  14. Dust and Planetary Rings

    NASA Astrophysics Data System (ADS)

    Siddiqui, Muddassir

    ABSTRACT Space is not empty it has comic radiations (CMBR), dust etc. Cosmic dust is that type of dust which is composed of particles in space which vary from few molecules to 0.1micro metres in size. This type of dust is made up of heavier atoms born in the heart of stars and supernova. Mainly it contains dust grains and when these dust grains starts compacting then it turns to dense clouds, planetary ring dust and circumstellar dust. Dust grains are mainly silicate particles. Dust plays a major role in our solar system, for example in zodiacal light, Saturn's B ring spokes, planetary rings at Jovian planets and comets. Observations and measurements of cosmic dust in different regions of universe provide an important insight into the Universe's recycling processes. Astronomers consider dust in its most recycled state. Cosmic dust have radiative properties by which they can be detected. Cosmic dusts are classified as intergalactic dusts, interstellar dusts and planetary rings. A planetary ring is a ring of cosmic dust and other small particles orbiting around a planet in flat disc shape. All of the Jovian planets in our solar system have rings. But the most notable one is the Saturn's ring which is the brightest one. In March 2008 a report suggested that the Saturn's moon Rhea may have its own tenuous ring system. The ring swirling around Saturn consists of chunks of ice and dust. Most rings were thought to be unstable and to dissipate over course of tens or hundreds of millions of years but it now appears that Saturn's rings might be older than that. The dust particles in the ring collide with each other and are subjected to forces other than gravity of its own planet. Such collisions and extra forces tend to spread out the rings. Pluto is not known to have any ring system but some Astronomers believe that New Horizons probe might find a ring system when it visits in 2015.It is also predicted that Phobos, a moon of Mars will break up and form into a planetary ring

  15. Cosmological Effects in Planetary Science

    NASA Technical Reports Server (NTRS)

    Blume, H. J.; Wilson, T. L.

    2010-01-01

    In an earlier discussion of the planetary flyby anomaly, a preliminary assessment of cosmological effects upon planetary orbits exhibiting the flyby anomaly was made. A more comprehensive investigation has since been published, although it was directed at the Pioneer anomaly and possible effects of universal rotation. The general subject of Solar System anomalies will be examined here from the point of view of planetary science.

  16. Universal planetary tectonics (supertectonics)

    NASA Astrophysics Data System (ADS)

    Kochemasov, G. G.

    2009-04-01

    Universal planetary tectonics (supertectonics) G. Kochemasov IGEM of the Russian Academy of Sciences, Moscow, Russia, kochem.36@mail.ru The wave planetology [1-3 & others] proceeds from the following: "planetary structures are made by orbits and rotations". A uniform reason makes uniform structures. Inertia-gravity waves arising in planetary bodies due to their movements in Keplerian elliptical orbits with periodically changing accelerations warp these bodies in such way that they acquire polyhedron shapes (after interference of standing waves of four directions). Strong Newtonian gravity makes bodies larger than ~400 to 500 km in diameter globular and polyhedra are rarely seen. Only geomorphologic, geologic and geophysical mapping can develop these hidden structures. But small bodies, normally less than ~ 300 to 400 km in diameter, often show parts of the polyhedra, rarely fully developed forms (the asteroid Steins and satellite Amalthea present rather perfect forms of "diamond"). Depending on warping wavelengths (they make harmonics) various Plato's figures superimposed on each other can be distinguished. The fundamental wave 1 produces a tetrahedron, intrinsically dichotomic figure in which a vertex (contraction) always is opposed to a face (expansion). From the recent examples the best is the saturnian northern hexagon (a face) opposed to the southern hurricane (a vertex). The first overtone wave 2 is responsible for creation of structural octahedra. Whole ‘diamonds" and their parts are known [4, 5]. Other overtones produce less developed (because of smaller wave amplitudes) planetary shapes complicating main forms. Thus, the first common structural peculiarity of planetary bodies is their polyhedron nature. Not less important is the second common structural peculiarity. As all globular or smaller more or less isometric bodies rotate, they have an angular momentum. It is inevitably different in tropic and extra-tropic belts having uneven radii or distances to

  17. Planetary rover technology development requirements

    NASA Technical Reports Server (NTRS)

    Bedard, Roger J., Jr.; Muirhead, Brian K.; Montemerlo, Melvin D.; Hirschbein, Murray S.

    1989-01-01

    Planetary surface (including lunar) mobility and sampling capability is required to support proposed future National Aeronautics and Space Administration (NASA) solar system exploration missions. The NASA Office of Aeronautics and Space Technology (OAST) is addressing some of these technology needs in its base research and development program, the Civil Space Technology Initiative (CSTI) and a new technology initiative entitled Pathfinder. The Pathfinder Planetary Rover (PPR) and Sample Acquisition, Analysis and Preservation (SAAP) programs will develop and validate the technologies needed to enable both robotic and piloted rovers on various planetary surfaces. The technology requirements for a planetary roving vehicle and the development plans of the PPR and SAAP programs are discussed.

  18. Planetary cratering mechanics

    NASA Technical Reports Server (NTRS)

    Okeefe, John D.; Ahrens, Thomas J.

    1992-01-01

    To obtain a quantitative understanding of the cratering process over a broad range of conditions, we have numerically computed the evolution of impact induced flow fields and calculated the time histories of the major measures of crater geometry (e.g., depth diameter, lip height ...) for variations in planetary gravity (0 to 10 exp 9 cm/sq seconds), material strength (0 to 140 kbar), thermodynamic properties, and impactor radius (0.05 to 5000 km). These results were fit into the framework of the scaling relations of Holsapple and Schmidt (1987). We describe the impact process in terms of four regimes: (1) penetration; (2) inertial; (3) terminal; and (4) relaxation.

  19. Robotic Planetary Drill Tests

    NASA Technical Reports Server (NTRS)

    Glass, Brian J.; Thompson, S.; Paulsen, G.

    2010-01-01

    Several proposed or planned planetary science missions to Mars and other Solar System bodies over the next decade require subsurface access by drilling. This paper discusses the problems of remote robotic drilling, an automation and control architecture based loosely on observed human behaviors in drilling on Earth, and an overview of robotic drilling field test results using this architecture since 2005. Both rotary-drag and rotary-percussive drills are targeted. A hybrid diagnostic approach incorporates heuristics, model-based reasoning and vibration monitoring with neural nets. Ongoing work leads to flight-ready drilling software.

  20. Planetary submillimeter spectroscopy

    NASA Technical Reports Server (NTRS)

    Klein, M. J.

    1988-01-01

    The aim is to develop a comprehensive observational and analytical program to study solar system physics and meterology by measuring molecular lines in the millimeter and submillimeter spectra of planets and comets. A primary objective is to conduct observations with new JPL and Caltech submillimeter receivers at the Caltech Submillimeter Observatory (CSO) on Mauna Kea, Hawaii. A secondary objective is to continue to monitor the time variable planetary phenomena (e.g., Jupiter and Uranus) at centimeter wavelength using the NASA antennas of the Deep Space Network (DSN).

  1. Planetary Spatial Analyst

    NASA Technical Reports Server (NTRS)

    Keely, Leslie

    2008-01-01

    This is a status report for the project entitled Planetary Spatial Analyst (PSA). This report covers activities from the project inception on October 1, 2007 to June 1, 2008. Originally a three year proposal, PSA was awarded funding for one year and required a revised work statement and budget. At the time of this writing the project is well on track both for completion of work as well as budget. The revised project focused on two objectives: build a solid connection with the target community and implement a prototype software application that provides 3D visualization and spatial analysis technologies for that community. Progress has been made for both of these objectives.

  2. Planetary entry experiments

    NASA Technical Reports Server (NTRS)

    Craig, Roger A.

    1994-01-01

    The final report summarizes the results from three research areas: (1) window design for the radiometric measurement of the forebody radiative heating experienced by atmospheric entry spaceraft; (2) survey of the current understanding of chemical species on selected solar system bodies and assess the importance of measurements with regard to vehicle environment and with regard to understanding of planetary atmospheres with emphasis on Venus, Mars, and Titan; and (3) measure and analyze the radiation (VUV to near-IR) from the shock heated gas cap of a blunt body in an Ames arc Jet wind-tunnel facility.

  3. Misclassified planetary nebulae

    NASA Astrophysics Data System (ADS)

    Sabbadin, F.

    1986-08-01

    The classifications of 130 objects as planetary nebulae (PNs) in the catalogs of Kohoutek (1965, 1969, and 1972) are reexamined by analyzing their images on the IR (755-885-nm) and red (610-690-nm) plates of the NIR photographic survey of the Galactic plane of Hoessel et al. (1985). Factors affecting the IR and red brightness of normal stars and emission-line objects are discussed, and it is shown that PNs should be brighter in the red than in the IR. Thirty-six supposed PNs for which this is not the case are identified, and it is suggested that they have been improperly classified.

  4. Dynamics of planetary rings

    NASA Astrophysics Data System (ADS)

    Araki, S.

    1991-02-01

    The modeling of the dynamics of particle collisions within planetary rings is discussed. Particles in the rings collide with one another because they have small random motions in addition to their orbital velocity. The orbital speed is roughly 10 km/s, while the random motions have an average speed of about a tenth of a millimeter per second. As a result, the particle collisions are very gentle. Numerical analysis and simulation of the ring dynamics, performed with the aid of a supercomputer, is outlined.

  5. Disequilibration by Planetary Collision

    NASA Astrophysics Data System (ADS)

    Asphaug, E. I.; Jutzi, M.

    2010-12-01

    Molten planets equilibrate gravitationally, chemically, and thermally. Large scale collisions (a.k.a. giant impacts, similar-sized collisions) can upset the apple cart by bringing core material, late in the game, into mixture with mantle products, and by shredding stratified planets into strands of mantle and clumps of core (c.g. Asphaug et al. Nature 2006). Atmophiles and volatiles come along for the ride, and can find themselves in disequilibrium mixtures not anticipated by one-dimensional models of planetary evolution, or by planet growth models in which planets stick, merge, and mix perfectly in the aftermath of a collision. We present very high resolution case studies of such collisions.

  6. Leveraging Knowledge: Impact on Low Cost Planetary Mission Design.

    ERIC Educational Resources Information Center

    Momjian, Jennifer

    This paper discusses innovations developed by the Jet Propulsion Laboratory (JPL) librarians to reduce the information query cycle time for teams planning low-cost, planetary missions. The first section provides background on JPL and its library. The second section addresses the virtual information environment, including issues of access, content,…

  7. Geochemical evidence for active tropical serpentinization in the Santa Elena Ophiolite, Costa Rica: An analog of a humid early Earth?

    NASA Astrophysics Data System (ADS)

    Sánchez-Murillo, Ricardo; Gazel, Esteban; Schwarzenbach, Esther M.; Crespo-Medina, Melitza; Schrenk, Matthew O.; Boll, Jan; Gill, Ben C.

    2014-05-01

    is a planetary process that has important consequences on geochemical cycles, supporting microbial activity through the formation of H2 and CH4 and having the potential to sequester atmospheric CO2. We present geochemical evidence of active serpentinization in the Santa Elena Ophiolite, Costa Rica which is sustained by peridotites with a degree of serpentinization less than 50% with no evidence of an internal heat source. Average spring water temperatures are 29.1°C. Two hyperalkaline spring systems were discovered, with a spring fluid pH up to 11.18. The fluids are characterized by low Mg (1.0-5.9 mg/L) and K (1.0-5.5 mg/L) and relative high Ca (29-167 mg/L), Na (16-27 mg/L), Cl (26-29 mg/L), hydroxide (41-63 mg/L), and carbonate (31-49 mg/L). Active CH4 (24.3% v/v) vents coupled with carbonate deposits (δ13CCO2 =-27 to -14‰; δ18OCO2 =-17 to - 6‰) also provide evidence for active serpentinization and carbonation. Isotope ratios of the alkaline fluids (δ18O = -7.9‰, δ2H = -51.4‰) and groundwater (δ18O = -7.6‰; δ2H = -48.0‰) suggests that, during base flow recession, springs are fed by groundwater circulation. Methanogenic Archaea, which comprises a relatively high percentage of the 16S rRNA gene tag sequences, suggests that biological methanogenesis may play a significant role in the system. Santa Elena's extreme varying weather results in a scenario that could be of significant importance for (a) improving the knowledge of conditions on a humid early Earth or Mars that had periodic changes in water supply, (b) revealing new insights on serpentinizing solute transport, and (c) modeling hydrogeochemical responses as a function of recharge.

  8. Evaluating Handheld X-Ray Fluorescence (XRF) Technology in Planetary Exploration: Demonstrating Instrument Stability and Understanding Analytical Constraints and Limits for Basaltic Rocks

    NASA Technical Reports Server (NTRS)

    Young, K. E.; Hodges, K. V.; Evans, C. A.

    2012-01-01

    While large-footprint X-ray fluorescence (XRF) instruments are reliable providers of elemental information about geologic samples, handheld XRF instruments are currently being developed that enable the collection of geochemical data in the field in short time periods (approx.60 seconds) [1]. These detectors are lightweight (1.3kg) and can provide elemental abundances of major rock forming elements heavier than Na. While handheld XRF detectors were originally developed for use in mining, we are working with commercially available instruments as prototypes to explore how portable XRF technology may enable planetary field science [2,3,4]. If an astronaut or robotic explorer visited another planetary surface, the ability to obtain and evaluate geochemical data in real-time would be invaluable, especially in the high-grading of samples to determine which should be returned to Earth. We present our results on the evaluation of handheld XRF technology as a geochemical tool in the context of planetary exploration.

  9. Chemical kinetics and modeling of planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Yung, Yuk L.

    1990-01-01

    A unified overview is presented for chemical kinetics and chemical modeling in planetary atmospheres. The recent major advances in the understanding of the chemistry of the terrestrial atmosphere make the study of planets more interesting and relevant. A deeper understanding suggests that the important chemical cycles have a universal character that connects the different planets and ultimately link together the origin and evolution of the solar system. The completeness (or incompleteness) of the data base for chemical kinetics in planetary atmospheres will always be judged by comparison with that for the terrestrial atmosphere. In the latter case, the chemistry of H, O, N, and Cl species is well understood. S chemistry is poorly understood. In the atmospheres of Jovian planets and Titan, the C-H chemistry of simple species (containing 2 or less C atoms) is fairly well understood. The chemistry of higher hydrocarbons and the C-N, P-N chemistry is much less understood. In the atmosphere of Venus, the dominant chemistry is that of chlorine and sulfur, and very little is known about C1-S coupled chemistry. A new frontier for chemical kinetics both in the Earth and planetary atmospheres is the study of heterogeneous reactions. The formation of the ozone hole on Earth, the ubiquitous photochemical haze on Venus and in the Jovian planets and Titan all testify to the importance of heterogeneous reactions. It remains a challenge to connect the gas phase chemistry to the production of aerosols.

  10. The final fate of planetary systems

    NASA Astrophysics Data System (ADS)

    Gaensicke, Boris

    2015-12-01

    The discovery of the first extra-solar planet around a main-sequence star in 1995 has changed the way we think about the Universe: our solar system is not unique. Twenty years later, we know that planetary systems are ubiquitous, orbit stars spanning a wide range in mass, and form in an astonishing variety of architectures. Yet, one fascinating aspect of planetary systems has received relatively little attention so far: their ultimate fate.Most planet hosts will eventually evolve into white dwarfs, Earth-sized stellar embers, and the outer parts of their planetary systems (in the solar system, Mars and beyond) can survive largely intact for billions of years. While scattered and tidally disrupted planetesimals are directly detected at a small number of white dwarfs in the form infrared excess, the most powerful probe for detecting evolved planetary systems is metal pollution of the otherwise pristine H/He atmospheres.I will present the results of a multi-cycle HST survey that has obtained COS observations of 136 white dwarfs. These ultraviolet spectra are exquisitely sensitive to the presence of metals contaminating the white atmosphere. Our sophisticated model atmosphere analysis demonstrates that at least 27% of all targets are currently accreting planetary debris, and an additional 29% have very likely done so in the past. These numbers suggest that planet formation around A-stars (the dominant progenitors of today's white dwarf population) is similarly efficient as around FGK stars.In addition to post-main sequence planetary system demographics, spectroscopy of the debris-polluted white dwarf atmospheres provides a direct window into the bulk composition of exo-planetesimals, analogous to the way we use of meteorites to determine solar-system abundances. Our ultraviolet spectroscopy is particularly sensitive to the detection of Si, a dominant rock-forming species, and we identify up to ten additional volatile and refractory elements in the most strongly

  11. Planetary image conversion task

    NASA Technical Reports Server (NTRS)

    Martin, M. D.; Stanley, C. L.; Laughlin, G.

    1985-01-01

    The Planetary Image Conversion Task group processed 12,500 magnetic tapes containing raw imaging data from JPL planetary missions and produced an image data base in consistent format on 1200 fully packed 6250-bpi tapes. The output tapes will remain at JPL. A copy of the entire tape set was delivered to US Geological Survey, Flagstaff, Ariz. A secondary task converted computer datalogs, which had been stored in project specific MARK IV File Management System data types and structures, to flat-file, text format that is processable on any modern computer system. The conversion processing took place at JPL's Image Processing Laboratory on an IBM 370-158 with existing software modified slightly to meet the needs of the conversion task. More than 99% of the original digital image data was successfully recovered by the conversion task. However, processing data tapes recorded before 1975 was destructive. This discovery is of critical importance to facilities responsible for maintaining digital archives since normal periodic random sampling techniques would be unlikely to detect this phenomenon, and entire data sets could be wiped out in the act of generating seemingly positive sampling results. Reccomended follow-on activities are also included.

  12. Planetary Ringmoon Systems

    NASA Technical Reports Server (NTRS)

    Cuzzi, J. N.; Morrison, David (Technical Monitor)

    1994-01-01

    The last decade has seen an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Much of the structure revealed was thoroughly puzzling and fired the imagination of workers in a variety of disciplines. Consequently, we have also seen steady progress in our understanding of these systems as our intuitions (and our computers) catch up with the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron to-several-meter size particles which comprise ring systems (refs 1-5). The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems and families of regular satellites are invariably found together, and there is an emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system.

  13. Young Planetary disks

    NASA Astrophysics Data System (ADS)

    Lecavelier Des Etangs, A.

    2007-07-01

    The present review focuses on UV observations of young planetary disks and consequently mostly on the gaseous content of those disks. Few examples are taken to illustrate the capability of the UV observatories to scrutinize in detail the gas content of low density circumstellar disks if they are seen edge-on or nearly edge-on. For instance, in the case of HD100546, FUSE observations re- vealed signatures of outflow and infall in the disk caused by interaction of the stellar magnetosphere with the circumstellar disk. Observations of numerous absorption lines from H2 around young stars give constrains on the gas temper- ature and density, and physical size of the absorbing layer. In the case of T-Tauri stars and one brown dwarf, emissions from exited H2 have been detected. In the case of Beta Pictoris, the observation of CO in the UV and search for H2 with FUSE demonstrated that the evaporation of frozen bodies like comets must produce the CO seen in the disk. Extensive observations of spectral variability of Beta Pictoris are now interpreted by extrasolar comets evaporating in the vicinity of the central star of this young planetary system.

  14. Planetary radar astronomy

    NASA Astrophysics Data System (ADS)

    Ostro, S. J.

    1983-03-01

    The present investigation is concerned with planetary radar research reported during the time from 1979 to 1982. A brief synopsis of radar definitions and technical terminology is also provided. In connection with the proximity of the moon to earth, lunar radar studies have been performed over a wider range of wavelengths than radar investigations of other planetary targets. The most recent study of lunar quasispecular scattering is due to Simpson and Tyler (1982). The latest efforts to interpret the lunar radar maps focus on maria-highlands regolith differences and models of crater ejecta evolution. The highly successful Pioneer Venus Radar Mapper experiment has provided a first look at Venus' global distributions of topography, lambda 17-cm radar reflectivity, and rms surface slopes. Attention is given to recent comparisons of Viking Orbiter images of Mars to groundbased radar altimetry of the planet, the icy Galilean satellites, radar observations of asteroids and comets, and lambda 4-cm and lambda 13-cm observations of Saturn's rings.

  15. Online Planetary Science Courses at Athabasca University

    NASA Astrophysics Data System (ADS)

    Connors, Martin; Munyikwa, Ken; Bredeson, Christy

    2016-01-01

    Athabasca University offers distance education courses in science, at freshman and higher levels. It has a number of geology and astronomy courses, and recently opened a planetary science course as the first upper division astronomy course after many years of offering freshman astronomy. Astronomy 310, Planetary Science, focuses on process in the Solar System on bodies other than Earth. This process-oriented course uses W. F. Hartmann's "Moons and Planets" as its textbook. It primarily approaches the subject from an astronomy and physics perspective. Geology 415, Earth's Origin and Early Evolution, is based on the same textbook, but explores the evidence for the various processes, events, and materials involved in the formation and evolution of Earth. The course provides an overview of objects in the Solar System, including the Sun, the planets, asteroids, comets, and meteoroids. Earth's place in the solar system is examined and physical laws that govern the motion of objects in the universe are looked at. Various geochemical tools and techniques used by geologists to reveal and interpret the evidence for the formation and evolution of bodies in the solar system as well as the age of earth are also explored. After looking at lines of evidence used to reconstruct the evolution of the solar system, processes involved in the formation of planets and stars are examined. The course concludes with a look at the origin and nature of Earth's internal structure. GEOL415 is a senior undergraduate course and enrols about 15-30 students annually. The courses are delivered online via Moodle and student evaluation is conducted through assignments and invigilated examinations.

  16. Fourier spectroscopy and planetary research

    NASA Technical Reports Server (NTRS)

    Hanel, R. A.; Kunde, V. G.

    1974-01-01

    The application of Fourier Transform Spectroscopy (FTS) to planetary research is reviewed. The survey includes FTS observations of the sun, all the planets except Uranus and Pluto, the Galilean satellites and Saturn's rings. Instrumentation and scientific results are considered and the prospects and limitations of FTS for planetary research in the forthcoming years are discussed.

  17. Lunar and Planetary Science XXXIV

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The 34th Lunar and Planetary Science Conference was held March 17-21, 2003. Topics included planetary exploration, crater research on Mars, Earth, Moon, and other planets or satellites, imaging techniques and image analysis, age determination, albedo studies, petrographic studies, isotope composition studies, instrument design, sampling methods, landform analysis, asteroids, impact analysis, impact melts, and related research.

  18. Reports of planetary astronomy, 1991

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A collection is presented of summaries designed to provide information about scientific research projects conducted in the Planetary Astronomy Program in 1990 and 1991, and to facilitate communication and coordination among concerned scientists and interested persons in universities, government, and industry. Highlights of recent accomplishments in planetary astronomy are included.

  19. The Birth of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    1997-01-01

    Models of planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large- enough to gravitationally trap substantial quantities of gas. Another potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed.

  20. Planetary Doppler Imaging

    NASA Astrophysics Data System (ADS)

    Murphy, N.; Jefferies, S.; Hart, M.; Hubbard, W. B.; Showman, A. P.; Hernandez, G.; Rudd, L.

    2014-12-01

    Determining the internal structure of the solar system's gas and ice giant planets is key to understanding their formation and evolution (Hubbard et al., 1999, 2002, Guillot 2005), and in turn the formation and evolution of the solar system. While internal structure can be constrained theoretically, measurements of internal density distributions are needed to uncover the details of the deep interior where significant ambiguities exist. To date the interiors of giant planets have been probed by measuring gravitational moments using spacecraft passing close to, or in orbit around the planet. Gravity measurements are effective in determining structure in the outer envelope of a planet, and also probing dynamics (e.g. the Cassini and Juno missions), but are less effective in probing deep structure or the presence of discrete boundaries. A promising technique for overcoming this limitation is planetary seismology (analogous to helioseismology in the solar case), postulated by Vorontsov, 1976. Using trapped pressure waves to probe giant planet interiors allows insight into the density and temperature distribution (via the sound speed) down to the planetary core, and is also sensitive to sharp boundaries, for example at the molecular to metallic hydrogen transition or at the core-envelope interface. Detecting such boundaries is not only important in understanding the overall structure of the planet, but also has implications for our understanding of the basic properties of matter at extreme pressures. Recent Doppler measurements of Jupiter by Gaulme et al (2011) claimed a promising detection of trapped oscillations, while Hedman and Nicholson (2013) have shown that trapped waves in Saturn cause detectable perturbations in Saturn's C ring. Both these papers have fueled interest in using seismology as a tool for studying the solar system's giant planets. To fully exploit planetary seismology as a tool for understanding giant planet structure, measurements need to be made

  1. Rheology of planetary ices

    SciTech Connect

    Durham, W.B.; Kirby, S.H.; Stern, L.A.

    1996-04-24

    The brittle and ductile rheology of ices of water, ammonia, methane, and other volatiles, in combination with rock particles and each other, have a primary influence of the evolution and ongoing tectonics of icy moons of the outer solar system. Laboratory experiments help constrain the rheology of solar system ices. Standard experimental techniques can be used because the physical conditions under which most solar system ices exist are within reach of conventional rock mechanics testing machines, adapted to the low subsolidus temperatures of the materials in question. The purpose of this review is to summarize the results of a decade-long experimental deformation program and to provide some background in deformation physics in order to lend some appreciation to the application of these measurements to the planetary setting.

  2. Planetary radio lasing

    NASA Technical Reports Server (NTRS)

    Calvert, W.

    1988-01-01

    Both the Earth's auroral kilometric radiation (AKR) and Jupiter's decametric radio S-bursts are attributed to natural radio lasing. Presumably consisting of self-excited, closed-loop wave feedback oscillations between local irregularities of the source plasma density, this radio lasing is comparable to that which occurs in man-made optical lasers, although at radio, rather than optical wavelengths. As a result, it should produce a multiple discrete emission spectrum and intense, coherent beams. Recent observations of the AKR's discreteness and coherence have clearly ruled out the previous open-loop amplifier model for such emissions, and recent observations of the Jovian S-bursts have shown the expected, regularly-spaced, longitudinal laser modes. These new observations thus confirm the proposed planetary cyclotron radio lasing at both planets.

  3. Photochemistry in planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Levine, J. S.; Graedel, T. E.

    1981-01-01

    Widely varying paths of evolutionary history, atmospheric processes, solar fluxes, and temperatures have produced vastly different planetary atmospheres. The similarities and differences between the earth atmosphere and those of the terrestrial planets (Venus and Mars) and of the Jovian planets are discussed in detail; consideration is also given to the photochemistry of Saturn, Uranus, Pluto, Neptune, Titan, and Triton. Changes in the earth's ancient atmosphere are described, and problems of interest in the earth's present troposphere are discussed, including the down wind effect, plume interactions, aerosol nucleation and growth, acid rain, and the fate of terpenes. Temperature fluctuations in the four principal layers of the earth's atmosphere, predicted decreases in the ozone concentration as a function of time, and spectra of particles in the earth's upper atmosphere are also presented. Finally, the vertical structure of the Venus cloud system and the thermal structure of the Jovian planets are shown graphically.

  4. Planetary heat flow measurements.

    PubMed

    Hagermann, Axel

    2005-12-15

    The year 2005 marks the 35th anniversary of the Apollo 13 mission, probably the most successful failure in the history of manned spaceflight. Naturally, Apollo 13's scientific payload is far less known than the spectacular accident and subsequent rescue of its crew. Among other instruments, it carried the first instrument designed to measure the flux of heat on a planetary body other than Earth. The year 2005 also should have marked the launch of the Japanese LUNAR-A mission, and ESA's Rosetta mission is slowly approaching comet Churyumov-Gerasimenko. Both missions carry penetrators to study the heat flow from their target bodies. What is so interesting about planetary heat flow? What can we learn from it and how do we measure it?Not only the Sun, but all planets in the Solar System are essentially heat engines. Various heat sources or heat reservoirs drive intrinsic and surface processes, causing 'dead balls of rock, ice or gas' to evolve dynamically over time, driving convection that powers tectonic processes and spawns magnetic fields. The heat flow constrains models of the thermal evolution of a planet and also its composition because it provides an upper limit for the bulk abundance of radioactive elements. On Earth, the global variation of heat flow also reflects the tectonic activity: heat flow increases towards the young ocean ridges, whereas it is rather low on the old continental shields. It is not surprising that surface heat flow measurements, or even estimates, where performed, contributed greatly to our understanding of what happens inside the planets. In this article, I will review the results and the methods used in past heat flow measurements and speculate on the targets and design of future experiments. PMID:16286290

  5. Reconnection in Planetary Magnetospheres

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    2000-01-01

    Current sheets in planetary magnetospheres that lie between regions of "oppositely-directed" magnetic field are either magnetopause-like, separating plasmas with different properties, or tail-like, separating plasmas of rather similar properties. The magnetopause current sheets generally have a nearly limitless supply of magnetized plasma that can reconnect, possibly setting up steady-state reconnection. In contrast, the plasma on either side of a tail current sheet is stratified so that, as reconnection occurs, the plasma properties, in particular the Alfven velocity, change. If the density drops and the magnetic field increases markedly perpendicular to the sheet, explosive reconnection can occur. Even though steady state reconnection can take place at magnetopause current sheets, the process often appears to be periodic as if a certain low average rate was demanded by the conditions but only a rapid rate was available. Reconnection of sheared fields has been postulated to create magnetic ropes in the solar corona, at the Earth's magnetopause, and in the magnetotail. However, this is not the only way to produce magnetic ropes as the Venus ionosphere shows. The geometry of the reconnecting regions and the plasma conditions both can affect the rate of reconnection. Sorting out the various controlling factors can be assisted through the examination of reconnection in planetary settings. In particular we observe similar small-scale tearing in the magnetopause current layers of the Earth, Saturn. Uranus and Neptune and the magnetodisk current sheet at Jupiter. These sites may be seeds for rapid reconnection if the reconnection site reaches a high Alfven velocity region. In the Jupiter magnetosphere this appears to be achieved with resultant substorm activity. Similar seeds may be present in the Earth's magnetotail with the first one to reach explosive growth dominating the dynamics of the tail.

  6. HUBBLE'S PLANETARY NEBULA GALLERY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [Top left] - IC 3568 lies in the constellation Camelopardalis at a distance of about 9,000 light-years, and has a diameter of about 0.4 light-years (or about 800 times the diameter of our solar system). It is an example of a round planetary nebula. Note the bright inner shell and fainter, smooth, circular outer envelope. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA [Top center] - NGC 6826's eye-like appearance is marred by two sets of blood-red 'fliers' that lie horizontally across the image. The surrounding faint green 'white' of the eye is believed to be gas that made up almost half of the star's mass for most of its life. The hot remnant star (in the center of the green oval) drives a fast wind into older material, forming a hot interior bubble which pushes the older gas ahead of it to form a bright rim. (The star is one of the brightest stars in any planetary.) NGC 6826 is 2,200 light- years away in the constellation Cygnus. The Hubble telescope observation was taken Jan. 27, 1996 with the Wide Field and Planetary Camera 2. Credits: Bruce Balick (University of Washington), Jason Alexander (University of Washington), Arsen Hajian (U.S. Naval Observatory), Yervant Terzian (Cornell University), Mario Perinotto (University of Florence, Italy), Patrizio Patriarchi (Arcetri Observatory, Italy) and NASA [Top right ] - NGC 3918 is in the constellation Centaurus and is about 3,000 light-years from us. Its diameter is about 0.3 light-year. It shows a roughly spherical outer envelope but an elongated inner balloon inflated by a fast wind from the hot central star, which is starting to break out of the spherical envelope at the top and bottom of the image. Credits: Howard Bond (Space Telescope Science Institute), Robin Ciardullo (Pennsylvania State University) and NASA [Bottom left] - Hubble 5 is a striking example of a 'butterfly' or bipolar (two-lobed) nebula. The heat generated by fast winds causes

  7. Physics of planetary rings

    NASA Astrophysics Data System (ADS)

    Gorkavyi, N.

    2007-08-01

    It is difficult to enumerate all the surprises presented by the planetary rings. The Saturnian rings are stratified into thousands of ringlets and the Uranian rings are compressed into narrow streams, which for some reason or other differ from circular orbits like the wheel of an old bicycle. The edge of the rings is jagged and the rings themselves are pegged down under the gravitational pressure of the satellites, bending like a ship's wake. There are spiral waves, elliptical rings, strange interlacing of narrow ringlets, and to cap it all one has observed in the Neptunian ring system three dense, bright arcs - like bunches of sausages on a transparent string. For celestial mechanics this is a spectacle as unnatural as a bear's tooth in the necklace of the English queen. In the dynamics of planetary rings the physics of collective interaction was supplemented by taking collisions between particles into account. One was led to study a kinetic equation with a rather complex collision integral - because the collisions are inelastic - which later on made it possible, both by using the Chapman-Enskog method and by using the solution of the kinetic equation for a plasma in a magnetic field, to reduce it to a closed set of (hydrodynamical) moment equations [1]. The hydrodynamical instabilities lead to the growth of short-wavelength waves and large-scale structures of the Saturnian rings [1]. We have shown that the formation of the existing dense Uranian rings is connected with the capture of positively drifting ring particles in inner Lindblad resonances which arrest this drift [1]. After the formation of dense rings at the positions of satellite resonances the collective interaction between resonant particles is amplified and the rings can leave the resonance and drift away from the planet and the parent resonance. We can expect in the C ring an appreciable positive ballistic particle drift caused by the erosion of the B ring by micrometeorites. It is therefore natural

  8. Planetary habitability: lessons learned from terrestrial analogues

    NASA Astrophysics Data System (ADS)

    Preston, Louisa J.; Dartnell, Lewis R.

    2014-01-01

    Terrestrial analogue studies underpin almost all planetary missions and their use is essential in the exploration of our Solar system and in assessing the habitability of other worlds. Their value relies on the similarity of the analogue to its target, either in terms of their mineralogical or geochemical context, or current physical or chemical environmental conditions. Such analogue sites offer critical ground-truthing for astrobiological studies on the habitability of different environmental parameter sets, the biological mechanisms for survival in extreme environments and the preservation potential and detectability of biosignatures. The 33 analogue sites discussed in this review have been selected on the basis of their congruence to particular extraterrestrial locations. Terrestrial field sites that have been used most often in the literature, as well as some lesser known ones which require greater study, are incorporated to inform on the astrobiological potential of Venus, Mars, Europa, Enceladus and Titan. For example, the possibility of an aerial habitable zone on Venus has been hypothesized based on studies of life at high-altitudes in the terrestrial atmosphere. We also demonstrate why many different terrestrial analogue sites are required to satisfactorily assess the habitability of the changing environmental conditions throughout Martian history, and recommend particular sites for different epochs or potential niches. Finally, habitable zones within the aqueous environments of the icy moons of Europa and Enceladus and potentially in the hydrocarbon lakes of Titan are discussed and suitable analogue sites proposed. It is clear from this review that a number of terrestrial analogue sites can be applied to multiple planetary bodies, thereby increasing their value for astrobiological exploration. For each analogue site considered here, we summarize the pertinent physiochemical environmental features they offer and critically assess the fidelity with which

  9. Planetary Landscape Geography

    NASA Astrophysics Data System (ADS)

    Hargitai, H.

    INTRODUCTION Landscape is one of the most often used category in physical ge- ography. The term "landshap" was introduced by Dutch painters in the 15-16th cen- tury. [1] The elements that build up a landscape (or environment) on Earth consists of natural (biogenic and abiogenic - lithologic, atmospheric, hydrologic) and artificial (antropogenic) factors. Landscape is a complex system of these different elements. The same lithology makes different landscapes under different climatic conditions. If the same conditions are present, the same landscape type will appear. Landscapes build up a hierarchic system and cover the whole surface. On Earth, landscapes can be classified and qualified according to their characteristics: relief forms (morphology), and its potential economic value. Aesthetic and subjective parameters can also be considered. Using the data from landers and data from orbiters we can now classify planetary landscapes (these can be used as geologic mapping units as well). By looking at a unknown landscape, we can determine the processes that created it and its development history. This was the case in the Pathfinder/Sojourner panoramas. [2]. DISCUSSION Planetary landscape evolution. We can draw a raw landscape develop- ment history by adding the different landscape building elements to each other. This has a strong connection with the planet's thermal evolution (age of the planet or the present surface materials) and with orbital parameters (distance from the central star, orbit excentricity etc). This way we can build a complex system in which we use differ- ent evolutional stages of lithologic, atmospheric, hydrologic and biogenic conditions which determine the given - Solar System or exoplanetary - landscape. Landscape elements. "Simple" landscapes can be found on asteroids: no linear horizon is present (not differentiated body, only impact structures), no atmosphere (therefore no atmospheric scattering - black sky as part of the landscape) and no

  10. From Geochemistry to Biochemistry: Simulating Prebiotic Chemistry Driven by Geochemical Gradients in Alkaline Hydrothermal Vents

    NASA Astrophysics Data System (ADS)

    Barge, Laurie

    2016-07-01

    Planetary water-rock interfaces generate energy in the form of redox, pH, and thermal gradients, and these disequilibria are particularly focused in hydrothermal vent systems where the reducing, heated hydrothermal fluid feeds back into the more oxidizing ocean. Alkaline hydrothermal vents have been proposed as a likely location for the origin of life on the early Earth due to various factors: including the hydrothermal pH / Eh gradients that resemble the ubiquitous electrical / proton gradients in biology, the catalytic hydrothermal precipitates that resemble inorganic catalysts in enzymes, and the presence of electron donors and acceptors in hydrothermal systems (e.g. H2 + CH4 and CO2) that are thought to have been utilized in the earliest metabolisms. Of particular importance for the emergence of metabolism are the mineral "chimneys" that precipitate at the vent fluid / seawater interface. Hydrothermal chimneys are flow-through chemical reactors that form porous and permeable inorganic membranes transecting geochemical gradients; in some ways similar to biological membranes that transect proton / ion gradients and harness these disequilibria to drive metabolism. These emergent chimney structures in the far-from-equilibrium system of the alkaline vent have many properties of interest to the origin of life that can be simulated in the laboratory: for example, they can generate electrical energy and drive redox reactions, and produce catalytic minerals (in particular the metal sulfides and iron oxyhydroxides - "green rust") that can facilitate chemical reactions towards proto-metabolic cycles and biosynthesis. Many of the factors prompting interest in alkaline hydrothermal vents on Earth may also have been present on early Mars, or even presently within icy worlds such as Europa or Enceladus - thus, understanding the disequilibria and resulting prebiotic chemistry in these systems can be of great use in assessing the potential for other environments in the Solar

  11. The Automated Planetary Space Station

    NASA Technical Reports Server (NTRS)

    Ivie, C. V.; Friedman, L. D.

    1977-01-01

    Results are presented for a study on mission definition and design to determine broad technology directions and needs for advanced planetary spacecraft and future planetary missions. The discussion covers mission selection, system design, and technology assessment and review for a multicomponent spacecraft exploration facility provided with nuclear power propulsion. As an example, the Automated Planetary Space Station at Jupiter is examined as a generic concept which has the capability of conducting in-depth investigations of different aspects of the entire Jovian system. Mission planning is discussed relative to low-thrust trajectory control, automatic target identification and landing, roving vehicle operation, and automated sample analysis.

  12. Spatial Query for Planetary Data

    NASA Technical Reports Server (NTRS)

    Shams, Khawaja S.; Crockett, Thomas M.; Powell, Mark W.; Joswig, Joseph C.; Fox, Jason M.

    2011-01-01

    Science investigators need to quickly and effectively assess past observations of specific locations on a planetary surface. This innovation involves a location-based search technology that was adapted and applied to planetary science data to support a spatial query capability for mission operations software. High-performance location-based searching requires the use of spatial data structures for database organization. Spatial data structures are designed to organize datasets based on their coordinates in a way that is optimized for location-based retrieval. The particular spatial data structure that was adapted for planetary data search is the R+ tree.

  13. Planetary Geophysics and Tectonics

    NASA Technical Reports Server (NTRS)

    Parmentier, E. M.

    1997-01-01

    Research supported by grant NAGW-1928 has addressed a variety of problems related to planetary evolution. One important focus has been on questions related to the role of chemical buoyancy in planetary evolution with application to both Venus and the Moon. We have developed a model for the evolution of the Moon (Hess and Parmentier, 1995) in which dense, highly radioactive, late stage magma ocean cumulates sink forming a core. This core heats the overlying, chemically layered mantle giving rise to a heated, chemically well-mixed layer that thickens with time. This Mixed layer eventually becomes hot enough and thick enough that its top begins to melt at a pressure low enough that melt is buoyant, thus creating mare basalts from a high pressure source of the correct composition and at an appropriate time in lunar evolution. In work completed during the last year, numerical experiments on convection in a chemically stably stratified fluid layer heated from below have been completed. These results show us how to calculate the evolution of a mixed layer in the Moon, depending on the heat production in the ilmenite- cumulate core and the chemical stratification of the overlying mantle. Chemical stratification of the mantle after its initial differentiation is would trap heat in the deep interior and prevent the rapid rise of plumes with accompanying volcanism. This trapping of heat in the interior can explain the thickness of the lunar lithosphere as a function of time as well as the magmatic evolution. We show that heat transported to the base of the lithosphere at a rate determined by current estimates of radioactivity in the Moon would not satisfy constraints on elastic lithosphere thickness from tectonic feature associated with basin loading. Trapping heat at depth by a chemically stratified mantle may also explain the absence of global compressional features on the surface that previous models predict for an initially hot lunar interior. For Venus, we developed a

  14. Planetary Protection Constraints For Planetary Exploration and Exobiology

    NASA Astrophysics Data System (ADS)

    Debus, A.; Bonneville, R.; Viso, M.

    According to the article IX of the OUTER SPACE TREATY (London / Washington January 27., 1967) and in the frame of extraterrestrial missions, it is required to preserve planets and Earth from contamination. For ethical, safety and scientific reasons, the space agencies have to comply with the Outer Space Treaty and to take into account the related planetary protection Cospar recommendations. Planetary protection takes also into account the protection of exobiological science, because the results of life detection experimentations could have impacts on planetary protection regulations. The validation of their results depends strongly of how the samples have been collected, stored and analyzed, and particularly of their biological and organic cleanliness. Any risk of contamination by organic materials, chemical coumpounds and by terrestrial microorganisms must be avoided. A large number of missions is presently scheduled, particularly on Mars, in order to search for life or traces of past life. In the frame of such missions, CNES is building a planetary protection organization in order handle and to take in charge all tasks linked to science and engineering concerned by planetary protection. Taking into account CNES past experience in planetary protection related to the Mars 96 mission, its planned participation in exobiological missions with NASA as well as its works and involvement in Cospar activities, this paper will present the main requirements in order to avoid celestial bodies biological contamination, focussing on Mars and including Earth, and to protect exobiological science.

  15. The search for signs of life on exoplanets at the interface of chemistry and planetary science

    PubMed Central

    Seager, Sara; Bains, William

    2015-01-01

    The discovery of thousands of exoplanets in the last two decades that are so different from planets in our own solar system challenges many areas of traditional planetary science. However, ideas for how to detect signs of life in this mélange of planetary possibilities have lagged, and only in the last few years has modeling how signs of life might appear on genuinely alien worlds begun in earnest. Recent results have shown that the exciting frontier for biosignature gas ideas is not in the study of biology itself, which is inevitably rooted in Earth’s geochemical and evolutionary specifics, but in the interface of chemistry and planetary physics. PMID:26601153

  16. Planetary Scientist Profile: Noah Petro

    NASA Video Gallery

    Noah Petro is a NASA planetary geologist who studies the surface of airless bodies in space, primarily focusing on the moon. In this video profile, Noah talks about how he was inspired to become a ...

  17. Studies of extended planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Hunten, D. M.

    1991-01-01

    The following topics are covered: (1) telescopic observations and analysis of planetary atmospheres (including the Moon and Mars) and the Io torus; (2) occultation observations; and (3) supporting laboratory studies.

  18. Infrared Radiation and Planetary Temperature

    NASA Astrophysics Data System (ADS)

    Pierrehumbert, Raymond T.

    2011-11-01

    Infrared radiative transfer theory, one of the most productive physical theories of the past century, has unlocked myriad secrets of the universe including that of planetary temperature and the connection between global warming and greenhouse gases.

  19. Refocusing NASA Planetary Science Funding

    NASA Astrophysics Data System (ADS)

    Zielinski, Sarah

    2006-10-01

    NASA should invest more money in data analysis for its planetary science missions, even if it means delaying or canceling afuture mission, members of the science committee of the NASA Advisory Council (NAC) suggested at a 12 October meeting.

  20. Planetary geosciences, 1989-1990

    NASA Technical Reports Server (NTRS)

    Zuber, Maria T. (Editor); James, Odette B. (Editor); Lunine, Jonathan I. (Editor); Macpherson, Glenn J. (Editor); Phillips, Roger J. (Editor)

    1992-01-01

    NASA's Planetary Geosciences Programs (the Planetary Geology and Geophysics and the Planetary Material and Geochemistry Programs) provide support and an organizational framework for scientific research on solid bodies of the solar system. These research and analysis programs support scientific research aimed at increasing our understanding of the physical, chemical, and dynamic nature of the solid bodies of the solar system: the Moon, the terrestrial planets, the satellites of the outer planets, the rings, the asteroids, and the comets. This research is conducted using a variety of methods: laboratory experiments, theoretical approaches, data analysis, and Earth analog techniques. Through research supported by these programs, we are expanding our understanding of the origin and evolution of the solar system. This document is intended to provide an overview of the more significant scientific findings and discoveries made this year by scientists supported by the Planetary Geosciences Program. To a large degree, these results and discoveries are the measure of success of the programs.

  1. Integration of planetary protection activities

    NASA Technical Reports Server (NTRS)

    Race, Margaret S.

    1995-01-01

    For decades, NASA has been concerned about the protection of planets and other solar system bodies from biological contamination. Its policies regarding biological contamination control for outbound and inbound planetary spacecraft have evolved to focus on three important areas: (1) the preservation of celestial objects and the space environment; (2) protection of Earth from extraterrestrial hazards; and (3) ensuring the integrity of its scientific investigations. Over the years as new information has been obtained from planetary exploration and research, planetary protection parameters and policies have been modified accordingly. The overall focus of research under this cooperative agreement has been to provide information about non-scientific and societal factors related to planetary protection and use it in the planning and implementation phases of future Mars sample return missions.

  2. Planetary Seismometers: An Overview

    NASA Astrophysics Data System (ADS)

    Knapmeyer, M.; Akito, A.; Bampasidis, G.; Banerdt, W. B.; Coustenis, A.; Fouch, M. J.; Garnero, E. J.; Khavroshkin, O.; Kobayashi, N.; Moussas, X.; Pike, W. T.; Seidensticker, K. J.; Solomonidou, A.; Yu, H.; Zakharov, A.

    2012-04-01

    Seismometers were part of lander payloads since the launch of Ranger 3 in early 1962, which was the first attempt to deliver scientific instruments to the surface of another celestial body. Since then, active and passive seismic experiments were conducted with great success on the Moon, and to a lesser extent on Mars and Venus. Proposals have been made or are in preparation for new experiments with single instruments or instrument networks on Venus, Moon, Mars, Phobos, Titan, Europa, and other bodies. One instrument (CASSE, sensitive for acoustic frequencies >= 30Hz) is currently flying to comet 67P/Churyumov-Gerasimenko on board of the Rosetta Mission. We give an overview of seismometers for use in planetary missions, including instruments of past and future missions. The focus is on the current developments as represented by the authors of the presentation. These encompass a Micro-Electromechanic System, several piezoelectric transducers that are able to resist strong decelerations, as well as new developments based on laser-interferometric sensing or hydrodynamic flow of electrolytic liquids.

  3. Extrasolar Planetary Transits

    NASA Astrophysics Data System (ADS)

    Cameron, Andrew Collier

    An extrasolar planet will transit the visible hemisphere of its host star if its orbital plane lies sufficiently close to the observer's line of sight. The resulting periodic dips in stellar flux reveal key system parameters, including the density of the host star and, if radial-velocity observations are available, the surface gravitational acceleration of the planet. In this chapter I present the essential methodology for modelling the time-dependent flux variation during a transit, and its use in determining the posterior probability distribution for the physical parameters of the system. Large-scale searches for transiting systems are an efficient way of discovering planets whose bulk densities, and hence compositions, can be accessed if their masses can also be determined. I present algorithms for detrending large ensembles of light curves, for searching for transit-like signals among them. I also discuss methods for identifying diluted stellar eclipsing binaries mimicking planetary transit signals, and validation of transit candidates too faint for radial-velocity follow-up. I review the use of time-resolved spectrophotometry and high-resolution spectroscopy during transits to identify the molecular constituents of exoplanetary atmospheres.

  4. Lunar and planetary studies

    NASA Technical Reports Server (NTRS)

    Muhleman, Duane O.; Goldreich, P.; Ingersoll, A. P.; Westphal, J. A.

    1988-01-01

    This grant supports the core program in planetary astronomy at Caltech. The research includes observations in the IR, sub-mm, mm and cm wavelengths at national and Caltech observatories with a strong emphasis on integrating the observations with spacecraft data and with models of atmospheric structure, dynamics and chemistry. Muhleman's group made extensive observations of Saturn, Uranus and Neptune which are being interpreted in terms of deep atmospheric structures which are obvious in the 2 and 6 cm maps of Saturn and Uranus. The microwave measurements are one of the few sources of information below the 2 bar level. Goldreich is investigating the dynamics of narrow rings with postdoctoral fellow, Pierre-Yves Longaretti. Their work has focused on the role of collisional stresses on the precession of the rings, since the Voyager radio science results imply that the previous model based on the ring's self-gravity is not the entire story. In addition Borderies, Goldreich and Tremaine have completed an investigation of the dynamics of the Encke division in Saturn's A ring.

  5. Planetary Vital Signs

    NASA Astrophysics Data System (ADS)

    Kennel, Charles; Briggs, Stephen; Victor, David

    2016-07-01

    The climate is beginning to behave in unusual ways. The global temperature reached unprecedented highs in 2015 and 2016, which led climatologists to predict an enormous El Nino that would cure California's record drought. It did not happen the way they expected. That tells us just how unreliable temperature has become as an indicator of important aspects of climate change. The world needs to go beyond global temperature to a set of planetary vital signs. Politicians should not over focus policy on one indicator. They need to look at the balance of evidence. A coalition of scientists and policy makers should start to develop vital signs at once, since they should be ready at the entry into force of the Paris Agreement in 2020. But vital signs are only the beginning. The world needs to learn how to use the vast knowledge we will be acquiring about climate change and its impacts. Is it not time to use all the tools at hand- observations from space and ground networks; demographic, economic and societal measures; big data statistical techniques; and numerical models-to inform politicians, managers, and the public of the evolving risks of climate change at global, regional, and local scales? Should we not think in advance of an always-on social and information network that provides decision-ready knowledge to those who hold the responsibility to act, wherever they are, at times of their choosing?

  6. Planetary upper atmospheres

    NASA Astrophysics Data System (ADS)

    Müller-Wodarg, Ingo

    2005-10-01

    Earth and most planets in our solar system are surrounded by permanent atmospheres. Their outermost layers, the thermospheres, ionospheres and exospheres, are regions which couple the atmospheres to space, the Sun and solar wind. Furthermore, most planets possess a magnetosphere, which extends into space considerably further than the atmosphere, but through magnetosphere-ionosphere coupling processes closely interacts with it. Auroral emissions, found on Earth and other panets, are manifestations of this coupling and a mapping of distant regions in the magnetosphere into the upper atmosphere along magnetic field lines. This article compares planetary upper atmospheres in our solar system and attempts to explain their differences via fundamental properties such as atmospheric gas composition, magnetosphere structure and distance from Sun. Understanding the space environment of Earth and its coupling to the Sun, and attempting to predict its behaviour ("Space Weather") plays an important practical role in protecting satellites, upon which many aspects to todays civilisation rely. By comparing our own space environment to that of other planets we gain a deeper understanding of its physical processes and uniqueness. Increasingly, we apply our knowledge also to atmospheres of extrasolar system planets, which will help assessing the possibility of life-elsewhere in the Universe.

  7. Kinematics of planetary nebulae. II

    NASA Astrophysics Data System (ADS)

    Purgathofer, A.; Perinotto, M.

    1981-08-01

    In a program of study of radial velocities of planetary nebulae, 84 spectra of eight planetary nebulae in the direction of the galactic anticenter have been obtained at the L. Figl Observatory near Vienna with an image tube spectrograph giving a reciprocal dispersion of 26 A/mm. With this material, the kinematical behavior of the objects was studied, and it is shown that most of them deviate significantly from circular motion in the Galaxy.

  8. Migrating microbes and planetary protection.

    PubMed

    Nicholson, Wayne L; Schuerger, Andrew C; Race, Margaret S

    2009-09-01

    Since the dawn of the space age, humans have wrestled with concerns about planetary cross-contamination. Spacecraft launched from Earth can transport hitchhiker microbes to new worlds on both robotic and crewed vehicles. As plans proceed for future life detection and human exploration missions, planetary protection considerations are again uppermost on the agendas of mission planners, and microbiologists have an important role to play. PMID:19726193

  9. Planetary Data Workshop, Part 1

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The community of planetary scientists addresses two general problems regarding planetary science data: (1) important data sets are being permanently lost; and (2) utilization is constrainted by difficulties in locating and accessing science data and supporting information necessary for its use. A means to correct the problems, provide science and functional requirements for a systematic and phased approach, and suggest technologies and standards appropriate to the solution were explored.

  10. Planetary Photojournal Home Page Graphic

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image is an unannotated version of the Planetary Photojournal Home Page graphic. This digital collage contains a highly stylized rendition of our solar system and points beyond. As this graphic was intended to be used as a navigation aid in searching for data within the Photojournal, certain artistic embellishments have been added (color, location, etc.). Several data sets from various planetary and astronomy missions were combined to create this image.

  11. Planetary Interior in the Laboratory

    SciTech Connect

    Chau, R; Bastea, M; Mitchell, A C; Minich, R W; Nellis, W J

    2003-01-31

    In the three years of this project, we have provided a complete database of the electrical conductivity of planetary materials to 180 GPa. The electrical conductivities of these planetary materials now provide a basis for future modeling of planets taking into account full magnetohydrodynamics. By using a full magnetohydrodynamics simulation, the magnetic fields of the planets can then be taken into account. Moreover, the electrical conductivities of the planetary materials have given us insight into the structure and nature of these dense fluids. We showed that simple monoatomic fluids such as hydrogen, nitrogen, and oxygen at planetary interior conditions undergo a common metallization process which can be explained on a simple basis of their radial charge density distributions. This model also shows that the metallization process is actually rather common and likely to take place in a number of materials such as carbon monoxide which is also present within planetary objects. On the other hand, we have also showed that a simple two component fluid like water and methane take on much different behaviors than say nitrogen due to the chemical interactions within these systems. The dynamics of an even more complex system, ''synthetic Uranus'' are still being analyzed but suggest that on some levels the behavior is very simple, i.e. the electrical conductivity is essentially the same as water, but the local dynamics are very complex. This project has shed much light on the nature of electrical transport within planetary interiors but also has shown that understanding chemical processes in the complex fluids within planetary interiors to be very important. Understanding those local interactions and processes is required to gain further insight into planetary interiors.

  12. The Importance of Planetary Rotation Period for Ocean Heat Transport

    PubMed Central

    Stevens, D.; Joshi, M.

    2014-01-01

    Abstract The climate and, hence, potential habitability of a planet crucially depends on how its atmospheric and ocean circulation transports heat from warmer to cooler regions. However, previous studies of planetary climate have concentrated on modeling the dynamics of atmospheres, while dramatically simplifying the treatment of oceans, which neglects or misrepresents the effect of the ocean in the total heat transport. Even the majority of studies with a dynamic ocean have used a simple so-called aquaplanet that has no continental barriers, which is a configuration that dramatically changes the ocean dynamics. Here, the significance of the response of poleward ocean heat transport to planetary rotation period is shown with a simple meridional barrier—the simplest representation of any continental configuration. The poleward ocean heat transport increases significantly as the planetary rotation period is increased. The peak heat transport more than doubles when the rotation period is increased by a factor of ten. There are also significant changes to ocean temperature at depth, with implications for the carbon cycle. There is strong agreement between the model results and a scale analysis of the governing equations. This result highlights the importance of both planetary rotation period and the ocean circulation when considering planetary habitability. Key Words: Exoplanet—Oceans—Rotation—Climate—Habitability. Astrobiology 14, 645–650. PMID:25041658

  13. Impact of lunar and planetary missions on the space station

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The impacts upon the growth space station of several advanced planetary missions and a populated lunar base are examined. Planetary missions examined include sample returns from Mars, the Comet Kopff, the main belt asteroid Ceres, a Mercury orbiter, and a saturn orbiter with multiple Titan probes. A manned lunar base build-up scenario is defined, encompassing preliminary lunar surveys, ten years of construction, and establishment of a permanent 18 person facility with the capability to produce oxygen propellant. The spacecraft mass departing from the space station, mission Delta V requirements, and scheduled departure date for each payload outbound from low Earth orbit are determined for both the planetary missions and for the lunar base build-up. Large aerobraked orbital transfer vehicles (OTV's) are used. Two 42 metric ton propellant capacity OTV's are required for each the the 68 lunar sorties of the base build-up scenario. The two most difficult planetary missions (Kopff and Ceres) also require two of these OTV's. An expendable lunar lander and ascent stage and a reusable lunar lander which uses lunar produced oxygen are sized to deliver 18 metric tons to the lunar surface. For the lunar base, the Space Station must hangar at least two non-pressurized OTV's, store 100 metric tons of cryogens, and support an average of 14 OTV launch, return, and refurbishment cycles per year. Planetary sample return missions require a dedicated quarantine module.

  14. The importance of planetary rotation period for ocean heat transport.

    PubMed

    Cullum, J; Stevens, D; Joshi, M

    2014-08-01

    The climate and, hence, potential habitability of a planet crucially depends on how its atmospheric and ocean circulation transports heat from warmer to cooler regions. However, previous studies of planetary climate have concentrated on modeling the dynamics of atmospheres, while dramatically simplifying the treatment of oceans, which neglects or misrepresents the effect of the ocean in the total heat transport. Even the majority of studies with a dynamic ocean have used a simple so-called aquaplanet that has no continental barriers, which is a configuration that dramatically changes the ocean dynamics. Here, the significance of the response of poleward ocean heat transport to planetary rotation period is shown with a simple meridional barrier--the simplest representation of any continental configuration. The poleward ocean heat transport increases significantly as the planetary rotation period is increased. The peak heat transport more than doubles when the rotation period is increased by a factor of ten. There are also significant changes to ocean temperature at depth, with implications for the carbon cycle. There is strong agreement between the model results and a scale analysis of the governing equations. This result highlights the importance of both planetary rotation period and the ocean circulation when considering planetary habitability. PMID:25041658

  15. Planetary Science with the Stratospheric Observatory for Infrared Astronomy (SOFIA)

    NASA Astrophysics Data System (ADS)

    Backman, Dana E.; Reach, William T.

    2015-11-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is currently conducting the third annual Cycle of guest investigator observing programs. Programs selected for the fourth Cycle (2016) were announced in October. The planetary science community has made a significant showing in all proposal Cycles, comprising approximately 15% of the time awarded in Cycles 1-3. SOFIA offers observers access to the complete infrared spectrum, with much less atmospheric absorption than from even the finest ground-based telescope sites. New capabilities include high-resolution spectroscopy in the mid-infrared with the Echelon-Cross-Echelle Spectrograph (EXES) that allows spectroscopy of molecules from narrow stratospheric lines of planetary atmospheres, plus imaging spectroscopy with the Field Imaging Far-Infrared Line Spectrometer (FIFI-LS) capable, for example, of simultaneous observations in 9 spatial pixels in each of two far-infrared spectral lines. Also, the FLITECAM near-IR and FORCAST mid-IR cameras include grisms that allow moderate-resolution spectral imaging at wavelengths inaccessible from the ground, and HIPO and FPI+ high-speed photometric imagers are capable of high-S/N measurements of stellar occultations and exoplanet transits. Planetary science targets observed to date include comets ISON and PanSTARRS, main belt asteroids, Mars, Jupiter, Neptune, Pluto, Europa, exoplanets, and debris disks. This poster will showcase science highlights, give details regarding the SOFIA observatory and instrument capabilities, and present observing program statistics.

  16. Planetary Geologic Mapping Handbook - 2009

    NASA Technical Reports Server (NTRS)

    Tanaka, K. L.; Skinner, J. A.; Hare, T. M.

    2009-01-01

    Geologic maps present, in an historical context, fundamental syntheses of interpretations of the materials, landforms, structures, and processes that characterize planetary surfaces and shallow subsurfaces (e.g., Varnes, 1974). Such maps also provide a contextual framework for summarizing and evaluating thematic research for a given region or body. In planetary exploration, for example, geologic maps are used for specialized investigations such as targeting regions of interest for data collection and for characterizing sites for landed missions. Whereas most modern terrestrial geologic maps are constructed from regional views provided by remote sensing data and supplemented in detail by field-based observations and measurements, planetary maps have been largely based on analyses of orbital photography. For planetary bodies in particular, geologic maps commonly represent a snapshot of a surface, because they are based on available information at a time when new data are still being acquired. Thus the field of planetary geologic mapping has been evolving rapidly to embrace the use of new data and modern technology and to accommodate the growing needs of planetary exploration. Planetary geologic maps have been published by the U.S. Geological Survey (USGS) since 1962 (Hackman, 1962). Over this time, numerous maps of several planetary bodies have been prepared at a variety of scales and projections using the best available image and topographic bases. Early geologic map bases commonly consisted of hand-mosaicked photographs or airbrushed shaded-relief views and geologic linework was manually drafted using mylar bases and ink drafting pens. Map publishing required a tedious process of scribing, color peel-coat preparation, typesetting, and photo-laboratory work. Beginning in the 1990s, inexpensive computing, display capability and user-friendly illustration software allowed maps to be drawn using digital tools rather than pen and ink, and mylar bases became obsolete

  17. NASA Planetary Science Summer School: Preparing the Next Generation of Planetary Mission Leaders

    NASA Astrophysics Data System (ADS)

    Lowes, L. L.; Budney, C. J.; Sohus, A.; Wheeler, T.; Urban, A.; NASA Planetary Science Summer School Team

    2011-12-01

    Sponsored by NASA's Planetary Science Division, and managed by the Jet Propulsion Laboratory, the Planetary Science Summer School prepares the next generation of engineers and scientists to participate in future solar system exploration missions. Participants learn the mission life cycle, roles of scientists and engineers in a mission environment, mission design interconnectedness and trade-offs, and the importance of teamwork. For this professional development opportunity, applicants are sought who have a strong interest and experience in careers in planetary exploration, and who are science and engineering post-docs, recent PhDs, and doctoral students, and faculty teaching such students. Disciplines include planetary science, geoscience, geophysics, environmental science, aerospace engineering, mechanical engineering, and materials science. Participants are selected through a competitive review process, with selections based on the strength of the application and advisor's recommendation letter. Under the mentorship of a lead engineer (Dr. Charles Budney), students select, design, and develop a mission concept in response to the NASA New Frontiers Announcement of Opportunity. They develop their mission in the JPL Advanced Projects Design Team (Team X) environment, which is a cross-functional multidisciplinary team of professional engineers that utilizes concurrent engineering methodologies to complete rapid design, analysis and evaluation of mission concept designs. About 36 students participate each year, divided into two summer sessions. In advance of an intensive week-long session in the Project Design Center at JPL, students select the mission and science goals during a series of six weekly WebEx/telecons, and develop a preliminary suite of instrumentation and a science traceability matrix. Students assume both a science team and a mission development role with JPL Team X mentors. Once at JPL, students participate in a series of Team X project design sessions

  18. Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Ksanfomaliti, L. V.

    2000-11-01

    The discovery of planetary systems around alien stars is an outstanding achievement of recent years. The idea that the Solar System may be representative of planetary systems in the Galaxy in general develops upon the knowledge, current until the last decade of the 20th century, that it is the only object of its kind. Studies of the known planets gave rise to a certain stereotype in theoretical research. Therefore, the discovery of exoplanets, which are so different from objects of the Solar System, alters our basic notions concerning the physics and very criteria of normal planets. A substantial factor in the history of the Solar System was the formation of Jupiter. Two waves of meteorite bombardment played an important role in that history. Ultimately there arose a stable low-entropy state of the Solar System, in which Jupiter and the other giants in stable orbits protect the inner planets from impacts by dangerous celestial objects, reducing this danger by many orders of magnitude. There are even variants of the anthropic principle maintaining that life on Earth owes its genesis and development to Jupiter. Some 20 companions more or less similar to Jupiter in mass and a few ``infrared dwarfs,'' have been found among the 500 solar-type stars belonging to the main sequence. Approximately half of the exoplanets discovered are of the ``hot-Jupiter'' type. These are giants, sometimes of a mass several times that of Jupiter, in very low orbits and with periods of 3-14 days. All of their parent stars are enriched with heavy elements, [Fe/H] = 0.1-0.2. This may indicate that the process of exoplanet formation depends on the chemical composition of the protoplanetary disk. The very existence of exoplanets of the hot-Jupiter type considered in the context of new theoretical work comes up against the problem of the formation of Jupiter in its real orbit. All the exoplanets in orbits with a semimajor axis of more than 0.15-0.20 astronomical units (AU) have orbital

  19. NASA Planetary Visualization Tool

    NASA Astrophysics Data System (ADS)

    Hogan, P.; Kim, R.

    2004-12-01

    NASA World Wind allows one to zoom from satellite altitude into any place on Earth, leveraging the combination of high resolution LandSat imagery and SRTM elevation data to experience Earth in visually rich 3D, just as if they were really there. NASA World Wind combines LandSat 7 imagery with Shuttle Radar Topography Mission (SRTM) elevation data, for a dramatic view of the Earth at eye level. Users can literally fly across the world's terrain from any location in any direction. Particular focus was put into the ease of usability so people of all ages can enjoy World Wind. All one needs to control World Wind is a two button mouse. Additional guides and features can be accessed though a simplified menu. Navigation is automated with single clicks of a mouse as well as the ability to type in any location and automatically zoom to it. NASA World Wind was designed to run on recent PC hardware with the same technology used by today's 3D video games. NASA World Wind delivers the NASA Blue Marble, spectacular true-color imagery of the entire Earth at 1-kilometer-per-pixel. Using NASA World Wind, you can continue to zoom past Blue Marble resolution to seamlessly experience the extremely detailed mosaic of LandSat 7 data at an impressive 15-meters-per-pixel resolution. NASA World Wind also delivers other color bands such as the infrared spectrum. The NASA Scientific Visualization Studio at Goddard Space Flight Center (GSFC) has produced a set of visually intense animations that demonstrate a variety of subjects such as hurricane dynamics and seasonal changes across the globe. NASA World Wind takes these animations and plays them directly on the world. The NASA Moderate Resolution Imaging Spectroradiometer (MODIS) produces a set of time relevant planetary imagery that's updated every day. MODIS catalogs fires, floods, dust, smoke, storms and volcanic activity. NASA World Wind produces an easily customized view of this information and marks them directly on the globe. When one

  20. Directed energy planetary defense

    NASA Astrophysics Data System (ADS)

    Lubin, Philip; Hughes, Gary B.; Bible, Johanna; Bublitz, Jesse; Arriola, Josh; Motta, Caio; Suen, Jon; Johansson, Isabella; Riley, Jordan; Sarvian, Nilou; Clayton-Warwick, Deborah; Wu, Jane; Milich, Andrew; Oleson, Mitch; Pryor, Mark; Krogen, Peter; Kangas, Miikka

    2013-09-01

    Asteroids and comets that cross Earth's orbit pose a credible risk of impact, with potentially severe disturbances to Earth and society. Numerous risk mitigation strategies have been described, most involving dedicated missions to a threatening object. We propose an orbital planetary defense system capable of heating the surface of potentially hazardous objects to the vaporization point as a feasible approach to impact risk mitigation. We call the system DE-STAR for Directed Energy System for Targeting of Asteroids and exploRation. DE-STAR is a modular phased array of kilowatt class lasers powered by photovoltaic's. Modular design allows for incremental development, test, and initial deployment, lowering cost, minimizing risk, and allowing for technological co-development, leading eventually to an orbiting structure that would be developed in stages with both technological and target milestones. The main objective of DE-STAR is to use the focused directed energy to raise the surface spot temperature to ~3,000K, allowing direct vaporization of all known substances. In the process of heating the surface ejecting evaporated material a large reaction force would alter the asteroid's orbit. The baseline system is a DE-STAR 3 or 4 (1-10km array) depending on the degree of protection desired. A DE-STAR 4 allows for asteroid engagement starting beyond 1AU with a spot temperature sufficient to completely evaporate up to 500-m diameter asteroids in one year. Small asteroids and comets can be diverted/evaporated with a DESTAR 2 (100m) while space debris is vaporized with a DE-STAR 1 (10m).

  1. Planetary Transmission Diagnostics

    NASA Technical Reports Server (NTRS)

    Lewicki, David G. (Technical Monitor); Samuel, Paul D.; Conroy, Joseph K.; Pines, Darryll J.

    2004-01-01

    This report presents a methodology for detecting and diagnosing gear faults in the planetary stage of a helicopter transmission. This diagnostic technique is based on the constrained adaptive lifting algorithm. The lifting scheme, developed by Wim Sweldens of Bell Labs, is a time domain, prediction-error realization of the wavelet transform that allows for greater flexibility in the construction of wavelet bases. Classic lifting analyzes a given signal using wavelets derived from a single fundamental basis function. A number of researchers have proposed techniques for adding adaptivity to the lifting scheme, allowing the transform to choose from a set of fundamental bases the basis that best fits the signal. This characteristic is desirable for gear diagnostics as it allows the technique to tailor itself to a specific transmission by selecting a set of wavelets that best represent vibration signals obtained while the gearbox is operating under healthy-state conditions. However, constraints on certain basis characteristics are necessary to enhance the detection of local wave-form changes caused by certain types of gear damage. The proposed methodology analyzes individual tooth-mesh waveforms from a healthy-state gearbox vibration signal that was generated using the vibration separation (synchronous signal-averaging) algorithm. Each waveform is separated into analysis domains using zeros of its slope and curvature. The bases selected in each analysis domain are chosen to minimize the prediction error, and constrained to have the same-sign local slope and curvature as the original signal. The resulting set of bases is used to analyze future-state vibration signals and the lifting prediction error is inspected. The constraints allow the transform to effectively adapt to global amplitude changes, yielding small prediction errors. However, local wave-form changes associated with certain types of gear damage are poorly adapted, causing a significant change in the

  2. Global geochemical cycles of carbon, sulfur and oxygen

    NASA Technical Reports Server (NTRS)

    Walker, J. C.

    1986-01-01

    Time resolved data on the carbon isotopic composition of carbonate minerals and the sulfur isotopic composition or sulfate minerals show a strong negative correlation during the Cretaceous. Carbonate minerals are isotopically heavy during this period while sulfate minerals are isotopically light. The implication is that carbon is being transferred from the oxidized, carbonate reservoir to the reservoir of isotopically light reduced organic carbon in sedimentary rocks while sulfur is being transferred from the reservoir of isotopically light sedimentary sulfide to the oxidized, sulfate reservoir. These apparently oppositely directed changes in the oxidation state of average sedimentary carbon and sulfur are surprising because of a well-established and easy to understand correlation between the concentrations of reduced organic carbon and sulfide minerals in sedimentary rocks. Rocks rich in reduced carbon are also rich in reduced sulfur. The isotopic and concentration data can be reconciled by a model which invokes a significant flux of hydrothermal sulfide to the deep sea, at least during the Cretaceous.

  3. [Geochemical cycling of mercury in the sediment of Hongfeng Reservior].

    PubMed

    He, Tian-Rong; Feng, Xin-Bin; Guo, Yan-Na; Meng, Bo; Li, Zhong-Gen; Qiu, Guang-Le; Liang, Lian

    2008-07-01

    Spatial and temporal distributions of total and methyl mercury and controlling factors were investigated based on cold vapor atomic fluorescence detection. Total mercury levels in the whole sediments are (0.392 +/- 0.070) microg/g, without significant variations between different seasons, but generally increase toward the sediment-water interface. Total mercury levels are higher compared to data reported in other uncontaminated reservoirs and Wujiangdu Reservoir. This indicates there are mercury contaminations in Hongfeng Reservoir. Methyl mercury concentrations are highest in spring, without significant variations in other seasons. The peak values of methyl mercury typically appear in the upper 8 cm of the sediment profiles which are also the zones of sulfate-reducing bacteria activities. The seasonal variation and maximum peak value distributions of methyl mercury in sediment are mainly controlled by seasonally migration of oxic/anoxic boundary layer. Total mercury concentrations in the pore water and partition coefficients for THg in solid phase and water phase are mainly controlled by temperature or redox potential. Total mercury concentrations in the pore water have no relationship with total mercury concentrations in solid phase. However, the methyl mercury concentrations in the pore water have a strong relationship with those in solid phase (r = 0.70, p < 0.001). The methyl mercury concentrations in solid phase and pore water are controlled by solid/water partition coefficient, as well as methyl mercury production. PMID:18828352

  4. Comparative Understanding of Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    Huestis, D. L.; Atreya, S. K.; Bolton, S. J.; Bougher, S. W.; Coustenis, A.; Edgington, S. G.; Friedson, A. J.; Griffith, C. A.; Guberman, S. L.; Hammel, H. B.; Lunine, J. I.; Mendillo, M.; Moses, J.; Mueller-Wodarg, I.; Orton, G. S.; Rages, K. A.; Slanger, T. G.; Titov, D. V.; Yelle, R.

    2001-11-01

    Observing, characterizing, and understanding planetary atmospheres are key components of solar system exploration. A planet's atmosphere is the interface between the surface and external energy and mass sources. Understanding how atmospheres are formed, evolve, and respond to perturbations is essential for addressing the long-range science objectives of identifying the conditions that are favorable for producing and supporting biological activity, managing the effects of human activity on the Earth's atmosphere, and planning and evaluating observations of extra-solar planets. Our current knowledge, based on very few observations, indicates that the planets and moons in the solar system have diverse atmospheres with a number of shared characteristics. Comparing and contrasting solar system atmospheres provides the best means of addressing the broad scientific goals. Additional space missions with specific atmospheric objectives are required. At the same time, investment of additional resources is needed in the infrastructure of observation and interpretation of planetary atmospheres. The Planetary Atmospheres Community Panel is considering and prioritizing potential recommendations in two broad categories. Possible recommendations that apply to multiple planets include creation of a new Comparative Planetary Atmospheres program, establishing a mechanism for secure funding for analysis and interpretation of mission data, creation of a new "Super-Discovery" program for more ambitious planetary missions, enhancement of laboratory and theory research, and deployment of space- or ground-based telescopes dedicated to planetary observations. Possible recommendations for specific planetary missions with atmospheric goals include deep-penetration multiprobes to determine elemental compositions of giant planet atmospheres, Venus and Mars atmospheric explorer missions, and a Post-Cassini atmospheric/surface mission to Titan.

  5. SUSTAINABILITY. Response to Comment on "Planetary boundaries: Guiding human development on a changing planet".

    PubMed

    Gerten, Dieter; Rockström, Johan; Heinke, Jens; Steffen, Will; Richardson, Katherine; Cornell, Sarah

    2015-06-12

    Jaramillo and Destouni claim that freshwater consumption is beyond the planetary boundary, based on high estimates of water cycle components, different definitions of water consumption, and extrapolation from a single case study. The difference from our analysis, based on mainstream assessments of global water consumption, highlights the need for clearer definitions of water cycle components and improved models and databases. PMID:26068844

  6. Probing Shocks of the Young Planetary Nebula NGC 7027

    NASA Astrophysics Data System (ADS)

    Montez, Rodolfo

    2013-09-01

    The rapid evolution of the planetary nebula NGC 7027 provides a rare glimpse at the evolution of the shocks. We propose a detailed spatial and spectroscopic study of the shock conditions in NGC 7027 that will enhance and bridge our understanding of the shocks seen in other planetary nebula. Comparison between the Cycle 1 observation and a new Cycle 15 observation will (i) confirm the presence of the two components in the extended X-ray emission, (ii) measure the changes (spatial and spectral) in the components, and, (iii) provide a valuable trove of tests and inputs for shock conditions and hydrodynamical simulations. We rely on the unprecedented spatial resolution and soft-sensitivity of Chandra.

  7. The fragility of planetary systems

    NASA Astrophysics Data System (ADS)

    Portegies Zwart, S. F.; Jílková, Lucie

    2015-07-01

    We specify the range to which perturbations penetrate a planetesimal system. Such perturbations can originate from massive planets or from encounters with other stars. The latter can have an origin in the star cluster in which the planetary system was born, or from random encounters once the planetary system has escaped its parental cluster. The probability of a random encounter, either in a star cluster or in the Galactic field depends on the local stellar density, the velocity dispersion and the time spend in that environment. By adopting order of magnitude estimates, we argue that the majority of planetary systems born in open clusters will have a Parking zone, in which planetesimals are affected by encounters in their parental star cluster but remain unperturbed after the star has left the cluster. Objects found in this range of semimajor axis and eccentricity preserve the memory of the encounter that last affected their orbits, and they can therefore be used to reconstruct this encounter. Planetary systems born in a denser environment, such as in a globular cluster are unlikely to have a Parking zone. We further argue that some planetary systems may have a Frozen zone, in which orbits are not affected either by the more inner massive planets or by external influences. Objects discovered in this zone will have preserved information about their formation in their orbital parameters.

  8. Stellar Ablation of Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Moore, Thomas E.; Horwitz, J. L.

    2007-01-01

    We review observations and theories of the solar ablation of planetary atmospheres, focusing on the terrestrial case where a large magnetosphere holds off the solar wind, so that there is little direct atmospheric impact, but also couples the solar wind electromagnetically to the auroral zones. We consider the photothermal escape flows known as the polar wind or refilling flows, the enhanced mass flux escape flows that result from localized solar wind energy dissipation in the auroral zones, and the resultant enhanced neutral atom escape flows. We term these latter two escape flows the "auroral wind." We review observations and theories of the heating and acceleration of auroral winds, including energy inputs from precipitating particles, electromagnetic energy flux at magnetohydrodynamic and plasma wave frequencies, and acceleration by parallel electric fields and by convection pickup processes also known as "centrifugal acceleration." We consider also the global circulation of ionospheric plasmas within the magnetosphere, their participation in magnetospheric disturbances as absorbers of momentum and energy, and their ultimate loss from the magnetosphere into the downstream solar wind, loading reconnection processes that occur at high altitudes near the magnetospheric boundaries. We consider the role of planetary magnetization and the accumulating evidence of stellar ablation of extrasolar planetary atmospheres. Finally, we suggest and discuss future needs for both the theory and observation of the planetary ionospheres and their role in solar wind interactions, to achieve the generality required for a predictive science of the coupling of stellar and planetary atmospheres over the full range of possible conditions.

  9. The Planetary Archive

    NASA Astrophysics Data System (ADS)

    Penteado, Paulo F.; Trilling, David; Szalay, Alexander; Budavári, Tamás; Fuentes, César

    2014-11-01

    We are building the first system that will allow efficient data mining in the astronomical archives for observations of Solar System Bodies. While the Virtual Observatory has enabled data-intensive research making use of large collections of observations across multiple archives, Planetary Science has largely been denied this opportunity: most astronomical data services are built based on sky positions, and moving objects are often filtered out.To identify serendipitous observations of Solar System objects, we ingest the archive metadata. The coverage of each image in an archive is a volume in a 3D space (RA,Dec,time), which we can represent efficiently through a hierarchical triangular mesh (HTM) for the spatial dimensions, plus a contiguous time interval. In this space, an asteroid occupies a curve, which we determine integrating its orbit into the past. Thus when an asteroid trajectory intercepts the volume of an archived image, we have a possible observation of that body. Our pipeline then looks in the archive's catalog for a source with the corresponding coordinates, to retrieve its photometry. All these matches are stored into a database, which can be queried by object identifier.This database consists of archived observations of known Solar System objects. This means that it grows not only from the ingestion of new images, but also from the growth in the number of known objects. As new bodies are discovered, our pipeline can find archived observations where they could have been recorded, providing colors for these newly-found objects. This growth becomes more relevant with the new generation of wide-field surveys, particularly LSST.We also present one use case of our prototype archive: after ingesting the metadata for SDSS, 2MASS and GALEX, we were able to identify serendipitous observations of Solar System bodies in these 3 archives. Cross-matching these occurrences provided us with colors from the UV to the IR, a much wider spectral range than that

  10. Planetary Image Geometry Library

    NASA Technical Reports Server (NTRS)

    Deen, Robert C.; Pariser, Oleg

    2010-01-01

    The Planetary Image Geometry (PIG) library is a multi-mission library used for projecting images (EDRs, or Experiment Data Records) and managing their geometry for in-situ missions. A collection of models describes cameras and their articulation, allowing application programs such as mosaickers, terrain generators, and pointing correction tools to be written in a multi-mission manner, without any knowledge of parameters specific to the supported missions. Camera model objects allow transformation of image coordinates to and from view vectors in XYZ space. Pointing models, specific to each mission, describe how to orient the camera models based on telemetry or other information. Surface models describe the surface in general terms. Coordinate system objects manage the various coordinate systems involved in most missions. File objects manage access to metadata (labels, including telemetry information) in the input EDRs and RDRs (Reduced Data Records). Label models manage metadata information in output files. Site objects keep track of different locations where the spacecraft might be at a given time. Radiometry models allow correction of radiometry for an image. Mission objects contain basic mission parameters. Pointing adjustment ("nav") files allow pointing to be corrected. The object-oriented structure (C++) makes it easy to subclass just the pieces of the library that are truly mission-specific. Typically, this involves just the pointing model and coordinate systems, and parts of the file model. Once the library was developed (initially for Mars Polar Lander, MPL), adding new missions ranged from two days to a few months, resulting in significant cost savings as compared to rewriting all the application programs for each mission. Currently supported missions include Mars Pathfinder (MPF), MPL, Mars Exploration Rover (MER), Phoenix, and Mars Science Lab (MSL). Applications based on this library create the majority of operational image RDRs for those missions. A

  11. Detection techniques for tenuous planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Hoenig, S. A.

    1971-01-01

    The development of new types of detectors for analysis of planetary atmospheres is discussed. Initially, the interest was in detectors for use under partial vacuum conditions. The program has been extended to include detectors for use at one atmosphere and adsorption system for control and separation of gases. Results to date have included detectors for O2 and H2 under partial vacuum conditions. Experiments on detectors for use at high pressures began in 1966, and systems for CO, H2, and O2, were reported. Electrically controlled adsorbent was developed. It was demonstrated that under proper conditions a thin film of semiconductor material could be electrically cycled to adsorb and desorb a specific gas. This work was extended to obtain quantitative data on the use of semiconductors as controllable adsorbents.

  12. Detection techniques for tenuous planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Hoenig, S. A.; Summerton, J. E.; Kirchner, J. D.; Allred, J. B.

    1974-01-01

    The development of new types of detectors for analysis of planetary atmospheres is discussed. Initially, the interest was in detectors for use under partial vacuum conditions; recently, the program has been extended to include detectors for use at one atmosphere and adsorption systems for control and separation of gases. Results to date have included detector for O2 and H2 under partial vacuum conditions. Experiments on detectors for use at high pressures began in 1966; and systems for CO, H2, and O2 were reported in 1967 and 1968. In 1968 studies began on an electrically controlled adsorbent. It was demonstrated that under proper conditions a thin film of semiconductor material could be electrically cycled to absorb and desorb a specific gas. This work was extended to obtain quantitative data on the use of semiconductors as controllable adsorbents.

  13. The formation of volcanic centers at the Colorado Plateau as a result of the passage of aqueous fluid through the oceanic lithosphere and the subcontinental mantle: New implications for the planetary water cycle in the western United States

    NASA Astrophysics Data System (ADS)

    Sommer, Holger; Regenauer-Lieb, Klaus; Gasharova, Biliana; Jung, Haemyeong

    2012-10-01

    could reach up to ˜1000 ppm wt H2O. However, the formation of antigorite in grain boundaries was found to be the primary hydration mechanism for harzburgitic samples originating from the subcontinental mantle (for hydration, T ≈ 600 °C). Additionally, the formation of antigorite in lherzolites could be found in annealed cracks. From these observations, we conclude that hydration induces multi-stage water enrichment of the mantle wedge by a process that is dominated by the growth and movement of ubiquitous cracks, which acts as planar defects. Cracks in the mantle seem to be the an important feature in both the water cycle of the subduction zone and the formation of the continental lithosphere.

  14. TAPIR--Finnish national geochemical baseline database.

    PubMed

    Jarva, Jaana; Tarvainen, Timo; Reinikainen, Jussi; Eklund, Mikael

    2010-09-15

    In Finland, a Government Decree on the Assessment of Soil Contamination and Remediation Needs has generated a need for reliable and readily accessible data on geochemical baseline concentrations in Finnish soils. According to the Decree, baseline concentrations, referring both to the natural geological background concentrations and the diffuse anthropogenic input of substances, shall be taken into account in the soil contamination assessment process. This baseline information is provided in a national geochemical baseline database, TAPIR, that is publicly available via the Internet. Geochemical provinces with elevated baseline concentrations were delineated to provide regional geochemical baseline values. The nationwide geochemical datasets were used to divide Finland into geochemical provinces. Several metals (Co, Cr, Cu, Ni, V, and Zn) showed anomalous concentrations in seven regions that were defined as metal provinces. Arsenic did not follow a similar distribution to any other elements, and four arsenic provinces were separately determined. Nationwide geochemical datasets were not available for some other important elements such as Cd and Pb. Although these elements are included in the TAPIR system, their distribution does not necessarily follow the ones pre-defined for metal and arsenic provinces. Regional geochemical baseline values, presented as upper limit of geochemical variation within the region, can be used as trigger values to assess potential soil contamination. Baseline values have also been used to determine upper and lower guideline values that must be taken into account as a tool in basic risk assessment. If regional geochemical baseline values are available, the national guideline values prescribed in the Decree based on ecological risks can be modified accordingly. The national geochemical baseline database provides scientifically sound, easily accessible and generally accepted information on the baseline values, and it can be used in various

  15. NASA Planetary Science Summer School: Preparing the Next Generation of Planetary Mission Leaders

    NASA Astrophysics Data System (ADS)

    Budney, C. J.; Lowes, L. L.; Sohus, A.; Wheeler, T.; Wessen, A.; Scalice, D.

    2010-12-01

    Sponsored by NASA’s Planetary Science Division, and managed by the Jet Propulsion Laboratory, the Planetary Science Summer School prepares the next generation of engineers and scientists to participate in future solar system exploration missions. Participants learn the mission life cycle, roles of scientists and engineers in a mission environment, mission design interconnectedness and trade-offs, and the importance of teamwork. For this professional development opportunity, applicants are sought who have a strong interest and experience in careers in planetary exploration, and who are science and engineering post-docs, recent PhDs, and doctoral students, and faculty teaching such students. Disciplines include planetary science, geoscience, geophysics, environmental science, aerospace engineering, mechanical engineering, and materials science. Participants are selected through a competitive review process, with selections based on the strength of the application and advisor’s recommendation letter. Under the mentorship of a lead engineer (Dr. Charles Budney), students select, design, and develop a mission concept in response to the NASA New Frontiers Announcement of Opportunity. They develop their mission in the JPL Advanced Projects Design Team (Team X) environment, which is a cross-functional multidisciplinary team of professional engineers that utilizes concurrent engineering methodologies to complete rapid design, analysis and evaluation of mission concept designs. About 36 students participate each year, divided into two summer sessions. In advance of an intensive week-long session in the Project Design Center at JPL, students select the mission and science goals during a series of six weekly WebEx/telecons, and develop a preliminary suite of instrumentation and a science traceability matrix. Students assume both a science team and a mission development role with JPL Team X mentors. Once at JPL, students participate in a series of Team X project design

  16. The complex planetary synchronization structure of the solar system

    NASA Astrophysics Data System (ADS)

    Scafetta, N.

    2014-01-01

    The complex planetary synchronization structure of the solar system, which since Pythagoras of Samos (ca. 570-495 BC) is known as the music of the spheres, is briefly reviewed from the Renaissance up to contemporary research. Copernicus' heliocentric model from 1543 suggested that the planets of our solar system form a kind of mutually ordered and quasi-synchronized system. From 1596 to 1619 Kepler formulated preliminary mathematical relations of approximate commensurabilities among the planets, which were later reformulated in the Titius-Bode rule (1766-1772), which successfully predicted the orbital position of Ceres and Uranus. Following the discovery of the ~ 11 yr sunspot cycle, in 1859 Wolf suggested that the observed solar variability could be approximately synchronized with the orbital movements of Venus, Earth, Jupiter and Saturn. Modern research has further confirmed that (1) the planetary orbital periods can be approximately deduced from a simple system of resonant frequencies; (2) the solar system oscillates with a specific set of gravitational frequencies, and many of them (e.g., within the range between 3 yr and 100 yr) can be approximately constructed as harmonics of a base period of ~ 178.38 yr; and (3) solar and climate records are also characterized by planetary harmonics from the monthly to the millennial timescales. This short review concludes with an emphasis on the contribution of the author's research on the empirical evidences and physical modeling of both solar and climate variability based on astronomical harmonics. The general conclusion is that the solar system works as a resonator characterized by a specific harmonic planetary structure that also synchronizes the Sun's activity and the Earth's climate. The special issue Pattern in solar variability, their planetary origin and terrestrial impacts (Mörner et al., 2013) further develops the ideas about the planetary-solar-terrestrial interaction with the personal contribution of 10

  17. Atomic hydrogen in planetary nebulae

    NASA Technical Reports Server (NTRS)

    Schneider, Stephen E.; Silverglate, Peter R.; Altschuler, Daniel R.; Giovanardi, Carlo

    1987-01-01

    The authors searched for neutral atomic hydrogen associated with 22 planetary nebulae and three evolved stars in the 21 cm line at the Arecibo Observatory. Objects whose radial velocities permitted discrimination from Galactic H I were chosen for observation. Hydrogen was detected in absorption from IC 4997. From the measurements new low limits are derived to the mass of atomic hydrogen associated with the undetected nebulae. Radio continuum observations were also made of several of the nebulae at 12.6 cm. The authors reexamine previous measurements of H I in planetary nebulae, and present the data on a consistent footing. The question of planetary nebula distances is considered at length. Finally, implications of the H I measurements for nebular evolution are discussed and it is suggested that atomic hydrogen seen in absorption was expelled from the progenitor star during the final 1000 yr prior to the onset of ionization.

  18. International Agreement on Planetary Protection

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The maintenance of a NASA policy, is consistent with international agreements. The planetary protection policy management in OSS, with Field Center support. The advice from internal and external advisory groups (NRC, NAC/Planetary Protection Task Force). The technology research and standards development in bioload characterization. The technology research and development in bioload reduction/sterilization. This presentation focuses on: forward contamination - research on the potential for Earth life to exist on other bodies, improved strategies for planetary navigation and collision avoidance, and improved procedures for sterile spacecraft assembly, cleaning and/or sterilization; and backward contamination - development of sample transfer and container sealing technologies for Earth return, improvement in sample return landing target assessment and navigation strategy, planning for sample hazard determination requirements and procedures, safety certification, (liaison to NEO Program Office for compositional data on small bodies), facility planning for sample recovery system, quarantine, and long-term curation of 4 returned samples.

  19. Dynamical Evolution of Planetary Embryos

    NASA Technical Reports Server (NTRS)

    Wetherill, George W.

    2002-01-01

    During the past decade, progress has been made by relating the 'standard model' for the formation of planetary systems to computational and observational advances. A significant contribution to this has been provided by this grant. The consequence of this is that the rigor of the physical modeling has improved considerably. This has identified discrepancies between the predictions of the standard model and recent observations of extrasolar planets. In some cases, the discrepancies can be resolved by recognition of the stochastic nature of the planetary formation process, leading to variations in the final state of a planetary system. In other cases, it seems more likely that there are major deficiencies in the standard model, requiring our identifying variations to the model that are not so strongly constrained to our Solar System.

  20. Robotic vehicles for planetary exploration

    NASA Astrophysics Data System (ADS)

    Wilcox, Brian; Matthies, Larry; Gennery, Donald; Cooper, Brian; Nguyen, Tam; Litwin, Todd; Mishkin, Andrew; Stone, Henry

    A program to develop planetary rover technology is underway at the Jet Propulsion Laboratory (JPL) under sponsorship of the National Aeronautics and Space Administration. Developmental systems with the necessary sensing, computing, power, and mobility resources to demonstrate realistic forms of control for various missions have been developed, and initial testing has been completed. These testbed systems and the associated navigation techniques used are described. Particular emphasis is placed on three technologies: Computer-Aided Remote Driving (CARD), Semiautonomous Navigation (SAN), and behavior control. It is concluded that, through the development and evaluation of such technologies, research at JPL has expanded the set of viable planetary rover mission possibilities beyond the limits of remotely teleoperated systems such as Lunakhod. These are potentially applicable to exploration of all the solid planetary surfaces in the solar system, including Mars, Venus, and the moons of the gas giant planets.

  1. From Planetary Mapping to Map Production: Planetary Cartography as integral discipline in Planetary Sciences

    NASA Astrophysics Data System (ADS)

    Nass, Andrea; van Gasselt, Stephan; Hargitai, Hendrik; Hare, Trent; Manaud, Nicolas; Karachevtseva, Irina; Kersten, Elke; Roatsch, Thomas; Wählisch, Marita; Kereszturi, Akos

    2016-04-01

    Cartography is one of the most important communication channels between users of spatial information and laymen as well as the open public alike. This applies to all known real-world objects located either here on Earth or on any other object in our Solar System. In planetary sciences, however, the main use of cartography resides in a concept called planetary mapping with all its various attached meanings: it can be (1) systematic spacecraft observation from orbit, i.e. the retrieval of physical information, (2) the interpretation of discrete planetary surface units and their abstraction, or it can be (3) planetary cartography sensu strictu, i.e., the technical and artistic creation of map products. As the concept of planetary mapping covers a wide range of different information and knowledge levels, aims associated with the concept of mapping consequently range from a technical and engineering focus to a scientific distillation process. Among others, scientific centers focusing on planetary cartography are the United State Geological Survey (USGS, Flagstaff), the Moscow State University of Geodesy and Cartography (MIIGAiK, Moscow), Eötvös Loránd University (ELTE, Hungary), and the German Aerospace Center (DLR, Berlin). The International Astronomical Union (IAU), the Commission Planetary Cartography within International Cartographic Association (ICA), the Open Geospatial Consortium (OGC), the WG IV/8 Planetary Mapping and Spatial Databases within International Society for Photogrammetry and Remote Sensing (ISPRS) and a range of other institutions contribute on definition frameworks in planetary cartography. Classical cartography is nowadays often (mis-)understood as a tool mainly rather than a scientific discipline and an art of communication. Consequently, concepts of information systems, mapping tools and cartographic frameworks are used interchangeably, and cartographic workflows and visualization of spatial information in thematic maps have often been

  2. Stability of inner planetary systems

    NASA Technical Reports Server (NTRS)

    Szebehely, V.

    1979-01-01

    The stability of inner planetary systems with arbitrary mass ratios is studied on the basis of the model of the plane restricted three-body problem. A quantitative stability criterion is obtained in terms of the difference between the critical value of the Jacobi constants (at which bifurcation can occur) and the critical value corresponding to a planetary orbit. An orbit is stable if it cannot leave a region that contains only the larger central body (Hill). For small values of the mass parameter, the maximum dimensionless radius of a Hill-stable orbit is 1 minus 2.4 times the cube root of the mass parameter.

  3. Molecular Hydrogen in Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Speck, Angela K.; Baldridge, Sean; Matsuura, Mikako

    2015-08-01

    Planetary Nebulae (PNe) have long played the role of laboratories for investigating atomic, molecular, dust and plasma physics, which have applications to diverse other astrophysical environments. In this presentation we will discuss clumpy structures within planetary nebulae that are the hosts to, and protectors of molecular gas in an otherwise forbidding ionized zone. We will present new observations of the molecular hydrogen emission from several PNe and discuss their implications for the formation, evolution and survival/demise of such molecular globules. The science behind dust and molecule formation and survival that apply to many other astronomical objects and places.

  4. Electromagnetic effects on planetary rings

    SciTech Connect

    Morfill, G.E.

    1983-01-01

    The role of electromagnetic effects in planetary rings is reviewed. The rings consist of a collection of solid particles with a size spectrum ranging from submicron to 10's of meters (at least in the case of Saturn's rings). Due to the interaction with the ambient plasma, and solar UV radiation, the particles carry electrical charges. Interactions of particles with the planetary electromagnetic field, both singly and collectively, are described, as well as the reactions and influence on plasma transients. The latter leads to a theory for the formation of Saturn's spokes, which is briefly reviewed.

  5. Virtual reality and planetary exploration

    NASA Technical Reports Server (NTRS)

    Mcgreevy, Michael W.

    1992-01-01

    NASA-Ames is intensively developing virtual-reality (VR) capabilities that can extend and augment computer-generated and remote spatial environments. VR is envisioned not only as a basis for improving human/machine interactions involved in planetary exploration, but also as a medium for the more widespread sharing of the experience of exploration, thereby broadening the support-base for the lunar and planetary-exploration endeavors. Imagery representative of Mars are being gathered for VR presentation at such terrestrial sites as Antarctica and Death Valley.

  6. Quantitative Studies in Planetary Volcanism

    NASA Technical Reports Server (NTRS)

    Baloga, Stephen M.

    2001-01-01

    Scientific research was conducted on volcanic processes on Mars, Venus, Io, the moon, and the Earth. The achievements led to scientific advances in the understanding of volcanic plumes, lava flow emplacements, coronae, and regoliths on the solid surfaces. This research led to multiple publications on each of the main topics of the proposal. Research was also presented at the annual Lunar and Planetary Science Conference at Houston. Typically, this grant contributed to 3-4 presentations each year. This grant demonstrated, numerous times, the usefulness of NASA mission data for advancing the understanding of volcanic processes on other planetary surfaces and the Earth.

  7. Density in a Planetary Exosphere

    NASA Technical Reports Server (NTRS)

    Herring, Jackson; Kyle, Herbert L.

    1961-01-01

    A discussion of the Opik-Singer theory of the density of a planetary exosphere is presented. Their density formula permits the calculation of the depth of the exosphere. Since the correctness of their derivation of the basic formula for the density distribution has been questioned, an alternate method based directly on Liouville's theorem is given. It is concluded that the Opik-Singer formula seems valid for the ballistic component of the exosphere; but for a complete description of the planetary exosphere, the ionized and bound-orbit components must also be included.

  8. Proceedings of the workshop on geochemical modeling

    SciTech Connect

    Not Available

    1986-01-01

    The following collection of papers was presented at a workshop on geochemical modeling that was sponsored by the Office of Civilian Radioactive Waste Management Program at the Lawrence Livermore National Laboratory (LLNL). The LLNL Waste Management Program sponsored this conference based on their belief that geochemical modeling is particularly important to the radioactive waste disposal project because of the need to predict the consequences of long-term water-rock interactions at the proposed repository site. The papers included in this volume represent a subset of the papers presented at the Fallen Leaf Lake Conference and cover a broad spectrum of detail and breadth in a subject that reflects the diverse research interests of the conference participants. These papers provide an insightful look into the current status of geochemical modeling and illustrate how various geochemical modeling codes have been applied to problems of geochemical interest. The emphasis of these papers includes traditional geochemical modeling studies of individual geochemical systems, the mathematical and theoretical development and refinement of new modeling capabilities, and enhancements of data bases on which the computations are based. The papers in this proceedings volume have been organized into the following four areas: Geochemical Model Development, Hydrothermal and Geothermal Systems, Sedimentary and Low Temperature Environments, and Data Base Development. The participants of this symposium and a complete list of the talks presented are listed in the appendices.

  9. Activities at the Lunar and Planetary Institute

    NASA Technical Reports Server (NTRS)

    Burke, K.

    1984-01-01

    The scientific and administrative activities of the Lunar and Planetary Institute are summarized. Recent research relating to geophysics, planetary geology, the origin of the Earth and Moon, the lunar surface, Mars, meteorites, and image processing techniques is discussed.

  10. Planetary quarantine. Space research and technology

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Planetary quarantine strategies for advanced spacecraft consider effects of satellite encounter, Jupiter atmosphere entry, space radiation, and cleaning and decontamination techniques on microbiological growth probability. Analytical restructuring is developed for microbial burden prediction and planetary contamination.

  11. International Infrastructure for Planetary Sciences: Universal Planetary Database Development Project 'the International Planetary Data Alliance'

    NASA Astrophysics Data System (ADS)

    Kasaba, Yasumasa; Crichton, D.; Capria, M. T.; Beebe, R.; Zender, J.

    2009-09-01

    The International Planetary Data Alliance (IPDA), formed under COSPAR in 2008, is a joint international effort to enable global access and exchange of high quality planetary science data, and to establish archive standards that make it easier to share data across international boundaries. In June - July 2009, we held the 4th Steering Committee meeting. Thanks to the many players from several agencies and institutions in the world, we got fruitful results in 6 projects: (1) Inter-operable Planetary Data Access Protocol (PDAP) implementations [led by J. Salgado@ESA], (2) Small bodies interoperability [led by I. Shinohara@JAXA & N. Hirata@U. Aizu], (3) PDAP assessment [led by Y. Yamamoto@JAXA], (4) Architecture and standards definition [led by D. Crichton@NASA], (5) Information model and data dictionary [led by S. Hughes@NASA], and (6) Venus Express Interoperability [led by N. Chanover@NMSU]. The projects demonstrated the feasibility of sharing data and emphasized the importance of developing common data standards to ensure world-wide access to international planetary archives. The Venus Express Interoperability project leveraged standards and technology efforts from both the Planetary Data System (PDS) and IPDA in order to deliver a new capability for data sharing between NASA/PDS and ESA/PSA. This project demonstrated a model and framework for linking compliant planetary archive systems for future international missions. The next step for IPDA, during the 2009-2010 period, will be to work with NASA/PDS to review and participate in an upgrade of its standards to improve both the consistency of the standards to build compliant international archives as well as improve long-term usability of the science data products. This paper presents the achievements and plans, which will be summarized in the paper which will appear in 'Space Research Today' in December 2009.

  12. Geochemical challenge to earthquake prediction.

    PubMed Central

    Wakita, H

    1996-01-01

    The current status of geochemical and groundwater observations for earthquake prediction in Japan is described. The development of the observations is discussed in relation to the progress of the earthquake prediction program in Japan. Three major findings obtained from our recent studies are outlined. (i) Long-term radon observation data over 18 years at the SKE (Suikoen) well indicate that the anomalous radon change before the 1978 Izu-Oshima-kinkai earthquake can with high probability be attributed to precursory changes. (ii) It is proposed that certain sensitive wells exist which have the potential to detect precursory changes. (iii) The appearance and nonappearance of coseismic radon drops at the KSM (Kashima) well reflect changes in the regional stress state of an observation area. In addition, some preliminary results of chemical changes of groundwater prior to the 1995 Kobe (Hyogo-ken nanbu) earthquake are presented. PMID:11607665

  13. Geochemical data synthesis and analysis

    NASA Technical Reports Server (NTRS)

    Philpotts, J. A.

    1979-01-01

    Data obtained at the Goddard Flight Center were collected for the purpose of completing analyses started at Goddard in order to maximize the scientific yield of the geochemistry program which was terminated in 1977. The major analytical task undertaken was to complete Gd analyses on a large number of samples already analyzed by mass spectrometry for other rare earth element abundances at Goddard. Gd values are important for pinning down the central part of the geochemically significant rare earth abundance pattern and are especially useful in the high precision definition of the utilitarian Eu anomaly. Isotope-dilution Gd abundances were obtained for 39 samples. The data are for 27 partition-coefficient samples, six Apollo 15 and 16 breccia samples, four terrestrial impactities, and associated rock standards.

  14. A Model for Siderophile Element Distribution in Planetary Differentiation

    NASA Technical Reports Server (NTRS)

    Humayun, M.; Rushmer, T.; Rankenburg, K.; Brandon, A. D.

    2005-01-01

    Planetary differentiation begins with partial melting of small planetesimals. At low degrees of partial melting, a sulfur-rich liquid segregates by physical mechanisms including deformation-assisted porous flow. Experimental studies of the physical mechanisms by which Fe-S melts segregate from the silicate matrix of a molten H chondrite are part of a companion paper. Geochemical studies of these experimental products revealed that metallic liquids were in equilibrium with residual metal in the H chondrite matrix. This contribution explores the geochemical signatures produced by early stages of core formation. Particularly, low-degree partial melt segregation of Fe-S liquids leaves residual metal in the silicate matrix. Some achondrites appear to be residues of partial melting, e.g., ureilites, which are known to contain metal. The metal in these achondrites may show a distinct elemental signature. To quantify the effect of sulfur on siderophile element contents of residual metal we have developed a model based on recent parametrizations of equilibrium solid metal-liquid metal partitioning experiments.

  15. PHREEQC. Geochemical Speciation Mass Transfer

    SciTech Connect

    Parkhurst, D.L.

    1995-01-01

    PHREEQC is designed to model geochemical reactions. Based on an ion association aqueous model, PHREEQC can calculate pH, redox potential, and mass transfer as a function of reaction progress. It can be used to describe geochemical processes for both far-field and near-field performance assessment and to evaluate data acquisition needs and test data. It can also calculate the composition of solutions in equilibrium with multiple phases. The data base, including elements, aqueous species, and mineral phases, is independent of the program and is completely user-definable. PHREEQC requires thermodynamic data for each solid, gaseous, or dissolved chemical species being modeled. The two data bases, PREPHR and DEQPAK7, supplied with PHREEQC are for testing purposes only and should not be applied to real problems without first being carefully examined. The conceptual model embodied in PHREEQC is the ion-association model of Pearson and Noronha. In this model a set of mass action equations are established for each ion pair (and controlling solid phases when making mass transfer calculations) along with a set of mass balance equations for each element considered. These sets of equations are coupled using activity coefficient values for each aqueous species and solved using a continued fraction approach for the mass balances combined with a modified Newton-Raphson technique for all other equations. The activity coefficient expressions in PHREEQC include the extended Debye-Huckel, WATEQ Debye-Huckel, and Davies equations from the original United States Geological Survey version of the program. The auxiliary preprocessor program PHTL, which is derived from EQTL, converts EQ3/6 thermodynamic data to PHREEQC format so that the two programs can be compared. PHREEQC can be used to determine solubility limits on the radionuclides present in the waste form. These solubility constraints may be input to the WAPPA leach model.

  16. The geochemical composition of the terrestrial surface (without soils) and comparison with the upper continental crust

    NASA Astrophysics Data System (ADS)

    Hartmann, Jens; Dürr, Hans H.; Moosdorf, Nils; Meybeck, Michel; Kempe, Stephan

    2012-01-01

    The terrestrial surface, the "skin of the earth", is an important interface for global (geochemical) material fluxes between major reservoirs of the Earth system: continental and oceanic crust, ocean and atmosphere. Because of a lack in knowledge of the geochemical composition of the terrestrial surface, it is not well understood how the geochemical evolution of the Earth's crust is impacted by its properties. Therefore, here a first estimate of the geochemical composition of the terrestrial surface is provided, which can be used for further analysis. The geochemical average compositions of distinct lithological classes are calculated based on a literature review and applied to a global lithological map. Comparison with the bulk composition of the upper continental crust shows that the geochemical composition of the terrestrial surface (below the soil horizons) is significantly different from the assumed average of the upper continental crust. Specifically, the elements Ca, S, C, Cl and Mg are enriched at the terrestrial surface, while Na is depleted (and probably K). Analysis of these results provide further evidence that chemical weathering, chemical alteration of minerals in marine settings, biogeochemical processes (e.g. sulphate reduction in sediments and biomineralization) and evaporite deposition are important for the geochemical composition of the terrestrial surface on geological time scales. The movement of significant amounts of carbonate to the terrestrial surface is identified as the major process for observed Ca-differences. Because abrupt and significant changes of the carbonate abundance on the terrestrial surface are likely influencing CO2-consumption rates by chemical weathering on geological time scales and thus the carbon cycle, refined, spatially resolved analysis is suggested. This should include the recognition of the geochemical composition of the shelf areas, now being below sea level.

  17. Priority Planetary Science Missions Identified

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-03-01

    The U.S. National Research Council's (NRC) planetary science decadal survey report, released on 7 March, lays out a grand vision for priority planetary science missions for 2013-2022 within a tightly constrained fiscal environment. The cost-conscious report, issued by NRC's Committee on the Planetary Science Decadal Survey, identifies high-priority flagship missions, recommends a number of potential midsized missions, and indicates support for some smaller missions. The report states that the highest-priority flagship mission for the decade is the Mars Astrobiology Explorer-Cacher (MAX-C)—the first of three components of a NASA/European Space Agency Mars sample return campaign—provided that the mission scope can be reduced so that MAX-C costs no more than $2.5 billion. The currently estimated mission cost of $3.5 billion “would take up a disproportionate near-term share of the overall budget for NASA's Planetary Science Division,” the report notes.

  18. Planetary Science Resource Data Model

    NASA Astrophysics Data System (ADS)

    Cecconi, B.; Berthier, J.; Bourrel, N.; Gangloff, M.; Erard, S.; Le Sidaner, P.; André, N.; Jacquey, C.; Lormant, N.

    2012-09-01

    One the goals of the Europlanet/IDIS project is the prototyping a Planetary Sciences Virtual Observatory (VO). Planetary sciences are covering several science thematics: atmospheres, surfaces, interiors, small bodies, orbital parameters, in situ exploration, plasma (waves, particle and fields), radio astronomy... They also include a large variety of data types: images, spectra, times series, movies, dynamic spectra, profiles, maps... and an even larger variety of physical parameters, including remote data, in-situ data, models, lab experiments, field analogs. The main challenge is thus to be able to homogeneously describe all the planetary science resources (dataset, files, services...). The skeleton of a such a description is the data model. The Planetary Science Resource Data Model (PSRDM) has been built using IVOA (International Virtual Observatory Alliance). We describe the content of Datasets and Granules (i.e., product, file, or the smallest granularity distributed by the service), not the access to the data. This description includes: Resource identification, Targets, Instruments (including hosting facility), Axis (including bounds, resolution, sampling, unit), Physical parameter (including UCD, unit).

  19. Reports of planetary astronomy - 1991

    NASA Technical Reports Server (NTRS)

    Rahe, Jurgen (Editor)

    1993-01-01

    This publication provides information about currently funded scientific research projects conducted in the Planetary Astronomy Program during 1991, and consists of two main sections. The first section gives a summary of research objectives, past accomplishments, and projected future investigations, as submitted by each principal investigator. In the second section, recent scientifically significant accomplishments within the Program are highlighted.

  20. Photometric calibration of planetary photographs

    NASA Technical Reports Server (NTRS)

    Beebe, R. F.

    1976-01-01

    The basic data and approach for calibrating photographic plates obtained with the 61 cm telescope at the Tortugas Mountain Station of New Mexico State University are summarized. Since this is the fundamental calibration of planetary data it is of use to all in-house users as well as other individuals who use the data.

  1. Virtual reality and planetary exploration

    NASA Technical Reports Server (NTRS)

    Mcgreevy, Michael W.

    1992-01-01

    Exploring planetary environments is central to NASA's missions and goals. A new computing technology called Virtual Reality has much to offer in support of planetary exploration. This technology augments and extends human presence within computer-generated and remote spatial environments. Historically, NASA has been a leader in many of the fundamental concepts and technologies that comprise Virtual Reality. Indeed, Ames Research Center has a central role in the development of this rapidly emerging approach to using computers. This ground breaking work has inspired researchers in academia, industry, and the military. Further, NASA's leadership in this technology has spun off new businesses, has caught the attention of the international business community, and has generated several years of positive international media coverage. In the future, Virtual Reality technology will enable greatly improved human-machine interactions for more productive planetary surface exploration. Perhaps more importantly, Virtual Reality technology will democratize the experience of planetary exploration and thereby broaden understanding of, and support for, this historic enterprise.

  2. Isotopic analysis of planetary solids

    NASA Astrophysics Data System (ADS)

    Tulej, M.; Riedo, A.; Neuland, M.; Meyer, S.; Wurz, P.

    2013-09-01

    Isotopic analysis of planetary surfaces is of considerable interest for planetology. Studies of isotope composition can deliver information on radio-isotope chronology of planetary soil/regolith, an insight to processes that altered planetary surface (space weathering) or on possible biogenic processes that occurred or still occur on the planet. Mass spectrometry is a well-suited method that delivers accurate and precise isotope composition. Among other instruments (LAZMA and LAMS), the miniature laser ablation/ionisation mass analyser, LMS developed in Bern for in situ space research can be used to measure the elemental and isotopic composition of planetary solids. LMS support mass spectrometric investigation with a mass resolution of m/Δm≈500-1500, dynamic range of at least 8 decades and detection sensitivity of ~10 ppb. Current studies of various solid materials and standard reference materials show that isotope composition can be conducted with an accuracy and precision at per mill level if the isotope concentration exceeds 10-100 ppm. Implications of the studies for in situ application are discussed.

  3. Reports of planetary astronomy, 1989

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This is a compilation of abstracts of reports from Principal Investigators funded through NASA's Planetary Astronomy Office. It provides a summarization of work conducted in this program in 1989. Each report contains a brief statement on the strategy of investigation and lists significant accomplishments within the area of the author's funded grant or contract, plans for future work, and publications.

  4. Lunar and Planetary Science XXXII

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This CD-ROM publication contains the extended abstracts that were accepted for presentation at the 32nd Lunar and Planetary Science Conference held at Houston, TX, March 12-16, 2001. The papers are presented in PDF format and are indexed by author, keyword, meteorite, program and samples for quick reference.

  5. 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.

  6. Use of Geochemical Indices in Environmental Assessment of Soil; the Predictable and the Predictably Unpredictable

    NASA Astrophysics Data System (ADS)

    Mikkonen, Hannah; Clarke, Bradley; van de Graaff, Robert; Reichman, Suzie

    2016-04-01

    application of geochemical indices without an understanding of site specific conditions could result in significant underestimation of anthropogenic impacts to soil and potential risks to the environment. The reliability and application of geochemical indices for estimation of background concentrations will be discussed, including comment on statistical limitations, (such as management of censored results and the behaviour of composition data) and miss-use/miss-interpretation of geochemical indices within the environmental assessment industry, including inferences of causation based on empirical relationships. HAMON, R. E., MCLAUGHLIN, M. J., GILKES, R. J., RATE, A. W., ZARCINAS, B., ROBERTSON, A., COZENS, G., RADFORD, N. & BETTENAY, L. 2004. Geochemical indices allow estimation of heavy metal background concentrations in soils. Global Biogeochemical Cycles, 18, GB1014. MYERS, J. & THORBJORNSEN, K. 2004. Identifying Metals Contamination in Soil: A Geochemical Approach. Soil & Sediment Contamination, 13, 1-16.

  7. Thermochemical cycles

    NASA Technical Reports Server (NTRS)

    Funk, J. E.; Soliman, M. A.; Carty, R. H.; Conger, W. L.; Cox, K. E.; Lawson, D.

    1975-01-01

    The thermochemical production of hydrogen is described along with the HYDRGN computer program which attempts to rate the various thermochemical cycles. Specific thermochemical cycles discussed include: iron sulfur cycle; iron chloride cycle; and hybrid sulfuric acid cycle.

  8. The global sulfur cycle

    NASA Technical Reports Server (NTRS)

    Sagan, D. (Editor)

    1985-01-01

    The results of the planetary biology microbial ecology's 1984 Summer Research Program, which examined various aspects of the global sulfur cycle are summarized. Ways in which sulfur flows through the many living and chemical species that inhabit the surface of the Earth were investigated. Major topics studied include: (1) sulfur cycling and metabolism of phototropic and filamentous sulfur bacteria; (2) sulfur reduction in sediments of marine and evaporite environments; (3) recent cyanobacterial mats; (4) microanalysis of community metabolism in proximity to the photic zone in potential stromatolites; and (5) formation and activity of microbial biofilms on metal sulfides and other mineral surfaces. Relationships between the global sulfur cycle and the understanding of the early evolution of the Earth and biosphere and current processes that affect global habitability are stressed.

  9. Studying planetary debris disks around isolated, hot white dwarfs

    NASA Astrophysics Data System (ADS)

    Brinkworth, Carolyn; Gaensicke, Boris; Marsh, Tom; Hoard, Donald; Girven, Jonathan

    2010-06-01

    While more than 440 extrasolar planets orbiting main sequence stars have been discovered, the destiny of planetary systems through the late stages of the evolution of their host stars is very uncertain. We identified metal-rich (CaII and MgII emission) gas disks around 5 relatively young, hot white dwarfs, three of which were the subject of a previous Spitzer program in Cycle-5. The Cycle-5 data revealed a large, dusty extension to the gaseous debris disks, likely originating with the tidal breakup of an asteroid left over from an ancient planetary system. Our recent intensive studies of the three original systems have now turned up variability in the line profiles of the gaseous disks, suggesting the exciting possibility that we are witnessing the real-time dynamical evolution of planetary debris around these white dwarfs. We propose to extend this study to two newly-discovered, cooler members of this small sample of objects, to determine whether dust and gas can also coexist around cooler stars. Since these stars should be too cool to produce the observed CaII emission, we suspect that there is additional mechanical heating in these systems, caused by the recent impacts of asteroids. If so, CaII emission would likely be the signature of the youngest, freshest debris disks around these stars.

  10. Lunar and Planetary Science XXXV: Origin of Planetary Systems

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session "Origin of Planetary Systems" included the following reports: (12753) Povenmire - Standard Comparison Small Main Belt Asteroid?; Gravitational Frequencies of Extra-Solar Planets; 'Jumping Jupiters' in Binary Star Systems; Hermes, Asteroid 2002 SY50 and the Northern Cetids - No Link Found!; What Kind of Accretion Model is Required for the Solar System; and Use of an Orbital Phase Curve of Extrasolar Planet for Specification of its Mass.

  11. Exploring the planetary boundary for chemical pollution.

    PubMed

    Diamond, Miriam L; de Wit, Cynthia A; Molander, Sverker; Scheringer, Martin; Backhaus, Thomas; Lohmann, Rainer; Arvidsson, Rickard; Bergman, Åke; Hauschild, Michael; Holoubek, Ivan; Persson, Linn; Suzuki, Noriyuki; Vighi, Marco; Zetzsch, Cornelius

    2015-05-01

    Rockström et al. (2009a, 2009b) have warned that humanity must reduce anthropogenic impacts defined by nine planetary boundaries if "unacceptable global change" is to be avoided. Chemical pollution was identified as one of those boundaries for which continued impacts could erode the resilience of ecosystems and humanity. The central concept of the planetary boundary (or boundaries) for chemical pollution (PBCP or PBCPs) is that the Earth has a finite assimilative capacity for chemical pollution, which includes persistent, as well as readily degradable chemicals released at local to regional scales, which in aggregate threaten ecosystem and human viability. The PBCP allows humanity to explicitly address the increasingly global aspects of chemical pollution throughout a chemical's life cycle and the need for a global response of internationally coordinated control measures. We submit that sufficient evidence shows stresses on ecosystem and human health at local to global scales, suggesting that conditions are transgressing the safe operating space delimited by a PBCP. As such, current local to global pollution control measures are insufficient. However, while the PBCP is an important conceptual step forward, at this point single or multiple PBCPs are challenging to operationalize due to the extremely large number of commercial chemicals or mixtures of chemicals that cause myriad adverse effects to innumerable species and ecosystems, and the complex linkages between emissions, environmental concentrations, exposures and adverse effects. As well, the normative nature of a PBCP presents challenges of negotiating pollution limits amongst societal groups with differing viewpoints. Thus, a combination of approaches is recommended as follows: develop indicators of chemical pollution, for both control and response variables, that will aid in quantifying a PBCP(s) and gauging progress towards reducing chemical pollution; develop new technologies and technical and social

  12. Nature and Composition of Planetary Surficial Deposits and Their Relationship to Planetary Crusts

    NASA Astrophysics Data System (ADS)

    McLennan, S. M.

    2010-12-01

    Planetary soils constitute micron to meter sized debris blankets covering all or parts of the surfaces of many planetary bodies. Recent results from the Martian surface, by the MER rovers and Phoenix lander, the Huygens probe at Titan and perhaps even the NEAR mission to asteroid 433 Eros suggest a continuum between classic planetary soils, such as those on the Moon, and conventional sediments, such as those on Earth. Controls on this variation are governed by complex interactions related to (1) impact and volcanic history, (2) presence and nature of atmospheres (and thus climate), (3) occurrence, composition and physical state of near-surface volatiles (e.g., water, methane), and (4) presence and nature of crustal tectonics, crustal evolution, and so forth. The Moon represents one extreme where surficial deposits result almost exclusively from impact processes. Absence of water and air restrict further reworking or transport on a significant scale after initial deposition. Disruption and mixing of lunar soils takes place but is related to impact gardening operating on relatively local scales and largely in a vertical sense; alteration is restricted to space weathering. The effect is that lunar soils are compositionally variable and match the composition of the crust in the vicinity of where they form. Thus lunar soils in the highlands are fundamentally different in composition than those on maria. Earth provides the other extreme where the highly dynamic geochemical and geophysical nature of the surface precludes preservation of classic planetary soils, although analogs may exist in ejecta blankets and eolian loess. Instead, a complex suite of sedimentary deposits form in response to chemical and physical weathering, erosion, transport and deposition by a variety of mechanisms involving water, wind, ice and biology. Although there is substantial sedimentary lithological differentiation (e.g., shales, sands, carbonates, evaporites), greatly influenced by the

  13. Planetary Science with the Stratospheric Observatory for Infrared Astronomy

    NASA Astrophysics Data System (ADS)

    Reach, William T.

    2014-11-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) has executed the first two of its annual Cycles of guest investigator observing proposals. Proposals submitted for the third Cycle are under review. The planetary science community has made a significant showing in all proposal Cycles, comprising approximately 15% of Cycles 1 and 2. SOFIA offers observers access to the complete infrared spectrum, with much less atmospheric absorption than from even the finest ground-based telescope sites. New capabilities include high-resolution spectroscopy in the mid-infrared with the Echelon-Cross-Echelle Spectrograph (EXES), which allows, for example, spectroscopy of molecules from narrow stratospheric lines of planetary atmospheres, and imaging spectroscopy with the Field Imaging Far-Infrared Line Spectrometer (FIFI-LS), which allows simultaneous observation in 9 spatial pixels each of two far-infrared lines. Observations to date related to the solar system include comets ISON and PanSTARRS, main belt asteroids, Jupiter, Neptune, Europa, exoplanets, and debris disks. The poster will show science highlights, observatory capabilities, and proposal statistics.

  14. Crossing the Boundaries in Planetary Atmospheres - From Earth to Exoplanets

    NASA Technical Reports Server (NTRS)

    Simon-Miller, Amy A.; Genio, Anthony Del

    2013-01-01

    The past decade has been an especially exciting time to study atmospheres, with a renaissance in fundamental studies of Earths general circulation and hydrological cycle, stimulated by questions about past climates and the urgency of projecting the future impacts of humankinds activities. Long-term spacecraft and Earth-based observation of solar system planets have now reinvigorated the study of comparative planetary climatology. The explosion in discoveries of planets outside our solar system has made atmospheric science integral to understanding the diversity of our solar system and the potential habitability of planets outside it. Thus, the AGU Chapman Conference Crossing the Boundaries in Planetary Atmospheres From Earth to Exoplanets, held in Annapolis, MD from June 24-27, 2013 gathered Earth, solar system, and exoplanet scientists to share experiences, insights, and challenges from their individual disciplines, and discuss areas in which thinking broadly might enhance our fundamental understanding of how atmospheres work.

  15. Geochemical Reference Earth Model: thermal and geoneutrino fluxes

    NASA Astrophysics Data System (ADS)

    McDonough, W. F.; Huang, Y.; Chubakov, V.; Mantovani, F.; Rudnick, R. L.

    2011-12-01

    Recent results from the KamLAND geoneutrino counting experiment demonstrated that heat derived from the decay of Th and U contributes only about 40% (20±9 TW) of the Earth's total present-day power (46±3 TW) (we consider here only Th and U, since they produce the only detectable geoneutrinos). A geochemical model (e.g., mantle samples) that uses a different approach from both cosmochemical (e.g., enstatite chondrite) and geophysical (e.g., parameterized convection) approaches, and has a bulk silicate Earth (BSE) with 8.2 x 10^16 kg of U, Th/U of 3.9 and K/U of 1.4 x 10^4, with none of these heat producing elements in the metallic core, due to their pronounced chemical affinities for silicates and oxides. Geochemical, cosmochemical and geophysical models predict that the BSE has 21, 11, and 30 TW of total radiogenic heat, respectively, with the contribution from Th and U being 17, 9, 26, and TW, respectively. Consequently, the recently measured geoneutrino flux from the KamLAND is now establishing limits on acceptable compositional models for the Earth. Thus, we are at an exciting stage of discovery, where geoneutrino data will soon be able to distinguish between different models of the amount of planetary nuclear power inside the Earth, the power driving plate tectonics, the geodynamo and compositional models for accretion. We are developing a refined 3-D model of the Earth with physical and chemical inputs that are internally consistent with existing constraints (incorporating global seismological, geochemical and heat flow data); the model predicts a surface flux of geoneutrinos, along with uncertainties, which can be compared with data from the KamLAND and Borexino experiments. This 3-D model has increasing descriptive resolution towards the surface, with geological constraints being applied for the top 220 km of the Earth. This model will provide insights into the Earth's energetics and global radiogenic heat production. Starting in 2013, the Canadian, SNO

  16. Integration of Planetary Protection Activities

    NASA Technical Reports Server (NTRS)

    Race, Margaret S.

    2000-01-01

    Research and activities under this grant have focused on a systematic examination and analysis of critical questions likely to impact planetary protection (PP) controls and implementation for Mars sample return missions (MSR). Four areas in the non-scientific and social realms were selected for special attention because of their importance to future mission planning and concern about critical timing or possible economic impacts on MSR mission implementation. These include: (1) questions of legal uncertainty and the decision making process, (2) public perception of risks associated with sample return, (3) risk communication and Education/Public Outreach , and (4) planetary protection implications of alternative mission architectures, for both robotic and human sample return missions. In its entirety, NAG 2-986 has encompassed three categories of activity: (1) research and analysis (Race), (2) subcontracted research (MacGregor/Decision Research), and (3) consulting services.

  17. Planetary nebulae and stellar evolution

    NASA Technical Reports Server (NTRS)

    Maran, S. P.

    1983-01-01

    Newly defined characteristics of planetary nebulae (PN) derived from analysis of a photometric survey of 57 PN are reported. The data were combined with measurements of 27 other PN made since 1918 and were found to indicate core masses ranging from 0.55-1.0 solar mass. N/O elemental abundance ratios observed were correlated with the planetary nuclei masses, and were in direct proportion. IUE data on PN that overlapped a large part of the survey indicated that the PN in the galactic disk are more massive than PN in the halo. It is suggested that PN evolve into white dwarfs, a hypothesis supported by astrometric solutions for three nearby visual binaries featuring white dwarfs with well-determined masses. It is noted, however, that PN with masses exceeding one solar mass have been sighted in the Magellanic Clouds.

  18. Evolution of Planetary Ringmoon Systems

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1995-01-01

    The last few decades have seen an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of these systems as our intuition (and our computers) catch up with the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is an emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system.

  19. A Planetary Science VO prototype

    NASA Astrophysics Data System (ADS)

    Erard, S.; Le Sidaner, P.; Berthier, J.; Cecconi, B.; Henry, F.; Lamy, L.; Chauvin, C.; Savalle, R.; Jacquey, C.; André, N.; Schmitt, B.

    2013-09-01

    The goal of the JRA4 Work Package of Europlanet-RI was to set the basis for a European Virtual Observatory in Planetary Science. The objective in this first step was to save time during searches in big archives and small databases, as well as to facilitate data access and visualization. The system is based on a new access protocol based on TAP, a specific client to query the available services, and intensive recycling of tools developed for the Astronomy VO. Some new databases were also produced in the EuroPlaNet-RI framework and are available in this context. This system should be extensible to all fields of Planetary Science, and open to external data providers.

  20. The chemistry of planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Huntress, W. T., Jr.

    1976-01-01

    Present knowledge concerning the chemistry of planetary atmospheres is reviewed along with the theories which attempt to explain observational data. The known gross atmospheric compositions of the terrestrial and giant planets are listed, differences between the atmospheres of earth and Venus are discussed, and the atmospheres of the giant planets are described. The origin and evolution of the atmospheres of earth, Venus, Mars, Jupiter, Saturn, and Uranus are outlined, and chemical processes in the atmospheres are examined, particularly cloud formation. The question of organic synthesis and evolution in the reducing atmospheres of the giant planets is considered. It is noted that laboratory work on the individual chemical processes and reactions involved in the evolution of organic compounds in planetary atmospheres, comets, and interstellar space points to the inevitability of organic-compound synthesis in all these situations and to the pervasiveness of organic chemistry throughout the universe.

  1. A vision for planetary exploration

    NASA Technical Reports Server (NTRS)

    Connolly, John F.; Callaway, Robert K.; Diogu, Mark K.; Grush, Gene R.; Lancaster, E. M.; Morgan, William C.; Petri, David A.; Roberts, Barney B.; Pieniazek, Lester A.; Polette, Thomas M.

    1992-01-01

    A vision for planetary exploration is proposed which combines historical perspective and current NASA studies with the realities of changing political climates, economic environments, and technological directions. The concepts of Strategic Implementation Architectures (SIA), Open System Infrastructure Standards (OSIS), and Minimum Service Level Infrastructure (MSLI) are presented in order to propose a structure for the SEI which allows the realization of incremental mission objectives, establishes an investment strategy that efficiently uses public resources, and encourages partnerships with the government. The SIA is a hypothetical master plan which will allow the implementation of the complete spectrum of envisioned system capabilities for planetary exploration. OSIS consists of standards for interconnection, interoperability, and administration. MSLI can be defined as the minimum level of services provided by the system that are not justified by profit or parochial motives.

  2. Teaching, Learning, and Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Brown, Robert A.

    2002-01-01

    This is the final report of a program that examined the fundamentals of education associated with space activities, promoted educational policy development in appropriate forums, and developed pathfinder products and services to demonstrate the utility of advanced communication technologies for space-based education. Our focus was on space astrophysics and planetary exploration, with a special emphasis on the themes of the Origins Program, with which the Principal Investigator (PI) had been involved from the outset. Teaching, Learning, and Planetary Exploration was also the core funding of the Space Telescope Science Institute's (ST ScI) Special Studies Office (SSO), and as such had provided basic support for such important NASA studies as the fix for Hubble Space Telescope (HST) spherical aberration, scientific conception of the HST Advanced Camera, specification of the Next-Generation Space Telescope (NGST), and the strategic plan for the second decade of the HST science program.

  3. Planetary radio astronomy from Voyager

    NASA Technical Reports Server (NTRS)

    Alexander, J. K.

    1983-01-01

    The technique of radio astronomy makes it possible for a remote observer to detect the presence of magnetic fields and plasmas in planetary environments. Prior to the flights of the Voyager spacecraft, radio astronomical studies of Jupiter from earth and from earth orbit had correctly predicted the strength and orientation of Jupiter's magnetic field and trapped radiation belts. The Voyager Planetary Radio Astronomy investigations have now provided measurements of the complete spectrum of low frequency radio emissions from both planets. Each Voyager instrument consists of a pair of orthogonal, 10-m, electric monopole antennas which are connected to a step-tuned, superheterodyne receiver operating over the frequency range from 1.2 kHz to 40.5 MHz. The Voyager trajectory provided observations from above both the sunlit and nightside hemispheres of Jupiter. Saturn's nonthermal radio emission has been observed at frequencies as low as 3 kHz and as high as 1.2 MHz.

  4. The PSA: Planetary Science Archive

    NASA Astrophysics Data System (ADS)

    Barthelemy, M.; Martinez, S.; Heather, D.; Vazquez, J. L.; Arviset, C.; Osuna, P.; PSA development Team

    2012-04-01

    Scientific and engineering data from ESA's planetary missions are made accessible to the world-wide scientific community via the Planetary Science Archive (PSA). The PSA consists of online services incorporating search, preview, download, notification and delivery basket functionality. Besides data from the GIOTTO spacecraft and several ground-based cometary observations, the PSA contains data from the Mars Express, Venus Express, Rosetta, SMART-1 and Huygens missions. The focus of the PSA activities is on the long-term preservation of data and knowledge from ESA's planetary missions. Scientific users can access the data online using several interfaces: - The Advanced Search Interface allows complex parameter based queries, providing the end user with a facility to complete very specific searches on meta-data and geometrical parameters. By nature, this interface requires careful use and heavy interaction with the end-user to input and control the relevant search parameters. - The Map-based Interface is currently operational only for Mars Express HRCS and OMEGA data. This interface allows an end-user to specify a region-of-interest by dragging a box onto a base map of Mars. From this interface, it is possible to directly visualize query results. The Map-based and Advanced interfaces are linked and cross-compatible. If a user defines a region-of-interest in the Map-based interface, the results can be refined by entering more detailed search parameters in the Advanced interface. - The FTP Browser Interface is designed for more experienced users, and allows for direct browsing and access of the data set content through ftp-tree search. Each dataset contains documentation and calibration information in addition to the scientific or engineering data. All data are prepared by the corresponding instrument teams, mostly located in Europe. PSA supports the instrument teams in the full archiving process, from the definition of the data products, meta-data and product labels

  5. The PSA: Planetary Science Archive

    NASA Astrophysics Data System (ADS)

    Barthelemy, Maud; Metselaar, Harold; Martinez, Santa; Heather, David; Vazquez, Jose Luis; Manaud, Nicolas; Ortiz, Iñaki; Arviset, Christophe; Osuna, Pedro

    2010-05-01

    Scientific and engineering data from ESA's planetary missions are made accessible to the world-wide scientific community via the Planetary Science Archive (PSA). The PSA consists of online services incorporating search, preview, download, notification and delivery basket functionality. Besides data from the GIOTTO spacecraft and several ground-based cometary observations, the PSA contains data from the Mars Express, Venus Express, Rosetta, and Huygens missions. Preparation for the release of data from the SMART-1 spacecraft is ongoing. The focus of the PSA activities is on the long-term preservation of data and knowledge from ESA's planetary missions. Scientific users can access the data online using several interfaces: - The Classical Interface allows complex parameter based queries, providing the end user with a facility to complete very specific searches on meta-data and geometrical parameters. By nature, this interface requires careful use and heavy interaction with the end-user to input and control the relevant search parameters. - The Map-based Interface is currently operational only for Mars Express HRCS and OMEGA data. This interface allows an end-user to specify a region-of-interest by dragging a box onto a base map of Mars. From this interface, it is possible to directly visualize query results. The Map-based and Classical interfaces are linked and cross-compatible. If a user defines a region-of-interest in the Map-based interface, the results can be refined by entering more detailed search parameters in the Classical interface. - The Dataset Browser Interface is designed for more experienced users, and allows for direct browsing and access of the data set content through ftp-tree search. Each dataset contains documentation and calibration information in addition to the scientific or engineering data. All data are prepared by the corresponding instrument teams, mostly located in Europe. PSA staff supports the instrument teams in the full archiving process

  6. The PSA: Planetary Science Archive

    NASA Astrophysics Data System (ADS)

    Barthelemy, M.; Metselaar, H.; Martinez, S.; Heather, D.; Vazquez, J. L.; Wirth, K.; Manaud, N.; Ortiz, I.; Arviset, C.; Fernandez, M.

    2009-04-01

    Scientific and engineering data from ESA's planetary missions are made accessible to the world-wide scientific community via the Planetary Science Archive (PSA). The PSA consists of online services incorporating search, preview, download, notification and delivery basket functionality. Besides data from the GIOTTO spacecraft and several ground-based cometary observations, the PSA contains data from the Mars Express, Venus Express, Rosetta, and Huygens missions. Preparation for the release of data from the SMART-1 spacecraft is ongoing. The focus of the PSA activities is on the long-term preservation of data and knowledge from ESA's planetary missions. Scientific users can access the data online using several interfaces: The Classical Interface allows complex parameter based queries, providing the end user with a facility to complete very specific searches on meta-data and geometrical parameters. By nature, this interface requires careful use and heavy interaction with the end-user to input and control the relevant search parameters. The Map-based Interface is currently operational only for Mars Express HRCS and OMEGA data. This interface allows an end-user to specify a region-of-interest by dragging a box onto a base map of Mars. From this interface, it is possible to directly visualize query results. The Map-based and Classical interfaces are linked and cross-compatible. If a user defines a region-of-interest in the Map-based interface, the results can be refined by entering more detailed search parameters in the Classical interface. The Dataset Browser Interface is designed for more experienced users, and allows for direct browsing and access of the data set content through ftp-tree search. Each dataset contains documentation and calibration information in addition to the scientific or engineering data. All data are prepared by the corresponding instrument teams, mostly located in Europe. PSA staff supports the instrument teams in the full archiving process

  7. Geochemical Modeling Of Aqueous Systems

    Energy Science and Technology Software Center (ESTSC)

    1995-09-07

    EQ3/6 is a software package for geochemical modeling of aqueous systems. This description pertains to version 7.2b. It addresses aqueous speciation, thermodynamic equilibrium, disequilibrium, and chemical kinetics. The major components of the package are EQ3NR, a speciation-solubility code, and EQ6 a reaction path code. EQ3NR is useful for analyzing groundwater chemistry data, calculating solubility limits, and determining whether certain reactions are in states of equilibrium or disequilibrium. It also initializes EQ6 calculations. EQ6 models themore » consequences of reacting an aqueous solution with a specified set of reactants (e.g., minerals or waste forms). It can also model fluid mixing and the effects of changes in temperature. Each of five supporting data files contain both standard state and activity coefficient-related data. Three support the use of the Davies or B-dot equations for the activity coefficients; the other two support the use of Pitzer''s equations. The temperature range of the thermodynamic data on the data files varies from 25 degrees C only to 0-300 degrees C.« less

  8. Collected radiochemical and geochemical procedures

    SciTech Connect

    Kleinberg, J

    1990-05-01

    This revision of LA-1721, 4th Ed., Collected Radiochemical Procedures, reflects the activities of two groups in the Isotope and Nuclear Chemistry Division of the Los Alamos National Laboratory: INC-11, Nuclear and radiochemistry; and INC-7, Isotope Geochemistry. The procedures fall into five categories: I. Separation of Radionuclides from Uranium, Fission-Product Solutions, and Nuclear Debris; II. Separation of Products from Irradiated Targets; III. Preparation of Samples for Mass Spectrometric Analysis; IV. Dissolution Procedures; and V. Geochemical Procedures. With one exception, the first category of procedures is ordered by the positions of the elements in the Periodic Table, with separate parts on the Representative Elements (the A groups); the d-Transition Elements (the B groups and the Transition Triads); and the Lanthanides (Rare Earths) and Actinides (the 4f- and 5f-Transition Elements). The members of Group IIIB-- scandium, yttrium, and lanthanum--are included with the lanthanides, elements they resemble closely in chemistry and with which they occur in nature. The procedures dealing with the isolation of products from irradiated targets are arranged by target element.

  9. Geochemical methods of prospecting for hydrocarbons

    SciTech Connect

    Duchscherer, W. Jr.

    1980-12-01

    Because the commonly used reflection-seismograph exploration technique misses many marginal low-relief structural prospects and regardless of its electronic computer sophistication, overlooks almost all stratigraphic traps, the hydrocarbon exploration industry should take a look at geochemical prospecting methods, which detect geochemical anomalies in the near-surface soils by measuring the thermal dissociation of the soil carbonates that are found overlying hydrocarbon accumulations. To promote understanding of such prospecting techniques, Geochemical Surveys reviews the methods used, the soil-alteration patterns, the lateral and vertical migration of hydrocarbon gases, the halo phenomenon (a ring or annual anomaly), the geochemical modification of sediments, and the data-interpretation and exploration procedures involved in a carbonate ..delta.. C analysis, which measures the residual, stable, cumulative effect of hydrocarbon migration.

  10. Northeast Regional Planetary Data Center

    NASA Technical Reports Server (NTRS)

    Schultz, Peter H.; Saunders, Stephen (Technical Monitor)

    2005-01-01

    In 1980, the Northeast Planetary Data Center (NEPDC) was established with Tim Mutch as its Director. The Center was originally located in the Sciences Library due to space limitations but moved to the Lincoln Field Building in 1983 where it could serve the Planetary Group and outside visitors more effectively. In 1984 Dr. Peter Schultz moved to Brown University and became its Director after serving in a similar capacity at the Lunar and Planetary Institute since 1976. Debbie Glavin has served as the Data Center Coordinator since 1982. Initially the NEPDC was build around Tim Mutch's research collection of Lunar Orbiter and Mariner 9 images with only partial sets of Apollo and Viking materials. Its collection was broadened and deepened as the Director (PHS) searched for materials to fill in gaps. Two important acquisitions included the transfer of a Viking collection from a previous PI in Tucson and the donation of surplused lunar materials (Apollo) from the USGS/Menlo Park prior to its building being torn down. Later additions included the pipeline of distributed materials such as the Viking photomosaic series and certain Magellan products. Not all materials sent to Brown, however, found their way to the Data Center, e.g., Voyager prints and negatives. In addition to the NEPDC, the planetary research collection is separately maintained in conjunction with past and ongoing mission activities. These materials (e.g., Viking, Magellan, Galileo, MGS mission products) are housed elsewhere and maintained independently from the NEPDC. They are unavailable to other researchers, educators, and general public. Consequently, the NEPDC represents the only generally accessible reference collection for use by researchers, students, faculty, educators, and general public in the Northeast corridor.

  11. Planetary Systems Around Neutron Stars

    NASA Astrophysics Data System (ADS)

    Wolszczan, Alexander

    1997-01-01

    This project was initiated in 1993, about one year after the announcement of two planets around PSR B1257+12. Its goal was to investigate planetary systems around neutron stars using high precision timing of radio pulsars as a tool. A microsecond precision of the pulse timing analysis, which is equivalent to a millimeter-per-second radial velocity resolution, makes it possible to detect asteroid-mass bodies in orbit around pulsars and to study the dynamics of pulsar planetary systems. The project originally consisted of two longterm efforts: (i) routine observations and timing analysis of the millisecond pulsar PSR B1257+12 which was found to be orbited by at least two earth-mass bodies (Wolszczan and Frail, Nature, 355, 145) and (ii) a sensitive all-sky search for millisecond pulsars to detect further examples of neutron stars with planetary systems. In the third year of the project, it was expanded to include long-term timing observations of slow pulsars in search for planetary systems around these younger neutron stars. The instrumentation used to conduct these investigations included the 305-m Arecibo antenna with the Penn State Pulsar Machine (PSPM-1), the 100-m Effelsberg telescope with the local pulse timing hardware, and the 32-m paraboloid of the Torun Centre for Astronomy in Torun, Poland (TCFA) with the PSPM-2, the second pulsar machine built at Penn State. The PI's collaborators included pulsar groups led by D. Backer (Berkeley), R. Foster (NRL), S. Kulkarni (Caltech), J. Taylor (Princeton) and R. Wielebinski (Bonn). One postdoc (Stuart Anderson), one graduate student (Brian Cadwell) and several undergraduates have been engaged in various aspects of research related to this project.

  12. Small Spacecraft for Planetary Science

    NASA Astrophysics Data System (ADS)

    Baker, John; Castillo-Rogez, Julie; Bousquet, Pierre-W.; Vane, Gregg; Komarek, Tomas; Klesh, Andrew

    2016-07-01

    As planetary science continues to explore new and remote regions of the Solar system with comprehensive and more sophisticated payloads, small spacecraft offer the possibility for focused and more affordable science investigations. These small spacecraft or micro spacecraft (< 100 kg) can be used in a variety of architectures consisting of orbiters, landers, rovers, atmospheric probes, and penetrators. A few such vehicles have been flown in the past as technology demonstrations. However, technologies such as new miniaturized science-grade sensors and electronics, advanced manufacturing for lightweight structures, and innovative propulsion are making it possible to fly much more capable micro spacecraft for planetary exploration. While micro spacecraft, such as CubeSats, offer significant cost reductions with added capability from advancing technologies, the technical challenges for deep space missions are very different than for missions conducted in low Earth orbit. Micro spacecraft must be able to sustain a broad range of planetary environments (i.e., radiations, temperatures, limited power generation) and offer long-range telecommunication performance on a par with science needs. Other capabilities needed for planetary missions, such as fine attitude control and determination, capable computer and data handling, and navigation are being met by technologies currently under development to be flown on CubeSats within the next five years. This paper will discuss how micro spacecraft offer an attractive alternative to accomplish specific science and technology goals and what relevant technologies are needed for these these types of spacecraft. Acknowledgements: Part of this work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology under contract to NASA. Government sponsorship acknowledged.

  13. Planetary Science Virtual Observatory architecture

    NASA Astrophysics Data System (ADS)

    Erard, S.; Cecconi, B.; Le Sidaner, P.; Berthier, J.; Henry, F.; Chauvin, C.; André, N.; Génot, V.; Jacquey, C.; Gangloff, M.; Bourrel, N.; Schmitt, B.; Capria, M. T.; Chanteur, G.

    2014-11-01

    In the framework of the Europlanet-RI program, a prototype of Virtual Observatory dedicated to Planetary Science was defined. Most of the activity was dedicated to the elaboration of standards to retrieve and visualize data in this field, and to provide light procedures to teams who wish to contribute with on-line data services. The architecture of this VO system and selected solutions are presented here, together with existing demonstrators.

  14. Planetary Data Workshop, Part 2

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Technical aspects of the Planetary Data System (PDS) are addressed. Methods and tools for maintaining and accessing large, complex sets of data are discussed. The specific software and applications needed for processing imaging and non-imaging science data are reviewed. The need for specific software that provides users with information on the location and geometry of scientific observations is discussed. Computer networks and user interface to the PDS are covered along with Computer hardware available to this data system.

  15. Mars 2020 Planetary Protection Status

    NASA Astrophysics Data System (ADS)

    Stricker, Moogega; Bernard, Douglas; Benardini, James Nick; Jones, Melissa

    2016-07-01

    The Mars 2020 (M2020) flight system consists of a cruise stage; an entry, descent and landing system (EDL); and a Radioisotope Thermoelectric Generator (RTG) powered roving science vehicle that will land on the surface of Mars. The M2020 Mission is designed to investigate key question related to the habitability of Mars and will conduct assessments that set the stage for potential future human exploration of Mars. Per its Program Level Requirements, the project will also acquire and cache samples of rock, regolith, and/or procedural "blank" samples for possible return to Earth by a subsequent mission. NASA has assigned the M2020 Mission as a Category V Restricted Earth Return due to the possible future return of collected samples. As indicated in NPR8020.12D, Section 5.3.3.2, the outbound leg of a Category V mission that could potentially return samples to Earth, Mars 2020 would be expected to meet the requirements of a Category IVb mission. The entire flight system is subject to microbial reduction requirements, with additional specific emphasis on the sample acquisition and caching. A bioburden accounting tool is being used to track the microbial population on the surfaces to ensure that the biological cleanliness requirements are met. Initial bioburden estimates based on MSL heritage allows M2020 to gauge more precisely how the bioburden is allocated throughout each hardware element. Mars 2020 has completed a Planetary Protection Plan with Planetary Implementation Plans at a mature draft form. Planetary protection sampling activities have commenced with the start of flight system fabrication and assembly. The status of the Planetary Protection activities will be reported.

  16. Reports of planetary astronomy, 1985

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This is a compilation of abstracts of reports from Principal Investigators funded through NASA's Planetary Astronomy Program, Office of Space Science and Applications. The purpose is to provide a document which succinctly summarizes work conducted in this program for 1985. Each report contains a brief statement on the strategy of investigation and lists significant accomplishments within the area of the author's funded grant or contract, plans for future work, and publications.

  17. Reports of planetary astronomy, 1986

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A compilation of abstracts of reports from Principal Investigators funded through NASA's Planetary Astronomy Program, Office of Space Science and Applications, is presented. The purpose is to provide a document which succinctly summarizes work conducted in this program for 1986. Each report contains a brief statement on the strategy of investigation and lists significant accomplishments within the area of the author's funded grant or contract, plans for future work, and publications.

  18. Stream Lifetimes Against Planetary Encounters

    NASA Technical Reports Server (NTRS)

    Valsecchi, G. B.; Lega, E.; Froeschle, Cl.

    2011-01-01

    We study, both analytically and numerically, the perturbation induced by an encounter with a planet on a meteoroid stream. Our analytical tool is the extension of pik s theory of close encounters, that we apply to streams described by geocentric variables. The resulting formulae are used to compute the rate at which a stream is dispersed by planetary encounters into the sporadic background. We have verified the accuracy of the analytical model using a numerical test.

  19. Planetary Exploration in the Classroom

    NASA Astrophysics Data System (ADS)

    Slivan, S. M.; Binzel, R. P.

    1997-07-01

    We have developed educational materials to seed a series of undergraduate level exercises on "Planetary Exploration in the Classroom." The goals of the series are to teach modern methods of planetary exploration and discovery to students having both science and non-science backgrounds. Using personal computers in a "hands-on" approach with images recorded by planetary spacecraft, students working through the exercises learn that modern scientific images are digital objects that can be examined and manipulated in quantitative detail. The initial exercises we've developed utilize NIH Image in conjunction with images from the Voyager spacecraft CDs. Current exercises are titled "Using 'NIH IMAGE' to View Voyager Images", "Resolving Surface Features on Io", "Discovery of Volcanoes on Io", and "Topography of Canyons on Ariel." We expect these exercises will be released during Fall 1997 and will be available via 'anonymous ftp'; detailed information about obtaining the exercises will be on the Web at "http://web.mit.edu/12s23/www/pec.html." This curriculum development was sponsored by NSF Grant DUE-9455329.

  20. The National Geochemical Survey; database and documentation

    USGS Publications Warehouse

    U.S. Geological Survey

    2004-01-01

    The USGS, in collaboration with other federal and state government agencies, industry, and academia, is conducting the National Geochemical Survey (NGS) to produce a body of geochemical data for the United States based primarily on stream sediments, analyzed using a consistent set of methods. These data will compose a complete, national-scale geochemical coverage of the US, and will enable construction of geochemical maps, refine estimates of baseline concentrations of chemical elements in the sampled media, and provide context for a wide variety of studies in the geological and environmental sciences. The goal of the NGS is to analyze at least one stream-sediment sample in every 289 km2 area by a single set of analytical methods across the entire nation, with other solid sample media substituted where necessary. The NGS incorporates geochemical data from a variety of sources, including existing analyses in USGS databases, reanalyses of samples in USGS archives, and analyses of newly collected samples. At the present time, the NGS includes data covering ~71% of the land area of the US, including samples in all 50 states. This version of the online report provides complete access to NGS data, describes the history of the project, the methodology used, and presents preliminary geochemical maps for all analyzed elements. Future editions of this and other related reports will include the results of analysis of variance studies, as well as interpretive products related to the NGS data.

  1. 11 -year planetary index of solar activity

    NASA Astrophysics Data System (ADS)

    Okhlopkov, Victor

    In papers [1,2] introduced me parameter - the average difference between the heliocentric longitudes of planets ( ADL ) , which was used for comparison with solar activity. The best connection of solar activity ( Wolf numbers used ) was obtained for the three planets - Venus, Earth and Jupiter. In [1,2] has been allocated envelope curve of the minimum values ADL which has a main periodicity for 22 years and describes well the alternating series of solar activity , which also has a major periodicity of 22. It was shown that the minimum values of the envelope curve extremes ADL planets Venus, Earth and Jupiter are well matched with the 11- year solar activity cycle In these extremes observed linear configuration of the planets Venus, Earth and Jupiter both in their location on one side of the Sun ( conjunctions ) and at the location on the opposite side of the Sun ( three configurations ) This work is a continuation of the above-mentioned , and here for minimum ADL ( planets are in conjunction ) , as well as on the minimum deviation of the planets from a line drawn through them and Sun at the location of the planets on opposite sides of the Sun , compiled index (denoted for brevity as JEV ) that uniquely describes the 11- year solar cycle A comparison of the index JEV with solar activity during the time interval from 1000 to 2013 conducted. For the period from 1000 to 1699 used the Schove series of solar activity and the number of Wolf (1700 - 2013 ) During the time interval from 1000 to 2013 and the main periodicity of the solar activity and the index ADL is 11.07 years. 1. Okhlopkov V.P. Cycles of Solar Activity and the Configurations of Planets // Moscow University Physics Bulletin, 2012 , Vol. 67 , No. 4 , pp. 377-383 http://www.springerlink.com/openurl.asp?genre=article&id=doi:10.3103/S0027134912040108. 2 Okhlopkov VP, Relationship of Solar Activity Cycles to Planetary Configurations // Bulletin of the Russian Academy of Sciences. Physics, 2013 , Vol. 77 , No. 5

  2. Geochemical processes at mineral surfaces

    SciTech Connect

    Davis, J.A.; Hayes, K.F.

    1986-01-01

    This volume includes 32 papers which were presented at a symposium on geochemical processes at mineral-water interfaces in 1985 and which bring to bear on this area a very wide range of expertise. The discontinuities in properties which occur at the mineral-water interface have profound effects on the movement of naturally occurring ions. Weathering and precipitation processes control the concentrations and speciation of ions in natural waters and the movements of these within the hydrosphere; both classes of processes take place at mineral-water interfaces. After an introductory overview, the book is divided into seven major sections, each dealing with one of the aspects of the processes occurring at the mineral-water interface. Five papers deal with the physical properties of the mineral-water interface; these represent a well-balanced mix of experimental and theoretical (mathematical modeling) work. Adsorption phenomena are dealt with in another five papers; these are largely experimental in character. Ion-exchange processes are discussed in four papers, one of which addresses the use of relaxation methods to study ion exchange kinetics at the microscopic level. Spectroscopic techniques (including electron-spin resonance and Moessbauer spectroscopy) are utilized in four papers. Chemical reactions, mainly redox processes, at mineral-water interfaces are treated in four papers, one of which deals with non-biological organic reactions. Solid-solution formation and equilibria are the subjects of another set of four articles, and the last group of papers deals with the processes involved in precipitation and dissolution, including weathering.

  3. Geochemical Origin of Biological Molecules

    NASA Astrophysics Data System (ADS)

    Bassez, Marie-Paule

    2013-04-01

    A model for the geochemical origin of biological molecules is presented. Rocks such as peridotites and basalts, which contain ferromagnesian minerals, evolve in the presence of water. Their hydrolysis is an exothermic reaction which generates heat and a release of H2 and of minerals with modified structures. The hydrogen reacts with the CO2 embedded inside the rock or with the CO2 of the environment to form CO in an hydrothermal process. With the N2 of the environment, and with an activation source arising from cosmic radiation, ferromagnesian rocks might evolve towards the abiotic formation of biological molecules, such as peptide like macromolecules which produce amino acids after acid hydrolysis. The reactions concerned are described. The production of hydrothermal CO is discussed in geological sites containing ferromagnesian silicate minerals and the low intensity of the Earth's magnetic field during Paleoarchaean Era is also discussed. It is concluded that excitation sources arising from cosmic radiation were much more abundant during Paleoarchaean Era and that macromolecular structures of biological relevance might consequently form during Archaean Eon, as a product of the chemical evolution of the rocks and of their mineral contents. This synthesis of abiotically formed biological molecules is consecutively discussed for meteorites and other planets such as Mars. This model for the geochemical origin of biological molecules has first been proposed in 2008 in the context of reactions involving catalysers such as kaolinite [Bassez 2008a] and then presented in conferences and articles [Bassez 2008b, 2009, 2012; Bassez et al. 2009a to 2012b]. BASSEZ M.P. 2008a Synthèse prébiotique dans les conditions hydrothermales, CNRIUT'08, Lyon 29-30/05/2008, Conf. and open access article:http://liris.cnrs.fr/~cnriut08/actes/ 29 mai 11h-12h40. BASSEZ M.P. 2008b Prebiotic synthesis under hydrothermal conditions, ISSOL'08, P2-6, Firenze-Italy, 24-29/08/2008. Poster at the

  4. Mineralogical and geochemical anomalous data of the K-T boundary samples

    NASA Technical Reports Server (NTRS)

    Miura, Y.; Shibya, G.; Imai, M.; Takaoka, N.; Saito, S.

    1988-01-01

    Cretaceous-Tertiary boundary problem has been discussed previously from the geological research, mainly by fossil changes. Although geochemical bulk data of Ir anomaly suggest the extraterrestrial origin of the K-T boundary, the exact formation process discussed mainly by mineralogical and geochemical study has been started recently, together with noble gas contents. The K-T boundary sample at Kawaruppu River, Hokkaido was collected, in order to compare with the typical K-T boundary samples of Bubbio, Italy, Stevns Klint, Denmark, and El Kef, Tunisia. The experimental data of the silicas and calcites in these K-T boundary samples were obtained from the X-ray unit-cell dimension (i.e., density), ESR signal and total linear absorption coefficient, as well as He and Ne contents. The K-T boundary samples are usually complex mixture of the terrestrial activities after the K-T boundary event. The mineralogical and geochemical anomalous data indicate special terrestrial atmosphere at the K-T boundary formation probably induced by asteroid impact, followed the many various terrestrial activities (especially the strong role of sea-water mixture, compared with terrestrial highland impact and impact craters in the other earth-type planetary bodies).

  5. Lunar and Planetary Science XXXVI, Part 14

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Contents include the following: Destruction of Presolar Silicates by Aqueous Alteration Observed in Murchison CM2 Chondrite. Generation of Chondrule Forming Shock Waves in Solar Nebula by X-Ray Flares. TEM and NanoSIMS Study of Hydrated/Anhydrous Phase Mixed IDPs: Cometary or Asteroidal Origin? Inflight Calibration of Asteroid Multiband Imaging Camera Onboard Hayabusa: Preliminary Results. Corundum and Corundum-Hibonite Grains Discovered by Cathodoluminescence in the Matrix of Acfer 094 Meteorite. Spatial Extent of a Deep Moonquake Nest A Preliminary Report of Reexamination. Modal Abundances of Carbon in Ureilites: Implications for the Petrogenesis of Ureilites. Trapped Noble Gas Components and Exposure History of the Enstatite Chondrite ALH84206. Deep-seated Crustal Material in Dhofar Lunar Meteorites: Evidence from Pyroxene Chemistry. Numerical Investigations of Kuiper Belt Binaries. Dust Devils on Mars: Effects of Surface Roughness on Particle Threshold. Hecates Tholus, Mars: Nighttime Aeolian Activity Suggested by Thermal Images and Mesoscale Atmospheric Model Simulations. Are the Apollo 14 High-Al Basalts Really Impact Melts? Garnet in the Lunar Mantle: Further Evidence from Volcanic Glass Beads. The Earth/Mars Dichotomy in Mg/Si and Al/Si Ratios: Is It Real? Dissecting the Polar Asymmetry in the Non-Condensable Gas Enhancement on Mars: A Numerical Modeling Study. Cassini VIMS Preliminary Exploration of Titan s Surface Hemispheric Albedo Dichotomy. An Improved Instrument for Investigating Planetary Regolith Microstructure. Isotopic Composition of Oxygen in Lunar Zircons Preliminary Design of Visualization Tool for Hayabusa Operation. Size and Shape Distributions of Chondrules and Metal Grains Revealed by X-Ray Computed Tomography Data. Properties of Permanently Shadowed Regolith. Landslides in Interior Layered Deposits, Valles Marineris, Mars: Effects of Water and Ground Shaking on Slope Stability. Mars: Recent and Episodic Volcanic, Hydrothermal, and Glacial

  6. Planetary Geology: Goals, Future Directions, and Recommendations

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Planetary exploration has provided a torrent of discoveries and a recognition that planets are not inert objects. This expanded view has led to the notion of comparative planetology, in which the differences and similarities among planetary objects are assessed. Solar system exploration is undergoing a change from an era of reconnaissance to one of intensive exploration and focused study. Analyses of planetary surfaces are playing a key role in this transition, especially as attention is focused on such exploration goals as returned samples from Mars. To assess how the science of planetary geology can best contribute to the goals of solar system exploration, a workshop was held at Arizona State University in January 1987. The participants discussed previous accomplishments of the planetary geology program, assessed the current studies in planetary geology, and considered the requirements to meet near-term and long-term exploration goals.

  7. Ordinary planetary systems - Architecture and formation

    NASA Technical Reports Server (NTRS)

    Levy, E. H.

    1993-01-01

    Today we believe ordinary planetary systems to be an unremarkable consequence of star formation. The solar system, so far the only confidently known example in the universe of a planetary system, displays a set of striking structural regularities. These structural regularities provide fossil clues about the conditions and mechanisms that gave rise to the planets. The formation of our planetary system, as well as its general characteristics, resulted from the physical environment in the disk-shaped nebula that accompanied the birth of the sun. Observations of contemporary star formation indicate that the very conditions and mechanisms thought to have produced our own planetary system are widely associated with the birth of stars elsewhere. Consequently, it is reasonable to believe that planetary systems occur commonly, at least in association with single, sunlike stars. Moreover, it is reasonable to believe that many planetary systems have gross characteristics resembling those of our own solar system.

  8. The Chandra planetary nebula survey (CHANPLANS). II. X-ray emission from compact planetary nebulae

    SciTech Connect

    Freeman, M.; Kastner, J. H.; Montez, R. Jr.; Balick, B.; Frew, D. J.; De Marco, O.; Parker, Q. A.; Jones, D.; Miszalski, B.; Sahai, R.; Blackman, E.; Frank, A.; Chu, Y.-H.; Guerrero, M. A.; Zijlstra, A.; Bujarrabal, V.; Corradi, R. L. M.; Nordhaus, J.; and others

    2014-10-20

    We present results from the most recent set of observations obtained as part of the Chandra X-ray observatory Planetary Nebula Survey (CHANPLANS), the first comprehensive X-ray survey of planetary nebulae (PNe) in the solar neighborhood (i.e., within ∼1.5 kpc of the Sun). The survey is designed to place constraints on the frequency of appearance and range of X-ray spectral characteristics of X-ray-emitting PN central stars and the evolutionary timescales of wind-shock-heated bubbles within PNe. CHANPLANS began with a combined Cycle 12 and archive Chandra survey of 35 PNe. CHANPLANS continued via a Chandra Cycle 14 Large Program which targeted all (24) remaining known compact (R {sub neb} ≲ 0.4 pc), young PNe that lie within ∼1.5 kpc. Results from these Cycle 14 observations include first-time X-ray detections of hot bubbles within NGC 1501, 3918, 6153, and 6369, and point sources in HbDs 1, NGC 6337, and Sp 1. The addition of the Cycle 14 results brings the overall CHANPLANS diffuse X-ray detection rate to ∼27% and the point source detection rate to ∼36%. It has become clearer that diffuse X-ray emission is associated with young (≲ 5 × 10{sup 3} yr), and likewise compact (R {sub neb} ≲ 0.15 pc), PNe with closed structures and high central electron densities (n{sub e} ≳ 1000 cm{sup –3}), and is rarely associated with PNe that show H{sub 2} emission and/or pronounced butterfly structures. Hb 5 is one such exception of a PN with a butterfly structure that hosts diffuse X-ray emission. Additionally, two of the five new diffuse X-ray detections (NGC 1501 and NGC 6369) host [WR]-type central stars, supporting the hypothesis that PNe with central stars of [WR]-type are likely to display diffuse X-ray emission.

  9. The Planetary Data System— Archiving Planetary Data for the use of the Planetary Science Community

    NASA Astrophysics Data System (ADS)

    Morgan, Thomas H.; McLaughlin, Stephanie A.; Grayzeck, Edwin J.; Vilas, Faith; Knopf, William P.; Crichton, Daniel J.

    2014-11-01

    NASA’s Planetary Data System (PDS) archives, curates, and distributes digital data from NASA’s planetary missions. PDS provides the planetary science community convenient online access to data from NASA’s missions so that they can continue to mine these rich data sets for new discoveries. The PDS is a federated system consisting of nodes for specific discipline areas ranging from planetary geology to space physics. Our federation includes an engineering node that provides systems engineering support to the entire PDS.In order to adequately capture complete mission data sets containing not only raw and reduced instrument data, but also calibration and documentation and geometry data required to interpret and use these data sets both singly and together (data from multiple instruments, or from multiple missions), PDS personnel work with NASA missions from the initial AO through the end of mission to define, organize, and document the data. This process includes peer-review of data sets by members of the science community to ensure that the data sets are scientifically useful, effectively organized, and well documented. PDS makes the data in PDS easily searchable so that members of the planetary community can both query the archive to find data relevant to specific scientific investigations and easily retrieve the data for analysis. To ensure long-term preservation of data and to make data sets more easily searchable with the new capabilities in Information Technology now available (and as existing technologies become obsolete), the PDS (together with the COSPAR sponsored IPDA) developed and deployed a new data archiving system known as PDS4, released in 2013. The LADEE, MAVEN, OSIRIS REx, InSight, and Mars2020 missions are using PDS4. ESA has adopted PDS4 for the upcoming BepiColumbo mission. The PDS is actively migrating existing data records into PDS4 and developing tools to aid data providers and users. The PDS is also incorporating challenge

  10. Europlanet Research Infrastructure: Planetary Sample Analysis Facilities

    NASA Astrophysics Data System (ADS)

    Cloquet, C.; Mason, N. J.; Davies, G. R.; Marty, B.

    2008-09-01

    study of long (e.g. Rb- Sr, Sm-Nd…) and short-lived radioisotope (e.g. Mg- Al, Hf-W..), including also Os isotopes, stable and non traditional stable isotope facilities (e.g. Fe, Pb, Zn…). The facility comprises three multicollector Thermal ionization mass spectrometers (TIMS) and two multi-collector ICP-MS one of which is fitted with 193 nm laser for in situ work. In addition these instruments are fully supported by sample preparation labs (crushing, mineral separation/picking), a clean lab and geochemical support (XRF; ICP; ICP-MS etc). Data that can be obtained on samples containing sub nano gram to nanogram amounts. Organic matter analysis at OU Leco Pegasus IV GCxGC-TOFMS - mass spectrometric complete characterisation of very complex mixtures of organic materials. The Pegasus EPSC Abstracts, Vol. 3, EPSC2008-A-00437, 2008 European Planetary Science Congress, Author(s) 2008 4D GCxGC-TOFMS system, from Leco, provides the analyst with four dimensions of analytical resolution for significantly more complete sample analysis compared to conventional GC-Mass Spectrometry. The main advantages include: 1) The significantly increased sensitivity over the whole mass range (5- 1000 amu); 2)The separation of compounds that coelute on standard gas chromatograph systems; 3) Separation of analytes by volatility and polarity enables traditionally unresolved mixtures to be examined in detail, and vastly increases the number of compounds identified; 4) Greatly increased signal to noise ratio, due to compounds being separated from the column bleed of the first column on the second GC column and an enormous increase in the Spectral Generation Rate. A number of different pyrolysis and injection sample introduction facilities are available and access to off-line data processing and reference libraries. This is the only instrument of this type in a European laboratory with a significant focus on extraterrestrial materials. Thermo MAT 253 GC-IRMS -isotopic measurements of H, C or N on

  11. Activities at the Lunar and Planetary Institute

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The activities of the Lunar and Planetary Institute for the period July to December 1984 are discussed. Functions of its departments and projects are summarized. These include: planetary image center; library information center; computer center; production services; scientific staff; visitors program; scientific projects; conferences; workshops; seminars; publications and communications; panels, teams, committees and working groups; NASA-AMES vertical gun range (AVGR); and lunar and planetary science council.

  12. The probabilistic structure of planetary contamination models

    NASA Technical Reports Server (NTRS)

    Harrison, J. M.; North, W. D.

    1973-01-01

    The analytical basis for planetary quarantine standards and procedures is presented. The heirarchy of planetary quarantine decisions is explained and emphasis is placed on the determination of mission specifications to include sterilization. The influence of the Sagan-Coleman probabilistic model of planetary contamination on current standards and procedures is analyzed. A classical problem in probability theory which provides a close conceptual parallel to the type of dependence present in the contamination problem is presented.

  13. Activities at the Lunar and Planetary Institute

    NASA Astrophysics Data System (ADS)

    1985-05-01

    The activities of the Lunar and Planetary Institute for the period July to December 1984 are discussed. Functions of its departments and projects are summarized. These include: planetary image center; library information center; computer center; production services; scientific staff; visitors program; scientific projects; conferences; workshops; seminars; publications and communications; panels, teams, committees and working groups; NASA-AMES vertical gun range (AVGR); and lunar and planetary science council.

  14. Mars Technology Program Planetary Protection Technology Development

    NASA Technical Reports Server (NTRS)

    Lin, Ying

    2006-01-01

    The objectives of the NASA Planetary Protection program are to preserve biological and organic conditions of solar-system bodies for future scientific exploration and to protect the Earth from potential hazardous extraterrestrial contamination. As the exploration of solar system continues, NASA remains committed to the implementation of planetary protection policy and regulations. To fulfill this commitment, the Mars Technology Program (MTP) has invested in a portfolio of tasks for developing necessary technologies to meet planetary protection requirements for the next decade missions.

  15. Nasa's Planetary Geologic Mapping Program: Overview

    NASA Astrophysics Data System (ADS)

    Williams, D. A.

    2016-06-01

    NASA's Planetary Science Division supports the geologic mapping of planetary surfaces through a distinct organizational structure and a series of research and analysis (R&A) funding programs. Cartography and geologic mapping issues for NASA's planetary science programs are overseen by the Mapping and Planetary Spatial Infrastructure Team (MAPSIT), which is an assessment group for cartography similar to the Mars Exploration Program Assessment Group (MEPAG) for Mars exploration. MAPSIT's Steering Committee includes specialists in geological mapping, who make up the Geologic Mapping Subcommittee (GEMS). I am the GEMS Chair, and with a group of 3-4 community mappers we advise the U.S. Geological Survey Planetary Geologic Mapping Coordinator (Dr. James Skinner) and develop policy and procedures to aid the planetary geologic mapping community. GEMS meets twice a year, at the Annual Lunar and Planetary Science Conference in March, and at the Annual Planetary Mappers' Meeting in June (attendance is required by all NASA-funded geologic mappers). Funding programs under NASA's current R&A structure to propose geological mapping projects include Mars Data Analysis (Mars), Lunar Data Analysis (Moon), Discovery Data Analysis (Mercury, Vesta, Ceres), Cassini Data Analysis (Saturn moons), Solar System Workings (Venus or Jupiter moons), and the Planetary Data Archiving, Restoration, and Tools (PDART) program. Current NASA policy requires all funded geologic mapping projects to be done digitally using Geographic Information Systems (GIS) software. In this presentation we will discuss details on how geologic mapping is done consistent with current NASA policy and USGS guidelines.

  16. Planetary sample rapid recovery and handling

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Methods for recovering and cost effectively handling planetary samples following return to the vicinity of Earth were designed for planetary mission planners. Three topics are addressed: (1) a rough cost estimate was produced for each of a series of options for the handling of planetary samples following their return to the vicinity of Earth; (2) the difficulty of quickly retrieving planetary samples from low circular and high elliptical Earth orbit is assessed; and (3) a conceptual design for a biological isolation and thermal control system for the returned sample and spacecraft is developed.

  17. Teaching, learning, and planetary exploration

    NASA Astrophysics Data System (ADS)

    Brown, Robert A.

    1992-12-01

    The progress accomplished in the first five months of the three-year grant period of Teaching, Learning, and Planetary Exploration is presented. The objectives of this project are to discover new education products and services based on space science, particularly planetary exploration. An Exploration in Education is the umbrella name for the education projects as they are seen by teachers and the interested public. As described in the proposal, our approach consists of: (1) increasing practical understanding of the potential role and capabilities of the research community to contribute to basic education using new discoveries; (2) developing an intellectual framework for these contributions by supplying criteria and templates for the teacher's stories; (3) attracting astronomers, engineers, and technical staff to the project and helping them form productive education partnerships for the future, (4) exploring relevant technologies and networks for authoring and communicating the teacher's stories; (5) enlisting the participation of potential user's of the teacher's stories in defining the products; (6) actually producing and delivering many educationally useful teacher's stories; and (7) reporting the pilot study results with critical evaluation. Technical progress was made by assembling our electronic publishing stations, designing electronic publications based on space science, and developing distribution approaches for electronic products. Progress was made addressing critical issues by developing policies and procedures for securing intellectual property rights and assembling a focus group of teachers to test our ideas and assure the quality of our products. The following useful materials are being produced: the TOPS report; three electronic 'PictureBooks'; one 'ElectronicArticle'; three 'ElectronicReports'; ten 'PrinterPosters'; and the 'FaxForum' with an initial complement of printed materials. We have coordinated with planetary scientists and astronomers

  18. Teaching, learning, and planetary exploration

    NASA Technical Reports Server (NTRS)

    Brown, Robert A.

    1992-01-01

    The progress accomplished in the first five months of the three-year grant period of Teaching, Learning, and Planetary Exploration is presented. The objectives of this project are to discover new education products and services based on space science, particularly planetary exploration. An Exploration in Education is the umbrella name for the education projects as they are seen by teachers and the interested public. As described in the proposal, our approach consists of: (1) increasing practical understanding of the potential role and capabilities of the research community to contribute to basic education using new discoveries; (2) developing an intellectual framework for these contributions by supplying criteria and templates for the teacher's stories; (3) attracting astronomers, engineers, and technical staff to the project and helping them form productive education partnerships for the future, (4) exploring relevant technologies and networks for authoring and communicating the teacher's stories; (5) enlisting the participation of potential user's of the teacher's stories in defining the products; (6) actually producing and delivering many educationally useful teacher's stories; and (7) reporting the pilot study results with critical evaluation. Technical progress was made by assembling our electronic publishing stations, designing electronic publications based on space science, and developing distribution approaches for electronic products. Progress was made addressing critical issues by developing policies and procedures for securing intellectual property rights and assembling a focus group of teachers to test our ideas and assure the quality of our products. The following useful materials are being produced: the TOPS report; three electronic 'PictureBooks'; one 'ElectronicArticle'; three 'ElectronicReports'; ten 'PrinterPosters'; and the 'FaxForum' with an initial complement of printed materials. We have coordinated with planetary scientists and astronomers

  19. Twenty-Second Lunar and Planetary Science Conference

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The papers in this collection were written for general presentation, avoiding jargon and unnecessarily complex terms. Some of the topics covered include: planetary evolution, planetary satellites, planetary composition, planetary surfaces, planetary geology, volcanology, meteorite impacts and composition, and cosmic dust. Particular emphasis is placed on Mars and the Moon.

  20. Pioneering Concepts of Planetary Habitability

    NASA Astrophysics Data System (ADS)

    Raulin Cerceau, Florence

    Famous astronomers such as Richard A. Proctor (1837-1888), Jules Janssen (1824-1907), and Camille Flammarion (1842-1925) studied the concept of planetary habitability a century before this concept was updated in the context of the recent discoveries of exoplanets and the development of planetary exploration in the solar system. They independently studied the conditions required for other planets to be inhabited, and these considerations led them to specify the term "habitability." Naturally, the planet Mars was at the heart of the discussion. Our neighboring planet, regarded as a sister planet of Earth, looked like a remarkable abode for life. During the second part of the nineteenth century, the possibility of Martian intelligent life was intensively debated, and hopes were still ardent to identify a kind of vegetation specific to the red planet. In such a context, the question of Mars' habitability seemed to be very valuable, especially when studying hypothetical Martian vegetation. At the dawn of the Space Age, German-born physician and pioneer of space medicine Hubertus Strughold (1898-1987) proposed in the book The Green and Red Planet: A Physiological Study of the Possibility of Life on Mars (1954) to examine the planets of the solar system through a "planetary ecology." This innovative notion, which led to a fresh view of the concept of habitability, was supposed to designate a new field involving biology: "the science of planets as an environment for life" (Strughold 1954). This notion was very close to the concept of habitability earlier designated by our nineteenth-century pioneers. Strughold also coined the term "ecosphere" to name the region surrounding a star where conditions allowed life-bearing planets to exist. We highlight in this chapter the historical aspects of the emergence of the (modern) concept of habitability. We will consider the different formulations proposed by the pioneers, and we will see in what way it can be similar to our

  1. Planetary magnetism. [emphasizing dynamo theories

    NASA Technical Reports Server (NTRS)

    Stevenson, D.

    1974-01-01

    The origin and maintenance of planetary magnetic fields are discussed. The discussion is not limited to dynamo theories, although these are almost universally favored. Thermoelectric currents are found to be a possible alternative for Jupiter. Two energy sources for dynamos are considered: convection and precessionally induced fluid flow. The earth is the most favorable planet for precessionally driven dynamo, although Neptune is a possibility. Jupiter is likely to have a convectionally driven dynamo, as may Saturn, but the relevant properties of Saturn are not yet well known. Conclusions for each planet are given.

  2. Planetary spectra for anisotropic scattering

    NASA Technical Reports Server (NTRS)

    Chamberlain, J. W.

    1975-01-01

    Some of the effects on planetary spectra that would be produced by departures from isotropic scattering are examined. The phase function is the simplest departure to handle analytically and the only phase function, other than the isotropic one, that can be incorporated into a Chandrasekhar first approximation. This approach has the advantage of illustrating trends resulting from anisotropies while retaining the simplicity that yields physical insight. An algebraic solution to the two sets of anisotropic H functions is developed in the appendix. It is readily adaptable to progammable desk calculators and gives emergent intensities accurate to 0.3 percent, which is sufficient even for spectroscopic analysis.

  3. Planetary rings and astrophysical discs

    NASA Astrophysics Data System (ADS)

    Latter, Henrik

    2016-05-01

    Disks are ubiquitous in astrophysics and participate in some of its most important processes. Of special interest is their role in star, planet and moon formation, the growth of supermassive black holes, and the launching of jets. Although astrophysical disks can be up to ten orders of magnitude larger than planetary rings and differ hugely in composition, all disks share to some extent the same basic dynamics and many physical phenomena. This review explores these areas of overlap. Topics covered include disk formation, accretion, collisions, instabilities, and satellite-disk interactions.

  4. Ultraviolet photometry of planetary nebulae

    NASA Technical Reports Server (NTRS)

    Holm, A. V.

    1972-01-01

    Nine of the planetary nebulae observed by the Wisconsin filter photometers are compared with 15 Monocerotis in the spectral region 1430-4250 A. The data are corrected for the degradation of the filters of stellar photometer number four with time. Comparisons with simple models indicate that most of the observed nebulae are subject to some interstellar extinction in the far ultraviolet. However, NGC 246 and NGC 1360 appear to be nearly unreddened. Thus far no unexpected features have been found in the observations.

  5. The effects of physical and geochemical heterogeneities on hydro-geochemical transport and effective reaction rates

    NASA Astrophysics Data System (ADS)

    Atchley, Adam L.; Navarre-Sitchler, Alexis K.; Maxwell, Reed M.

    2014-09-01

    The role of coupled physical and geochemical heterogeneities in hydro-geochemical transport is investigated by simulating three-dimensional transport in a heterogeneous system with kinetic mineral reactions. Ensembles of 100 physically heterogeneous realizations were simulated for three geochemical conditions: 1) spatially homogeneous reactive mineral surface area, 2) reactive surface area positively correlated to hydraulic heterogeneity, and 3) reactive surface area negatively correlated to hydraulic heterogeneity. Groundwater chemistry and the corresponding effective reaction rates were calculated at three transverse planes to quantify differences in plume evolution due to heterogeneity in mineral reaction rates and solute residence time (τ). The model is based on a hypothetical CO2 intrusion into groundwater from a carbon capture utilization and storage (CCUS) operation where CO2 dissolution and formation of carbonic acid created geochemical dis-equilibrium between fluids and the mineral galena that resulted in increased aqueous lead (Pb2 +) concentrations. Calcite dissolution buffered the pH change and created conditions of galena oversaturation, which then reduced lead concentrations along the flow path. Near the leak kinetic geochemical reactions control the release of solutes into the fluid, but further along the flow path mineral solubility controls solute concentrations. Simulation results demonstrate the impact of heterogeneous distribution of geochemical reactive surface area in coordination with physical heterogeneity on the effective reaction rate (Krxn,eff) and Pb2 + concentrations within the plume. Dissimilarities between ensemble Pb2 + concentration and Krxn,eff are attributed to how geochemical heterogeneity affects the time (τeq) and therefore advection distance (Leq) required for the system to re-establish geochemical equilibrium. Only after geochemical equilibrium is re-established, Krxn,eff and Pb2 + concentrations are the same for all three

  6. The effects of physical and geochemical heterogeneities on hydro-geochemical transport and effective reaction rates.

    PubMed

    Atchley, Adam L; Navarre-Sitchler, Alexis K; Maxwell, Reed M

    2014-09-01

    The role of coupled physical and geochemical heterogeneities in hydro-geochemical transport is investigated by simulating three-dimensional transport in a heterogeneous system with kinetic mineral reactions. Ensembles of 100 physically heterogeneous realizations were simulated for three geochemical conditions: 1) spatially homogeneous reactive mineral surface area, 2) reactive surface area positively correlated to hydraulic heterogeneity, and 3) reactive surface area negatively correlated to hydraulic heterogeneity. Groundwater chemistry and the corresponding effective reaction rates were calculated at three transverse planes to quantify differences in plume evolution due to heterogeneity in mineral reaction rates and solute residence time (τ). The model is based on a hypothetical CO2 intrusion into groundwater from a carbon capture utilization and storage (CCUS) operation where CO2 dissolution and formation of carbonic acid created geochemical dis-equilibrium between fluids and the mineral galena that resulted in increased aqueous lead (Pb(2+)) concentrations. Calcite dissolution buffered the pH change and created conditions of galena oversaturation, which then reduced lead concentrations along the flow path. Near the leak kinetic geochemical reactions control the release of solutes into the fluid, but further along the flow path mineral solubility controls solute concentrations. Simulation results demonstrate the impact of heterogeneous distribution of geochemical reactive surface area in coordination with physical heterogeneity on the effective reaction rate (Krxn,eff) and Pb(2+) concentrations within the plume. Dissimilarities between ensemble Pb(2+) concentration and Krxn,eff are attributed to how geochemical heterogeneity affects the time (τeq) and therefore advection distance (Leq) required for the system to re-establish geochemical equilibrium. Only after geochemical equilibrium is re-established, Krxn,eff and Pb(2+) concentrations are the same for all

  7. Design of Virtual Environments for the Comprehension of Planetary Phenomena Based on Students' Ideas.

    ERIC Educational Resources Information Center

    Bakas, Christos; Mikropoulos, Tassos A.

    2003-01-01

    Explains the design and development of an educational virtual environment to support the teaching of planetary phenomena, particularly the movements of Earth and the sun, day and night cycle, and change of seasons. Uses an interactive, three-dimensional (3D) virtual environment. Initial results show that the majority of students enthused about…

  8. Planetary Boundary Layer from AERI and MPL

    SciTech Connect

    Sawyer, Virginia

    2014-02-13

    The distribution and transport of aerosol emitted to the lower troposphere is governed by the height of the planetary boundary layer (PBL), which limits the dilution of pollutants and influences boundary-layer convection. Because radiative heating and cooling of the surface strongly affect the PBL top height, it follows diurnal and seasonal cycles and may vary by hundreds of meters over a 24-hour period. The cap the PBL imposes on low-level aerosol transport makes aerosol concentration an effective proxy for PBL height: the top of the PBL is marked by a rapid transition from polluted, well-mixed boundary-layer air to the cleaner, more stratified free troposphere. Micropulse lidar (MPL) can provide much higher temporal resolution than radiosonde and better vertical resolution than infrared spectrometer (AERI), but PBL heights from all three instruments at the ARM SGP site are compared to one another for validation. If there is agreement among them, the higher-resolution remote sensing-derived PBL heights can accurately fill in the gaps left by the low frequency of radiosonde launches, and thus improve model parameterizations and our understanding of boundary-layer processes.

  9. Hemispherical Parker waves driven by thermal shear in planetary dynamos

    NASA Astrophysics Data System (ADS)

    Dietrich, W.; Schmitt, D.; Wicht, J.

    2013-11-01

    Planetary and stellar magnetic fields are thought to be sustained by helical motions (α-effect) and, if present, differential rotation (Ω-effect). In the Sun, the strong differential rotation in the tachocline is responsible for an efficient Ω-effect creating a strong axisymmetric azimuthal magnetic field. This is a prerequisite for Parker dynamo waves that may be responsible for the solar cycle. In the liquid iron cores of terrestrial planets, the Coriolis force organizes convection into columns with a strong helical flow component. These likely dominate magnetic field generation while the Ω-effect is of secondary importance. Here we use numerical simulations to show that the planetary dynamo scenario may change when the heat flux through the outer boundary is higher in one hemisphere than in the other. A hemispherical dynamo is promoted that is dominated by fierce thermal wind responsible for a strong Ω-effect. As a consequence Parker dynamo waves are excited equivalent to those predicted for the Sun. They obey the same dispersion relation and propagation characteristics. We suggest that Parker waves may therefore also play a role in planetary dynamos for all scenarios where zonal flows become an important part of convective motions.

  10. A modular gas-cooled cermet reactor system for planetary base power

    SciTech Connect

    Jahshan, S.N.; Borkowski, J.A. )

    1993-01-15

    Fission nuclear power is foreseen as the source for electricity in planetary colonization and exploration. A six module gas-cooled, cermet-fueled reactor is proposed that can meet the design objectives. The highly enriched core is compact and can operate at high temperature for a long life. The helium coolant powers six modular Brayton cycles that compare favorably with the SP-100-based Brayton cycle.

  11. Geochemical evolution of magmatism in Archean granite-greenstone terrains

    NASA Astrophysics Data System (ADS)

    Samsonov, A. V.; Larionova, Yu. O.

    2006-05-01

    Evolution of Archean magmatism is one of the key problems concerning the early formation stages of the Earth crust and biosphere, because that evolution exactly controlled variable concentrations of chemical elements in the World Ocean, which are important for metabolism. Geochemical evolution of magmatism between 3.5 and 2.7 Ga is considered based on database characterizing volcanic and intrusive rock complexes of granite-greenstone terrains (GGT) studied most comprehensively in the Karelian (2.9-2.7 Ga) and Kaapvaal (3.5-2.9 Ga) cratons and in the Pilbara block (3.5-2.9 Ga). Trends of magmatic geochemical evolution in the mentioned GGTs were similar in general. At the early stage of their development, tholeiitic magmas were considerably enriched in chalcophile and siderophile elements Fe2O3, MgO, Cr, Ni, Co, V, Cu, and Zn. At the next stage, calc-alkaline volcanics of greenstone belts and syntectonic TTG granitoids were enriched in lithophile elements Rb, Cs, Ba, Th, U, Pb, Nb, La, Sr, Be and others. Elevated concentrations of both the “crustal” and “mantle-derived” elements represented a distinctive feature of predominantly intrusive rocks of granitoid composition, which were characteristic of the terminal stage of continental crust formation in the GGTs, because older silicic rocks and lithospheric mantle were jointly involved into processes of magma generation. On the other hand, the GGTs different in age reveal specific trends in geochemical evolution of rock associations close in composition and geological position. First, the geochemical cycle of GGT evolution was of a longer duration in the Paleoarchean than in the Meso-and Neoarchean. Second, the Paleoarche an tholeiitic associations had higher concentrations of LREE and HFSE (Zr, Ti, Th, Nb, Ta, Hf) than their Meso-and Neoarchean counterparts. Third, the Y and Yb concentrations in Paleoarchean calc-alkaline rock associations are systematically higher than in Neoarchean rocks of the same type

  12. Laboratory Spectroscopy of Planetary Molecules

    NASA Astrophysics Data System (ADS)

    Brown, L.; Orton, G.

    2007-08-01

    An international team of laboratory spectroscopists are working in concert to support remote sensing of planetary atmospheres and Titan. An overview of high resolution laboratory investigations will be presented for spectral bands from the rotational wavelengths into the near infrared. The studies include measurements and theoretical analyses of the line positions, intensities and/or broadening coefficients needed to improve the spectroscopic databases required for planetary applications. The molecular studies include water (H2O) broadened by carbon dioxide in the far- and mid- infrared; positions, intensities, broadening and line mixing of carbon dioxide (CO2) in the near-IR; broadening and line mixing of methane in the mid- and near-IR; frequencies of methyl cyanide (CH3CN) in the rotational region and line positions, intensities and nitrogen broadening of methyl cyanide in the low fundamental bands; global theoretical modeling of the phosphine (PH3) parameters; and frequencies of acetaldehyde (CH3CHO), methylamine (CH3NH2) and deuterated acetylene (HCCD, DCCD) in the rotational region.

  13. Laboratory Spectroscopy of Planetary Molecules

    NASA Astrophysics Data System (ADS)

    Brown, L.; Drouin, B.; Miller, C.; Pearson, J.; Orton, G.; Toth, R.; Benner, C.; Devi, M.; Blake, T.; Masiello, T.; Sams, R.; Butler, R.; Champion, J.; Chelin, P.; Dehayem, A.; Kleiner, I.; Orphal, J.; Sagui, L.; Gamache, R.; Humphrey, C.; Liu, W.; Predoi

    An international team of laboratory spectroscopists are working in concert to support remote sensing of planetary atmospheres and Titan. An overview of high resolution laboratory investigations will be presented for spectral bands from the rotational wavelengths into the near infrared. The studies include measurements and theoretical analyses of the line positions, intensities and/or broadening coefficients needed to improve the spectroscopic databases required for planetary applications. The molecular studies include water (H2O) broadened by carbon dioxide in the far- and mid-infrared; positions, intensities, broadening and line mixing of carbon dioxide (CO2) in the near-IR; broadening and line mixing of methane in the mid- and near-IR; frequencies of methyl cyanide (CH3CN) in the rotational region and line positions, intensities and nitrogen broadening of methyl cyanide in the low fundamental bands; global theoretical modeling of the phosphine (PH3) parameters; and frequencies of acetaldehyde (CH3CHO), methylamine (CH3NH2) and deuterated acetylene (HCCD, DCCD) in the rotational region.

  14. Theory of Planetary System Formation

    NASA Technical Reports Server (NTRS)

    Cassen, Patrick

    1996-01-01

    Observations and theoretical considerations support the idea that the Solar System formed by the collapse of tenuous interstellar matter to a disk of gas and dust (the primitive solar nebula), from which the Sun and other components separated under the action of dissipative forces and by the coagulation of solid material. Thus, planets are understood to be contemporaneous byproducts of star formation. Because the circumstellar disks of new stars are easier to observe than mature planetary systems, the possibility arises that the nature and variety of planets might be studied from observations of the conditions of their birth. A useful theory of planetary system formation would therefore relate the properties of circumstellar disks both to the initial conditions of star formation and to the consequent properties of planets to those of the disk. Although the broad outlines of such a theory are in place, many aspects are either untested, controversial, or otherwise unresolved; even the degree to which such a comprehensive theory is possible remains unknown.

  15. Control technique for planetary rover

    NASA Technical Reports Server (NTRS)

    Nakatani, Ichiro; Kubota, Takashi; Adachi, Tadashi; Saitou, Hiroaki; Okamoto, Sinya

    1994-01-01

    Beginning next century, several schemes for sending a planetary rover to the moon or Mars are being planned. As part of the development program, autonomous navigation technology is being studied to allow the rover the ability to move autonomously over a long range of unknown planetary surface. In the previous study, we ran the autonomous navigation experiment on an outdoor test terrain by using a rover test-bed that was controlled by a conventional sense-plan-act method. In some cases during the experiment, a problem occurred with the rover moving into untraversable areas. To improve this situation, a new control technique has been developed that gives the rover the ability of reacting to the outputs of the proximity sensors, a reaction behavior if you will. We have developed a new rover test-bed system on which an autonomous navigation experiment was performed using the newly developed control technique. In this outdoor experiment, the new control technique effectively produced the control command for the rover to avoid obstacles and be guided to the goal point safely.

  16. Interactive investigations into planetary interiors

    NASA Astrophysics Data System (ADS)

    Rose, I.

    2015-12-01

    Many processes in Earth science are difficult to observe or visualize due to the large timescales and lengthscales over which they operate. The dynamics of planetary mantles are particularly challenging as we cannot even look at the rocks involved. As a result, much teaching material on mantle dynamics relies on static images and cartoons, many of which are decades old. Recent improvements in computing power and technology (largely driven by game and web development) have allowed for advances in real-time physics simulations and visualizations, but these have been slow to affect Earth science education.Here I demonstrate a teaching tool for mantle convection and seismology which solves the equations for conservation of mass, momentum, and energy in real time, allowing users make changes to the simulation and immediately see the effects. The user can ask and answer questions about what happens when they add heat in one place, or take it away from another place, or increase the temperature at the base of the mantle. They can also pause the simulation, and while it is paused, create and visualize seismic waves traveling through the mantle. These allow for investigations into and discussions about plate tectonics, earthquakes, hot spot volcanism, and planetary cooling.The simulation is rendered to the screen using OpenGL, and is cross-platform. It can be run as a native application for maximum performance, but it can also be embedded in a web browser for easy deployment and portability.

  17. Lunar and Planetary Science XXVIII

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The present conference discusses such topics as density crossovers in lunar picrites, the geology of the Cassini impact basin, Mars, nanobacteria in carbonates, the properties of shocked aerogels, a chemical model of Comet Halley, lunar mascons, the impact evolution of icy regoliths, the geology of the Venera 8 landing site, the photogeologic mapping of northern Venus, HST observations of Mars, observational constraints on the rotational dynamics of Mars, and primordial magnetic field measurements from the moon. Also discussed are models of the S2 fluorescence spectra of comets, Martian crater ejecta, the heights of Venusian steep-sided domes, cloud-climate interactions on Venus, the Humorum basin geology from Clementine data, an early Amazonian lake in the Gale crater of Mars, nebular fractionations and Mn-Cr systematics, the Rock Chipper planetary surface sample collection, Mariner 10 stereo images of Mercury, remote and local stresses and Calderas on Mars, the electrostatic charging of saltating particles, SO2 detected on Callisto, the Mars Explorer Planetary Data System, an assessment of explosive venting on Europa, the sequential faulting history of the Mars Valles Marineris, a search for Martian sediments, the composition and internal structure of Europa, long-term and 'diurnal' tidal stresses on Europa, and episodic greenhouse climates on Mars.

  18. Planetary Protection Considerations for JIMO

    NASA Technical Reports Server (NTRS)

    Koukol, R. C.

    2003-01-01

    Europa is the only body in the solar system besides Mars that is currently viewed as a body of significant interest relative to the process of chemical evolution and/or the origin of life or for which scientific opinion provides a significant chance of contamination which could jeopardize a future biological experiment. Thus, both NASA and COSPAR policy require that Europa be protected from biological contamination that could result from scientific exploration conducted by robotic spacecraft. In 2000, the Task Group on the Forward Contamination of Europa (Space Studies Board) published its report on Preventing the Forward Contamination of Europa recommending a limit of 10(exp -4) probability of contamination of Europa's ocean per mission (at any time in the future) by a single viable terrestrial microbe. While NASA guidelines do not yet explicitly reflect this new recommendation, it is likely that the SSB recommendation will be adopted by NASA planetary protection in the form of a sterility requirement or at least a stringent total microbial burden requirement. In our presentation, we will present an overview of the anticipated planetary protection requirements for both orbiters and landers destined for Europa and some of the challenges these requirements will present.

  19. Infrastructure for Planetary Sciences: Universal planetary database development project

    NASA Astrophysics Data System (ADS)

    Kasaba, Yasumasa; Capria, M. T.; Crichton, D.; Zender, J.; Beebe, R.

    The International Planetary Data Alliance (IPDA), formally formed under COSPAR (Formal start: from the COSPAR 2008 at Montreal), is a joint international effort to enable global access and exchange of high quality planetary science data, and to establish archive stan-dards that make it easier to share the data across international boundaries. In 2008-2009, thanks to the many players from several agencies and institutions, we got fruitful results in 6 projects: (1) Inter-operable Planetary Data Access Protocol (PDAP) implementations [led by J. Salgado@ESA], (2) Small bodies interoperability [led by I. Shinohara@JAXA N. Hirata@U. Aizu], (3) PDAP assessment [led by Y. Yamamoto@JAXA], (4) Architecture and standards definition [led by D. Crichton@NASA], (5) Information model and data dictionary [led by S. Hughes@NASA], and (6) Venus Express Interoperability [led by N. Chanover@NMSU]. 'IPDA 2009-2010' is important, especially because the NASA/PDS system reformation is now reviewed as it develops for application at the international level. IPDA is the gate for the establishment of the future infrastructure. We are running 8 projects: (1) IPDA Assessment of PDS4 Data Standards [led by S. Hughes (NASA/JPL)], (2) IPDA Archive Guide [led by M.T. Capria (IASF/INAF) and D. Heather (ESA/PSA)], (3) IPDA Standards Identification [led by E. Rye (NASA/PDS) and G. Krishna (ISRO)], (4) Ancillary Data Standards [led by C. Acton (NASA/JPL)], (5) IPDA Registries Definition [led by D. Crichton (NASA/JPL)], (6) PDAP Specification [led by J. Salgado (ESA/PSA) and Y. Yamamoto (JAXA)], (7) In-teroperability Assessment [R. Beebe (NMSU) and D. Heather (ESA/PSA)], and (8) PDAP Geographic Information System (GIS) extension [N. Hirata (Univ. Aizu) and T. Hare (USGS: thare@usgs.gov)]. This paper presents our achievements and plans summarized in the IPDA 5th Steering Com-mittee meeting at DLR in July 2010. We are now just the gate for the establishment of the Infrastructure.

  20. Planetary Balloon-Based Science Platform Evaluation and Program Implementation

    NASA Technical Reports Server (NTRS)

    Dankanich, John W.; Kremic, Tibor; Hibbitts, Karl; Young, Eliot F.; Landis, Rob

    2016-01-01

    This report describes a study evaluating the potential for a balloon-based optical telescope as a planetary science asset to achieve decadal class science. The study considered potential science achievable and science traceability relative to the most recent planetary science decadal survey, potential platform features, and demonstration flights in the evaluation process. Science Potential and Benefits: This study confirms the cost the-benefit value for planetary science purposes. Forty-four (44) important questions of the decadal survey are at least partially addressable through balloon based capabilities. Planetary science through balloon observations can provide significant science through observations in the 300 nm to 5 m range and at longer wavelengths as well. Additionally, balloon missions have demonstrated the ability to progress from concept to observation to publication much faster than a space mission increasing the speed of science return. Planetary science from a balloon-borne platform is a relatively low-cost approach to new science measurements. This is particularly relevant within a cost-constrained planetary science budget. Repeated flights further reduce the cost of the per unit science data. Such flights offer observing time at a very competitive cost. Another advantage for planetary scientists is that a dedicated asset could provide significant new viewing opportunities not possible from the ground and allow unprecedented access to observations that cannot be realized with the time allocation pressures faced by current observing assets. In addition, flight systems that have a relatively short life cycle and where hardware is generally recovered, are excellent opportunities to train early career scientists, engineers, and project managers. The fact that balloon-borne payloads, unlike space missions, are generally recovered offers an excellent tool to test and mature instruments and other space craft systems. Desired Gondola Features: Potential

  1. The stepwise growth of tectonic plates across Earth's evolving supercontinent cycle

    NASA Astrophysics Data System (ADS)

    Van Kranendonk, M. J.; Kirkland, C. L.

    2012-04-01

    Plate tectonics both creates and recycles crust, but the rate of continental growth over Earth history remains contentious: some believe it formed fast and early, others more gradually and, perhaps, episodically, through the supercontinent cycle. Time constrained analysis of both oxygen and hafnium isotopes in zircon grains and incompatible elements (Zr, Th) from magmatic rocks confirms the importance of Earth's supercontinent cycle not only on the degree of crustal recycling rates that arises from the aggregation and dispersal of supercontinents, but also on mantle temperatures, crustal growth rates, and climatic conditions. These changes are used to infer a conditioned duality of the Earth system between alternating periods of hot and cold mantle that arise in response to the supercontinent cycle. Hot mantle periods that accompany supercontinent aggregation events are characterised by mantle superplume events, increased crustal recycling and warm, reducing climatic conditions. Cool mantle periods during supercontinent rifting result from core insulation by slab graveyards and are characterised by low rates of crust production and cool, more oxidizing conditions. Changes in the intensity of the orogenic cycle through time since its inception at c. 3.2 Ga are ascribed to self-reorganisation of progressively larger tectonic plates (tessellation of a sphere) that accommodate the secular decrease in planetary heat. Bursts of crust extraction during Neoarchean and Mesoproterozoic supercontinent assembly led to overstep periods of large plates on subduction-cooled, melt-depleted mantle, accompanied by global ice ages. Optimal packing (pentagonal dodecahedron) of the plates was attained on dispersal of Nuna at 1.4 Ga, leading to a peak in geochemical and isotopic proxies of orogenic intensity during c. 1.2 Ga assembly of Rodinia (large plates on warmer Earth), with declining intensity thereafter as a function of decreasing heat with same-size plates.

  2. Lunar and Planetary Science XXXVI, Part 13

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Mars Express HRSC Data. Mapping Compositional Diversity on Mars: Spatial Distribution and Geological Implications. A New Simulation Chamber for Studying Planetary Environments. Folded Structure in Terra Sirenum. Mars. Nitrogen-Noble Gas Static Mass Spectrometry of Genesis Collector Materials. Neon Isotope Heterogeneity in the Terrestrial Mantle: Implication for the Acquisition of Volatile Elements in Terrestrial Planets. The Cosmic Clock, the Cycle of Terrestrial Mass Extinctions.

  3. Hierarchies of Models: Toward Understanding Planetary Nebulae

    NASA Technical Reports Server (NTRS)

    Knuth, Kevin H.; Hajian, Arsen R.; Clancy, Daniel (Technical Monitor)

    2003-01-01

    Stars like our sun (initial masses between 0.8 to 8 solar masses) end their lives as swollen red giants surrounded by cool extended atmospheres. The nuclear reactions in their cores create carbon, nitrogen and oxygen, which are transported by convection to the outer envelope of the stellar atmosphere. As the star finally collapses to become a white dwarf, this envelope is expelled from the star to form a planetary nebula (PN) rich in organic molecules. The physics, dynamics, and chemistry of these nebulae are poorly understood and have implications not only for our understanding of the stellar life cycle but also for organic astrochemistry and the creation of prebiotic molecules in interstellar space. We are working toward generating three-dimensional models of planetary nebulae (PNe), which include the size, orientation, shape, expansion rate and mass distribution of the nebula. Such a reconstruction of a PN is a challenging problem for several reasons. First, the data consist of images obtained over time from the Hubble Space Telescope (HST) and spectra obtained from Kitt Peak National Observatory (KPNO) and Cerro Tololo Inter-American Observatory (CTIO). These images are of course taken from a single viewpoint in space, which amounts to a very challenging tomographic reconstruction. Second, the fact that we have two disparate and orthogonal data types requires that we utilize a method that allows these data to be used together to obtain a solution. To address these first two challenges we employ Bayesian model estimation using a parameterized physical model that incorporates much prior information about the known physics of the PN. In our previous works we have found that the forward problem of the comprehensive model is extremely time consuming. To address this challenge, we explore the use of a set of hierarchical models, which allow us to estimate increasingly more detailed sets of model parameters. These hierarchical models of increasing complexity are akin

  4. Observations and Modeling of Tropical Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    Laraia, Anne

    2016-01-01

    This thesis is a comprised of three different projects within the topic of tropical atmospheric dynamics. First, I analyze observations of thermal radiation from Saturn's atmosphere and from them, determine the latitudinal distribution of ammonia vapor near the 1.5-bar pressure level. The most prominent feature of the observations is the high brightness temperature of Saturn's subtropical latitudes on either side of the equator. After comparing the observations to a microwave radiative transfer model, I find that these subtropical bands require very low ammonia relative humidity below the ammonia cloud layer in order to achieve the high brightness temperatures observed. We suggest that these bright subtropical bands represent dry zones created by a meridionally overturning circulation. Second, I use a dry atmospheric general circulation model to study equatorial superrotation in terrestrial atmospheres. A wide range of atmospheres are simulated by varying three parameters: the pole-equator radiative equilibrium temperature contrast, the convective lapse rate, and the planetary rotation rate. A scaling theory is developed that establishes conditions under which superrotation occurs in terrestrial atmospheres. The scaling arguments show that superrotation is favored when the off-equatorial baroclinicity and planetary rotation rates are low. Similarly, superrotation is favored when the convective heating strengthens, which may account for the superrotation seen in extreme global-warming simulations. Third, I use a moist slab-ocean general circulation model to study the impact of a zonally-symmetric continent on the distribution of monsoonal precipitation. I show that adding a hemispheric asymmetry in surface heat capacity is sufficient to cause symmetry breaking in both the spatial and temporal distribution of precipitation. This spatial symmetry breaking can be understood from a large-scale energetic perspective, while the temporal symmetry breaking requires

  5. Hierarchies of Models: Toward Understanding Planetary Nebulae

    NASA Technical Reports Server (NTRS)

    Knuth, Kevin H.; Hajian, Arsen R.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    Stars like our sun (initial masses between 0.8 to 8 solar masses) end their lives as swollen red giants surrounded by cool extended atmospheres. The nuclear reactions in their cores create carbon, nitrogen and oxygen, which are transported by convection to the outer envelope of the stellar atmosphere. As the star finally collapses to become a white dwarf, this envelope is expelled from the star to form a planetary nebula (PN) rich in organic molecules. The physics, dynamics, and chemistry of these nebulae are poorly understood and have implications not only for our understanding of the stellar life cycle but also for organic astrochemistry and the creation of prebiotic molecules in interstellar space. We are working toward generating three-dimensional models of planetary nebulae (PNe), which include the size, orientation, shape, expansion rate and mass distribution of the nebula. Such a reconstruction of a PN is a challenging problem for several reasons. First, the data consist of images obtained over time from the Hubble Space Telescope (HST) and spectra obtained from Kitt Peak National Observatory (KPNO) and Cerro Tololo Inter-American Observatory (CTIO). These images are of course taken from a single viewpoint in space, which amounts to a very challenging tomographic reconstruction. Second, the fact that we have two disparate and orthogonal data types requires that we utilize a method that allows these data to be used together to obtain a solution. To address these first two challenges we employ Bayesian model estimation using a parameterized physical model that incorporates much prior information about the known physics of the PN. In our previous works we have found that the forward problem of the comprehensive model is extremely time consuming. To address this challenge, we explore the use of a set of hierarchical models, which allow us to estimate increasingly more detailed sets of model parameters. These hierarchical models of increasing complexity are akin

  6. Post Viking planetary protection requirements study

    NASA Technical Reports Server (NTRS)

    Wolfson, R. P.

    1977-01-01

    Past planetary quarantine requirements were reviewed in the light of present Viking data to determine the steps necessary to prevent contamination of the Martian surface on future missions. The currently used term planetary protection reflects a broader scope of understanding of the problems involved. Various methods of preventing contamination are discussed in relation to proposed projects, specifically the 1984 Rover Mission.

  7. Introduction to the special issue: Planetary geomorphology

    NASA Astrophysics Data System (ADS)

    Burr, Devon M.; Howard, Alan D.

    2015-07-01

    Planetary geomorphology is the study of extraterrestrial landscapes. In recognition of the promise for productive interaction between terrestrial and planetary geomorphologists, the 45th annual Binghamton Geomorphology Symposium (BGS) focused on Planetary Geomorphology. The aim of the symposium was to bring planetary and terrestrial geomorphologists together for symbiotic and synthetic interactions that would enrich both subdisciplines. In acknowledgment of the crucial role of terrestrial field work in planetary geomorphology and of the BGS tradition, the symposium began with a field trip to the Appalachian Mountains, followed by a dinner talk of recent results from the Mars Surface Laboratory. On Saturday and Sunday, the symposium was organized around major themes in planetary geomorphology, starting with the geomorphic processes that are most common in our Solar System-impact cratering, tectonism, volcanism-to set the stage for other geomorphic processes, including aeolian, fluvial, lacustrine, and glacial/polar. On Saturday evening, the banquet talk provided an historical overview of planetary geomorphology, including its roots in the terrestrial geosciences. The symposium concluded with a full-afternoon tutorial on planetary geomorphologic datasets. This special issue of Geomorphology consists of papers by invited authors from the 2014 BGS, and this introduction provides some context for these papers.

  8. The Formation of a Planetary Nebula.

    ERIC Educational Resources Information Center

    Harpaz, Amos

    1991-01-01

    Proposes a scenario to describe the formation of a planetary nebula, a cloud of gas surrounding a very hot compact star. Describes the nature of a planetary nebula, the number observed to date in the Milky Way Galaxy, and the results of research on a specific nebula. (MDH)

  9. Impact erosion of terrestrial planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Ahrens, Thomas J.

    1992-01-01

    I review current ideas about the nature of the planetesimals - composition, size distribution, and the planetary encounter velocity. Previous papers on accretion and erosion of planetary atmospheres as a result of multiple impacts are reviewed. Finally, the effects of blowing off a substantial fraction of the atmosphere from a terrestrial planet due to a single giant body impact are discussed.

  10. Meteoritics and Planetary Science Supplement. Volume 35

    NASA Technical Reports Server (NTRS)

    Sears, Derek W. G. (Editor); Binzel, Richard P. (Editor); Gaffey, Michael J. (Editor); Kraehenbuehl, Urs (Editor); Pieters, Carle M. (Editor); Shaw, Denis (Editor); Wieler, Rainer (Editor); Brownlee, Donald E. (Editor); Goldstein, Joseph I. (Editor); Lyon, Ian C. (Editor)

    2000-01-01

    This special supplement of the Meteoritics and Planetary Science Society Journal contains the abstracts of 324 technical presentations, and the presentations of awards during the Annual meeting of the Meteoritical Society. The abstracts review current research on meteors and planetary sciences.

  11. Dust waves in rotating planetary magnetospheres

    SciTech Connect

    Haque, Q.; Saleem, H.

    2005-10-31

    Low frequency electrostatic drift and acoustic waves are studied in rotating dusty plasmas. Linear dispersion relation is found. It is pointed out that rotation of the planet can introduce dust drift waves through Coriolis force in the planetary magnetospheres. This mode can couple with dust acoustic mode. Coriolis force effect may give rise to dipolar vortices in rotating dusty plasmas of planetary magnetospheres.

  12. Lunar and Planetary Science XXXV: Education

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session "Education" includes the following topics: 1) Convection, Magnetism, Orbital Resonances, Impacts, and Volcanism: Energies and Processes in the Solar System: Didactic Activities; 2) Knowledge Management in Aerospace-Education and Training Issues; 3) Creating Easy-to-Understand Planetary Maps; 4) Planetary Environment comparison in the Education of Astrobiology; and 5) Design and Construction of a Mechanism for the Orbital Resonances Simulation.

  13. An outline of planetary geoscience. [philosophy

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A philosophy for planetary geoscience is presented to aid in addressing a number of major scientific questions; answers to these questions should constitute the basic geoscientific knowledge of the solar system. However, any compilation of major questions or basic knowledge in planetary geoscience involves compromises and somewhat arbitrary boundaries that reflect the prevalent level of understanding at the time.

  14. Rethinking the Ancient Sulfur Cycle

    NASA Astrophysics Data System (ADS)

    Fike, David A.; Bradley, Alexander S.; Rose, Catherine V.

    2015-05-01

    The sulfur biogeochemical cycle integrates the metabolic activity of multiple microbial pathways (e.g., sulfate reduction, disproportionation, and sulfide oxidation) along with abiotic reactions and geological processes that cycle sulfur through various reservoirs. The sulfur cycle impacts the global carbon cycle and climate primarily through the remineralization of organic carbon. Over geological timescales, cycling of sulfur is closely tied to the redox state of Earth's exosphere through the burial of oxidized (sulfate) and reduced (sulfide) sulfur species in marine sediments. Biological sulfur cycling is associated with isotopic fractionations that can be used to trace the fluxes through various metabolic pathways. The resulting isotopic data provide insights into sulfur cycling in both modern and ancient environments via isotopic signatures in sedimentary sulfate and sulfide phases. Here, we review the deep-time δ34S record of marine sulfates and sulfides in light of recent advances in understanding how isotopic signatures are generated by microbial activity, how these signatures are encoded in marine sediments, and how they may be altered following deposition. The resulting picture shows a sulfur cycle intimately coupled to ambient carbon cycling, where sulfur isotopic records preserved in sedimentary rocks are critically dependent on sedimentological and geochemical conditions (e.g., iron availability) during deposition.

  15. Expanding the Planetary Analog Test Sites in Hawaii - Planetary Basalt Manipulation

    NASA Astrophysics Data System (ADS)

    Kelso, R.

    2013-12-01

    The Pacific International Space Center for Exploration Systems (PISCES) is one of the very few planetary surface research test sites in the country that is totally funded by the state legislature. In recent expansions, PISCES is broadening its work in planetary test sites to include much more R&D work in the planetary surface systems, and the manipulation of basalt materials. This is to include laser 3D printing of basalt, 'lunar-concrete' construction in state projects for Hawaii, renewable energy, and adding lava tubes/skylights to their mix of high-quality planetary analog test sites. PISCES Executive Director, Rob Kelso, will be providing program updates on the interest of the Hawaii State Legislature in planetary surface systems, new applied research initiatives in planetary basalts and interests in planetary construction.

  16. Automatic quality assessment of planetary images

    NASA Astrophysics Data System (ADS)

    Sidiropoulos, P.; Muller, J.-P.

    2015-10-01

    A significant fraction of planetary images are corrupted beyond the point that much scientific meaning can be extracted. For example, transmission errors result in missing data which is unrecoverable. The available planetary image datasets include many such "bad data", which both occupy valuable scientific storage resources and create false impressions about planetary image availability for specific planetary objects or target areas. In this work, we demonstrate a pipeline that we have developed to automatically assess the quality of planetary images. Additionally, this method discriminates between different types of image degradation, such as low-quality originating from camera flaws or low-quality triggered by atmospheric conditions, etc. Examples of quality assessment results for Viking Orbiter imagery will be also presented.

  17. On the Diversity of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1997-01-01

    Models of planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. A potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed.

  18. Mechanistic Studies of Planetary Haze Formation

    NASA Astrophysics Data System (ADS)

    Hicks, Raea Kay

    2015-10-01

    controlling the total mass produced depends on pressure. We also report an overall increase with pressure in the N/C ratio, which supports the importance of a pressure- dependent mechanism for nitrogen incorporation. In order to understand carbon incorporation into early Earth aerosols, we devised an analysis technique that allows retrieval of the elemental analysis from unit-mass resolution (UMR) mass spectra of isotopically-labeled data. A quadrupole aerosol mass spectrometer (Q-AMS) was used to obtain UMR data of 13C-labeled and unlabeled aerosol generated by FUV photochemistry of gas mixtures containing 0.1% of either CH4 or 13CH 4 in N2. In this method, the differences in the positions of ion groups in the resulting spectra are used to estimate the mass fraction of carbon in the aerosol, and estimation of the remaining elements follows. Analysis of the UMR data yields an elemental composition of 63+/-7% C, 8+/-1% H, and 29+/-7% N by mass. Unlabeled aerosols formed under the same conditions are found by the HR-ToF-AMS to have an elemental composition of 63+/-3% C, 8+/-1% H, 20+/-4% N, and 9+/-3% O by mass, in good agreement with the UMR method. This favorable comparison verifies the method, which expands the UMR mass spectrometry toolkit. Chemical mechanisms posited to explain the aerosol-forming chemistry treat CH4 as carbon source in these hazes and treat CO2 as a source of oxygen only. We have generated early Earth aerosol analogs in the laboratory by FUV irradiation of gas mixtures containing isotopically-labeled permutations of 1,000 ppmv unlabeled and 13C-labeled CH 4 and CO2 in N2. Products in the particle phase were analyzed by the Q-AMS and the HR-ToF-AMS. Results indicate that CH 4 can account for 100% of the total carbon contained in the hazes. These results have implications for the geochemical interpretations of inclusions found in Archaean rocks on Earth, and for the astrobiological potential of other planetary atmospheres.

  19. Resonance lock and planetary dynamics

    NASA Astrophysics Data System (ADS)

    Haghighipour, Nader

    1999-11-01

    The main purpose of this study is to utilize the method of partial averaging in order to analyze the dynamics of a planetary system while captured in resonance. A restricted planar circular three-body system, consisting of a star and two planets, is studied as a simple model for a planetary system. The mass of the inner planet is considered to be larger and the system is assumed to be moving in a freely rotating uniform interplanetary medium with constant density. Numerical integrations of this system indicate a resonance capture when the dynamical friction of the interplanetary medium is taken into account. As a result of this resonance trapping, the ratio of orbital periods of the two planets becomes nearly commensurable and the eccentricity and semimajor axis of the osculating orbit of the outer planet and also its angular momentum and total energy become constant. It appears from the numerical work that the resulting commensurability and also the resonant values of the orbital elements of the outer planet are essentially independent of the initial relative positions of the two bodies. In order to analytically explain this resonance phenomenon, the method of partial averaging near a resonance is utilized and the dynamics of the partially averaged system at resonance is studied. The finding that resonance lock occurs for all initial relative positions of the two planets is confirmed by analyzing the dynamics of the first order partially averaged system at resonance. It is also shown in this study that the first- order partially averaged system at resonance does not provide a complete picture of the evolutionary dynamics of the system and the similarity between the dynamical behavior of the averaged system and the main planetary system holds only for short time intervals. To overcome these limitations, the method of partial averaging near a resonance is extended to the second order of perturbation and a complete picture of the dynamical behavior of the system at

  20. Resonance Trapping in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Pour, Nader H.

    1998-09-01

    We study dynamics of a planetary system that consists of a star and two planets taking into account dynamical friction. Numerical integrations of a restricted planar circular three body model of this system indicate resonance capture. The main purpose of this paper is to present the results of an extensive numerical experiment performed on this model and also to present analytical arguments for the observed resonance trapping and its consequences. The equations of motion are written in terms of Delaunay variables and the recently developed method of partial averaging near resonance* is employed in order to account for the behavior of the system at resonance. * C.Chicone, B.Mashhoon and D.Retzloff, Ann.Inst.Henri Poincare, Vol.64, no 1, 1996, p.87-125.

  1. Recent advances in planetary magnetism

    NASA Technical Reports Server (NTRS)

    Ness, N. F.

    1978-01-01

    During the past decade, significant advances in the in situ measurements of planetary magnetic fields have been made. The U.S.A. and U.S.S.R. have conducted spacecraft investigations of all the planets, from innermost Mercury out to Jupiter. Unexpectedly, Mercury was found to possess a global magnetic field but neither the Moon nor Venus do. The results at Mars are incomplete but if a global field exists, it is clearly quite weak. The main magnetic field of Jupiter has been measured directly for the first time and confirms, as well as augments appreciably, the past 2 decades of ground-based radio astronomical studies which provided indirect evidence of the field. Progress in developing analytically complete models of the dynamo process suggests a possible common origin for Mercury, earth and Jupiter.

  2. Isotopic ratios in planetary atmospheres.

    PubMed

    de Bergh, C

    1995-03-01

    Recent progress on measurements of isotopic ratios in planetary or satellite atmospheres include measurements of the D/H ratio in the methane of Uranus, Neptune and Titan and in the water of Mars and Venus. Implications of these measurements on our understanding of the formation and evolution of the planets and satellite are discussed. Our current knowledge of the carbon, nitrogen and oxygen isotopic ratios in the atmospheres of these planets, as well as on Jupiter and Saturn, is also reviewed. We finally show what progress can be expected in the very near future due to some new ground-based instrumentation particularly well suited to such studies, and to forthcoming space missions. PMID:11539257

  3. Remote Sensing of Planetary Surfaces

    NASA Technical Reports Server (NTRS)

    Jakosky, Bruce M.

    2001-01-01

    Our efforts have been focused on understanding the physical properties of planetary surfaces using remote sensing techniques. Specific application has been to the surfaces of the Moon and Mars. Our approach has been to use thermal-infrared emission and radar reflectance and scattering as a way of exploring the decimeter-scale structure of these surfaces. At this scale, the techniques are sensitive to physical parameters such as the average or effective particle size of surface materials, the degree of induration or physical bonding between individual regolith grains, and the abundance of rocks of different sizes resting on or admixed in to the surface. The results are relevant to understanding the geological processes that have affected the surface and, in the case of Mars, determining site safety and scientific relevance for planning upcoming lander, rover, and sample-return spacecraft missions. Specific results are discussed below, and publications that have resulted are listed at the end.

  4. The Birth of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1997-01-01

    An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments, and they predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates.

  5. The Birth of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissaur, Jack L.

    1997-01-01

    An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments. They predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates.

  6. Doppler tracking of planetary spacecraft

    NASA Technical Reports Server (NTRS)

    Kinman, Peter W.

    1992-01-01

    This article concerns the measurement of Doppler shift on microwave links that connect planetary spacecraft with the Deep Space Network. Such measurements are made by tracking the Doppler effect with phase-locked loop receivers. A description of equipment and techniques as well as a summary of the appropriate mathematical models are given. The two-way Doppler shift is measured by transmitting a highly-stable microwave (uplink) carrier from a ground station, having the spacecraft coherently transpond this carrier, and using a phase-locked loop receiver at the ground station to track the returned (downlink) carrier. The largest sources of measurement error are usually plasma noise and thermal noise. The plasma noise, which may originate in the ionosphere or the solar corona, is discussed; and a technique to partially calibrate its effect, involving the use of two simultaneous downlink carriers that are coherently related, is described. Range measurements employing Doppler rate-aiding are also described.

  7. Planetary explorer liquid propulsion study

    NASA Technical Reports Server (NTRS)

    Mckevitt, F. X.; Eggers, R. F.; Bolz, C. W.

    1971-01-01

    An analytical evaluation of several candidate monopropellant hydrazine propulsion system approaches is conducted in order to define the most suitable configuration for the combined velocity and attitude control system for the Planetary Explorer spacecraft. Both orbiter and probe-type missions to the planet Venus are considered. The spacecraft concept is that of a Delta launched spin-stabilized vehicle. Velocity control is obtained through preprogrammed pulse-mode firing of the thrusters in synchronism with the spacecraft spin rate. Configuration selection is found to be strongly influenced by the possible error torques induced by uncertainties in thruster operation and installation. The propulsion systems defined are based on maximum use of existing, qualified components. Ground support equipment requirements are defined and system development testing outlined.

  8. Planetary system detection by POINTS

    NASA Technical Reports Server (NTRS)

    Reasenberg, Robert D.

    1993-01-01

    The final report and semiannual reports 1, 2, and 3 in response to the study of 'Planetary System Detection by POINTS' is presented. The grant covered the period from 15 Jun. 1988 through 31 Dec. 1989. The work during that period comprised the further development and refinement of the POINTS concept. The status of the POINTS development at the end of the Grant period was described by Reasenberg in a paper given at the JPL Workshop on Space Interferometry, 12-13 Mar. 1990, and distributed as CfA Preprint 3138. That paper, 'POINTS: a Small Astrometric Interferometer,' follows as Appendix-A. Our proposal P2276-7-09, dated July 1990, included a more detailed description of the state of the development of POINTS at the end of the tenure of Grant NAGW-1355. That proposal, which resulted in Grant NAGW-2497, is included by reference.

  9. Planetary gamma-ray spectroscopy

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.

    1978-01-01

    The measured intensities of certain gamma rays of specific energies escaping from a planetary surface can be used to determine the abundances of a number of elements. The fluxes of the more intense gamma-ray lines emitted from 32 elements were calculated using current nuclear data and existing models for the source processes. The source strengths for neutron-capture reactions were modified from those previously used. The fluxes emitted form a surface of average lunar composition are reported for 292 gamma-ray lines. These theoretical fluxes were used elsewhere to convert the data from the Apollo gamma-ray spectrometers to elemental abundances and can be used with measurements from future missions to map the concentrations of a number of elements over a planet's surface. Detection sensitivities for these elements are examined and applications of gamma-ray spectroscopy for future orbiters to Mars and other solar-system objects are discussed.

  10. Extravehicular Activity and Planetary Protection

    NASA Technical Reports Server (NTRS)

    Buffington, J. A.; Mary, N. A.

    2015-01-01

    The first human mission to Mars will be the farthest distance that humans have traveled from Earth and the first human boots on Martian soil in the Exploration EVA Suit. The primary functions of the Exploration EVA Suit are to provide a habitable, anthropometric, pressurized environment for up to eight hours that allows crewmembers to perform autonomous and robotically assisted extravehicular exploration, science/research, construction, servicing, and repair operations on the exterior of the vehicle, in hazardous external conditions of the Mars local environment. The Exploration EVA Suit has the capability to structurally interface with exploration vehicles via next generation ingress/egress systems. Operational concepts and requirements are dependent on the mission profile, surface assets, and the Mars environment. This paper will discuss the effects and dependencies of the EVA system design with the local Mars environment and Planetary Protection. Of the three study areas listed for the workshop, EVA identifies most strongly with technology and operations for contamination control.

  11. Planetary protection - some legal questions

    NASA Astrophysics Data System (ADS)

    Fasan, E.

    2004-01-01

    When we legally investigate the topic of Planetary Protection, we have to realise that there are primarily two very distinct parts of our juridical work: We have to study lexlata, theexistingapplicableLaw, especially Space Law, and also lexferenda, whatshouldbethe law . With this in mind, we have to deliberate the legal meaning of the notions "Planetary", and "Protection". About " Planetary": Our own Earth is our most important planet. At present only here do exist human beings, who are sensu strictu the only legal subjects. We make the law, we have to apply it, and we are to be protected as well as bound by it. But what is further meant by "Planetary"? Is it planets in an astronomical sense only, the nine planets which revolve around our fixed star, namely the sun, or is it also satellites, moving around most of these planets, as our own Moon circles Earth. "The Moon and other Celestial Bodies (C.B.)" are subject to Space Law, especially to International Treaties, Agreements, Resolutions of the UN, etc. I propose that they and not only the planets in an strictly astronomical sense are to be protected. But I do not think that the said notion also comprises asteroids, comets, meteorites, etc. although they too belong to our solar system. Our investigation comes to the result that such bodies have a different (lesser) legal quality. Also we have to ask Protectionfrom what ? From: Natural bodies - Meteorites, NEO Asteroids, Comets which could hit Earth or C.B.Artificial Objects: Space Debris threatening especially Earth and near Earth orbits.Terrestrial Life - no infection of other celestial bodies. Alien life forms which could bring about "harmful contamination" of Earth and the life, above all human life, there, etc. Here, astrobiological questions have to be discussed. Special realms on C.B. which should be protected from electronic "noise" such as craters SAHA or Deadalus on the Moon, also taking into account the "Common Heritage" Principle. Then, we have to

  12. Planetary protection - some legal questions

    NASA Astrophysics Data System (ADS)

    Fasan, E.

    When we legally investigate the topic of Planetary Protection, we have to realise that there are primarily two very distinct parts of our juridical work: We have to study lex lata, the existing applicable Law, especially Space Law, and also lex ferenda, what should be the law. With this in mind, we have to deliberate the legal meaning of "Planetary", and of "Protection". About "Planetary": Our own Earth is the most important planet. At present only here do exist human beings, who are sensu strictu the only legal subjects. We make the law, we have to apply it, and we are to be protected as well as bound by it. Then, we have to discuss what is further meant by "Planetary": Is it planets in an astronomical sense only, the nine planets which revolve around our fixed star, namely the sun, or is it also satellites, moving around most of these planets, as our own Moon circles Earth. "The Moon and other Celestial Bodies (C.B)" are subject to Space Law, especially to International Treaties, Agreements, Resolutions of the UN etc. I propose that they and not only the planets in an strictly astronomical sense are to be protected. But I do not think that the said notion also comprises asteroids, comets, meteorites etc. although they too belong to our solar system. Our investigation comes to the result that such bodies have a different (lesser) legal quality. Also we have to ask Protection from what? From: Natural bodies - Meteorites, NEO Asteroids, Comets which could hit Earth or C.B. Artificial Objects: Space Debris threatening especially Earth and near Earth orbits. Terrestrial Life - no infection of other celestial bodies. Alien life forms which could bring about "harmful contamination" of Earth and the life, above all human life, there etc. Here, astrobiological questions have to be discussed. Special realms on C.B. which should be protected from Electronic "Noise" such as craters SAHA or Deadalus on the Moon, also taking into account the "Common Heritage" Principle. Then

  13. Planetary Atmospheres at High Resolution

    NASA Astrophysics Data System (ADS)

    Gurwell, M.; Butler, B.; Moullet, A.

    2013-10-01

    The long millimeter through submillimeter bands are particularly well suited for studying the wide variety of planetary atmospheres in our solar system. Temperatures ranging from a few 10s to hundreds of degrees, coupled with typically high densities (relative to the ISM) mean that thermal ‘continuum’ emission can be strong and molecular rotational transitions can be well-populated. Large bodies (Jovian and terrestrial planets) can be reasonably well studied by current interferometers such as the Submillimeter Array, IRAM Plateau de Bure Interferometer, and Combined Array for Research in Millimeter-wave Astronomy, yet many smaller bodies with atmospheres can only be crudely studied, primarily due to lack of sensitivity on baselines long enough to well resolve the object. Newly powerful interferometers such as the Atacama Large Millimeter/Submillimeter Array will usher in a new era of planetary atmospheric exploration. The vast sensitivity and spatial resolution of these arrays will increase our ability to image all bodies with extremely fine fidelity (due to the large number of antennas), and for study of smaller objects by resolving their disks into many pixels while providing the sensitivity necessary to detect narrow and/or weak line emission. New science topics will range from detailed mapping of HDO, ClO, and sulfur species in the mesosphere of Venus and PH3 and H2S in the upper tropospheres of the gas and ice giants, high SNR mapping of winds on Mars, Neptune and Titan, down to spectroscopic imaging of volcanic eruptions within the tenuous atmosphere on Io, resolved imaging of CO and other species in the atmosphere of Pluto, and even potentially detection of gases within the plumes of Enceladus.

  14. Voyager planetary radio astronomy studies

    NASA Technical Reports Server (NTRS)

    Staelin, David H.; Eikenberry, Stephen S.

    1993-01-01

    Analysis of nonthermal radio emission data obtained by the Planetary Radio Astronomy (PRA) spectrometers on the Voyager 1 and 2 spacecraft was performed. This PRA data provided unique insights into the radio emission characteristics of the outer planets because of PRA's unique spectral response below the terrestrial ionospheric plasma frequency and its unprecedented proximity to the source. Of those results which were documented or published, this final report surveys only the highlights and cites references for more complete discussions. Unpublished results for Uranus, Neptune, and theoretical Ionian current distributions are presented at greater length. The most important conclusion to be drawn from these observations is that banded spectral emission is common to the radio emission below 1-2 MHz observed from all four Jovian planets. In every case multiple spectral features evolve on time scales of seconds to minutes. To the extent these features drift in frequency, they appear never to cross one another. The Neptunian spectral features appear to drift little or not at all, their evolution consisting principally of waxing and waning. Since other evidence strongly suggests that most or all of this radio emission is occurring near the local magnetospheric electron cyclotron frequency, this implies that this emission preferentially occurs at certain continually changing planetary radii. It remains unknown why certain radii might be favored, unless radial electric field components or other means serve to differentiate radially the magnetospheric plasma density, particle energy vectors, or particle coherence. Calculation of the spatial distribution and intensity of the Io-generated magnetospheric currents are also presented; these currents may be limited principally by wave impedance and local field strengths.

  15. Orion Nebula and Planetary Nebulae

    NASA Technical Reports Server (NTRS)

    Dufour, Reginald J.

    1998-01-01

    This report summarizes the research performed at Rice University related to NASA-Ames University consortium grant NCC2-5199 during the two year period 1996 September 1 through 1998 August 31. The research program, titled Orion Nebula and Planetary Nebulae, involved the analysis of Hubble Space Telescope (HST) imagery and spectroscopy of the Orion Nebula and of the planetary nebulae NGC 6818 and NGC 6210. In addition, we analyzed infrared spectra of the Orion Nebula taken with the Infrared Space Observatory (ISO) The primary collaborators at NASA-Ames were Drs. R. H. Rubin, A. G. C. M. Tielens, S. W. J. Colgan, and S. D. Lord (Tielens & Lord has since changed institutions). Other collaborators include Drs. P. G. Martin (CITA, Toronto), G. J. Ferland (U. KY), J. A. Baldwin (CTIO, Chile), J. J. Hester (ASU), D. K. Walter (SCSU), and P. Harrington (U. MD). In addition to the Principal Investigator, Professor Reginald J. Dufour of the Department of Space Physics & Astronomy, the research also involved two students, Mr. Matthew Browning and Mr. Brent Buckalew. Mr. Browning will be graduating from Rice in 1999 May with a B.A. degree in Physics and Mr. Buckalew continues as a graduate student in our department, having recently received a NASA GSRP research fellowship (sponsored by Ames). The collaboration was very productive, with two refereed papers already appearing in the literature, several others in preparation, numerous meeting presentations and two press releases. Some of our research accomplishments are highlighted below. Attached to the report are copies of the two major publications. Note that this research continues to date and related extensions of it recently has been awarded time with the HST for 1999-2000.

  16. Geochemical Reaction Mechanism Discovery from Molecular Simulation

    DOE PAGESBeta

    Stack, Andrew G.; Kent, Paul R. C.

    2014-11-10

    Methods to explore reactions using computer simulation are becoming increasingly quantitative, versatile, and robust. In this review, a rationale for how molecular simulation can help build better geochemical kinetics models is first given. We summarize some common methods that geochemists use to simulate reaction mechanisms, specifically classical molecular dynamics and quantum chemical methods and discuss their strengths and weaknesses. Useful tools such as umbrella sampling and metadynamics that enable one to explore reactions are discussed. Several case studies wherein geochemists have used these tools to understand reaction mechanisms are presented, including water exchange and sorption on aqueous species and mineralmore » surfaces, surface charging, crystal growth and dissolution, and electron transfer. The impact that molecular simulation has had on our understanding of geochemical reactivity are highlighted in each case. In the future, it is anticipated that molecular simulation of geochemical reaction mechanisms will become more commonplace as a tool to validate and interpret experimental data, and provide a check on the plausibility of geochemical kinetic models.« less

  17. Geochemical Reaction Mechanism Discovery from Molecular Simulation

    SciTech Connect

    Stack, Andrew G.; Kent, Paul R. C.

    2014-11-10

    Methods to explore reactions using computer simulation are becoming increasingly quantitative, versatile, and robust. In this review, a rationale for how molecular simulation can help build better geochemical kinetics models is first given. We summarize some common methods that geochemists use to simulate reaction mechanisms, specifically classical molecular dynamics and quantum chemical methods and discuss their strengths and weaknesses. Useful tools such as umbrella sampling and metadynamics that enable one to explore reactions are discussed. Several case studies wherein geochemists have used these tools to understand reaction mechanisms are presented, including water exchange and sorption on aqueous species and mineral surfaces, surface charging, crystal growth and dissolution, and electron transfer. The impact that molecular simulation has had on our understanding of geochemical reactivity are highlighted in each case. In the future, it is anticipated that molecular simulation of geochemical reaction mechanisms will become more commonplace as a tool to validate and interpret experimental data, and provide a check on the plausibility of geochemical kinetic models.

  18. Heat transfer and planetary evolution

    NASA Astrophysics Data System (ADS)

    Tozer, D. C.

    1985-06-01

    The object of this account is to show how much one can interprete and predict about the present state of material forming planet size objects, despite the fact we do not and could never have the kind of exact or prior knowledge of initial conditions and in situ material behaviour that would make a formal mathematical analysis of the dynamical problems of planetary evolution an efficient or meaningful exercise The interest and usefulness of results obtained within these limitations stem from the highly non linear nature of planetary scale heat transfer problems when posed in any physically plausible form. The non linearity arising from a strongly temperature dependent rheology assumed for in situ planetary material is particularly valuable in deriving results insensitive to such uncertainties. Qualitatively, the thermal evolution of a planet is quite unlike that given by heat conduction calculation below a very superficial layer, and much unnecessary argument and confusion results from a persistent failure to recognise that fact. At depths that are no greater on average than a few tens of kilometres in the case of Earth, the temperature distribution is determined by a convective flow regime inaccessble to the laboratory experimenter and to the numerical methods regularly employed to study convective movement. A central and guiding quantitative result is the creation in homogeneous planet size objects having surface temperatures less than about half the absolute melting temperature of their material, of internal states with horizontally a veraged viscosity values ˜1021 poise. This happens in times short compared with the present Solar System age. The significance of this result for an understanding of such processes and features as isostasy, continental drift, a minimum in seismic S wave velocity in Earth's upper mantle, a uniformity of mantle viscosity values, the survival of liquid planetary cores and the differentiation of terrestrial planet material is examined

  19. The Twenty-Fifth Lunar and Planetary Science Conference. Part 1: A-G

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Papers from the conference are presented, and the topics covered include the following: planetary geology, meteorites, planetary composition, meteoritic composition, planetary craters, lunar craters, meteorite craters, petrology, petrography, volcanology, planetary crusts, geochronology, geomorphism, mineralogy, lithology, planetary atmospheres, impact melts, volcanoes, planetary evolution, tectonics, planetary mapping, asteroids, comets, lunar soil, lunar rocks, lunar geology, metamorphism, chemical composition, meteorite craters, and planetary mantles.

  20. The geochemical geometry of mantle plumes

    NASA Astrophysics Data System (ADS)

    Jackson, Matthew

    2015-04-01

    Lavas erupted at oceanic hotspot volcanoes exhibit tremendous isotopic variability, which indicates that the mantle sources of the hotspots are highly heterogeneous geochemically. A key question is how the surface expression of hotspot lavas relates to the spatial distribution of the geochemical components within upwelling mantle plumes. Significant progress has been made in recent years relating the geographic distribution of geochemical heterogeneities in hotspot lavas to parallel volcanic lineaments that define the traces of oceanic hotspot tracks. For example, a well known geographic separation of parallel volcanic lineaments at Hawaii - the Loa and Kea trends - are also isotopically resolved. In addition to the Hawaiian example, clear patterns relating the geographic distribution of geochemical components along hotspot tracks are emerging from a suite of global hotspots, and these patterns suggest that geochemical heterogeneities are highly organized within upwelling mantle plume conduits. At the Samoan hotspot, the Pb-isotopic compositions measured in lavas reveal several geochemical groups, and each group corresponds to a different geographic lineament of volcanoes. Each group has a geochemical signature that relates to each of the canonical low 3He/4He mantle endmembers: EMII (enriched mantle 2), EMI (enriched mantle 1), HIMU (high U/Pb) and DM (depleted mantle). In Pb-isotopic space, the four geochemical groups each form an array that trends toward a common component (thus forming an "X-shape" in Pb-isotopic space). The region of isotope space where the 4 Pb-isotopic array intersect is defined by the highest 3He/4He (up to 34 Ra, or ratio to atmosphere) in the Samoan hotspot. In Pb-isotopic space, 3He/4He decreases monotonically along each of the Pb-isotopic groups away from the common region of convergence. In order to quantify the relationship between He and Pb isotopes, 3He/4He is plotted versus distance from the common component in Pb-isotopic space

  1. Iron cycling in the Amazon River Basin: the isotopic perspective

    NASA Astrophysics Data System (ADS)

    Poitrasson, Franck; Vieira, Lucieth; Mulholland, Daniel; Seyler, Patrick; Sondag, Francis; Allard, Thierry

    2014-05-01

    interaction between organic matter and iron in rivers, and ultimately the nature of their source in soils. As such, they may become a powerfull tracer of changes occurring on the continents in response to both weathering context and human activities. References: Bergquist, B.A., Boyle, E.A., 2006. Iron isotopes in the Amazon River system: Weathering and transport signatures. Earth and Planetary Science Letters, 248: 54-68. Emmanuel, S., Erel, Y., Matthews, A., Teutsch, N., 2005. A preliminary mixing model for Fe isotopes in soils. Chemical Geology, 222: 23-34. Fantle, M.S., DePaolo, D.J., 2004. Iron isotopic fractionation during continental weathering. Earth and Planetary Science Letters, 228: 547-562. Ingri, J., Malinovsky, D., Rodushkin, I., Baxter, D.C., Widerlund, A., Andersson, P., Gustafsson, O., Forsling, W., Ohlander, B., 2006. Iron isotope fractionation in river colloidal matter. Earth and Planetary Science Letters, 245: 792-798. Poitrasson, F., Viers, J., Martin, F., Braun, J.J., 2008. Limited iron isotope variations in recent lateritic soils from Nsimi, Cameroon: Implications for the global Fe geochemical cycle. Chemical Geology, 253: 54-63. Wiederhold, J.G., Teutsch, N., Kraemer, S.M., Halliday, A.N., Kretzchmar, R., 2007. Iron isotope fractionation in oxic soils by mineral weathering and podzolization. Geochimica et Cosmochimica Acta, 71: 5821-5833.

  2. Alaska Geochemical Database (AGDB)-Geochemical data for rock, sediment, soil, mineral, and concentrate sample media

    USGS Publications Warehouse

    Granitto, Matthew; Bailey, Elizabeth A.; Schmidt, Jeanine M.; Shew, Nora B.; Gamble, Bruce M.; Labay, Keith A.

    2011-01-01

    The Alaska Geochemical Database (AGDB) was created and designed to compile and integrate geochemical data from Alaska in order to facilitate geologic mapping, petrologic studies, mineral resource assessments, definition of geochemical baseline values and statistics, environmental impact assessments, and studies in medical geology. This Microsoft Access database serves as a data archive in support of present and future Alaskan geologic and geochemical projects, and contains data tables describing historical and new quantitative and qualitative geochemical analyses. The analytical results were determined by 85 laboratory and field analytical methods on 264,095 rock, sediment, soil, mineral and heavy-mineral concentrate samples. Most samples were collected by U.S. Geological Survey (USGS) personnel and analyzed in USGS laboratories or, under contracts, in commercial analytical laboratories. These data represent analyses of samples collected as part of various USGS programs and projects from 1962 to 2009. In addition, mineralogical data from 18,138 nonmagnetic heavy mineral concentrate samples are included in this database. The AGDB includes historical geochemical data originally archived in the USGS Rock Analysis Storage System (RASS) database, used from the mid-1960s through the late 1980s and the USGS PLUTO database used from the mid-1970s through the mid-1990s. All of these data are currently maintained in the Oracle-based National Geochemical Database (NGDB). Retrievals from the NGDB were used to generate most of the AGDB data set. These data were checked for accuracy regarding sample location, sample media type, and analytical methods used. This arduous process of reviewing, verifying and, where necessary, editing all USGS geochemical data resulted in a significantly improved Alaska geochemical dataset. USGS data that were not previously in the NGDB because the data predate the earliest USGS geochemical databases, or were once excluded for programmatic reasons

  3. Planetary Data System (PDS) Strategic Roadmap

    NASA Astrophysics Data System (ADS)

    Law, Emily; McNutt, Ralph; Crichton, Daniel J.; Morgan, Tom

    2016-07-01

    The Planetary Data System (PDS) archives and distributes scientific data from NASA planetary missions, astronomical observations, and laboratory measurements. NASA's Science Mission Directorate (SMD) sponsors the PDS. Its purpose is to ensure the long-term usability of NASA data and to stimulate advanced research. The Planetary Science Division (PSD) within the SMD at NASA Headquarters has directed the PDS to set up a Roadmap team to formulate a PDS Roadmap for the period 2017-2026. The purpose of this activity is to provide a forecast of both the rapidly changing Information Technology (IT) environment and the changing expectations of the planetary science communities with respect to Planetary Data archives including, specifically, increasing assessability to all planetary data. The Roadmap team will also identify potential actions that could increase interoperability with other archive and curation elements within NASA and with the archives of other National Space Agencies. The Roadmap team will assess the current state of the PDS and report their findings to the PSD Director by April 15, 2017. This presentation will give an update of this roadmap activity and serve as an opportunity to engage the planetary community at large to provide input to the Roadmap.

  4. On the Migratory Behavior of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah Ilene

    For centuries, an orderly view of planetary system architectures dominated the discourse on planetary systems. However, there is growing evidence that many planetary systems underwent a period of upheaval, during which giant planets "migrated" from where they formed. This thesis addresses a question key to understanding how planetary systems evolve: is planetary migration typically a smooth, disk-driven process or a violent process involving strong multi-body gravitational interactions? First, we analyze evidence from the dynamical structure of debris disks dynamically sculpted during planets' migration. Based on the orbital properties our own solar systems Kuiper belt, we deduce that Neptune likely underwent both planet-planet scattering and smooth migration caused by interactions with leftover planetesimals. In another planetary system, beta Pictoris, we find that the giant planet discovered there must be responsible for the observed warp of the systems debris belt, reconciling observations that suggested otherwise. Second, we develop two new approaches for characterizing planetary orbits: one for distinguishing the signal of a planets orbit from aliases, spurious signals caused by gaps in the time sampling of the data, and another to measure the eccentricity of a planet's orbit from transit photometry, "the photoeccentric effect." We use the photoeccentric effect to determine whether any of the giant planets discovered by the Kepler Mission are currently undergoing planetary migration on highly elliptical orbits. We find a lack of such "super-eccentric" Jupiters, allowing us to place an upper limit on the fraction of hot Jupiters created by the stellar binary Kozai mechanism. Finally, we find new correlations between the orbital properties of planets and the metallicity of their host stars. Planets orbiting metal-rich stars show signatures of strong planet-planet gravitational interactions, while those orbiting metal-poor stars do not. Taken together, the

  5. Disequilibrium in planetary atmospheres and the search for habitability

    NASA Astrophysics Data System (ADS)

    Simoncini, E.

    It has long been observed that Earth's atmosphere is uniquely far from its thermochemical equilibrium state in terms of its chemical composition. Studying this state of disequilibrium is important for its potential role in the detection of life on other suitable planets \\citep{Lovelock_1965,Kleidon_2010,Simoncini_2015}. We developed a methodology to calculate the extent of atmospheric chemical disequilibrium\\citep{Simoncini_2015,Kondepudi_1996}. This tool allows us to understand, on a thermodynamic basis, how life affected - and still affects - geochemical processes on Earth, and if other planetary atmospheres are habitable or have a disequilibrium similar to the Earth's one. A new computational framework called KROME has been applied to atmospheric models in order to give a correct computation of reactions´ kinetics \\citep{Grassi_2015}. In this work we present a first computation of the extent of disequilibrium for the present Earth atmosphere, considering the specific contribution of the different atmospheric processes, such as thermochemical reactions, eddy diffusion, photochemistry, deposition, and the effect of the biosphere. We then assess the effect of life on atmospheric disequilibrium of the Earth and provide a useful discussion about how the study of atmospheric disequilibrium can help in finding habitable (exo)planets. We finally compare the chemical disequilibrium of Earth and Mars atmospheres, for present and early conditions.

  6. Colloquium on Water in Planetary Regoliths, Hanover, N.H., October 5-7, 1976, Proceedings

    NASA Technical Reports Server (NTRS)

    Bowen, S.L.; Wright, E.

    1976-01-01

    The papers abstracted in this volume deal with the occurrence, detection, and measurement of water on planetary bodies in the solar system; relevant aspects of the terrestrial water balance; the most probable status of water on other planetary bodies; and the methods of water detection and measurement available for consideration in designing planetary exploration missions. Topics include the water inventory for earth, high-energy protons as an early source of regolith water, the evolution of water on Mars, the chemical evolution of the Martian atmosphere by surface weathering, some geochemical aspects of excess volatiles on Mars, fluvial erosion on Mars, water in the outer solar system, and the stability of water on the Galilean satellites. Other papers discuss gamma-ray attenuation methods for determining the water content of soil, Viking biology-experiment results relevant to water on Mars, IR detection of water ice on satellite surfaces during the Mariner Jupiter/Saturn mission, electrical sounding of the lunar regolith, the detection of water on the moon and Mars by orbital gamma-ray spectroscopy, and the Viking Martian soil-water analyzer.

  7. PELS (Planetary Environmental Liquid Simulator): a new type of simulation facility to study extraterrestrial aqueous environments.

    PubMed

    Martin, Derek; Cockell, Charles S

    2015-02-01

    Investigations of other planetary bodies, including Mars and icy moons such as Enceladus and Europa, show that they may have hosted aqueous environments in the past and may do so even today. Therefore, a major challenge in astrobiology is to build facilities that will allow us to study the geochemistry and habitability of these extraterrestrial environments. Here, we describe a simulation facility (PELS: Planetary Environmental Liquid Simulator) with the capability for liquid input and output that allows for the study of such environments. The facility, containing six separate sample vessels, allows for statistical replication of samples. Control of pressure, gas composition, UV irradiation conditions, and temperature allows for the precise replication of aqueous conditions, including subzero brines under martian atmospheric conditions. A sample acquisition system allows for the collection of both liquid and solid samples from within the chamber without breaking the atmospheric conditions, enabling detailed studies of the geochemical evolution and habitability of past and present extraterrestrial environments. The facility we describe represents a new frontier in planetary simulation-continuous flow-through simulation of extraterrestrial aqueous environments. PMID:25651097

  8. Planetary migration, accretion, and atmospheres

    NASA Astrophysics Data System (ADS)

    Dobbs-Dixon, Ian M.

    This dissertation explores three distinct projects in the field of planetary formation and evolution: type I migration, cessation of mass accretion, and the atmospheric dynamics of hot Jupiters. All three of these projects touch on outstanding or unresolved issues in the field. Each attempts to unify analytic and numerical approaches in order to physically motivate solutions while simultaneously probing areas currently inaccessible to purely analytic approaches. The first section, type I migration, explores the outstanding problem of the rapid inward migration of low mass planets embedded in protoplanetary disks. Analytic estimates of migration predict characteristic timescales that are much shorter then either observed disk lifetimes or theoretical core-accretion formation timescales. If migration is actually as efficient as these analytic estimates predict, planet formation across the observed range of masses and semimajor axis' is difficult. Here I introduce several new formalisms to both allow the disk to adiabatically adjust to the presence of a planet and include the effect of axisymmetric disk self-gravity. I find that these modifications increase migration timescales by approximately 4 times. In addition to these numerical improvements, I present simulations of migration in lower sound-speed regions of the disk on the grounds that self shadowing within the disk could yield substantially cooler gas temperatures then those derived by most irradiated disk models. In such regions the planetary perturbation excites a secondary instability, leading to the formation of vortices. These vortices cause a substantial reduction in the net torque, increasing migration timescales by up to approximately 200 times the analytically predicted rate. The second section addresses the mechanism for shutting off accretion onto giant planets. According to the conventional sequential accretion scenario, giant planets acquire a majority of their gas in a runaway phase. Conventional

  9. Mars Technology Program: Planetary Protection Technology Development

    NASA Technical Reports Server (NTRS)

    Lin, Ying

    2006-01-01

    This slide presentation reviews the development of Planetary Protection Technology in the Mars Technology Program. The goal of the program is to develop technologies that will enable NASA to build, launch, and operate a mission that has subsystems with different Planetary Protection (PP) classifications, specifically for operating a Category IVb-equivalent subsystem from a Category IVa platform. The IVa category of planetary protection requires bioburden reduction (i.e., no sterilization is required) The IVb category in addition to IVa requirements: (i.e., terminal sterilization of spacecraft is required). The differences between the categories are further reviewed.

  10. Physics of planetary atmospheres and ionospheres

    NASA Technical Reports Server (NTRS)

    Bauer, S. J.

    1981-01-01

    The traditional atmospheric regions, the distinction between homosphere and heterosphere, and changing atmospheric composition are discussed. The validity of the barometric law based on a Maxwell-Boltzmann distribution, for the major part of a planetary atmosphere and its breakdown in the exosphere due to escape of atmospheric particles is considered. The formation and maintenance of photochemical and diffusion-controlled ionospheric layers are treated. Their applicability to planetary ionospheres is dealt with. The spatial extent of magnetic and nonmagnetic planet ionospheres is investigated. Thermal and nonthermal processes responsible for the mass loss of planetary atmospheres are surveyed.

  11. Sulphur geodynamic cycle

    PubMed Central

    Kagoshima, Takanori; Sano, Yuji; Takahata, Naoto; Maruoka, Teruyuki; Fischer, Tobias P.; Hattori, Keiko

    2015-01-01

    Evaluation of volcanic and hydrothermal fluxes to the surface environments is important to elucidate the geochemical cycle of sulphur and the evolution of ocean chemistry. This paper presents S/3He ratios of vesicles in mid-ocean ridge (MOR) basalt glass together with the ratios of high-temperature hydrothermal fluids to calculate the sulphur flux of 100 Gmol/y at MOR. The S/3He ratios of high-temperature volcanic gases show sulphur flux of 720 Gmol/y at arc volcanoes (ARC) with a contribution from the mantle of 2.9%, which is calculated as 21 Gmol/y. The C/S flux ratio of 12 from the mantle at MOR and ARC is comparable to the C/S ratio in the surface inventory, which suggests that these elements in the surface environments originated from the upper mantle. PMID:25660256

  12. Deep sulfur cycle

    NASA Astrophysics Data System (ADS)

    Shimizu, N.; Mandeville, C. W.

    2009-12-01

    Geochemical cycle of sulfur in near-surface reservoirs has been a subject of intense studies for decades. It has been shown that sulfur isotopic compositions of sedimentary sulfides and sulfates record interactions of the atmosphere, hydrosphere, biosphere and lithosphere, with δ34S of sedimentary sulfides continuously decreasing from 0‰ toward present-day values of ~-30 to -40‰ over the Phanerozoic (e.g., Canfield, 2004). It has also been shown that microbial reduction of the present-day seawater sulfate (δ34S=+21‰) results in large shifts in isotopic compositions of secondary pyrites in altered oceanic crust (to δ34S=-70‰: Rouxel et al., 2009). How much of these near surface isotopic variations survive during deep geochemical cycle of sulfur interacting with the mantle infinite reservoir with δ34S=0‰? Could extent of their survival be used as a tracer of processes and dynamics involved in deep geochemical cycle? As a first step toward answering these questions, δ34S was determined in-situ using a Cameca IMS 1280 ion microprobe at Woods Hole Oceanographic Institution in materials representing various domains of deep geochemical cycle. They include pyrites in altered MORB as potential subducting materials and pyrites in UHP eclogites as samples that have experienced subduction zone processes, and mantle-derived melts are represented by olivine-hosted melt inclusions in MORB and those in IAB, and undegassed submarine OIB glasses. Salient features of the results include: (1) pyrites in altered MORB (with O. Rouxel; from ODP site 801 and ODP Hole 1301B) range from -70 to +19‰, (2) pyrites in UHP eclogites from the Western Gneiss Region, Norway (with B. Hacker and A. Kylander-Clark) show a limited overall range from -3.4 to + 2.8‰ among five samples, with one of them covering almost the entire range, indicating limited scale lengths of isotopic equilibration during subduction, (3) olivine-hosted melt inclusions in arc basalts from Galunggung (-2

  13. Sulphur geodynamic cycle

    NASA Astrophysics Data System (ADS)

    Kagoshima, Takanori; Sano, Yuji; Takahata, Naoto; Maruoka, Teruyuki; Fischer, Tobias P.; Hattori, Keiko

    2015-02-01

    Evaluation of volcanic and hydrothermal fluxes to the surface environments is important to elucidate the geochemical cycle of sulphur and the evolution of ocean chemistry. This paper presents S/3He ratios of vesicles in mid-ocean ridge (MOR) basalt glass together with the ratios of high-temperature hydrothermal fluids to calculate the sulphur flux of 100 Gmol/y at MOR. The S/3He ratios of high-temperature volcanic gases show sulphur flux of 720 Gmol/y at arc volcanoes (ARC) with a contribution from the mantle of 2.9%, which is calculated as 21 Gmol/y. The C/S flux ratio of 12 from the mantle at MOR and ARC is comparable to the C/S ratio in the surface inventory, which suggests that these elements in the surface environments originated from the upper mantle.

  14. Sulphur geodynamic cycle.

    PubMed

    Kagoshima, Takanori; Sano, Yuji; Takahata, Naoto; Maruoka, Teruyuki; Fischer, Tobias P; Hattori, Keiko

    2015-01-01

    Evaluation of volcanic and hydrothermal fluxes to the surface environments is important to elucidate the geochemical cycle of sulphur and the evolution of ocean chemistry. This paper presents S/(3)He ratios of vesicles in mid-ocean ridge (MOR) basalt glass together with the ratios of high-temperature hydrothermal fluids to calculate the sulphur flux of 100 Gmol/y at MOR. The S/(3)He ratios of high-temperature volcanic gases show sulphur flux of 720 Gmol/y at arc volcanoes (ARC) with a contribution from the mantle of 2.9%, which is calculated as 21 Gmol/y. The C/S flux ratio of 12 from the mantle at MOR and ARC is comparable to the C/S ratio in the surface inventory, which suggests that these elements in the surface environments originated from the upper mantle. PMID:25660256

  15. Fragile cycles

    NASA Astrophysics Data System (ADS)

    Bonatti, Ch.; Díaz, L. J.

    We study diffeomorphisms f with heterodimensional cycles, that is, heteroclinic cycles associated to saddles p and q with different indices. Such a cycle is called fragile if there is no diffeomorphism close to f with a robust cycle associated to hyperbolic sets containing the continuations of p and q. We construct a codimension one submanifold of Diff(S×S) that consists of diffeomorphisms with fragile heterodimensional cycles. Our construction holds for any manifold of dimension ⩾4.

  16. Lunar and Planetary Science XXXVI, Part 19

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The topics include: 1) The abundances of Iron-60 in Pyroxene Chondrules from Unequilibrated Ordinary Chondrites; 2) LL-Ordinary Chondrite Impact on the Moon: Results from the 3.9 Ga Impact Melt at the Landing Site of Appolo 17; 3) Evaluation of Chemical Methods for Projectile Identification in Terrestrial and Lunar Impactites; 4) Impact Cratering Experiments in Microgravity Environment; 5) New Achondrites with High-Calcium Pyroxene and Its implication for Igneous Differentiation of Asteroids; 6) Climate History of the Polar Regions of Mars Deduced form Geologic Mapping Results; 7) The crater Production Function for Mars: A-2 Cumulative Power-Law Slope for Pristine Craters Greater than 5 km in Diameter Based on Crater Distribution for Northern Plains Materials; 8) High Resolution Al-26 Chronology: Resolved Time Interval Between Rim and Interior of a Highly Fractionated Compact Type a CAI from Efremovka; 9) Assessing Aqueous Alteration on Mars Using Global Distributions of K and Th; 10) FeNi Metal Grains in LaPaz Mare Basalt Meteorites and Appolo 12 Basalts; 11) Unique Properties of Lunar Soil for In Situ Resource Utilization on the Moon; 12) U-Pb Systematics of Phosphates in Nakhlites; 13) Measurements of Sound Speed in Granular Materials Simulated Regolith; 14) The Effects of Oxygen, Sulphur and Silicon on the Dihedral Angles Between Fe-rich Liquid Metal and Olivine, Ringwoodite and Silicate Perovskite: Implications for Planetary Core Formation; 15) Seismic Shaking Removal of Craters 0.2-0.5 km in Diameter on Asteroid 433 Eros; 16) Focused Ion Beam Microscoopy of ALH84001 Carbonate Disks; 17) Simulating Micro-Gravity in the Laboratory; 18) Mars Atmospheric Sample Return Instrument Development; 19) Combined Remote LIBS and Raman Spectroscopy Measurements; 20) Unusual Radar Backscatter Properties Along the Northern Rim of Imbrium Basin; 21) The Mars Express/NASAS Project at JPL; 22) The Geology of the Viking 2 Lander Site Revisited; 23) An Impact Genesis for Loki

  17. Planetary cores: current knowledge and future prospects

    NASA Astrophysics Data System (ADS)

    Nimmo, F.

    2011-12-01

    Observations of planetary cores tell us about the: formation; evolution; and present-day state of silicate bodies. In this review I will highlight recent results and future prospects. Formation. Core formation is detectable geochemically from siderophile element abundances and both unstable (e.g. Hf-W [1]) and stable (e.g. Cr [2], Si [3]) isotopic systems. Hf-W studies tell us that small bodies (like Vesta and perhaps Mars [4]) underwent differentiation very early, presumably due to 26Al decay [1]. Larger silicate-dominated bodies experienced stochastic addition of core material over tens of Myr, during large impacts [5]. Bodies with massive cores may result from hit-and-run collisions [6] or mantle-stripping impacts [7]. The apparent existence of a lunar core [8] places constraints on the Moon's formation. Evolution. Core solidification results in significant volume changes and surface contraction. Surface tectonics thus provides a constraint on core evolution [e.g. 9]. Dynamo generation usually depends on the rate of core cooling/solidification, which in turn depends on the mantle's ability to remove heat. Thus, an extant or ancient dynamo tells us about the long-term thermal evolution of the body [10]. In some cases, magnetic field characteristics may be related to the details of core structure and/or solidification. In others, mechanical forcing, such as tidally-driven motion [11] or impacts [12] may cause dynamo activity. Bodies with (presumed) liquid cores but no dynamo (Io, Venus) also require explanation. Present day. A body's angular momentum and tidal response depend on core properties such as CMB topography, inner core viscosity, magnetic field strength and other factors. Thus, measurements of time-varying spin state and/or gravity can be used to infer the existence of a liquid layer [13-15] and (for the Earth) core properties such as the magnetic field strength [16]. Ground-based radar observations of Mercury [14] and (in future) Europa and Io should

  18. Developing Zircon as a Probe of Planetary Impact History

    NASA Astrophysics Data System (ADS)

    Wielicki, Matthew

    2014-12-01

    The identification of Meteor Crater in Arizona as an extraterrestrial impact by Eugene Shoemaker provided the first evidence of this geologic phenomenon and opened the door to a new field of research that has eventually lead to the identification of over ~150 terrestrial impact structures. Subsequently impacts have been evoked in the formation of the moon, delivery of volatiles and bio-precursors to early Earth, creation of habitats for the earliest life and, in more recent times, major mass extinction events. However, understanding the impact flux to the Earth-Moon system has been complicated by the constant weathering and erosion at Earth's surface and the complex nature of impactite samples such that only a hand full of terrestrial craters have been accurately and precisely dated. Currently 40Ar/39Ar step-heating analysis of impactite samples is commonly used to infer impact ages but can be problematic due to the presence of relic clasts, incomplete 40Ar outgassing or excess 40Ar, and recoil and shock effects. The work presented here attempts to develop zircon geochronology to probe planetary impact histories as an alternative to current methods and provides another tool by which to constrain the bolide flux to the Earth-Moon system. Zircon has become the premier geo-chronometer in earth science and geochemical investigation of Hadean zircon from Western Australia has challenged the long-standing, popular conception that the near-surface Hadean Earth was an uninhabitable and hellish world; Zircons may preserve environmental information regarding their formation and thus provide a rare window into conditions on early Earth. Isotopic and petrologic analyses of these ancient grains have been interpreted to suggest that early Earth was more habitable than previously envisioned, with water oceans, continental crust, and possibly even plate tectonics. The Hadean is also suspected to be a time of major planetary bombardment however identifying impact signatures within

  19. Planetary Research Center. [astronomical photography of planetary surfaces and atmospheres

    NASA Technical Reports Server (NTRS)

    Baum, W. A.; Millis, R. L.; Bowell, E. L. G.

    1974-01-01

    Extensive Earth-based photography of Mars, Jupiter, and Venus is presented which monitors the atmospheric and/or surface changes that take place day to day. Color pictures are included of the 1973 dust storm on Mars, showing the daily cycle of the storm's regeneration. Martian topography, and the progress of the storm is examined. Areas most affected by the storm are summarized.

  20. Planetary protection - assaying new methods

    NASA Astrophysics Data System (ADS)

    Nellen, J.; Rettberg, P.; Horneck, G.

    Space age began in 1957 when the USSR launched the first satellite into earth orbit. In response to this new challenge the International Council for Science, formerly know as International Council of Scientific Unions (ICSU), established the Committee on Space Research (COSPAR) in 1958. The role of COSPAR was to channel the international scientific research in space and establish an international forum. Through COSPAR the scientific community agreed on the need for screening interplanetary probes for forward (contamination of foreign planets) and backward (contamination of earth by returned samples/probes) contamination. To prevent both forms of contamination a set of rules, as a guideline was established. Nowadays the standard implementation of the planetary protection rules is based on the experience gained during NASA's Viking project in 1975/76. Since then the evaluation-methods for microbial contamination of spacecrafts have been changed or updated just slowly. In this study the standard method of sample taking will be evaluated. New methods for examination of those samples, based on the identification of life on the molecular level, will be reviewed and checked for their feasibility as microbial detection systems. The methods will be examined for their qualitative (detection and verification of different organisms) and quantitative (detection limit and concentration verification) qualities. Amongst the methods analyzed will be i.e. real-time / PCR (poly-chain-reaction), using specific primer-sets for the amplification of highly conserved rRNA or DNA regions. Measurement of intrinsic fluorescence, i.e ATP using luciferin-luciferase reagents. The use of FAME (fatty acid methyl esters) and microchips for microbial identification purposes. The methods will be chosen to give a good overall coverage of different possible molecular markers and approaches. The most promising methods shall then be lab-tested and evaluated for their use under spacecraft assembly

  1. An unmagnetized early planetary body

    NASA Astrophysics Data System (ADS)

    Weiss, B. P.; Wang, H.; Downey, B. G.; Shuster, D. L.; Gattacceca, J.; Sharp, T. G.; Fu, R. R.; Kuan, A. T.; Suavet, C. R.; Irving, A. J.

    2014-12-01

    Modern paleomagnetic studies of achondrites have found that at least several planetesimals generated dynamos with inferred surface magnetic fields ranging from tens to hundreds of μT. In fact, an achondrite without evidence for paleomagnetic fields has not been previously identified, hinting that the dynamo process may have been extremely common among early planetary bodies. To further expand our understanding of the diversity of planetesimal dynamos, we have been studying the paleomagnetism the ungrouped achondrite NWA 7325. This ancient meteorite (Pb/Pb and Al/Mg ages of ~4563 Ma) is highly depleted in siderophile elements, indicating that it formed on a differentiated body that underwent large-scale metal-silicate fractionation. We present new paleomagnetic, rock magnetic transmission and scanning electron microscopy, and Ar/Ar analyses of this rock that constrain the field intensity in which it cooled. In particular, we employ a new controlled oxygen fugacity system that enables us to conduct thermal demagnetization while greatly mitigating oxidation-reduction reactions. This system is critical because of the extremely reduced conditions (at least 3 log units below the iron-wüstite buffer) in which this meteorite formed. The extremely fine grain size (<200 nm) of many FeNi metal grains in NWA 7325 (pseudo single domain-superparamagnetic size) means that it has extremely high fidelity magnetic recording properties. We find no stable remanent magnetization and no evidence for any magnetic fields greater than ~2 μT at the time of last cooling below the Curie point. Our Ar/Ar thermochronometry suggests that the last major thermal event experienced by NWA 7325 was at 500 Ma. Because this age is well after the expected lifetime of early planetesimal dynamos, our data indicate that any crustal fields on the parent body are extremely weak. This stands in stark contrast to Vesta, for which our analyses of the eucrite ALHA 81001 suggest has substantial (~10

  2. Broad bounds on Earth's accretion and core formation constrained by geochemical models

    NASA Astrophysics Data System (ADS)

    Rudge, John F.; Kleine, Thorsten; Bourdon, Bernard

    2010-06-01

    The Earth formed through the accretion of numerous planetary embryos that were already differentiated into a metallic core and silicate mantle. Prevailing models of Earth's formation, constrained by the observed abundances of metal-loving siderophile elements in Earth's mantle, assume full metal-silicate equilibrium, whereby all memory of the planetary embryos' earlier differentiation is lost. Using the hafnium-tungsten (Hf-W) and uranium-lead (U-Pb) isotopic dating systems, these models suggest rapid accretion of Earth's main mass within about 10 million years (Myr) of the formation of the Solar System. Accretion terminated about 30 or 100 Myr after formation of the Solar System, owing to a giant impact that formed the Moon. Here we present geochemical models of Earth's accretion that preserve some memory of the embryos' original differentiation. These disequilibrium models allow some fraction of the embryos' metallic cores to directly enter the Earth's core, without equilibrating with Earth's mantle. We show that disequilibrium models are as compatible with the geochemical observations as equilibrium models, yet still provide bounds on Earth's accretion and core formation. We find that the Hf-W data mainly constrain the degree of equilibration rather than the timing, whereas the U-Pb data confirm that the end of accretion is consistent with recent estimates of the age of the Moon. Our results indicate that only 36% of the Earth's core must have formed in equilibrium with Earth's mantle. This low degree of equilibration is consistent with the siderophile element abundances in Earth's mantle.

  3. Assessing planetary and regional nitrogen boundaries related to food security and adverse environmental impacts

    NASA Astrophysics Data System (ADS)

    de Vries, Wim; Kros, Hans; Kroeze, Carolien; Seitzinger, Sybil

    2014-05-01

    In this presentation, we first discuss the concept of -, governance interest in- and criticism on planetary boundaries, specifically with respect to the nitrogen (N) cycle. We then systematically evaluate the criticism and argue that planetary N boundaries need to include both the benefits and adverse impacts of reactive N (Nr) and the spatial variability of Nr impacts, in terms of shortage and surplus, being main arguments for not deriving such boundaries. Next, we present an holistic approach for an updated planetary N boundary by considering the need to: (i) avoid adverse impacts of elevated Nr emissions to water, air and soils, and (ii) feed the world population in an adequate way. The derivation of a planetary N boundary, in terms of anthropogenic fixation of di-nitrogen (N2) by growing legumes and production of N fertilizer, is illustrated by (i) identification of multiple threat N indicators and setting critical limits for them, (ii) back calculating critical N losses from critical limits for N indicators, while accounting for the spatial variability of indicators and their exceedance and (iii) back calculating critical N fixation rates from critical N losses. The derivation of the needed planetary N fixation is assessed from the global population, the recommended dietary N consumption per capita and the N use efficiency in the complete chain from N fixation to N consumption. Results of example applications show that the previously suggested planetary N boundary of 25% of the current value is too low in view of needed N fixation and also unnecessary in view of most environmental impacts. We also illustrate the impacts of changes in the N use efficiency on planetary boundaries in terms of critical N fixation rates.

  4. On the stability of circumbinary planetary systems

    NASA Astrophysics Data System (ADS)

    Popova, E. A.; Shevchenko, I. I.

    2016-07-01

    The dynamics of circumbinary planetary systems (the systems in which the planets orbit a central binary) with a small binary mass ratio discovered to date is considered. The domains of chaotic motion have been revealed in the "pericentric distance-eccentricity" plane of initial conditions for the planetary orbits through numerical experiments. Based on an analytical criterion for the chaoticity of planetary orbits in binary star systems, we have constructed theoretical curves that describe the global boundary of the chaotic zone around the central binary for each of the systems. In addition, based on Mardling's theory describing the separate resonance "teeth" (corresponding to integer resonances between the orbital periods of a planet and the binary), we have constructed the local boundaries of chaos. Both theoretical models are shown to describe adequately the boundaries of chaos on the numerically constructed stability diagrams, suggesting that these theories are efficient in providing analytical criteria for the chaoticity of planetary orbits.

  5. The wide field/planetary camera

    NASA Technical Reports Server (NTRS)

    Westphal, J. A.; Baum, W. A.; Code, A. D.; Currie, D. G.; Danielson, G. E.; Gunn, J. E.; Kelsall, T. F.; Kristian, J. A.; Lynds, C. R.; Seidelmann, P. K.

    1982-01-01

    A wide site of potential astronomical and solar system scientific studies using the wide field planetary camera on space telescope are described. The expected performance of the camera as it approaches final assembly and testing is also detailed.

  6. Annual review of earth and planetary science

    SciTech Connect

    Wetherill, G.W. )

    1992-01-01

    This volume contains papers on topics of earth and planetary science, including: volcanism and mantle plumes, primary radiation of terrestrial vertebrates, the effect of tropical topography on global climate, cosmic-ray exposure of chondrites, and planet magnetospheres.

  7. Precise Chemical Analyses of Planetary Surfaces

    NASA Technical Reports Server (NTRS)

    Kring, David; Schweitzer, Jeffrey; Meyer, Charles; Trombka, Jacob; Freund, Friedemann; Economou, Thanasis; Yen, Albert; Kim, Soon Sam; Treiman, Allan H.; Blake, David; Lisse, Carey

    1996-01-01

    We identify the chemical elements and element ratios that should be analyzed to address many of the issues identified by the Committee on Planetary and Lunar Exploration (COMPLEX). We determined that most of these issues require two sensitive instruments to analyze the necessary complement of elements. In addition, it is useful in many cases to use one instrument to analyze the outermost planetary surface (e.g. to determine weathering effects), while a second is used to analyze a subsurface volume of material (e.g., to determine the composition of unaltered planetary surface material). This dual approach to chemical analyses will also facilitate the calibration of orbital and/or Earth-based spectral observations of the planetary body. We determined that in many cases the scientific issues defined by COMPLEX can only be fully addressed with combined packages of instruments that would supplement the chemical data with mineralogic or visual information.

  8. Planetary science: Cometary dust under the microscope

    NASA Astrophysics Data System (ADS)

    Kolokolova, Ludmilla

    2016-09-01

    The Rosetta spacecraft made history by successfully orbiting a comet. Data from the craft now reveal the structure of the comet's dust particles, shedding light on the processes that form planetary systems. See Letter p.73

  9. Reports of planetary geology program, 1983

    NASA Technical Reports Server (NTRS)

    Holt, H. E. (Compiler)

    1984-01-01

    Several areas of the Planetary Geology Program were addressed including outer solar system satellites, asteroids, comets, Venus, cratering processes and landform development, volcanic processes, aeolian processes, fluvial processes, periglacial and permafrost processes, geomorphology, remote sensing, tectonics and stratigraphy, and mapping.

  10. Planetary Regolith Delivery Systems for ISRU

    NASA Technical Reports Server (NTRS)

    Mantovani, James G.; Townsend, Ivan I., III

    2012-01-01

    The challenges associated with collecting regolith on a planetary surface and delivering it to an in-situ resource utilization system differ significantly from similar activities conducted on Earth. Since system maintenance on a planetary body can be difficult or impossible to do, high reliability and service life are expected of a regolith delivery system. Mission costs impose upper limits on power and mass. The regolith delivery system must provide a leak-tight interface between the near-vacuum planetary surface and the pressurized ISRU system. Regolith delivery in amounts ranging from a few grams to tens of kilograms may be required. Finally, the spent regolith must be removed from the ISRU chamber and returned to the planetary environment via dust tolerant valves capable of operating and sealing over a large temperature range. This paper will describe pneumatic and auger regolith transfer systems that have already been field tested for ISRU, and discuss other systems that await future field testing.

  11. Planetary science: Flow of an alien ocean

    NASA Astrophysics Data System (ADS)

    Goodman, Jason

    2014-01-01

    Liquid water may lurk beneath the frozen surfaces of Jupiter's moon Europa and other icy worlds. Extending ocean science beyond Earth, planetary oceanographers are linking Europa's ocean dynamics to its enigmatic surface geology.

  12. MHD Solutions for Proto-Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    García-Segura, G.; López, J. A.; Franco, J.

    2004-07-01

    This paper provides solutions for the origin of post-AGB winds, their acceleration up to high speed, and the subsequent formation of extremely collimated proto-planetary nebulae. Several wind models with terminal velocities from a few tens of kms up to 103 kms are calculated, which produce proto-planetary nebulae with linear momentum in the range 1036-1040 gcms and with kinetic energies in the range 1042-1047 erg. These results match available observations of proto-planetary nebulae. In the present simplistic scheme, the driver of the wind is just the magnetic pressure at the stellar surface. Other forces are not taken into account in this study, except gravity. We conclude that mass-loss rates of post-AGB stars and transition times from late AGB up to planetary nebula central stars could be directly linked with the production of magnetic field at the stellar core.

  13. Significant achievements in the planetary geology program

    NASA Technical Reports Server (NTRS)

    Head, J. W. (Editor)

    1984-01-01

    Recent developments in planetology research are summarized. Important developments are summarized in topics ranging from solar system evolution, comparative planetology, and geologic processes active on other planetary bodies, to techniques and instrument development for exploration.

  14. 2nd International Planetary Probe Workshop

    NASA Technical Reports Server (NTRS)

    Venkatapathy, Ethiraj; Martinez, Ed; Arcadi, Marla

    2005-01-01

    Included are presentations from the 2nd International Planetary Probe Workshop. The purpose of the second workshop was to continue to unite the community of planetary scientists, spacecraft engineers and mission designers and planners; whose expertise, experience and interests are in the areas of entry probe trajectory and attitude determination, and the aerodynamics/aerothermodynamics of planetary entry vehicles. Mars lander missions and the first probe mission to Titan made 2004 an exciting year for planetary exploration. The Workshop addressed entry probe science, engineering challenges, mission design and instruments, along with the challenges of reconstruction of the entry, descent and landing or the aerocapture phases. Topics addressed included methods, technologies, and algorithms currently employed; techniques and results from the rich history of entry probe science such as PAET, Venera/Vega, Pioneer Venus, Viking, Galileo, Mars Pathfinder and Mars MER; upcoming missions such as the imminent entry of Huygens and future Mars entry probes; and new and novel instrumentation and methodologies.

  15. Reports of planetary geology program, 1980. [Bibliography

    NASA Technical Reports Server (NTRS)

    Holt, H. E. (Compiler); Kosters, E. C. (Compiler)

    1980-01-01

    This is a compilation of abstracts of reports which summarize work conducted in the Planetary Geology Program. Each report reflects significant accomplishments within the area of the author's funded grant or contract.

  16. Improving Access to Planetary Data for Education

    NASA Astrophysics Data System (ADS)

    Montgomery, J.

    2005-12-01

    Over the years the National Aeronautics and Space Administration (NASA) has collected an enormous amount of observational data from space missions. Using this scientific data in high school or college science education courses can be invaluable. Factors that impeded wide spread use of NASA planetary data in science education include accessibility to data and freely available software tools used to analyze and visually model planetary data sets. To address these issues we created a Graphical Analyses and Visualization Software Tool for Planetary Data (GAVPD). GAVPD is a web based software tool that can be used to visualize and analyze planetary data over the internet. GAVPD has a simple web based interface that allows users to create visual projections of altimeter data and make 2D and 3D surface measurements graphically. GAVPD is in currently a prototype and work is underway to extend its capability to other types of data sets.

  17. A survey for PAH emission in H II regions, planetary and proto-planetary nebulae

    NASA Technical Reports Server (NTRS)

    Demuizon, M.; Cox, P.; Lequeux, J.

    1989-01-01

    The results of a systematic investigation of polycyclic aromatic hydrocarbon (PAH) emission in H II regions, planetary nebulae (PN), and proto-planetary nebulae (PNN), are reported. Data is obtained from the low resolution spectra (LRS) of IRAS. The results show that: PAHs are formed in carbon rich objects; and PAH emission is ubiquitous in general interstellar medium and requires the presence of ultraviolet photons, in planetary and proto-planetary nebulae, PAH emission is seen only where an ionizing flux is present and in carbon rich objects.

  18. Planetary science data archiving in Europe

    NASA Astrophysics Data System (ADS)

    Heather, David

    2012-07-01

    Europe is currently enjoying a time of plenty in terms of planetary science missions and the resulting planetary data. The European Space Agency are flying or developing missions to many planetary bodies and are co-operating with other Agencies to ensure maximization of resources. Prior to the arrival of Mars Express at the Red Planet on 25th December 2003, Europe had very little experience in the development and management of planetary data. Since then, with the continuing MEX operations, the launch and successful operation of Venus Express, the ongoing Rosetta mission and its recent asteroid encounters, the SMART-1 technology tester mission to the Moon, the Huygens probe to Titan, and with contributing payload on ISRO's Chandrayaan-1 mission to the Moon, Europe has had a flood of data to deal with. We have had to learn fast! In addition to the basic challenges of managing and distributing such an influx of new data, there has been considerable effort in Europe to develop and manage the resources required to query and use them from within the community. The Integrated and Distributed Information Service (IDIS), part of the EU funded Europlanet activities, is a good example of this, aiming to centralize data sources and useful resources for scientists wishing to use the planetary data. Europe has been working very closely with international partners to globalize planetary data archiving standards, and all major planetary data providers and distributors in Europe are participating fully in the International Planetary Data Alliance (IPDA). A major focus of this work has been in the development of a protocol that will allow for the interoperability of archives and sharing of data across the globe. Close interactions are also ongoing with NASA's Planetary Data System as the standards used for planetary data archiving evolve. This talk will outline the planetary science data archiving situation in Europe, and summarize the various ongoing efforts to coordinate at an

  19. Extrasolar Planetary Imaging Coronagraph (EPIC)

    NASA Astrophysics Data System (ADS)

    Clampin, Mark

    2009-01-01

    The Extrasolar Planetary Imaging Coronagraph (EPIC) is a proposed NASA Exoplanet Probe mission to image and characterize extrasolar giant planets. EPIC will provide insights into the physical nature and architecture of a variety of planets in other solar systems. Initially, it will detect and characterize the atmospheres of planets identified by radial velocity surveys, determine orbital inclinations and masses and characterize the atmospheres around A and F type stars which cannot be found with RV techniques. It will also observe the inner spatial structure of exozodiacal disks. EPIC has a heliocentric Earth trailing drift-away orbit, with a 5 year mission lifetime. The robust mission design is simple and flexible ensuring mission success while minimizing cost and risk. The science payload consists of a heritage optical telescope assembly (OTA), and visible nulling coronagraph (VNC) instrument. The instrument achieves a contrast ratio of 10^9 over a 5 arcsecond field-of-view with an unprecedented inner working angle of 0.13 arcseconds over the spectral range of 440-880 nm. The telescope is a 1.65 meter off-axis Cassegrain with an OTA wavefront error of lambda/9, which when coupled to the VNC greatly reduces the requirements on the large scale optics.

  20. Archiving of Planetary Ring Data

    NASA Technical Reports Server (NTRS)

    Elliot, James L.

    2001-01-01

    Stellar occultation data provide our only Earth-based means of probing planetary rings at kilometer spatial resolution. The occultation data archive at MIT contains original data and analysis products of stellar occultations by the ring systems of the planets Jupiter, Saturn, Uranus, and Neptune observed by members of the group (and other groups) from 1977 to the present. During this time period, several media have been used to record and store the original and processed data: (1) chart records; (2) printed output, (3) audio reel tape; (4) audio cassette tape; (5) 7-track, 1/2-inch computer tape; (6) 9-track, 1/2-inch computer tape at 800, 1600, and 6250 bpi; (7) NOVA disk platters (2.5 and 5.0 Mbyte); (8) write once optical disks; (9) punched cards; and (10) read-write optical disks. With the rapid change of computer technology over this time period, some of these media have become not only obsolete, but nearly extinct. In particular, it has become nearly impossible to find any facilities that can still read 800 bpi tapes, which contain the only copies of several important data sets for the ring system of Uranus. In particular, we have an extensive ring data collection that includes data sets for the following Uranian ring occultations: U0, U11, U12, U13, U14, U25, U17, and U36.

  1. Meteoric Ions in Planetary Ionospheres

    NASA Technical Reports Server (NTRS)

    Pesnell, W. D.; Grebowsky, Joseph M.; Vondrak, Richard R. (Technical Monitor)

    2001-01-01

    Solar system debris, in the form of meteoroids, impacts every planet. The flux, relative composition and speed of the debris at each planet depends on the planet's size and location in the solar system. Ablation in the atmosphere evaporates the meteoric material and leaves behind metal atoms. During the ablation process metallic ions are formed by impact ionization. For small inner solar system planets, including Earth, this source of ionization is typically small compared to either photoionization or charge exchange with ambient molecular ions. For Earth, the atmosphere above the main deposition region absorbs the spectral lines capable of ionizing the major metallic atoms (Fe and Mg) so that charge exchange with ambient ions is the dominant source. Within the carbon dioxide atmosphere of Mars (and possibly Venus), photoionization is important in determining the ion density. For a heavy planet like Jupiter, far from the sun, impact ionization of ablated neutral atoms by impacts with molecules becomes a prominent source of ionization due to the gravitational acceleration to high incident speeds. We will describe the processes and location and extent of metal ion layers for Mars, Earth and Jupiter, concentrating on flagging the uncertainties in the models at the present time. This is an important problem, because low altitude ionosphere layers for the planets, particularly at night, probably consist predominantly of metallic ions. Comparisons with Earth will be used to illustrate the differing processes in the three planetary atmospheres.

  2. Electrostatic forces in planetary rings

    NASA Technical Reports Server (NTRS)

    Goertz, C. K.; Shan, Linhua; Havnes, O.

    1988-01-01

    The average charge on a particle in a particle-plasma cloud, the plasma potential inside the cloud, and the Coulomb force acting on the particle are calculated. The net repulsive electrostatic force on a particle depends on the plasma density, temperature, density of particles, particle size, and the gradient of the particle density. In a uniformly dense ring the electrostatic repulsion is zero. It is also shown that the electrostatic force acts like a pressure force, that even a collisionless ring can be stable against gravitational collapse, and that a finite ring thickness does not necessarily imply a finite velocity dispersion. A simple criterion for the importance of electrostatic forces in planetary rings is derived which involves the calculation of the vertical ring thickness which would result if only electrostatic repulsion were responsible for the finite ring thickness. Electrostatic forces are entirely negligible in the main rings of Saturn and the E and G rings. They may also be negligible in the F ring. However, the Uranian rings and Jupiter's ring seem to be very much influenced by electrostatic repulsion. In fact, electrostatic forces could support a Jovian ring which is an order of magnitude more dense than observed.

  3. Dynamical habitability of planetary systems.

    PubMed

    Dvorak, Rudolf; Pilat-Lohinger, Elke; Bois, Eric; Schwarz, Richard; Funk, Barbara; Beichman, Charles; Danchi, William; Eiroa, Carlos; Fridlund, Malcolm; Henning, Thomas; Herbst, Tom; Kaltenegger, Lisa; Lammer, Helmut; Léger, Alain; Liseau, René; Lunine, Jonathan; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Selsis, Frank; Schneider, Jean; Stam, Daphne; Tinetti, Giovanna; White, Glenn J

    2010-01-01

    The problem of the stability of planetary systems, a question that concerns only multiplanetary systems that host at least two planets, is discussed. The problem of mean motion resonances is addressed prior to discussion of the dynamical structure of the more than 350 known planets. The difference with regard to our own Solar System with eight planets on low eccentricity is evident in that 60% of the known extrasolar planets have orbits with eccentricity e > 0.2. We theoretically highlight the studies concerning possible terrestrial planets in systems with a Jupiter-like planet. We emphasize that an orbit of a particular nature only will keep a planet within the habitable zone around a host star with respect to the semimajor axis and its eccentricity. In addition, some results are given for individual systems (e.g., Gl777A) with regard to the stability of orbits within habitable zones. We also review what is known about the orbits of planets in double-star systems around only one component (e.g., gamma Cephei) and around both stars (e.g., eclipsing binaries). PMID:20307181

  4. Toward directed energy planetary defense

    NASA Astrophysics Data System (ADS)

    Lubin, Philip; Hughes, Gary B.; Bible, Johanna; Bublitz, Jesse; Arriola, Josh; Motta, Caio; Suen, Jon; Johansson, Isabella; Riley, Jordan; Sarvian, Nilou; Clayton-Warwick, Deborah; Wu, Jane; Milich, Andrew; Oleson, Mitch; Pryor, Mark; Krogen, Peter; Kangas, Miikka; O'Neill, Hugh

    2014-02-01

    Asteroids and comets that cross Earth's orbit pose a credible risk of impact, with potentially severe disturbances to Earth and society. We propose an orbital planetary defense system capable of heating the surface of potentially hazardous objects to the vaporization point as a feasible approach to impact risk mitigation. We call the system DE-STAR, for Directed Energy System for Targeting of Asteroids and exploRation. The DE-STAR is a modular-phased array of kilowatt class lasers powered by photovoltaic's. Modular design allows for incremental development, minimizing risk, and allowing for technological codevelopment. An orbiting structure would be developed in stages. The main objective of the DE-STAR is to use focused directed energy to raise the surface spot temperature to ˜3000 K, sufficient to vaporize all known substances. Ejection of evaporated material creates a large reaction force that would alter an asteroid's orbit. The baseline system is a DE-STAR 3 or 4 (1- to 10-km array) depending on the degree of protection desired. A DE-STAR 4 allows initial engagement beyond 1 AU with a spot temperature sufficient to completely evaporate up to 500-m diameter asteroids in 1 year. Small objects can be diverted with a DE-STAR 2 (100 m) while space debris is vaporized with a DE-STAR 1 (10 m).

  5. Sonar equations for planetary exploration.

    PubMed

    Ainslie, Michael A; Leighton, Timothy G

    2016-08-01

    The set of formulations commonly known as "the sonar equations" have for many decades been used to quantify the performance of sonar systems in terms of their ability to detect and localize objects submerged in seawater. The efficacy of the sonar equations, with individual terms evaluated in decibels, is well established in Earth's oceans. The sonar equations have been used in the past for missions to other planets and moons in the solar system, for which they are shown to be less suitable. While it would be preferable to undertake high-fidelity acoustical calculations to support planning, execution, and interpretation of acoustic data from planetary probes, to avoid possible errors for planned missions to such extraterrestrial bodies in future, doing so requires awareness of the pitfalls pointed out in this paper. There is a need to reexamine the assumptions, practices, and calibrations that work well for Earth to ensure that the sonar equations can be accurately applied in combination with the decibel to extraterrestrial scenarios. Examples are given for icy oceans such as exist on Europa and Ganymede, Titan's hydrocarbon lakes, and for the gaseous atmospheres of (for example) Jupiter and Venus. PMID:27586766

  6. Zinc abundances of planetary nebulae

    NASA Astrophysics Data System (ADS)

    Smith, C. L.; Zijlstra, A. A.; Dinerstein, H. L.

    2014-07-01

    Zinc is a useful surrogate element for measuring Fe/H as, unlike iron, it is not depleted in the gas phase media. Zn/H and O/Zn ratios have been derived using the [Zn IV] emission line at 3.625 μm for a sample of nine Galactic planetary nebulae, seven of which are based upon new observations using the Very Large Telescope (VLT). Based on photoionization models, O/O++ is the most reliable ionization correction factor for zinc that can readily be determined from optical emission lines, with an estimated accuracy of 10 per cent or better for all targets in our sample. The majority of the sample is found to be subsolar in [Zn/H]. [O/Zn] in half of the sample is found to be consistent with solar within uncertainties, whereas the remaining half are enhanced in [O/Zn]. [Zn/H] and [O/Zn] as functions of Galactocentric distance have been investigated and there is little evidence to support a trend in either case.

  7. GALEX Observations of Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Panda, Swayamtrupta

    2016-05-01

    The first ultraviolet (UV) photometric observations of planetary nebulae (PNe) are presented using observations made by the Galaxy Evolution Explorer (GALEX). We have found 108 PNe detected by GALEX and resolved their angular diameters in near-UV (NUV) and also in far-UV (FUV) for 28 PNe considering a 3σ emission level beyond the background. Of the PNe, 57 are elliptical, 41 are circular and the rest 10 are bipolar in NUV. The emission lines that contribute to the NUV intrinsic flux are C III] and He II. The measured intrinsic luminosities considering the sole contribution from the central stars have been found to lie in the range of 10^37-10^51 erg/s. The comparative study of the angular sizes against effective wavelengths in 5 distinct regimes has shown that the listed PNe are bright in NUV which opens up the discussion related to the extent of hotness, the very high temperatures of the CSPNe and the exact nature of it. The intensity contour plots of the PNe have also provided us with over 10 well-defined candidates having bipolar morphological signatures, the origin and evolution of whose can be traced back to the dynamics of stellar winds in the post-AGB stage.

  8. Dissociative recombination in planetary ionospheres

    NASA Technical Reports Server (NTRS)

    Fox, J. L.

    1993-01-01

    Ionization in planetary atmospheres can be produced by solar photoionization, photoelectron impact ionization, and, in auroral regions, by impact of precipitating particles. This ionization is lost mainly in dissociative recombination (DR) of molecular ions. Although atomic ions cannot undergo DR, they can be transformed locally through ion-molecule reactions into molecular ions, or they may be transported vertically or horizontally to regions of the atmosphere where such transformations are possible. Because DR reactions tend to be very exothermic, they can be an important source of kinetically or internally excited fragments. In interplanetary thermospheres, the neutral densities decrease exponentially with altitude. Below the homopause (or turbopause), the atmosphere is assumed to be throughly mixed by convection and/or turbulence. Above the homopause, diffusion is the major transport mechanism, and each species is distributed according to its mass, with the logarithmic derivative of the density with repect to altitude given approximately by -1/H, where H = kT/mg is the scale height. In this expression, T is the neutral temperature, g is the local acceleratiion of gravity, and m is the mass of the species. Thus lighter species become relatively more abundant, and heavier species less abundant, as the altitude increases. This variation of the neutral composition can lead to changes in the ion composition; furthermore, as the neutral densities decrease, dissociative recombination becomes more important relative to ion-neutral reactions as a loss mechanism for molecular ions.

  9. The Origin of Planetary Nitrogen

    NASA Technical Reports Server (NTRS)

    Owen, T.; Niemann, H.; Mahaffy, P.; Atreya, S.

    2006-01-01

    The nitrogen found today in planetary atmospheres appears to come from two sources: N2 and condensed, nitrogen-containing compounds. On Jupiter and thus presumably on the other giant planets, the nitrogen is present mainly as ammonia but was apparently delivered primarily in the form of N2, whereas on the inner planets and Titan, the nitrogen is present as N2 but was delivered as condensed compounds, dominated by ammonia. This analysis is consistent with abundance data from the Interstellar Medium and models for the solar nebula. For Jupiter and the inner planets, it is substantiated by measurements of N-l5/N-14 and is supported by investigations of comets and meteorites, soon to be supplemented by solar wind data from the Genesis Mission. The Cassini-Huygens Mission may be able to constrain models for Saturn s ammonia abundance that could test the proportion of N2 captured by the planet. The Titan story is less direct, depending on studies of noble gases. These studies in turn suggest an evolutionary stage of the early Earth s atmosphere that included the ammonia and methane postulated by S. L. Miller (1953) in his classical experiments on the production of biogenic compounds.

  10. A mineralogical instrument for planetary applications

    NASA Technical Reports Server (NTRS)

    Blake, David F.; Vaniman, David T.; Bish, David L.

    1994-01-01

    The mineralogy of a planetary surface can be used to identify the provenance of soil or sediment and reveal the volcanic, metamorphic and/or sedimentological history of a particular region. We have discussed elsewhere the applications and the instrument design of possible X-ray diffraction and X-ray fluorescence (XRD/XRF) devices for the mineralogical characterization of planetary surfaces. In this abstract we evaluate some aspects of sample-detector geometry and sample collection strategies.

  11. Ten year planetary ephemeris: 1986-1995

    NASA Technical Reports Server (NTRS)

    Espenak, F.

    1986-01-01

    Accurate geocentric positions are tabulated at five day intervals for the Sun, Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune during the ten year period 1986 through 1995. The apparent angular diameters, radial velocities, declinations and mean times of meridian transit of the seven planets and the Sun are graphically depicted for each year in the interval. Appendices are included which discuss the theory of planetary orbits and a FORTRAN program for calculating planetary ephemerides.

  12. Post-main-sequence planetary system evolution

    PubMed Central

    Veras, Dimitri

    2016-01-01

    The fates of planetary systems provide unassailable insights into their formation and represent rich cross-disciplinary dynamical laboratories. Mounting observations of post-main-sequence planetary systems necessitate a complementary level of theoretical scrutiny. Here, I review the diverse dynamical processes which affect planets, asteroids, comets and pebbles as their parent stars evolve into giant branch, white dwarf and neutron stars. This reference provides a foundation for the interpretation and modelling of currently known systems and upcoming discoveries. PMID:26998326

  13. Fourier spectroscopy on planetary missions including Voyager

    NASA Technical Reports Server (NTRS)

    Hanel, R. A.

    1981-01-01

    In the last dozen years spaceborne Fourier transform spectrometers have obtained infrared emission spectra of Earth, Mars, Jupiter, Saturn and Titan as well as of the Galilean and other Saturnian satellites and Saturn's rings. Intercomparisons of the properties of planetary atmospheres and of the characteristics of solid surfaces are now feasible. The principles of remotely sensing the environment on a planetary body are dicussed. Special consideration is given to the most recent results obtained by the Voyager infrared investigation on the Saturn system.

  14. Preface: New challenges for planetary protection

    NASA Astrophysics Data System (ADS)

    Kminek, Gerhard

    2016-05-01

    Planetary protection as a discipline goes back to the advent of the space age and the formation of the Committee on Space Research (COSPAR). Planetary protection constraints are in place to ensure that scientific investigations related to the search for extraterrestrial life are not compromised and that the Earth is protected from the potential hazard posed by extraterrestrial matter carried by a spacecraft returning from an interplanetary mission.

  15. Several evolutionary channels for bright planetary nebulae

    NASA Astrophysics Data System (ADS)

    Richer, Michael G.; McCall, Marshall L.

    2016-08-01

    The populations of bright planetary nebulae in the discs of spirals appear to differ in their spectral properties from those in ellipticals and the bulges of spirals. The bright planetary nebulae from the bulge of the Milky Way are entirely compatible with those observed in the discs of spiral galaxies. The similarity might be explained if the bulge of the Milky Way evolved secularly from the disc, in which case the bulge should be regarded as a pseudo-bulge.

  16. International Planetary Data Alliance (IPDA) Information Model

    NASA Technical Reports Server (NTRS)

    Hughes, John Steven; Beebe, R.; Guinness, E.; Heather, D.; Huang, M.; Kasaba, Y.; Osuna, P.; Rye, E.; Savorskiy, V.

    2007-01-01

    This document is the third deliverable of the International Planetary Data Alliance (IPDA) Archive Data Standards Requirements Identification project. The goal of the project is to identify a subset of the standards currently in use by NASAs Planetary Data System (PDS) that are appropriate for internationalization. As shown in the highlighted sections of Figure 1, the focus of this project is the Information Model component of the Data Architecture Standards, namely the object models, a data dictionary, and a set of data formats.

  17. Post-main-sequence planetary system evolution.

    PubMed

    Veras, Dimitri

    2016-02-01

    The fates of planetary systems provide unassailable insights into their formation and represent rich cross-disciplinary dynamical laboratories. Mounting observations of post-main-sequence planetary systems necessitate a complementary level of theoretical scrutiny. Here, I review the diverse dynamical processes which affect planets, asteroids, comets and pebbles as their parent stars evolve into giant branch, white dwarf and neutron stars. This reference provides a foundation for the interpretation and modelling of currently known systems and upcoming discoveries. PMID:26998326

  18. Post-main-sequence planetary system evolution

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri

    2016-02-01

    The fates of planetary systems provide unassailable insights into their formation and represent rich cross-disciplinary dynamical laboratories. Mounting observations of post-main-sequence planetary systems necessitate a complementary level of theoretical scrutiny. Here, I review the diverse dynamical processes which affect planets, asteroids, comets and pebbles as their parent stars evolve into giant branch, white dwarf and neutron stars. This reference provides a foundation for the interpretation and modelling of currently known systems and upcoming discoveries.

  19. Planetary geology in the 1980s

    NASA Technical Reports Server (NTRS)

    Veverka, J.

    1984-01-01

    The geologic aspects of solar system studies are defined and the goals of planetary geology are discussed. Planetary geology is the study of the origin, evolution, and distribution of matter condensed in the form of planets, satellites, asteroids, and comets. It is a multidisciplinary effort involving investigators with backgrounds in geology, chemistry, physics, astronomy, geodesy, cartography, and other disciplines concerned with the solid planets. The report is primarily restricted to the kinds of experiments and observations made through unmanned missions.

  20. The effect of planetary illumination on climate modelling of Earth-like exomoons

    NASA Astrophysics Data System (ADS)

    Forgan, Duncan; Yotov, Vergil

    2014-07-01

    From analytical studies of tidal heating, eclipses and planetary illumination, it is clear that the exomoon habitable zone (EHZ) - the set of moon and host planet orbits that permit liquid water on an Earth-like moon's surface - is a manifold of higher dimension than the planetary HZ. This paper outlines the first attempt to produce climate models of exomoons which possess all the above sources and sinks of energy. We expand on our previous 1D latitudinal energy balance models, which follow the evolution of the temperature on an Earth-like moon orbiting a Jupiter-like planet, by adding planetary illumination. We investigate the EHZ in four dimensions, running two separate suites of simulations. The first investigates the EHZ by varying the planet's orbit, keeping the moon's orbit fixed, to compare the EHZ with planetary HZs. In general, planetary illumination pushes EHZs slightly further away from the star. Secondly, we fix the planet's orbit and vary the moon's orbit, to investigate the circumplanetary inner habitable edge. We demonstrate that an outer edge can exist due to eclipses (rather than merely orbital stability), but this edge may be pushed outwards when the effect of the carbonate-silicate cycle is taken into account.

  1. Integrated Geochemical-Petrographic Insights on Neoproterozoic Ocean Oxygenation

    NASA Astrophysics Data System (ADS)

    Hood, A.; Planavsky, N.; Wallace, M. W.; Wang, X.; Gueguen, B.

    2015-12-01

    Novel isotope systems have the potential to provide new insights into biogeochemical cycling in Earth's evolving oceans. However, much recent paleo-redox work has been done without extensive consideration of sample preservation or paleoenvironmental setting. Neoproterozoic reef complexes from South Australia provide a perfect setting to test geochemical redox proxies (e.g. uranium isotopes and trace metal chemistry) within a well-defined sedimentological and petrographic context. These reefs developed significant frameworks over ~1km of steep platform relief from the seafloor, and contain a variety of carbonate components including primary dolomite marine cements. Analysis of a variety of components within these reefs reveals significant variation in uranium isotope composition and trace metal chemistry between components, even within a single sample. Marine cements, which precipitated directly from seawater, have much lower contamination element concentrations (e.g. Al, Zr, Th) than depositional micrites, and appear to represent the best archive of ancient ocean conditions. These cements have high levels of Fe, Mn in shallow and deep reef facies (e.g. 2-3wt% Fe), but only Fe-oxide inclusions in peritidal settings. This distribution suggests ferruginous conditions under a surficial chemocline in this Neoproterozoic seawater. Uranium isotopes from pristine marine cements have relatively heavy values compared to modern seawater (median = -0.22 δ238U). These values are essentially unfractionated from riverine inputs, which we interpret as tracking extensive near quantitative low-T reduction of U(VI) to U(IV) by abundant soluble iron in seawater. Depositional components and late stage cements have a much lighter and more variable U isotope compositions (-0.71 to -0.08 δ238U). This work highlights the need for fundamental petrographic constraints on the preservation of depositional geochemical signatures in the future use and development of sedimentary redox proxies.

  2. Geochemical processes during five years of aquifer storage recovery.

    PubMed

    Herczeg, Andrew L; Rattray, Karen J; Dillon, Peter J; Pavelic, Paul; Barry, Karen E

    2004-01-01

    A key factor in the long-term viability of aquifer storage recovery (ASR) is the extent of mineral solution interaction between two dissimilar water types and consequent impact on water quality and aquifer stability. We collected geochemical and isotopic data from three observation wells located 25, 65, and 325 m from an injection well at an experimental ASR site located in a karstic, confined carbonate aquifer in South Australia. The experiment involved five major injection cycles of a total of 2.5 x 10(5) m3 of storm water (total dissolved solids [TDS] approximately 150 mg/L) into the brackish (TDS approximately 2400 mg/L) aquifer. Approximately 60% of the mixture was pumped out during the fifth year of the experiment. The major effect on water quality within a 25 m radius of the injection well following injection of storm water was carbonate dissolution (35 +/- 6 g of CaCO3 dissolved/m3 of aquifer) and sulfide mineral oxidation (50 +/- 10 g as FeS2/m3 after one injection). < 0.005% of the total aquifer carbonate matrix was dissolved during each injection event, and approximately 0.2% of the total reduced sulfur. Increasing amounts of ambient ground water was entrained into the injected mixture during each of the storage periods. High 14C(DIC) activities and slightly more negative delta13C(DIC) values measured immediately after injection events show that substantial CO2(aq) is produced by oxidation of organic matter associated with injectant. There were no detectable geochemical reactions while pumping during the recovery phase in the fifth year of the experiment. PMID:15161160

  3. Using Geochemical Indicators to Distinguish High Biogeochemical Activity in Sediments

    NASA Astrophysics Data System (ADS)

    Kenwell, A. M.; Navarre-Sitchler, A.; Prugue, R.; Spear, J. R.; Williams, K. H.; Maxwell, R. M.

    2014-12-01

    A better understanding of how microbial communities interact with their surroundings in physically and chemically heterogeneous subsurface environments will lead to improved quantification of biogeochemical reactions and associated nutrient cycling. This study develops a methodology to predict elevated rates of biogeochemical activity (microbial "hotspots") in subsurface environments by correlating microbial community structure with the spatial distribution of geochemical indicators in subsurface sediments. Statistical hierarchical cluster analyses (HCA) of X-ray fluorescence (XRF), simulated precipitation leachate, bioavailable Fe and Mn, total organic carbon (TOC), microbial community structure, grain size, bulk density and moisture content data were used to identify regions of the subsurface characterized by biogeochemical hotspots and sample characteristics indicative of these hotspots within fluvially-derived aquifer sediments. The methodology has been applied to (a) alluvial materials collected at a former uranium mill site near Rifle, Colorado and (b) relatively undisturbed floodplain deposits (soils and sediments) collected along the East River near Crested Butte, Colorado. At Rifle, 33 sediment samples were taken from 8 sediment cores and at the East River 33 soil/sediment samples were collected across and perpendicular to 3 active meanders. The East River watershed exhibits characteristic fluvial progression and serves as a representative example of many headwater catchments with the upper Colorado River basin. Initial clustering revealed that operationally defined hotspots were characterized by high organic carbon, bioavailable iron and dark colors but not necessarily low hydraulic conductivity. Applying the method to identify hotspots in both contaminated and natural floodplain deposits and their associated alluvial aquifers demonstrates the broad applicability of a geochemical indicator based approach.

  4. the Geochemical Structure of the Hawaiian Plume

    NASA Astrophysics Data System (ADS)

    Huang, S.; Frey, F. A.

    2005-12-01

    The spatial arrangement of modern Hawaiian volcanoes forms two offset trends, the Kea and Loa trends. Lavas from these two volcanic trends have important geochemical differences; e.g., Loa and Kea trend lavas form different trends in 87Sr/86Sr and 208Pb*/206Pb* vs 3He/4He plots (e.g., Kurz et al., 1995; Lassiter et al., 1996). Abouchami et al. (2005) noted that, compared with Kea trend lavas, Loa trend lavas have relatively higher 208Pb/204Pb at a given 206Pb/204Pb, i.e., Loa trend lavas have higher 208Pb*/206Pb*. Kea and Loa trend lavas also form different trends in plots of 208Pb*/206Pb* vs Hf, Sr and Nd isotopic ratios. An important observation is that in these isotopic ratio plots, Loihi lavas are located at the intersections of the near-linear Loa and Kea trends; implying that the Loihi component (high 3He/4He) is a common source component for Loa and Kea trend volcanoes. The other ends of the Loa and Kea trends are defined by Koolau and Mauna Kea lavas, and are designated as the Koolau and Kea components. Loa trend lavas sample the Koolau and Loihi components, and the Kea trend lavas sample the Kea and Loihi components. The Loa-Kea geochemical differences have been inferred to reflect source characteristics. Consequently, different models for the structure of the Hawaiian plume have been proposed, for example, a concentrically zoned plume (Lassiter et al., 1996) and a bilaterally asymmetric plume (Abouchami et al., 2005). Based on the temporal variations of geochemical compositions of shield lavas from several Hawaiian shields, such as Mauna Kea, Koolau and Haleakala, as well as melt inclusion study, Kurz et al. (2004) and Ren et al. (2005) proposed that although the plume is grossly zoned, there are Kea- and Loa-type sources present throughout the plume. In this study, we propose that Loa and Kea volcanoes sample a common, geochemically heterogeneous mantle plume source which contains the Koolau, Kea and Loihi components. These geochemical heterogeneities

  5. Geochemical dynamics in selected Yellowstone hydrothermal features

    NASA Astrophysics Data System (ADS)

    Druschel, G.; Kamyshny, A.; Findlay, A.; Nuzzio, D.

    2010-12-01

    Yellowstone National Park has a wide diversity of thermal features, and includes springs with a range of pH conditions that significantly impact sulfur speciation. We have utilized a combination of voltammetric and spectroscopic techniques to characterize the intermediate sulfur chemistry of Cinder Pool, Evening Primrose, Ojo Caliente, Frying Pan, Azure, and Dragon thermal springs. These measurements additionally have demonstrated the geochemical dynamics inherent in these systems; significant variability in chemical speciation occur in many of these thermal features due to changes in gas supply rates, fluid discharge rates, and thermal differences that occur on second time scales. The dynamics of the geochemical settings shown may significantly impact how microorganisms interact with the sulfur forms in these systems.

  6. Space weather at different planetary environments

    NASA Astrophysics Data System (ADS)

    Plainaki, Christina; Milillo, Anna; Andriopoulou, Maria; Dandouras, Iannis; Radioti, Aikaterini; Lilensten, Jean; Coustenis, Athena; Nordheim, Tom; Orsini, Stefano; Mura, Alessandro; Mangano, Valeria

    2015-04-01

    Different aspects of the conditions in the Sun, solar wind and magnetospheric plasmas, at various planetary systems of our Solar System, can influence the performance and reliability of space-borne technological systems. The science study of the so-called Planetary Space Weather considers different cross-disciplinary issues, including: - the interaction of solar wind/magnetospheric plasmas with planetary/satellite surfaces, ionospheres and thick (e.g. at Jupiter, Saturn, Uranus, Mars, Venus, Titan) or tenuous (e.g. Ganymede, Europa, Mercury, our Moon) atmospheres, including the generation of auroras - the satellite interactions with their neutral environments and dust - the variability of the magnetospheric regions under different solar wind conditions - radiation belts, and their interactions with atmospheres/satellites/rings, in different planetary environments - the inter-comparisons of space weather conditions in different planetary environments In this paper, a brief review of theoretical and data analysis studies regarding planetary space weather in different bodies of our Solar System is presented. The importance of such studies for the in-situ data interpretations as well as for the preparation of future space missions is outlined.

  7. Migration-induced architectures of planetary systems.

    PubMed

    Szuszkiewicz, Ewa; Podlewska-Gaca, Edyta

    2012-06-01

    The recent increase in number of known multi-planet systems gives a unique opportunity to study the processes responsible for planetary formation and evolution. Special attention is given to the occurrence of mean-motion resonances, because they carry important information about the history of the planetary systems. At the early stages of the evolution, when planets are still embedded in a gaseous disc, the tidal interactions between the disc and planets cause the planetary orbital migration. The convergent differential migration of two planets embedded in a gaseous disc may result in the capture into a mean-motion resonance. The orbital migration taking place during the early phases of the planetary system formation may play an important role in shaping stable planetary configurations. An understanding of this stage of the evolution will provide insight on the most frequently formed architectures, which in turn are relevant for determining the planet habitability. The aim of this paper is to present the observational properties of these planetary systems which contain confirmed or suspected resonant configurations. A complete list of known systems with such configurations is given. This list will be kept by us updated from now on and it will be a valuable reference for studying the dynamics of extrasolar systems and testing theoretical predictions concerned with the origin and the evolution of planets, which are the most plausible places for existence and development of life. PMID:22684330

  8. Automatic Feature Extraction from Planetary Images

    NASA Technical Reports Server (NTRS)

    Troglio, Giulia; Le Moigne, Jacqueline; Benediktsson, Jon A.; Moser, Gabriele; Serpico, Sebastiano B.

    2010-01-01

    With the launch of several planetary missions in the last decade, a large amount of planetary images has already been acquired and much more will be available for analysis in the coming years. The image data need to be analyzed, preferably by automatic processing techniques because of the huge amount of data. Although many automatic feature extraction methods have been proposed and utilized for Earth remote sensing images, these methods are not always applicable to planetary data that often present low contrast and uneven illumination characteristics. Different methods have already been presented for crater extraction from planetary images, but the detection of other types of planetary features has not been addressed yet. Here, we propose a new unsupervised method for the extraction of different features from the surface of the analyzed planet, based on the combination of several image processing techniques, including a watershed segmentation and the generalized Hough Transform. The method has many applications, among which image registration and can be applied to arbitrary planetary images.

  9. Aerobots and Hydrobots for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Barrett, Chris

    2000-01-01

    In this new Millennium, NASA will expand its presence in space. Many new planetary bodies have been discovered, and some previously known bodies are now believed to have oceans. We now know of 66 moons in our own Solar System, one with an atmosphere, 16 with water ice or oceans, and 5 with both. In addition, we now know of 20 extra-solar planets. In order to expand our presence in space and explore in a cost effective manner, we need a repertoire of new types of planetary exploration vehicles to explore both atmospheres and oceans. To address this need a spectrum of new classes of vehicles are being developed. These include aerobots and hydrobots, and incorporate Department of Defense miniaturization developments and smart materials. This paper outlines: the remarkable miniaturization developments applicable to robotic vehicles for the exploration of planetary atmospheres and oceans; Aerobots, the vehicles designed for planetary atmospheric exploration; Hydrobots, those designed for planetary ocean exploration; planetary atmospheric data; and Europa ocean exploration missions.

  10. Synthesizing Earth's geochemical data for hydrogeochemical analysis

    NASA Astrophysics Data System (ADS)

    Brantley, S. L.; Kubicki, J.; Miller, D.; Richter, D.; Giles, L.; Mitra, P.

    2007-12-01

    For over 200 years, geochemical, microbiological, and chemical data have been collected to describe the evolution of the surface earth. Many of these measurements are data showing variations in time or in space. To forward predict hydrologic response to changing tectonic, climatic, or anthropogenic forcings requires synthesis of these data and utilization in hydrogeochemical models. Increasingly, scientists are attempting to synthesize such data in order to make predictions for new regions or for future time periods. However, to make such complex geochemical data accessible requires development of sophisticated cyberinfrastructures that both invite uploading as well as usage of data. Two such cyberinfrastructure (CI) initiatives are currently developing, one to invite and promote the use of environmental kinetics data (laboratory time course data) through ChemxSeer, and the other to invite and promote the use of spatially indexed geochemical data for the Earth's Critical Zone through CZEN.org. The vision of these CI initiatives is to provide cyber-enhanced portals that encourage domain scientists to upload their data before publication (in private cyberspace), and to make these data eventually publicly accessible (after an embargo period). If the CI can be made to provide services to the domain specialist - e.g. to provide data analysis services or data comparison services - we envision that scientists will upload data. In addition, the CI can promote the use and comparison of datasets across disciplines. For example, the CI can facilitate the use of spatially indexed geochemical data by scientists more accustomed to dealing with time-course data for hydrologic flow, and can provide user-friendly interfaces with CI established to facilitate the use of hydrologic data. Examples of the usage of synthesized data to predict soil development over the last 13ky and its effects on active hydrological flow boundaries in surficial systems will be discussed for i) a N

  11. Geochemical patterns in the soils of Cyprus.

    PubMed

    Cohen, David R; Rutherford, Neil F; Morisseau, Eleni; Zissimos, Andreas M

    2012-03-15

    The soil geochemical atlas of Cyprus is a recent addition to the series of national to continental-scale geochemical mapping programmes implemented over the last two decades for environmental and resource applications. The study has been conducted at the high sampling density of 1 site per 1km(2), with multi-element and multi-method analysis performed on samples of top soil (0-25cm) and sub soil (50-75cm) from a grid of over 5350 sites across a major portion of Cyprus. Major and most trace elements display sharp concentration changes across the main geological boundaries but a high degree of spatial continuity and consistency of values within those boundaries. Some elements display one to two orders of magnitude difference in median concentrations between the soils developed over ultramafic or mafic units and those developed over sedimentary rocks or alluvial units. The ratio of aqua regia-extractable to total metal contents provides an indication of the general mineralogical host for a number of trace elements. The majority of soils are near-neutral to alkaline with the small proportion of areas with soil pH<5 largely restricted to the major Cu deposits. There is strong correlation between top soil and sub soil geochemical values. Where the concentrations of some elements (including Pb, Hg and Sn) are indicative of contamination, the values are typically higher in the top soil samples in these areas. Variations in the concentration of elements with strong redox controls on mobility are linked to changes in sedimentary environment between deep and shallow marine conditions. Some element patterns can be related to the effects of urbanisation and sulphide mining operations; however the dominant control on soil geochemistry is the parent geology and regolith forming processes. The atlas demonstrates the effectiveness of high-density sampling in mapping local to regional-scale features of the geochemical landscape. PMID:22330424

  12. Summary report on geochemical barrier special study

    SciTech Connect

    Not Available

    1988-12-01

    Long-term management of uranium mill tailings must provide assurance that soluble contaminants will not migrate beyond the Point of Compliance. Conventional management alternatives provide containment through the use of physical barriers which are designed to prevent migration of water through the tailings pile. An alternative is to geochemically modify the tailings to immobilize the contaminants. This investigation examined three potential geochemical modifiers to determine their ability to immobilize inorganic groundwater contaminants found in uranium mill tailings. These modifiers were hydrated lime (Ca(OH){sub 2}), limestone (CaCO{sub 3}), and a sphaegnum peat moss. This investigation focused on both the geochemical interactions between the tailings and the modifiers, and the effects the modifiers had on the physical strength of the tailings. The geochemical investigations began with characterization of the tailings by X-ray diffraction and scanning electron microscopy. This was followed by batch leaching experiments in which various concentrations of each modifier were added to tailings in shaker flasks and allowed to come to equilibrium. Finally, column experiments were conducted to simulate flow through a tailings pile. The results show that all of the modifiers were at least moderately effective at immobilizing most of the groundwater contaminants of concern at uranium mill tailings sites. Hydrated lime was able to achieve 90 percent concentration reduction of arsenic, cadmium, selenium, uranium, and sulfate when added at a two percent concentration. Limestone was somewhat less effective and peat removed greater than 90 percent of arsenic, lead, uranium, and sulfate at a one percent concentration. The column tests showed that kinetic and/or mass transfer limitations are important and that sufficient time must be allowed for the immobilization reactions to occur.

  13. Planetary Geologic Mapping Handbook - 2010. Appendix

    NASA Technical Reports Server (NTRS)

    Tanaka, K. L.; Skinner, J. A., Jr.; Hare, T. M.

    2010-01-01

    Geologic maps present, in an historical context, fundamental syntheses of interpretations of the materials, landforms, structures, and processes that characterize planetary surfaces and shallow subsurfaces. Such maps also provide a contextual framework for summarizing and evaluating thematic research for a given region or body. In planetary exploration, for example, geologic maps are used for specialized investigations such as targeting regions of interest for data collection and for characterizing sites for landed missions. Whereas most modern terrestrial geologic maps are constructed from regional views provided by remote sensing data and supplemented in detail by field-based observations and measurements, planetary maps have been largely based on analyses of orbital photography. For planetary bodies in particular, geologic maps commonly represent a snapshot of a surface, because they are based on available information at a time when new data are still being acquired. Thus the field of planetary geologic mapping has been evolving rapidly to embrace the use of new data and modern technology and to accommodate the growing needs of planetary exploration. Planetary geologic maps have been published by the U.S. Geological Survey (USGS) since 1962. Over this time, numerous maps of several planetary bodies have been prepared at a variety of scales and projections using the best available image and topographic bases. Early geologic map bases commonly consisted of hand-mosaicked photographs or airbrushed shaded-relief views and geologic linework was manually drafted using mylar bases and ink drafting pens. Map publishing required a tedious process of scribing, color peel-coat preparation, typesetting, and photo-laboratory work. Beginning in the 1990s, inexpensive computing, display capability and user-friendly illustration software allowed maps to be drawn using digital tools rather than pen and ink, and mylar bases became obsolete. Terrestrial geologic maps published by

  14. Fictitious Supercontinent Cycles

    NASA Astrophysics Data System (ADS)

    Marvin Herndon, J.

    2014-05-01

    "Supercontinent cycles" or "Wilson cycles" is the idea that before Pangaea there were a series of supercontinents that each formed and then broke apart and separated before colliding again, re-aggregating, and suturing into a new supercontinent in a continuing sequence. I suggest that "supercontinent cycles" are artificial constructs, like planetary orbit epicycles, attempts to describe geological phenomena within the framework of problematic paradigms, namely, planetesimal Earth formation and plate tectonics' mantle convection. The so-called 'standard model of solar system formation' is problematic as it would lead to insufficiently massive planetary cores and necessitates additional ad hoc hypotheses such as the 'frost line' between Mars and Jupiter to explain planetary differences and whole-planet melting to explain core formation from essentially undifferentiated matter. The assumption of mantle convection is crucial for plate tectonics, not only for seafloor spreading, but also for continental movement; continent masses are assumed to ride atop convection cells. In plate tectonics, plate collisions are thought to be the sole mechanism for fold-mountain formation. Indeed, the occurrence of mountain chains characterized by folding which significantly predate the breakup of Pangaea is the primary basis for assuming the existence of supercontinent cycles with their respective periods of ancient mountain-forming plate collisions. Mantle convection is physically impossible. Rayleigh Number justification has been misapplied. The mantle bottom is too dense to float to the surface by thermal expansion. Sometimes attempts are made to obviate the 'bottom heavy' prohibition by adopting the tacit assumption that the mantle behaves as an ideal gas with no viscous losses, i.e., 'adiabatic'. But the mantle is a solid that does not behave as an ideal gas as evidenced by earthquakes occurring at depths as great as 660 km. Absent mantle convection, plate tectonics is not valid

  15. The frequency and chemical composition of rocky planetary debris around young white dwarfs: Plugging the last gaps

    NASA Astrophysics Data System (ADS)

    Gaensicke, Boris

    2014-10-01

    Many planetary systems will survive the post main-sequence evolution of their host stars into white dwarfs (WDs). In the solar system, Mars, the asteroid belt, and the outer planets will eventually orbit the WD remnant of the Sun, and many WDs are known to have remnants of planetary systems. Historically, planetary debris was detected in ~20% of WDs with cooling ages >0.5Gyr from Ca K detections. However, the Ca II ionisation balance makes the ground-based detection of planetary debris at younger, hotter WDs impossible.We have carried out a very successful Cycle 18/19 COS snapshot survey of 100 WDs with cooling ages of 20-200Myr, and detect metal pollution in up to 50% of all targets via the strong Si resonance lines. This survey also showed that terrestrial material is common around A-stars, that rocky exo-planetary bodies display a similar variety in abundances as the meteorites in our solar system, and that water-rich Ceres-like asteroids still exist in evolved planetary systems. We propose to close the last gaps in the statistics of evolved planetary systems: an extension of our snapshot survey to cooling ages of 5-25Myr and 100-300Myr. Our orbital integrations suggest that mass-loss during the AGB phase can stirr up instabilities leading to planet-planet collisions, which should be most frequent during the first 10Myr, and the proposed observations will unambiguously test these predictions. In addition, the extended sample will improve the statistics on the formation of planetary systems as a function of host star mass, and build up a deeper insight into the abundances of rocky exo-planetary material that will guide models of terrestrial planet formation

  16. Menstrual Cycle

    MedlinePlus

    ... Pregnancy This information in Spanish ( en español ) The menstrual cycle Day 1 starts with the first day of ... drop around Day 25 . This signals the next menstrual cycle to begin. The egg will break apart and ...

  17. Controls on OIB and MORB Geochemical Variabilty

    NASA Astrophysics Data System (ADS)

    Shorttle, O.; Maclennan, J.

    2014-12-01

    The geochemical variability preserved in Ocean Island and Mid-ocean ridge basalt (MORB) is a key tracer of the magmatic storage and transport processes they experience during their ascent through the mantle and crust. The effect of these processes is to collapse the huge diversity of melt compositions predicted to form during polybaric fractional melting of a lithologically heterogeneous mantle, into the narrow range we see expressed in most ocean island and mid-ocean ridge settings. Magma mixing can therefore be seen as contaminating the variance structure of primitive mantle melts, akin to the way in which wall-rock assimilation contaminates melts by chemical addition. The key observation from the melt inclusion and whole-rock records from ocean islands such as Iceland, is that as crystallisation proceeds mixing in magma chambers progressively reduces geochemical variability, until by ~5wt% MgO almost all primary chemical diversity has been lost. These chemical systematics allow us to extend the observations made at ocean islands to make predictions about how mixing processes should operate in MORB generally and the key factors controlling mixing efficiency: melt flow out of the mantle, crustal thickness, magma supply rate, and by extension spreading rate, and mantle potential temperature. However, with its low sampling density, the global MORB database does not easily allow testing of these hypotheses. We have developed a novel geospatial statistical analysis to bridge the gap between observations made on a small scale - at single ocean islands and ridge segments - to the entire global dataset of MORB chemistry. By analysing the geochemical variance in MORB over a range of bandwidths we have captured the ~200km lengthscale at which the simple relationships between geochemical variability and MgO appear. Our results demonstrate that on short lengthscales mantle chemical structure and magmatic processes operate coherently in destruction of geochemical variability

  18. Ranking Geochemical Energy Availability in Hydrothermal Ecosystems

    NASA Astrophysics Data System (ADS)

    Holland, M. E.; Shock, E. L.; Meyer-Dombard, D.; Amend, J. P.

    2004-12-01

    The energy available to hyperthermophilic microorganisms in hot springs can be theoretically estimated using thermodynamic calculations based on geochemical measurements. The relative abundance of different geochemical energy sources (the "ranking" of these reactions) in particular hot springs may provide one explanation for the differences in hot spring microbial communities and also facilitate the culture of ecologically-relevant microorganisms. Geochemical sampling of seven Yellowstone National Park hot springs was repeated five times from 1999 to 2004 with the intent to compare the geochemistry and geochemical energy available to microorganisms. These seven hot springs were located in three separate regions of Yellowstone National Park: three hot springs, including Obsidian Pool, were sampled in the Mud Volcano area; two in the Sylvan Springs area (Gibbon Meadows); and one each in Imperial Meadows and Sentinel Meadows (Lower Geyser Basin). The hot springs were 75 to 93° C (with one 65° C exception) and spanned the bulk of the pH range at Yellowstone (pH 1.8 to 7.6). Geochemical measurements made on hot springs included redox-active species containing C, N, O, H, S, and Fe; these species were measured by field spectrophotometry and ion chromatography of fluid samples and gas chromatographic analysis of gas samples. From these measurements chemical affinities were calculated for 179 inorganic reactions which encompass the suite of autotrophic energy sources potentially available in each pool. Composite affinities for each reaction were compiled for each of the seven primary pools. The composite for each pool was assembled from repeat measurements from the primary pool as well as nearby pools with similar geochemistry. Calculations show that over half of these inorganic reactions could provide enough energy for a microorganism to survive, based on the threshold value of energy required by {it E. coli} (20 kJ per mole of electron pairs). Some microorganisms

  19. Extrasolar Planetary Imaging Coronagraph (EPIC)

    NASA Astrophysics Data System (ADS)

    Clampin, Mark; Melnick, Gary; Lyon, Richard; Kenyon, Scott; Sasselov, Dimitar; Tolls, Volker; Ford, Holland; Golimowski, David; Petro, Larry; Hartig, George; Sparks, William; Illingworth, Garth; Lin, Doug; Seager, Sara; Weinberger, Alycia; Harwit, Martin; Marley, Mark; Schneider, Jean; Shao, Michael; Levine, Marty; Ge, Jian; Woodruff, Robert

    2006-06-01

    The Extrasolar Planetary Imaging Coronagraph (EPIC) is a proposed NASA Discovery mission to image and characterize extrasolar giant planets in orbits with semi-major axes between 2 and 10 AU. EPIC will provide insights into the physical nature of a variety of planets in other solar systems complimenting radial velocity (RV) and astrometric planet searches. It will detect and characterize the atmospheres of planets identified by radial velocity surveys, determine orbital inclinations and masses, characterize the atmospheres around A and F type stars which cannot be found with RV techniques, and observe the inner spatial structure and colors of debris disks. EPIC has a proposed launch date of 2012 to heliocentric Earth trailing drift-away orbit, with a 3 year mission lifetime (5 year goal), and will revisit planets at least three times at intervals of 9 months. The robust mission design is simple and flexible ensuring mission success while minimizing cost and risk. The science payload consists of a heritage optical telescope assembly (OTA), and visible nulling coronagraph (VNC) instrument. The instrument achieves a contrast ratio of 109 over a 4.84 arcsecond field-of-view with an unprecedented inner working angle of 0.14 arcseconds over the spectral range of 440-880 nm, with spectral resolutions from 10 - 150. The telescope is a 1.5 meter offaxis Cassegrain with an OTA wavefront error of λ/9, which when coupled to the VNC greatly reduces the requirements on the large scale optics, compressing them to stability requirements within the relatively compact VNC optical chain. The VNC features two integrated modular nullers, a spatial filter array (SFA), and an E2V-L3 photon counting CCD. Direct null control is accomplished from the science focal mitigating against complex wavefront and amplitude sensing and control strategies.

  20. Geophysics of Small Planetary Bodies

    NASA Technical Reports Server (NTRS)

    Asphaug, Erik I.

    1998-01-01

    As a SETI Institute PI from 1996-1998, Erik Asphaug studied impact and tidal physics and other geophysical processes associated with small (low-gravity) planetary bodies. This work included: a numerical impact simulation linking basaltic achondrite meteorites to asteroid 4 Vesta (Asphaug 1997), which laid the groundwork for an ongoing study of Martian meteorite ejection; cratering and catastrophic evolution of small bodies (with implications for their internal structure; Asphaug et al. 1996); genesis of grooved and degraded terrains in response to impact; maturation of regolith (Asphaug et al. 1997a); and the variation of crater outcome with impact angle, speed, and target structure. Research of impacts into porous, layered and prefractured targets (Asphaug et al. 1997b, 1998a) showed how shape, rheology and structure dramatically affects sizes and velocities of ejecta, and the survivability and impact-modification of comets and asteroids (Asphaug et al. 1998a). As an affiliate of the Galileo SSI Team, the PI studied problems related to cratering, tectonics, and regolith evolution, including an estimate of the impactor flux around Jupiter and the effect of impact on local and regional tectonics (Asphaug et al. 1998b). Other research included tidal breakup modeling (Asphaug and Benz 1996; Schenk et al. 1996), which is leading to a general understanding of the role of tides in planetesimal evolution. As a Guest Computational Investigator for NASA's BPCC/ESS supercomputer testbed, helped graft SPH3D onto an existing tree code tuned for the massively parallel Cray T3E (Olson and Asphaug, in preparation), obtaining a factor xIO00 speedup in code execution time (on 512 cpus). Runs which once took months are now completed in hours.

  1. The Language of Planetary Light

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This graph of data from NASA's Spitzer Space telescope shows changes in the infrared light output of two star-planet systems (one above, one below) located hundreds of light-years away. The data were taken while the planets, called HD 209458b and TrES-1, disappeared behind their stars in what is called a 'secondary eclipse.' The dip seen in the center of each graph represents the time when the planets were eclipsed, and tells astronomers exactly how much light they emit.

    Why a secondary eclipse? When a planet transits, or passes in front of, its star, it partially blocks the light of the star. When the planet swings around behind the star, the star completely blocks its light. This drop in total light can be measured to determine the amount of light coming from just the planet.

    Why infrared? In visible light, the glare of a star overwhelms its planetary companion and the little light the planet reflects. In infrared, a star shines less brightly, and its planet gives off its own internal light, or heat radiation, making the planet easier to detect.

    By observing these secondary eclipses at different infrared wavelengths, astronomers can obtain the planet's temperature, and, in the future, they may be able to pick out chemicals sprinkled throughout a planet's atmosphere. The technique also reveals whether a planet's orbit is elongated or circular.

    This strategy will not work for all known extrasolar planets. It is ideally suited to study those Jupiter-sized planets previously discovered to cross, or transit, between us and the Sun-like stars they orbit, out to distances of 500 light-years. NASA's Spitzer Space Telescope was the first to successfully employ this technique.

    The data of HD 209458b were taken by Spitzer's multiband imaging photometer using the 24-micron array. The data of TrES-1 were taken by Spitzer's infrared array camera using the 8-micron array.

  2. Turning Planetary Theory Upside Down

    NASA Astrophysics Data System (ADS)

    2010-04-01

    The discovery of nine new transiting exoplanets is announced today at the RAS National Astronomy Meeting (NAM2010). When these new results were combined with earlier observations of transiting exoplanets astronomers were surprised to find that six out of a larger sample of 27 were found to be orbiting in the opposite direction to the rotation of their host star - the exact reverse of what is seen in our own Solar System. The new discoveries provide an unexpected and serious challenge to current theories of planet formation. They also suggest that systems with exoplanets of the type known as hot Jupiters are unlikely to contain Earth-like planets. "This is a real bomb we are dropping into the field of exoplanets," says Amaury Triaud, a PhD student at the Geneva Observatory who, with Andrew Cameron and Didier Queloz, leads a major part of the observational campaign. Planets are thought to form in the disc of gas and dust encircling a young star. This proto-planetary disc rotates in the same direction as the star itself, and up to now it was expected that planets that form from the disc would all orbit in more or less the same plane, and that they would move along their orbits in the same direction as the star's rotation. This is the case for the planets in the Solar System. After the initial detection of the nine new exoplanets [1] with the Wide Angle Search for Planets (WASP, [2]), the team of astronomers used the HARPS spectrograph on the 3.6-metre ESO telescope at the La Silla observatory in Chile, along with data from the Swiss Euler telescope, also at La Silla, and data from other telescopes to confirm the discoveries and characterise the transiting exoplanets [3] found in both the new and older surveys. Surprisingly, when the team combined the new data with older observations they found that more than half of all the hot Jupiters [4] studied have orbits that are misaligned with the rotation axis of their parent stars. They even found that six exoplanets in this

  3. Turning Planetary Theory Upside Down

    NASA Astrophysics Data System (ADS)

    2010-04-01

    The discovery of nine new transiting exoplanets is announced today at the RAS National Astronomy Meeting (NAM2010). When these new results were combined with earlier observations of transiting exoplanets astronomers were surprised to find that six out of a larger sample of 27 were found to be orbiting in the opposite direction to the rotation of their host star - the exact reverse of what is seen in our own Solar System. The new discoveries provide an unexpected and serious challenge to current theories of planet formation. They also suggest that systems with exoplanets of the type known as hot Jupiters are unlikely to contain Earth-like planets. "This is a real bomb we are dropping into the field of exoplanets," says Amaury Triaud, a PhD student at the Geneva Observatory who, with Andrew Cameron and Didier Queloz, leads a major part of the observational campaign. Planets are thought to form in the disc of gas and dust encircling a young star. This proto-planetary disc rotates in the same direction as the star itself, and up to now it was expected that planets that form from the disc would all orbit in more or less the same plane, and that they would move along their orbits in the same direction as the star's rotation. This is the case for the planets in the Solar System. After the initial detection of the nine new exoplanets [1] with the Wide Angle Search for Planets (WASP, [2]), the team of astronomers used the HARPS spectrograph on the 3.6-metre ESO telescope at the La Silla observatory in Chile, along with data from the Swiss Euler telescope, also at La Silla, and data from other telescopes to confirm the discoveries and characterise the transiting exoplanets [3] found in both the new and older surveys. Surprisingly, when the team combined the new data with older observations they found that more than half of all the hot Jupiters [4] studied have orbits that are misaligned with the rotation axis of their parent stars. They even found that six exoplanets in this

  4. A geochemical atlas of South Carolina--an example using data from the National Geochemical Survey

    USGS Publications Warehouse

    Sutphin, David M.

    2005-01-01

    National Geochemical Survey data from stream-sediment and soil samples, which have been analyzed using consistent methods, were used to create maps, graphs, and tables that were assembled in a consistent atlas format that characterizes the distribution of major and trace chemical elements in South Carolina. Distribution patterns of the elements in South Carolina may assist mineral exploration, agriculture, waste-disposal-siting issues, health, environmental, and other studies. This atlas is an example of how data from the National Geochemical Survey may be used to identify general or regional patterns of elemental occurrences and to provide a snapshot of element concentration in smaller areas.

  5. The biogeochemistry of metal cycling

    NASA Technical Reports Server (NTRS)

    Nealson, Kenneth H. (Editor); Nealson, Molly (Editor); Dutcher, F. Ronald (Editor)

    1990-01-01

    The results of the Planetary Biology and Microbial Ecology's summer 1987 program are summarized. The purpose of the interdisciplinary PBME program is to integrate, via lectures and laboratory work, the contributions of university and NASA scientists and student interns. The 1987 program examined various aspects of the biogeochemistry of metal cycling, and included such areas as limnology, metal chemistry, metal geochemistry, microbial ecology, and interactions with metals. A particular area of focus was the use of remote sensing in the study of biogeochemistry. Abstracts and bibliographies of the lectures and reports of the laboratory projects are presented.

  6. Europlanet Research Infrastructure: Planetary Simulation Facilities

    NASA Astrophysics Data System (ADS)

    Davies, G. R.; Mason, N. J.; Green, S.; Gómez, F.; Prieto, O.; Helbert, J.; Colangeli, L.; Srama, R.; Grande, M.; Merrison, J.

    2008-09-01

    EuroPlanet The Europlanet Research Infrastructure consortium funded under FP7 aims to provide the EU Planetary Science community greater access for to research infrastructure. A series of networking and outreach initiatives will be complimented by joint research activities and the formation of three Trans National Access distributed service laboratories (TNA's) to provide a unique and comprehensive set of analogue field sites, laboratory simulation facilities, and extraterrestrial sample analysis tools. Here we report on the infrastructure that comprises the second TNA; Planetary Simulation Facilities. 11 laboratory based facilities are able to recreate the conditions found in the atmospheres and on the surfaces of planetary systems with specific emphasis on Martian, Titan and Europa analogues. The strategy has been to offer some overlap in capabilities to ensure access to the highest number of users and to allow for progressive and efficient development strategies. For example initial testing of mobility capability prior to the step wise development within planetary atmospheres that can be made progressively more hostile through the introduction of extreme temperatures, radiation, wind and dust. Europlanet Research Infrastructure Facilties: Mars atmosphere simulation chambers at VUA and OU These relatively large chambers (up to 1 x 0.5 x 0.5 m) simulate Martian atmospheric conditions and the dual cooling options at VUA allows stabilised instrument temperatures while the remainder of the sample chamber can be varied between 220K and 350K. Researchers can therefore assess analytical protocols for instruments operating on Mars; e.g. effect of pCO2, temperature and material (e.g., ± ice) on spectroscopic and laser ablation techniques while monitoring the performance of detection technologies such as CCD at low T & variable p H2O & pCO2. Titan atmosphere and surface simulation chamber at OU The chamber simulates Titan's atmospheric composition under a range of

  7. Japanese contributions to International Planetary Data Alliance

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yukio; Kasaba, Yasumasa; Hirata, Naru; Shinohara, Iku

    2012-07-01

    In this presentation, we will introduce Japanese contributions to the data archives for international collaborations. In Japan, the importance of planetary data archive was not recognized enough until early in 2000's. While NASA and ESA started their collaborations to their archives: PDS and PSA, and tried to make the new standard, JAXA was looking for the way of contributions because Japan did not have own data and archiving policy. The activities of NASA and ESA extended to the international collaborations, and International Planetary Data Alliance was established. JAXA had an opportunity to join the IPDA as an agency member. One of the contributions, the IPDA chairman was undertaken by Japanese member. The projects in IPDA were managed and were proceeded successfully during the term. For the technical part, JAXA is making several pilot systems to share planetary data. Planetary Data Access Protocol, PDAP, developed by IPDA, is implemented in JAXA's system, and provides a search system for Hayabusa and Kaguya (SELENE) data. Not only for Japanese data, but also Apollo's seismic data archives are prepared for scientific communities. The seismic data on the moon has not been measured for a long time, and Apollo's data are still precious and should be archived together with much information. The contributions to planetary data archives has just started and continues as a member of IPDA.

  8. Architectures of Planetary System - Snapshots in Time

    NASA Astrophysics Data System (ADS)

    Montgomery, Michele; Goel, Amit

    2015-08-01

    Architectures of planetary systems are observable snapshots in time, a study of which can aide in our understanding of how planetary systems form and evolve dynamically. For example, if we compare architectures of exoplanetary systems having various stellar host ages with laws that apply to our own Solar System architecture, population, and age, we gain insights into when these laws hold with stellar age and which systems are outliers at various stellar ages. In this work, we study Keplerian motion in confirmed planetary systems as a function of stellar age. Systems eliminated from the study are those with unknown planetary orbital periods, unknown planetary semi-major axis, and/or unknown stellar ages, the latter of which eliminates several Kepler multi-planet systems. As expected, we find Keplerian motion holds for systems that are the age of the Solar System or older, but this result does not seem to hold true for younger systems. In this work we discuss these findings, we identify the outlier systems at various stellar ages from our statistical analysis, and we provide explanations as to why these exo-systems are outliers.

  9. Identifying chemicals that are planetary boundary threats.

    PubMed

    MacLeod, Matthew; Breitholtz, Magnus; Cousins, Ian T; de Wit, Cynthia A; Persson, Linn M; Rudén, Christina; McLachlan, Michael S

    2014-10-01

    Rockström et al. proposed a set of planetary boundaries that delimit a "safe operating space for humanity". Many of the planetary boundaries that have so far been identified are determined by chemical agents. Other chemical pollution-related planetary boundaries likely exist, but are currently unknown. A chemical poses an unknown planetary boundary threat if it simultaneously fulfills three conditions: (1) it has an unknown disruptive effect on a vital Earth system process; (2) the disruptive effect is not discovered until it is a problem at the global scale, and (3) the effect is not readily reversible. In this paper, we outline scenarios in which chemicals could fulfill each of the three conditions, then use the scenarios as the basis to define chemical profiles that fit each scenario. The chemical profiles are defined in terms of the nature of the effect of the chemical and the nature of exposure of the environment to the chemical. Prioritization of chemicals in commerce against some of the profiles appears feasible, but there are considerable uncertainties and scientific challenges that must be addressed. Most challenging is prioritizing chemicals for their potential to have a currently unknown effect on a vital Earth system process. We conclude that the most effective strategy currently available to identify chemicals that are planetary boundary threats is prioritization against profiles defined in terms of environmental exposure combined with monitoring and study of the biogeochemical processes that underlie vital Earth system processes to identify currently unknown disruptive effects. PMID:25181298

  10. Access to the Online Planetary Research Literature

    NASA Astrophysics Data System (ADS)

    Henneken, E. A.; Accomazzi, A.; Kurtz, M. J.; Grant, C. S.; Thompson, D.; Di Milia, G.; Bohlen, E.; Murray, S. S.

    2009-12-01

    The SAO/NASA Astrophysics Data System (ADS) provides various free services for finding, accessing, and managing bibliographic data, including a basic search form, the myADS notification service, and private library capabilities (a useful tool for building bibliographies), plus access to scanned pages of published articles. The ADS also provides powerful search capabilities, allowing users to find e.g. the most instructive or most important articles on a given subject . For the Planetary Sciences, the citation statistics of the ADS have improved considerably with the inclusion of the references from Elsevier journals, including Icarus, Planetary and Space Science, and Earth and Planetary Science Letters. We currently have about 78 journals convering the planetary and space sciences (Advances in Space Research, Icarus, Solar Physics, Astrophusics and Space Science, JGRE, Meteoritics, to name a few). Currently, this set of journals represents about 180,000 articles and 1.1 million references. Penetration into the Solar Physics, Planetary Sciences and Geophysics community has increased significantly. During the period 2004-2008, user access to JGR and Icarus increased by a factor of 4.4, while e.g. access to the Astrophysical Journal "only" increased by a factor of 1.8.

  11. Parallel Architectures for Planetary Exploration Requirements (PAPER)

    NASA Technical Reports Server (NTRS)

    Cezzar, Ruknet; Sen, Ranjan K.

    1989-01-01

    The Parallel Architectures for Planetary Exploration Requirements (PAPER) project is essentially research oriented towards technology insertion issues for NASA's unmanned planetary probes. It was initiated to complement and augment the long-term efforts for space exploration with particular reference to NASA/LaRC's (NASA Langley Research Center) research needs for planetary exploration missions of the mid and late 1990s. The requirements for space missions as given in the somewhat dated Advanced Information Processing Systems (AIPS) requirements document are contrasted with the new requirements from JPL/Caltech involving sensor data capture and scene analysis. It is shown that more stringent requirements have arisen as a result of technological advancements. Two possible architectures, the AIPS Proof of Concept (POC) configuration and the MAX Fault-tolerant dataflow multiprocessor, were evaluated. The main observation was that the AIPS design is biased towards fault tolerance and may not be an ideal architecture for planetary and deep space probes due to high cost and complexity. The MAX concepts appears to be a promising candidate, except that more detailed information is required. The feasibility for adding neural computation capability to this architecture needs to be studied. Key impact issues for architectural design of computing systems meant for planetary missions were also identified.

  12. Fourier transform spectroscopy for future planetary missions

    NASA Astrophysics Data System (ADS)

    Brasunas, John C.; Hewagama, Tilak; Kolasinski, John R.; Kostiuk, Theodor

    2015-11-01

    Thermal-emission infrared spectroscopy is a powerful tool for exploring the composition, temperature structure, and dynamics of planetary atmospheres; and the temperature of solid surfaces. A host of Fourier transform spectrometers (FTS) such as Mariner IRIS, Voyager IRIS, and Cassini CIRS from NASA Goddard have made and continue to make important new discoveries throughout the solar system.Future FTS instruments will have to be more sensitive (when we concentrate on the colder, outer reaches of the solar system), and less massive and less power-hungry as we cope with decreasing resource allotments for future planetary science instruments. With this in mind, NASA Goddard was funded via the Planetary Instrument Definition and Development Progrem (PIDDP) to develop CIRS-lite, a smaller version of the CIRS FTS for future planetary missions. Following the initial validation of CIRS-lite operation in the laboratory, we have been acquiring atmospheric data in the 8-12 micron window at the 1.2 m telescope at the Goddard Geophysical and Astronomical Observatory (GGAO) in Greenbelt, MD. Targets so far have included Earth's atmosphere (in emission, and in absorption against the moon), and Venus.We will present the roadmap for making CIRS-lite a viable candidate for future planetary missions.

  13. Daly Lecture: Geochemical Insights into Mantle Geodynamics and Plume Structure (Invited)

    NASA Astrophysics Data System (ADS)

    Weis, D. A.

    2010-12-01

    with time (such as an increase of Pb isotopic ratios). Hawaiian post-shield and rejuvenated lavas have more Kea-like geochemical characteristics than the underlying shield lavas with only two exceptions. Their isotopic compositions are much less variable and extend towards more depleted values that depart from the shield mixing trends and that do not intersect MORB-type compositions. Comparable observations have been made on other oceanic islands [6] and this implies that the depleted component in mantle plumes is distinct from the MORB source, and is most likely unique to each plume. These results from Hawaii will be compared to other hotspots in different tectonic settings, such as Kerguelen, Galapagos, and Iceland, and some implications for mantle geodynamics will be discussed. [1] Gast et al. (1964) Science 145, 1181-1185. [2] Tatsumoto (1978) Earth and Planetary Science Letters 38, 63-87. [3] Abouchami et al. (2005) Nature 434, 3401-3406. [4] Weis et al. (2009) Eos Trans. AGU, 90(52), Abstract V41F-03. [5] Farnetani and Hofmann (2009, 2010) Earth and Planetary Science Letters 282, 314-322; 295, 231-240. [6] White (2010) Annual Review of Earth and Planetary Sciences 38, 133-160.

  14. Optical Communications from Planetary Distances

    NASA Technical Reports Server (NTRS)

    Davarian, F.; Farr, W.; Hemmati, H.; Piazzolla, S.

    2008-01-01

    Future planetary campaigns, including human missions, will require data rates difficult to realize by microwave links. Optical channels not only provide an abundance of bandwidth, they also allow for significant size, weight, and power reduction. Moreover, optical-based tracking may enhance spacecraft navigation with respect to microwave-based tracking. With all its advantages, optical communications from deep space is not without its challenges. Due to the extreme distance between the two ends of the link, specialized technologies are needed to enable communications in the deep space environment. Although some of the relevant technologies have been developed in the last decade, they remain to be validated in an appropriate domain. The required assets include efficient pulsed laser sources, modulators, transmitters, receivers, detectors, channel encoders, precise beam pointing technologies for the flight transceiver and large apertures for the ground receiver. Clearly, space qualification is required for the systems that are installed on a deep space probe. Another challenge is atmospheric effects on the optical beam. Typical candidate locations on the ground have a cloud-free line of sight only on the order of 60-70% of the time. Furthermore, atmospheric losses and background light can be problematic even during cloud-free periods. Lastly, operational methodologies are needed for efficient and cost effective management of optical links. For more than a decade, the National Aeronautics and Space Administration (NASA) has invested in relevant technologies and procedures to enable deep space optical communications capable of providing robust links with rates in the order of 1 Gb/s from Mars distance. A recent publication indicates that potential exists for 30-dB improvement in performance through technology development with respect to the state-of-the-art in the early years of this decade. The goal is to fulfill the deep space community needs from about 2020 to the

  15. Ideas for a three-aircraft planetary observing fleet

    NASA Astrophysics Data System (ADS)

    Carlson, David J.; Schumann, Ulrich

    2003-04-01

    A new generation of research aircraft, based on modern mid-sized business jets, will provide access to upper regions of the atmosphere and remote regions of the planet not reachable by the current research aircraft. Equipped with extensive research modifications, modern instruments, and advanced air-to-ground communication systems, these new aircraft will allow investigators to attack key questions in global atmospheric dynamics, global cycles of water and carbon, global energy budgets, and regional and global air quality and chemical transport. A three-aircraft fleet of these aircraft could provide unprecedented coordinated intercalibrated coverage of the planetary atmosphere and surfaces in a manner that greatly enhances the total ground, ocean, and satellite observing system.

  16. Science with the Second Wide Field and Planetary Camera

    NASA Astrophysics Data System (ADS)

    Trauger, J.

    1992-07-01

    With the commencement of Cycle 4 observations, the General Observor community will have access to the second Wide Field and Planetary Camera (WFPC2), a replacement for the orginal WFPC instrument. WFPC2, a wide-field photometric camera which covers the spectrum from 12000 to 10000 Angstroms, will be installed in the Hubble radial bay during the currently manifested December 1993 Shuttle servicing mission. Besides optical correction for the aberrated Hubble primary mirror, the WFPC2 incorporates evolutionary improvement in photometric imaging capabilities. The CCD sensors, signal chain electronics, filter set, FUV performance, internal calibrations, and operational efficiency have all been improved through new technologies and lessons learned from WFPC operations and Hubble experience since launch. Here we provide an overview of the new instrument, beginning with the assumption that the reader is already familiar with the original WFPC now in service.

  17. Compact Focal Plane Assembly for Planetary Science

    NASA Technical Reports Server (NTRS)

    Brown, Ari; Aslam, Shahid; Huang, Wei-Chung; Steptoe-Jackson, Rosalind

    2013-01-01

    A compact radiometric focal plane assembly (FPA) has been designed in which the filters are individually co-registered over compact thermopile pixels. This allows for construction of an ultralightweight and compact radiometric instrument. The FPA also incorporates micromachined baffles in order to mitigate crosstalk and low-pass filter windows in order to eliminate high-frequency radiation. Compact metal mesh bandpass filters were fabricated for the far infrared (FIR) spectral range (17 to 100 microns), a game-changing technology for future planetary FIR instruments. This fabrication approach allows the dimensions of individual metal mesh filters to be tailored with better than 10- micron precision. In contrast, conventional compact filters employed in recent missions and in near-term instruments consist of large filter sheets manually cut into much smaller pieces, which is a much less precise and much more labor-intensive, expensive, and difficult process. Filter performance was validated by integrating them with thermopile arrays. Demonstration of the FPA will require the integration of two technologies. The first technology is compact, lightweight, robust against cryogenic thermal cycling, and radiation-hard micromachined bandpass filters. They consist of a copper mesh supported on a deep reactive ion-etched silicon frame. This design architecture is advantageous when constructing a lightweight and compact instrument because (1) the frame acts like a jig and facilitates filter integration with the FPA, (2) the frame can be designed so as to maximize the FPA field of view, (3) the frame can be simultaneously used as a baffle for mitigating crosstalk, and (4) micron-scale alignment features can be patterned so as to permit high-precision filter stacking and, consequently, increase the filter bandwidth and sharpen the out-of-band rolloff. The second technology consists of leveraging, from another project, compact and lightweight Bi0.87Sb0.13/Sb arrayed thermopiles

  18. Diurnal Forcing of Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Houben, Howard C.

    1997-01-01

    Much progress has been made on calculations of the Martian seasonal water cycle using the Mars Climate Model developed for this purpose. Two papers, documenting the model and the water transport results obtained with it have been published in the Journal of Geophysical Research - Planets. An additional paper describing results related to the evolution of the seasonal water cycle as a result of orbital changes was published in Advances in Space Research. Since that time, further studies have concentrated on the consequences of the soil adsorption required to match the observed water cycle and its relation to the stability of ground ice and other potential water reservoirs. Earth-related studies have concentrated on incorporating an efficient and realistic microphysical model into the Ames Stratospheric General Circulation Model used to simulate the spread of the ML Pinatubo and other volcanic clouds in the stratosphere. In addition, visualizations of the simulations are being incorporated into a video describing the UARS mission. A paper describing the new stratospheric aerosol microphysics package (and its consequences for volcanic cloud evolution) will be submitted in the near future. The paper will discuss the relative importance of condensation and coagulation to early particle growth and the separation of the cloud by sedimentation of the larger particles. A more general paper which highlights the observation that particle number densities did not increase dramatically after the ML Pinatubo eruption is planned. Simulations of atmospheric transport will be extended to include studies of terrestrial tropospheric tracers using the Fifth-Generation Penn State/NCAR Mesoscale Model.

  19. A Geochemical Speciation Program Based on PHREEQE

    Energy Science and Technology Software Center (ESTSC)

    1992-02-18

    HARPHRQ is a program based on the code PHREEQE and is designed to model geochemical reactions. Like PHREEQE, it can calculate the pH, redox potential and mass transfer as a function of reaction progress and the composition of solution in equilibrium with multiple phases. In addition, HARPHRQ includes options to allow the composition of a solution at a fixed pH to be calculated and to automatically add or remove mineral phases as they become saturatedmore » or exhausted. A separate module can also be interfaced to give a choice of sorption models including the triple-layer model.« less

  20. DNA-based methods of geochemical prospecting

    DOEpatents

    Ashby, Matthew

    2011-12-06

    The present invention relates to methods for performing surveys of the genetic diversity of a population. The invention also relates to methods for performing genetic analyses of a population. The invention further relates to methods for the creation of databases comprising the survey information and the databases created by these methods. The invention also relates to methods for analyzing the information to correlate the presence of nucleic acid markers with desired parameters in a sample. These methods have application in the fields of geochemical exploration, agriculture, bioremediation, environmental analysis, clinical microbiology, forensic science and medicine.

  1. The geochemical significance of contaminant assemblages

    SciTech Connect

    Hites, R.A.

    1996-12-31

    Molecular markers are groups of compounds that come from specific sources. Following the dispersion and reactions of these compounds in the environment can frequently help us understand biotic and abiotic geochemical processes. This talk will focus on collections of anthropogenic compounds as they move through the earth`s atmosphere. We will present two examples: (a) We have used the concentrations of mixtures of twenty-two highly chlorinated pesticides in tree bark to understand the global dispersion of these compounds and to distinguish the {open_quotes}global distillation effect{close_quotes} from local sources.

  2. The New ESA Planetary Science Archive

    NASA Astrophysics Data System (ADS)

    Barbarisi, I.; Rios, C.; Macfarlane, A. J.; Docasal, R.; Gonzalez, J.; Arviset, C.; De Marchi, G.; Martinez, S.; Grotheer, E.; Lim, T.; Besse, S.; Heather, D.; Fraga, D.; Barthelemy, M.

    2015-12-01

    The ESA's Planetary Science Archive (PSA) is the central repository for all scientific and engineering data returned by ESA's planetary missions, making them accessible to the world-wide scientific community.With the advent of new ESA planetary missions, currently in development Bepi Colombo (Mercury) and ExoMars16 (Mars), and later on ExoMars18 (Mars Rover) and JUICE (Jupiter and moons), the PSA faces the need of supporting new functionalities and requirements.Within this scenario there is a need for a new concept of the PSA, supporting both the evolution of the PDS standard (PDS4), and the growing need for better interfaces and advanced applications toward a better science exploitation. We introduce the new PSA layout, conceived for better data discovery and retrieval, with special emphasis on GIS technology, interoperability and visualization capabilities.

  3. In search of other planetary systems

    NASA Technical Reports Server (NTRS)

    Black, D. C.

    1980-01-01

    Numerous recent developments have led to an increasing awareness of and interest in the detection of other planetary systems. A brief review of the modern history of this subject is presented with emphasis on the status of data concerning Barnard's star. A discussion is given of plausible observable effects of other planetary systems with numerical examples to indicate the nature of the detection problem. Possible types of information (in addition to discovery) that observations of these effects might yield (e.g., planetary mass and temperature) are outlined. Also discussed are various candidate detection techniques (e.g., astrometric observations) which might be employed to conduct a search, the current state-of-the art of these techniques in terms of measurement accuracy, and the capability of existing or planned facilities (e.g., space telescope) to perform a search. Finally, consideration is given to possible search strategies and the scope of a comprehensive search program.

  4. Origins of Structure in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Murray-Clay, Ruth

    2016-01-01

    Observations confirm that planet formation is a ubiquitous process that produces a diversity of planetary systems. However, a class of solar system analogs has yet to be identified among the thousands of currently known planets and candidates, the overwhelming majority of which are more easily detectable than direct counterparts of the Sun's worlds. To understand whether our solar system's history was unusual and, more generally, to properly characterize the galactic population of extrasolar planets, we must identify how differences in formation environment translate into different planetary system architectures. In this talk, I will consider our solar system in the context of theoretical advances in planet formation driven by the study of extrasolar planets. Along the way, I will discuss several examples of physical processes operating at different stages of planet formation that imprint observable structures on the dynamical and compositional demographics of planetary systems.

  5. Planetary astronomy and supporting laboratory research

    NASA Technical Reports Server (NTRS)

    Valero, F. P. J.

    1988-01-01

    The aim was to obtain form laboratory measurements the molecular parameters needed to interpret observations of planetary and cometary spectra, and to develop the analytical and computational techniques to interpret the observed spectra in terms of planetary atmospheres including solids and cometary ices. The gas phase molecular parameters measured include the intensities and half-widths of vib-rotational lines, total intensities of absorption bands, temperature dependencies, and absorption and pressure parameters in random-band models of absorption bands. Computation of line shapes of H2 quadrupole lines from quantum mechanical first principles for comparison with laboratory data and use in modeling of planetary atmospheres was accomplished. The solid phase measurements include band profile and quantitative intensity measurements and dependence on composition as well as thermal and photolytic processing which mimics the particular astrophysical environments. Work on GeH4, PH3, has made significant progress.

  6. Cubesat Application for Planetary Entry Missions (CAPE)

    NASA Technical Reports Server (NTRS)

    Esper, Jaime; Baumann, Jean-Pierre; Herdrich, Georg

    2013-01-01

    The Cubesat Application for Planetary Entry Missions (CAPE) concept describes a high-performing Cubesat system which includes a propulsion module and miniaturized technologies capable of surviving atmospheric entry heating, while reliably transmitting scientific and engineering data. The Micro Return Capsule 2 (MIRKA2) is CAPE’s first planetary entry probe flight prototype. Within this context, this paper summarizes CAPE’s configuration and typical operational scenario. It also summarizes MIRKA2’s design and basic aerodynamic characteristics, and discusses potential challenges drawn from the experience of missions such as Stardust and MUSES-C. CAPE not only opens the door to new planetary mission capabilities, it also offers relatively low-cost opportunities especially suitable to university participation.

  7. Remote sensor support requirements for planetary missions

    NASA Technical Reports Server (NTRS)

    Weddell, J. B.; Wheeler, A. E.

    1971-01-01

    The study approach, methods, results, and conclusions of remote sensor support requirements for planetary missions are summarized. Major efforts were made to (1) establish the scientific and engineering knowledge and observation requirements for planetary exploration in the 1975 to 1985 period; (2) define the state of the art and expected development of instrument systems appropriate for sensing planetary environments; (3) establish scaling laws relating performance and support requirements of candidate remote sensor systems; (4) establish fundamental remote sensor system capabilities, limitations, and support requirements during encounter and other dynamical conditions for specific missions; and (5) construct families of candidate remote sensors compatible with selected missions. It was recommended that these data be integrated with earlier results to enhance utility, and that more restrictions be placed on the system.

  8. Energy Balance Models and Planetary Dynamics

    NASA Technical Reports Server (NTRS)

    Domagal-Goldman, Shawn

    2012-01-01

    We know that planetary dynamics can have a significant affect on the climate of planets. Planetary dynamics dominate the glacial-interglacial periods on Earth, leaving a significant imprint on the geological record. They have also been demonstrated to have a driving influence on the climates of other planets in our solar system. We should therefore expect th.ere to be similar relationships on extrasolar planets. Here we describe a simple energy balance model that can predict the growth and thickness of glaciers, and their feedbacks on climate. We will also describe model changes that we have made to include planetary dynamics effects. This is the model we will use at the start of our collaboration to handle the influence of dynamics on climate.

  9. Planetary protection policy (U.S.A.)

    NASA Technical Reports Server (NTRS)

    Rummel, John D.

    1992-01-01

    Through existing treaty obligations of the United States, NASA is committed to exploring space while avoiding biological contamination of the planets, and to the protection of the earth against harm from materials returned from space. Because of the similarities between Mars and earth, plans for the exploration of Mars evoke discussions of these Planetary Protection issues. U.S. Planetary Protection Policy will be focused on the preservation of these goals in an arena that will change with the growth of scientific knowledge about the Martian environment. Early opportunities to gain the appropriate data will be used to guide later policy implementation. Because human presence on Mars will result in the end of earth's separation from the Martian environment, it is expected that precursor robotic missions will address critical planetary protection concerns before humans arrive.

  10. ChanPlaNS: The Chandra Planetary Nebula Survey

    NASA Astrophysics Data System (ADS)

    Kastner, Joel; Montez, Rodolfo; Freeman, Marcus; ChanPlaNS Team

    2015-01-01

    The physical mechanisms responsible for the morphological diversity among planetary nebulae (PNe) have been the subject of intense interest and hot debate among PN researchers over the past two decades. The PN shaping problem is multifaceted, with connections to (and implications for) a wide variety of astrophysical systems. Two areas of particular importance are (1) binary star astrophysics and (2) wind interactions and their implications for nebular shaping. X-ray observations play a pivotal role in the study of both of these fundamental aspects of PNe, by revealing (1) point-like X-ray sources at PN central stars that may be indicative of binary companions, and (2) diffuse X-ray emission generated by energetic, PN-shaping shocks. To assess the frequency of appearance and characteristics of these respective PN X-ray sources, we have undertaken the Chandra Planetary Nebula Survey (ChanPlaNS), the first comprehensive X-ray survey of planetary nebulae (PNe) in the solar neighborhood. ChanPlaNS began with a combined Cycle 12 Large Program and archival survey of 35 PNe, with emphasis on high-excitation nebulae, and continued via a Cycle 14 Large Program targeting an additional 24 known compact (R_neb <~ 0.4 pc) PNe. For the latter category of relatively young nebulae, we estimate that the ChanPlaNS survey is ~90% complete within ~1.5 kpc from the Sun. For the ~60 nebulae within this distance observed by Chandra, the point source detection rate is ~36%, and the diffuse X-ray source detection rate is ~27%. However, the point-like and diffuse X-ray detection rates, respectively, are significantly higher for PNe known to harbor binary central stars (~60%) and for the compact (young) PN subsample (~50%). These results demonstrate the potential for insight into PN shaping processes provided by ChanPlaNS. In companion presentations at this meeting (Montez et al.; Freeman et al.), we present highlights of the astrophysics gleaned to date from these Chandra detections (and

  11. The Influence of Planetary Mass on the Dynamical Lifetime of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, J. J.; Duncan, M. J.; Young, Richard E. (Technical Monitor)

    1997-01-01

    Recent numerical and analytic studies of planetary orbits have demonstrated the importance of resonances and chaos in destabilizing planetary systems. Newton's "clockwork" description of regular, predictable planetary orbits has been replaced by a view in which many systems can have long but finite lifetimes. This new knowledge has altered our perceptions of the later stages of planetary growth and of the stability of planetary systems. Stability criteria are inexact and time dependent. Most previous studies have focused on the effects in initial planetary orbits on the stability of the system. We are conducting an investigation which focuses on the dependence of stability criteria on planetary mass. Synthetic systems are created by increasing the masses of the planets in our Solar System or of the moons of a particular planet; these systems are then integrated until orbit crossing occurs. We have found that over some ranges, the time until orbit crossing varies to a good approximation as a power clothe factor by which the masses of the secondaries arc increased; some scatter occurs as a consequence of vie chaotic nature of orbital evolution. The slope of this power law varies substantially from system to system, and for moons it is mildly dependent on the inclusion of the planet's quadrupole moment in the gravitational potential.

  12. Mission Implementation Constraints on Planetary Muon Radiography

    NASA Technical Reports Server (NTRS)

    Jones, Cathleen E.; Kedar, Sharon; Naudet, Charles; Webb, Frank

    2011-01-01

    Cost: Use heritage hardware, especially use a tested landing system to reduce cost (Phoenix or MSL EDL stage). The sky crane technology delivers higher mass to the surface and enables reaching targets at higher elevation, but at a higher mission cost. Rover vs. Stationary Lander: Rover-mounted instrument enables tomography, but the increased weight of the rover reduces the allowable payload weight. Mass is the critical design constraint for an instrument for a planetary mission. Many factors that are minor factors or do not enter into design considerations for terrestrial operation are important for a planetary application. (Landing site, diurnal temperature variation, instrument portability, shock/vibration)

  13. Developing the planetary science virtual observatory

    NASA Astrophysics Data System (ADS)

    Erard, Stéphane; Capria, Maria Teresa; Chanteur, Gerard; Le Sidaner, Pierre; Henry, Florence; Cecconi, Baptiste; Andre, Nicolas; Schmitt, Bernard; Genot, Vincent; Chauvin, Cyril

    In the framework of the Europlanet-RI program, a prototype Virtual Observatory dedicated to Planetary Science has been set up. Most of the activity was dedicated to the definition of standards to handle data in this field. The aim was to facilitate searches in big archives as well as sparse databases, to make on-line data access and visualization possible, and to allow small data providers to make their data available in an interoperable environment with minimum effort. This system makes intensive use of studies and developments led in Astronomy (IVOA, International Virtual Observatory Alliance), Solar and Heliospheric Sciences (HELIO, Heliophysics Integrated Observatory), Space Physics (SPASE, Space Physics Archive Search and Extract) and Planetary Data Space Archive services (IPDA, International Planetary Data Alliance). In particular, it remains consistent with extensions of IVOA standards. The current architecture is aiming at connecting existing data services with IVOA protocols (Cone Search, TAP (Table Access Protocol)…) or with the IPDA protocol (PDAP, Planetary Data Access Protocol) whenever relevant. However, a more general standard has been devised to handle the specific complexity of Planetary Science, e.g. in terms of measurement types and coordinate frames. This protocol, named EPN-TAP (Europlanet-TAP), is based on TAP and includes precise requirements to describe the contents of a data service. It is based on an IVOA compliant data model (EPNcore). A light framework (DaCHS/GAVO) and a procedure have been identified to install small data services, and several hands-on sessions have been organized already. The data services are declared in standard IVOA registries. Support to new data services in Europe will be provided in the framework of the proposed H2020 Europlanet program, with a focus on planetary mission support (Rosetta, Cassini…). Although TAP services can be accessed and queried from tools such as TOPCAT, a full client has been developed

  14. Technology for return of planetary samples

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Technological requirements of a planetary return sample mission were studied. The state-of-the-art for problems unique to this class of missions was assessed and technological gaps were identified. The problem areas where significant advancement of the state-of-the-art is required are: life support for the exobiota during the return trip and within the Planetary Receiving Laboratory (PRL); biohazard assessment and control technology; and quarantine qualified handling and experimentation methods and equipment for studying the returned sample in the PRL. Concepts for solving these problems are discussed.

  15. The NASA planetary biology internship experience

    NASA Technical Reports Server (NTRS)

    Hinkle, G.; Margulis, L.

    1991-01-01

    By providing students from around the world with the opportunity to work with established scientists in the fields of biogeochemistry, remote sensing, and origins of life, among others, the NASA Planetary Biology Internship (PBI) Program has successfully launched many scientific careers. Each year approximately ten interns participate in research related to planetary biology at NASA Centers, NASA-sponsored research in university laboratories, and private institutions. The PBI program also sponsors three students every year in both the Microbiology and Marine Ecology summer courses at the Marine Biological Laboratory. Other information about the PBI Program is presented including application procedure.

  16. Tips and Tools for Teaching Planetary Science

    NASA Astrophysics Data System (ADS)

    Schneider, N. M.

    2011-10-01

    The poster will describe handson exercises with demonstrations, clicker questions and discussion to demonstrate how to help students understand planets on a deeper conceptual level. We'll also discuss ways to take the latest discoveries beyond "wow" and turn them into teachable moments. The goal is to give modern strategies for teaching planetary science, emphasizing physical concepts and comparative principles. All will be given digital copies of video clips, demonstration descriptions, clicker questions, web links and powerpoint slidesets on recent planetary science discoveries.

  17. 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.

  18. Detection techniques for tenuous planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Hoenig, S. A.

    1978-01-01

    The application of detectors developed for analysis of planetary atmospheres under partial vacuum conditions, and data obtained during dust charging studies to various industrial problems is summarized. A specialized apparatus for dust measurements on a planetary lander was designed with the capability of measuring ambient dust density as a function of particle size, as well as for observing the charge of the collected dust. the optical system operates on an intermittent basis and requires only low power. No radioactive source or delicate detection equipment is required. Advances in monitoring catalyst operation by means of exoelection emission are also reported.

  19. Mission operations systems for planetary exploration

    NASA Technical Reports Server (NTRS)

    Mclaughlin, William I.; Wolff, Donna M.

    1988-01-01

    The purpose of the paper is twofold: (1) to present an overview of the processes comprising planetary mission operations as conducted at the Jet Propulsion Laboratory, and (2) to present a project-specific and historical context within which this evolving process functions. In order to accomplish these objectives, the generic uplink and downlink functions are described along with their specialization to current flight projects. Also, new multimission capabilities are outlined, including prototyping of advanced-capability software for subsequent incorporation into more automated future operations. Finally, a specific historical ground is provided by listing some major operations software plus a genealogy of planetary missions beginning with Mariner 2 in 1962.

  20. Trace elements as quantitative probes of differentiation processes in planetary interiors

    SciTech Connect

    Drake, M.J.

    1980-02-01

    Abundances of trace elements in extrusive igneous rocks may be used as petrological and geochemical probes of the source regions of the rocks if differentiation processes, partition coefficients, phase equilibria, and initial concentrations in the source region are known. The characteristic trace element signature that each mineral in the source region imparts on the magma forms the conceptual basis for trace element modeling. The task of the trace element geochemist is to solve mathematically the inverse problem. Given trace element abundances in a magma, what is the ode of its source region. The most successful modeling has been performed for small planetary bodies which underwent relatively simple igneous differentiation events. An example is the eucrite parent body, a planet which produced basals at approx. =4.6 Gy. and has been quiescent ever since. This simple differentiation history permits the calculation of its bulk composition (a feldspathic peridotite) and has led to the tentative identification of asteroid 4 Westa as the eucrite parent body. The differentiation of iron meteorite groups in parent body cores is amenable to similar treatment. The 'anomalous' behavior of Cr, suggests that IIIA, B irons and main group pallasites equilibrated with troilite, spinel, ferromagnesian silicates, or some combination thereof. The moon has undergone more complex differentiation, and quantitative geochemical modeling is correspondingly more difficult. Nevertheless, modeling the two-stage evolution of mare basals raises the possibility that the primordial moon did not have chondritic relative abundances of such refractory elements as Ca, Al, U, and the rare-earth elements. The nonchondritic element ratios are characteristic of planetary, not nebular, fractionation processes and are consistent with the derivation of the moon from a precursor planet, possibly the earth.