Properties and evolution of NEO families created by tidal disruption at Earth

NASA Astrophysics Data System (ADS)

Schunová, Eva; Jedicke, Robert; Walsh, Kevin J.; Granvik, Mikael; Wainscoat, Richard J.; Haghighipour, Nader

2014-08-01

We have calculated the coherence and detectable lifetimes of synthetic near-Earth object (NEO) families created by catastrophic disruption of a progenitor as it suffers a very close Earth approach. The closest or slowest approaches yield the most violent ‘s-class’ disruption events where the largest remaining fragment after disruption and reaccumulation retains less than 50% of the parent’s mass. The resulting fragments have a ‘string of pearls’ configuration after their reaccummulation into gravitationally bound components (Richardson, D.C., Bottke, W.F., Love, S.G. [1998]. Icarus 134, 47-76). We found that the average absolute magnitude (H) difference between the parent body and the largest fragment is ΔH∼1.0. The average slope of the absolute magnitude (H) distribution, N(H)∝10, for the fragments in the s-class families is steeper than the slope of the NEO population (Mainzer, A., et al. [2011]. Astrophys. J. 743, 156) in the same size range. The es remain coherent as statistically significant clusters of orbits within the NEO population for an average of τbarc=(14.7±0.6)×103 yr after disruption. The detectable lifetimes of tidally disrupted families are extremely short compared to the multi-Myr and -Gyr lifetimes of main belt families due to the chaotic dynamical environment in NEO space-they are detectable with the techniques developed by Fu et al. and Schunová et al. (Fu, H., Jedicke, R., Durda, D.D., Fevig, R., Binzel, R.P. [2005]. Icarus 178(2), 434-449 and Schunová, E., Granvik, M., Jedicke, R., Gronchi, G., Wainscoat, R., Abe, S. [2012]. Icarus 220, 1050-1063) for an average duration (τbardet) ranging from about 2000 to about 12,000 years for progenitors in the absolute magnitude (Hp) range from 20 to 13 corresponding to diameters in the range from about 0.5 to 10 km respectively. The maximum absolute magnitude of a progenitor capable of producing an observable NEO family (i.e. detectable by our family finding technique) is Hp,max=20

The Mission Accessible Near-Earth Objects Survey (MANOS): spectroscopy results

NASA Astrophysics Data System (ADS)

Thomas, Cristina A.; Moskovitz, Nicholas; Hinkle, Mary L.; Mommert, Michael; Polishook, David; Thirouin, Audrey; Binzel, Richard; Christensen, Eric J.; DeMeo, Francesca E.; Person, Michael J.; Trilling, David E.; Willman, Mark; Burt, Brian

2016-10-01

The Mission Accessible Near-Earth Object Survey (MANOS) is an ongoing physical characterization survey to build a large, uniform catalog of physical properties including lightcurves and visible wavelength spectroscopy. We will use this catalog to investigate the global properties of the small NEO population and identify individual objects that can be targets of interest for future exploration. To accomplish our goals, MANOS uses a wide variety of telescopes (1-8m) in both the northern and southern hemispheres. We focus on targets that have been recently discovered and operate on a regular cadence of remote and queue observations to enable rapid characterization of small NEOs. Targets for MANOS are selected based on three criteria: mission accessibility, size, and observability. With our resources, we observe 5-10 newly discovered sub-km NEOs per month. MANOS has been operating for three years and we have observed over 500 near-Earth objects in that time.We will present results from the spectroscopy component of the MANOS program. Visible wavelength spectra are obtained using DeVeny on the Discovery Channel Telescope (DCT), Goodman on the Southern Astrophysical Research (SOAR) telescope, and GMOS on Gemini North and South. Over 300 NEO spectra have been obtained during our program. We will present preliminary results from our spectral sample. We will discuss the compositional diversity of the small NEO population and how the observed NEOs compare to the meteorite population.MANOS is funded by the NASA Near-Earth Object Observations program.

Lost Near-Earth Object Candidates

NASA Astrophysics Data System (ADS)

Veres, Peter; Farnocchia, Davide; Williams, Gareth; Keys, Sonia; Boardman, Ian; Holman, Matthew J.; Payne, Matthew J.

2017-10-01

The number of discovered Near-Earth Objects (NEOs) increases rapidly, currently exceeding 16,000 NEOs. 2016 was the most productive year ever with 1,888 NEO discoveries. The NEO discovery process typically begins with three to five detections of a previously unidentified object that are reported to the Minor Planet Center (MPC). According to the plane-of-sky motion, the MPC ranks all of the new candidate discoveries for the likelihood of being NEOs using the so-called digest score. If the digest score is greater than 65 the observations appear on the publicly accessible NEO Confirmation Page (NEOCP). Objects on the NEOCP are followed up in subsequent hours and days. When enough observations are collected to ensure that the object is real and that the orbit is determined, the NEO is officially announced with its new designation by a Minor Planet Electronic Circular. However, 14% of NEO candidates never get confirmed and are therefore lost due to the lack of follow-up observations. We analyzed the lost NEO candidates that appeared on NEOCP in 2013-2016 and investigated the reasons why they were not confirmed. In particular, we studied the properties of the lost NEO candidates with a digest score of 100 that were reported by the two most prolific discovery sites - Pan-STARRS1 (F51) and Mt. Lemmon Survey (G96). We derived their plane-of-sky positions and rates, brightness, and ephemeris uncertainties, and assessed correlations with the phase of the moon and seasonal effects apparent in the given observatory’s data. We concluded that lost NEO candidates typically have a larger rate of motion and larger uncertainties than those of confirmed objects. However, many of the lost candidates could be recovered. In fact, the 1-sigma plane-of-sky uncertainty was still within ±0.5 deg in 79% (F51) and 69% (G96) of the cases 24 hours after discovery and in 31% (F51) and 30% (G96) of the cases 48 hours after discovery. If all of the NEO candidates with a digest score of 100 had

The Mission Accessible Near-Earth Objects Survey (MANOS)

NASA Technical Reports Server (NTRS)

Abell, Paul; Moskovitz, Nicholas; DeMeo, Francesca; Endicott, Thomas; Busch, Michael; Roe, Henry; Trilling, David; Thomas, Cristina; Willman, Mark; Grundy, Will;

An High Resolution Near-Earth Objects Population Enabling Next-Generation Search Strategies

NASA Technical Reports Server (NTRS)

Tricaico, Pasquale; Beshore, E. C.; Larson, S. M.; Boattini, A.; Williams, G. V.

2010-01-01

Over the past decade, the dedicated search for kilometer-size near-Earth objects (NEOs), potentially hazardous objects (PHOs), and potential Earth impactors has led to a boost in the rate of discoveries of these objects. The catalog of known NEOs is the fundamental ingredient used to develop a model for the NEOs population, either by assessing and correcting for the observational bias (Jedicke et al., 2002), or by evaluating the migration rates from the NEOs source regions (Bottke et al., 2002). The modeled NEOs population is a necessary tool used to track the progress in the search of large NEOs (Jedicke et al., 2003) and to try to predict the distribution of the ones still undiscovered, as well as to study the sky distribution of potential Earth impactors (Chesley & Spahr, 2004). We present a method to model the NEOs population in all six orbital elements, on a finely grained grid, allowing us the design and test of targeted and optimized search strategies. This method relies on the observational data routinely reported to the Minor Planet Center (MPC) by the Catalina Sky Survey (CSS) and by other active NEO surveys over the past decade, to determine on a nightly basis the efficiency in detecting moving objects as a function of observable quantities including apparent magnitude, rate of motion, airmass, and galactic latitude. The cumulative detection probability is then be computed for objects within a small range in orbital elements and absolute magnitude, and the comparison with the number of know NEOs within the same range allows us to model the population. When propagated to the present epoch and projected on the sky plane, this provides the distribution of the missing large NEOs, PHOs, and potential impactors.

Near Earth Object (NEO) Mitigation Options Using Exploration Technologies

NASA Technical Reports Server (NTRS)

Arnold William; Baysinger, Mike; Crane, Tracie; Capizzo, Pete; Sutherlin, Steven; Dankanich, John; Woodcock, Gordon; Edlin, George; Rushing, Johnny; Fabisinski, Leo;

Results from the LCOGT Near-Earth Object Follow-up Network

NASA Astrophysics Data System (ADS)

Greenstreet, Sarah; Lister, Tim; Gomez, Edward; Christensen, Eric; Larson, Steve

2015-11-01

Las Cumbres Observatory Global Telescope Network (LCOGT) has deployed a homogeneous telescope network of nine 1-meter and two 2-meter telescopes to five locations in the northern and southern hemispheres, with plans to extend to twelve 1-meter telescopes at 6 locations. The versitility and design of this network allows for rapid response to target of opportunity events as well as the long-term monitoring of slowly changing astronomical phenomena. The network's global coverage and the apertures of telescopes available make LCOGT ideal for follow-up and characterization of Solar System objects (e.g. asteroids, Kuiper Belt Objects, comets, Near-Earth Objects (NEOs)) and ultimately for the discovery of new objects.LCOGT has completed the first phase of the deployment with the installation and commissioning of the nine 1-meter telescopes at McDonald Observatory (Texas), Cerro Tololo (Chile), SAAO (South Africa) and Siding Spring Observatory (Australia). This is complimented by the two 2-meter telescopes at Haleakala (Hawaii) and Siding Spring Observatory. The telescope network has been fully operational since May 2014, and observations are being executed remotely and robotically. Future expansion to sites in the Canary Islands and Tibet are planned for 2016.The LCOGT near-Earth object group is using the network to confirm newly detected NEO candidates produced by the major sky surveys such as Catalina Sky Survey (CSS), PanSTARRS (PS1) and NEOWISE, with several hundred targets being followed per year. Follow-up astrometry and photometry of radar-targeted objects and those on the Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) or Asteroid Retrieval Mission (ARM) lists are improving orbits, producing light curves and rotation periods, and better characterizing these NEOs. Recent results include the first period determinations for several of the Goldstone-targeted NEOs. In addition, we are in the process of building a NEO portal that will allow

Methodology and Results of the Near-Earth Object (NEO) Human Space Flight (HSF) Accessible Targets Study (NHATS)

NASA Technical Reports Server (NTRS)

Barbee, Brent W.; Mink, Ronald G.; Adamo, Daniel R.; Alberding, Cassandra M.

2011-01-01

Near-Earth Asteroids (NEAs) have been identified by the Administration as potential destinations for human explorers during the mid-2020s. Planning such ambitious missions requires selecting potentially accessible targets from the growing known population of 8,008 NEAs. NASA is therefore conducting the Near-Earth Object (NEO) Human Space Flight (HSF) Accessible Targets Study (NHATS), in which the trajectory opportunities to all known NEAs are being systematically evaluated with respect to a set of defined constraints. While the NHATS algorithms have identified hundreds of NEAs which satisfy purposely inclusive trajectory constraints, only a handful of them offer truly attractive mission opportunities in the time frame of greatest interest. In this paper we will describe the structure of the NHATS algorithms and the constraints utilized in the study, present current study results, and discuss various mission design considerations for future human space flight missions to NEAs.

The Mission Accessible Near-Earth Objects Survey (MANOS): photometric results

NASA Astrophysics Data System (ADS)

Thirouin, Audrey; Moskovitz, Nicholas; Binzel, Richard; Christensen, Eric J.; DeMeo, Francesca; Person, Michael J.; Polishook, David; Thomas, Cristina; Trilling, David E.; Willman, Mark; Hinkle, Mary L.; Burt, Brian; Avner, Dan

2016-10-01

The Mission Accessible Near-Earth Object Survey (MANOS) is a physical characterization survey of Near-Earth Objects (NEOs) to provide physical data for several hundred mission accessible NEOs across visible and near-infrared wavelengths. Using a variety of 1-m to 8-m class telescopes, we observe 5 to 10 newly discovered sub-km NEOs per month in order to derive their rotational properties and taxonomic class.Rotational data can provide useful information about physical properties, like shape, surface heterogeneity/homogeneity, density, internal structure, and internal cohesion. Here, we present results of the MANOS photometric survey for more than 200 NEOs. We report lightcurves from our first three years of observing and show objects with rotational periods from a couple of hours down to a few seconds. MANOS found the three fastest rotators known to date with rotational periods below 20s. A physical interpretation of these ultra-rapid rotators is that they are bound through a combination of cohesive and/or tensile strength rather than gravity. Therefore, these objects are important to understand the internal structure of NEOs. Rotational properties are used for statistical study to constrain overall properties of the NEO population. We also study rotational properties according to size, and dynamical class. Finally, we report a sample of NEOs that are fully characterized (lightcurve and visible spectra) as the most suitable candidates for a future robotic or human mission. Viable mission targets are objects with a rotational period >1h, and a delta-v lower than 12 km/s. Assuming the MANOS rate of object characterization, and the current NEO population estimates by Tricarico (2016), and by Harris and D'Abramo (2015), 10,000 to 1,000,000 NEOs with diameters between 10m and 1km are expected to be mission accessible. We acknowledge funding support from NASA NEOO grant number NNX14AN82G, and NOAO survey program.

Survey of Technologies Relevant to Defense From Near-Earth Objects

NASA Technical Reports Server (NTRS)

Adams, R. B.; Alexander, R.; Bonometti, J.; Chapman, J.; Fincher, S.; Hopkins, R.; Kalkstein, M.; Polsgrove, T.; Statham, G.; White, S.

2004-01-01

Several recent near-miss encounters with asteroids and comets have focused attention on the threat of a catastrophic impact with the Earth. This Technical Publication reviews the historical impact record and current understanding of the number and location of near-Earth objects (NEOs) to address their impact probability. Various ongoing projects intended to survey and catalog the NEO population are also reviewed. Details are given of a Marshall Space Flight Center-led study intended to develop and assess various candidate systems for protection of the Earth against NEOs. Details of analytical tools, trajectory tools, and a tool that was created to model both the undeflected inbound path of an NEO as well as the modified, postdeflection path are given. A representative selection of these possible options was modeled and evaluated. It is hoped that this study will raise the level of attention about this very real threat and also demonstrate that successful defense is both possible and practicable, provided appropriate steps are taken.

Human and Robotic Exploration of Near-Earth Objects

NASA Technical Reports Server (NTRS)

Abell, Paul A.

2010-01-01

A study in late 2006 was sponsored by the Advanced Projects Office within NASA's Constellation Program to examine the feasibility of sending the Orion Crew Exploration Vehicle to a near-Earth object (NEO). The ideal mission profile would involve two or three astronauts on a 90 to 180 day flight, which would include a 7 to 14 day stay for proximity operations at the target NEO. More recently U.S. President Obama stated on April 15, 2010 that the next goal for human spaceflight will be to send human beings to a near-Earth asteroid by 2025. Given this direction from the White House, NASA has been involved in studying various strategies for NEO exploration in order to follow U.S. space exploration policy. Prior to sending a human mission, a series of robotic spacecraft would be launched to reduce the risk to crew, and enhance the planning for the proximity and surface operations at the NEO. The human mission would ideally follow five or more years later. This mission would be the first human expedition to an interplanetary body beyond the Earth-Moon system and would prove useful for testing technologies required for human missions to Mars and other solar system destinations. Piloted missions to NEOs would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific investigations of these primitive objects. The main scientific advantage of sending piloted missions to NEOs would be the flexibility of the crew to perform tasks and to adapt to situations in real time. A crewed vehicle would be able to test several different sample collection techniques and target specific areas of interest via extra-vehicular activities (EVAs) more efficiently than robotic spacecraft. Such capabilities greatly enhance the scientific return from these missions to NEOs, destinations vital to understanding the evolution and thermal histories of primitive bodies during the formation of the

Physical Characterization of the Near-Earth Object Population

NASA Technical Reports Server (NTRS)

Binzel, Richard P.

2003-01-01

This program seeks to address the fundamental question: What are the relationships between asteroids, comets, and meteorites? To answer this question, we are studying the population of asteroids near the Earth which likely contain both asteroids and extinct comets and which is the immediate source for meteorites. An analysis of new and existing visible wavelength spectral data for more than 100 (Near-Earth Objects) NEOs, and Keck albedo data for more than 20 NEOs is underway. New asteroid-meteorite links are being found, the NEO population and hazard is being characterized, and the extinct comet component is being constrained. These results are contained within the following publication work during the current period: 1 book, 2 book chapters, 1 published paper, 2 papers submitted, 2 papers in preparation, 1 Ph. D. thesis in preparation, and 7 meeting abstracts/presentations.

Synergistic Activities of Near-Earth Object Exploration

NASA Technical Reports Server (NTRS)

Abell, Paul

2011-01-01

U.S. President Obama stated on April 15, 2010 that the next goal for human spaceflight will be to send human beings to near-Earth asteroids by 2025. Missions to NEOs would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific examinations of these primitive objects. Information obtained from a human investigation of a NEO, together with ground-based observations and prior spacecraft investigations of asteroids and comets, will also provide a real measure of ground truth to data obtained from terrestrial meteorite collections. Major advances in the areas of geochemistry, impact history, thermal history, isotope analyses, mineralogy, space weathering, formation ages, thermal inertias, volatile content, source regions, solar system formation, etc. can be expected from human NEO missions. Samples directly returned from a primitive body would lead to the same kind of breakthroughs for understanding NEOs that the Apollo samples provided for understanding the Earth-Moon system and its formation history. In addition, robotic precursor and human exploration missions to NEOs would allow the NASA and its international partners to gain operational experience in performing complex tasks (e.g., sample collection, deployment of payloads, retrieval of payloads, etc.) with crew, robots, and spacecraft under microgravity conditions at or near the surface of a small body. This would provide an important synergy between the worldwide Science and Exploration communities, which will be crucial for development of future international deep space exploration architectures and has potential benefits for future exploration of other destinations beyond low-Earth orbit.

NASA Earth Observations (NEO): Data Imagery for Education and Visualization

NASA Astrophysics Data System (ADS)

Ward, K.

2008-12-01

NASA Earth Observations (NEO) has dramatically simplified public access to georeferenced imagery of NASA remote sensing data. NEO targets the non-traditional data users who are currently underserved by functionality and formats available from the existing data ordering systems. These users include formal and informal educators, museum and science center personnel, professional communicators, and citizen scientists. NEO currently serves imagery from 45 different datasets with daily, weekly, and/or monthly temporal resolutions, with more datasets currently under development. The imagery from these datasets is produced in coordination with several data partners who are affiliated either with the instrument science teams or with the respective data processing center. NEO is a system of three components -- website, WMS (Web Mapping Service), and ftp archive -- which together are able to meet the wide-ranging needs of our users. Some of these needs include the ability to: view and manipulate imagery using the NEO website -- e.g., applying color palettes, resizing, exporting to a variety of formats including PNG, JPEG, KMZ (Google Earth), GeoTIFF; access the NEO collection via a standards-based API (WMS); and create customized exports for select users (ftp archive) such as Science on a Sphere, NASA's Earth Observatory, and others.

Properties and evolution of near-Earth-object families created by tidal disruption at the Earth

NASA Astrophysics Data System (ADS)

Schunova, E.; Walsh, K.; Granvik, M.; Jedicke, R.; Wainscoat, R.; Haghighipour, N.

2014-07-01

We have calculated the coherence and detectable lifetimes of synthetic near-Earth object (NEO) families created by catastrophic disruption of a progenitor as it suffers a very close Earth approach. The closest or slowest approaches yield the most violent 'S-class' disruption events and create a 'string of pearls' configuration of the resulting fragments after their reaccummulation into gravitationally bound components [3]. We found that the average absolute magnitude (H) difference between the parent body and the largest fragment is Δ H ˜ 1.0. The average slope of the absolute magnitude (H) distribution, N(H)∝10^{(0.55±0.04) H}, for the fragments in the S-class families is steeper than the slope of the NEO population [2] in the same size range. The families remain coherent as statistically significant clusters of orbits within the NEO population for an average of barτ_c = (14.7±0.6)×10^3 years after disruption. The detectable lifetimes of tidally disrupted families are extremely short compared to the multi-Myr and -Gyr lifetimes of main belt families due to the chaotic dynamical environment in NEO space -- they are detectable with the techniques developed by [1] and [4] for an average duration (barτ_{det}) ranging from about 2,000 to about 12,000 years for progenitors in the absolute magnitude (H_p) range from 20 to 13 corresponding to diameters in the range from about 0.5 to 10 km respectively. The maximum absolute magnitude of a progenitor capable of producing an observable NEO family (i.e. detectable by our family finding technique) is H_{p,max} = 20 (about 350 m diameter). The short detectability lifetime explains why zero NEO families have been discovered to-date. Nonetheless, every tidal disruption event of a progenitor with diameter greater than 0.5 km is capable of producing several million fragments in the 1 m to 10 m diameter range that can contribute to temporary local density enhancements of small NEOs in Earth's vicinity. These objects may be

The Mission Accessible Near-Earth Object Survey (MANOS): Project Status

NASA Astrophysics Data System (ADS)

Moskovitz, Nicholas; Thirouin, Audrey; Mommert, Michael; Thomas, Cristina A.; Skiff, Brian; Polishook, David; Burt, Brian; Trilling, David E.; DeMeo, Francesca E.; Binzel, Richard P.; Christensen, Eric J.; Willman, Mark; Hinkle, Mary

2017-10-01

The Mission Accessible Near-Earth Object Survey (MANOS) is a physical characterization survey of sub-km, low delta-v, newly discovered near-Earth objects (NEOs). MANOS aims to collect astrometry, lightcurve photometry, and reflectance spectra for a representative sample of these important target of opportunity objects in a rarely observed size range. We employ a diverse set of large aperture (2-8 meter) telescopes and observing modes (queue, remote, classical) to overcome the challenge of observing faint NEOs moving at high non-sidereal rates with short observing windows. We target approximately 10% of newly discovered NEOs every month for follow-up characterization.The first generation MANOS ran from late 2013 to early 2017, using telescopes at Lowell Observatory, NOAO, and the University of Hawaii. This resulted in the collection of data for over 500 targets. These data are continuing to provide new insights into the NEO population as a whole as well as for individual objects of interest. Science highlights include identification of the four fastest rotating minor planets found to date with rotation periods under 20 seconds, constraints on the distribution of NEO morphologies as quantified by de-biased estimates for lightcurve-derived axis ratios, and the compositional distribution of NEOs at sizes under 100 meters.The second generation MANOS will begin in late 2017 and will employ much of the same strategies while continuing to build a comprehensive dataset of NEO physical properties. This will grow the MANOS sample to ~1000 objects and provide the means to better address key questions related to understanding the physical properties of NEOs, their viability as exploration mission targets, and their relationship to Main Belt asteroids and meteorites. This continuation of MANOS will include an increased focus on spectroscopic observations at near-IR wavelengths using a new instrument called NIHTS (the Near-Infrared High-Throughput Spectrograph) at Lowell

Physical characterization of the near-Earth object population

NASA Astrophysics Data System (ADS)

Ieva, S.; Dotto, E.; Mazzotta Epifani, E.; Perna, D.; Perozzi, E.; Micheli, M.

2017-08-01

The Near-Earth Object (NEO) population, being the remnants of the building blocks that originally formed our solar system, allows us to understand the initial conditions that were present in the protosolar nebula. Its investigation can provide crucial information on the origin and early evolution of the solar system, and shed light on the delivery of water and organic-rich material to the early Earth. Furthermore, the possible impact of NEOs poses a serious hazard to our planet. There is an urgent need to undertake a comprehensive physical characterization of the NEO population, particularly for the ones with the higher likelihood of catastrophic impact with the Earth. One of the main aims of the NEOShield-2 project (2015-2017), financed by the European Commission in the framework of the HORIZON 2020 program, is to undertake an extensive observational campaign and provide a physical and compositional characterization for a large number of NEOs in the < 300 m size range, retrieving in particular their mitigation-relevant properties (size, shape, albedo, diameter, composition, internal structure, ...) in order to design impact mitigation missions and assess the consequences of an impact on Earth. We carried out visible photometric measurements for a sample of 158 uncharacterized NEOs. We also made use of visible and near-infrared spectroscopy to assess NEO composition and perform a mineralogical analysis. We found that carbonaceous C-complex asteroids deserve a special attention, since their physical structure ( e.g., primitive nature, porosity) and their orbital parameters (mainly the inclination) make at the moment challenging the design of a successful mitigation strategy. Indeed, the most advanced mitigation technique (the kinetic impactor) is less effective on these bodies, and the high inclination of some possible impactors require a launch vehicle capability beyond the one currently available.

The Mission Accessible Near-Earth Object Survey (MANOS)

NASA Astrophysics Data System (ADS)

Moskovitz, N.; Manos Team

2014-07-01

Near-Earth objects (NEOs) are essential to understanding the origin of the Solar System through their compositional links to meteorites. As tracers of various regions within the Solar System they can provide insight to more distant, less accessible populations. Their relatively small sizes and complex dynamical histories make them excellent laboratories for studying ongoing Solar System processes such as space weathering, planetary encounters, and non-gravitational dynamics. Knowledge of their physical properties is essential to impact hazard assessment. Finally, the proximity of NEOs to Earth make them favorable targets for robotic and human exploration. However, in spite of their scientific importance, only the largest (km-scale) NEOs have been well studied and a representative sample of physical characteristics for sub-km NEOs does not exist. To address these issues we are conducting the Mission Accessible Near-Earth Object Survey (MANOS), a fully allocated multi-year survey of sub-km NEOs that will provide a large, uniform catalog of physical properties including light curves, spectra, and astrometry. From this comprehensive catalog, we will derive global properties of the NEO population, as well as identify individual targets that are of potential interest for exploration. We will accomplish these goals for approximately 500 mission-accessible NEOs across the visible and near-infrared ranges using telescope assets in both the northern and southern hemispheres. MANOS has been awarded large survey status by NOAO to employ Gemini-N, Gemini-S, SOAR, the Kitt Peak 4 m, and the CTIO 1.3 m. Access to additional facilities at Lowell Observatory (DCT 4.3 m, Perkins 72'', Hall 42'', LONEOS), the University of Hawaii, and the Catalina Sky Survey provide essential complements to this suite of telescopes. Targets for MANOS are selected based on three primary criteria: mission accessibility (i.e. Δ v < 7 km/s), size (H > 20), and observability. Our telescope assets allow

Near Earth Objects - a threat and an opportunity

NASA Astrophysics Data System (ADS)

Tate, Jonathan R.

2003-05-01

In the past decade the hazard posed to the Earth by Near Earth Objects (NEOs) has generated considerable scientific and public interest. A number of major films, television programmes and media reports have brought the issue to public attention. From an educational perspective an investigation into NEOs and the effects of impacts on the Earth forms a topical and dynamic basis for study in a huge range of subjects, not just scientific. There are clear routes to chemistry, physics, mathematics and biology, but history, psychology, geography, palaeontology and geology are just a selection of other subjects involved. A number of projects have been established, mainly in the USA, to determine the extent of the hazard, and to develop ways of countering it, but the present situation is far from satisfactory. Current detection and follow-up programmes are underfunded and lack international coordination.

Sentry: An Automated Close Approach Monitoring System for Near-Earth Objects

NASA Astrophysics Data System (ADS)

Chamberlin, A. B.; Chesley, S. R.; Chodas, P. W.; Giorgini, J. D.; Keesey, M. S.; Wimberly, R. N.; Yeomans, D. K.

2001-11-01

In response to international concern about potential asteroid impacts on Earth, NASA's Near-Earth Object (NEO) Program Office has implemented a new system called ``Sentry'' to automatically update the orbits of all NEOs on a daily basis and compute Earth close approaches up to 100 years into the future. Results are published on our web site (http://neo.jpl.nasa.gov/) and updated orbits and ephemerides made available via the JPL Horizons ephemeris service (http://ssd.jpl.nasa.gov/horizons.html). Sentry collects new and revised astrometric observations from the Minor Planet Center (MPC) via their electronic circulars (MPECs) in near real time as well as radar and optical astrometry sent directly from observers. NEO discoveries and identifications are detected in MPECs and processed appropriately. In addition to these daily updates, Sentry synchronizes with each monthly batch of MPC astrometry and automatically updates all NEO observation files. Daily and monthly processing of NEO astrometry is managed using a queuing system which allows for manual intervention of selected NEOs without interfering with the automatic system. At the heart of Sentry is a fully automatic orbit determination program which handles outlier rejection and ensures convergence in the new solution. Updated orbital elements and their covariances are published via Horizons and our NEO web site, typically within 24 hours. A new version of Horizons, in development, will allow computation of ephemeris uncertainties using covariance data. The positions of NEOs with updated orbits are numerically integrated up to 100 years into the future and each close approach to any perturbing body in our dynamic model (all planets, Moon, Ceres, Pallas, Vesta) is recorded. Significant approaches are flagged for extended analysis including Monte Carlo studies. Results, such as minimum encounter distances and future Earth impact probabilities, are published on our NEO web site.

Scientific Exploration of Near-Earth Objects via the Crew Exploration Vehicle

NASA Technical Reports Server (NTRS)

Abell, Paul A.; Korsmeyer, D. J.; Landis, R. R.; Lu, E.; Adamo (D.); Jones (T.); Lemke, L.; Gonzales, A.; Gershman, B.; Morrison, D.;

Physical modeling and high-performance GPU computing for characterization, interception, and disruption of hazardous near-Earth objects

NASA Astrophysics Data System (ADS)

Kaplinger, Brian Douglas

For the past few decades, both the scientific community and the general public have been becoming more aware that the Earth lives in a shooting gallery of small objects. We classify all of these asteroids and comets, known or unknown, that cross Earth's orbit as near-Earth objects (NEOs). A look at our geologic history tells us that NEOs have collided with Earth in the past, and we expect that they will continue to do so. With thousands of known NEOs crossing the orbit of Earth, there has been significant scientific interest in developing the capability to deflect an NEO from an impacting trajectory. This thesis applies the ideas of Smoothed Particle Hydrodynamics (SPH) theory to the NEO disruption problem. A simulation package was designed that allows efficacy simulation to be integrated into the mission planning and design process. This is done by applying ideas in high-performance computing (HPC) on the computer graphics processing unit (GPU). Rather than prove a concept through large standalone simulations on a supercomputer, a highly parallel structure allows for flexible, target dependent questions to be resolved. Built around nonclassified data and analysis, this computer package will allow academic institutions to better tackle the issue of NEO mitigation effectiveness.

MARCO POLO: near earth object sample return mission

NASA Astrophysics Data System (ADS)

Barucci, M. A.; Yoshikawa, M.; Michel, P.; Kawagushi, J.; Yano, H.; Brucato, J. R.; Franchi, I. A.; Dotto, E.; Fulchignoni, M.; Ulamec, S.

2009-03-01

MARCO POLO is a joint European-Japanese sample return mission to a Near-Earth Object. This Euro-Asian mission will go to a primitive Near-Earth Object (NEO), which we anticipate will contain primitive materials without any known meteorite analogue, scientifically characterize it at multiple scales, and bring samples back to Earth for detailed scientific investigation. Small bodies, as primitive leftover building blocks of the Solar System formation process, offer important clues to the chemical mixture from which the planets formed some 4.6 billion years ago. Current exobiological scenarios for the origin of Life invoke an exogenous delivery of organic matter to the early Earth: it has been proposed that primitive bodies could have brought these complex organic molecules capable of triggering the pre-biotic synthesis of biochemical compounds. Moreover, collisions of NEOs with the Earth pose a finite hazard to life. For all these reasons, the exploration of such objects is particularly interesting and urgent. The scientific objectives of MARCO POLO will therefore contribute to a better understanding of the origin and evolution of the Solar System, the Earth, and possibly Life itself. Moreover, MARCO POLO provides important information on the volatile-rich (e.g. water) nature of primitive NEOs, which may be particularly important for future space resource utilization as well as providing critical information for the security of Earth. MARCO POLO is a proposal offering several options, leading to great flexibility in the actual implementation. The baseline mission scenario is based on a launch with a Soyuz-type launcher and consists of a Mother Spacecraft (MSC) carrying a possible Lander named SIFNOS, small hoppers, sampling devices, a re-entry capsule and scientific payloads. The MSC leaves Earth orbit, cruises toward the target with ion engines, rendezvous with the target, conducts a global characterization of the target to select a sampling site, and delivers small

The Pan-STARRS search for Near-Earth Objects

NASA Astrophysics Data System (ADS)

Wainscoat, Richard J.; Weryk, Robert; Chambers, Kenneth

2018-01-01

The Pan-STARRS1 telescope on Haleakala, Hawaii has become the leading discovery telescope for Near-Earth Objects (NEOs), and is now responsible for discovering almost half of all new NEOs, more than half of all larger NEOs, and more than half of all new comets. The survey routinely reaches depths of V=22 or fainter (in dark sky conditions) over an area of approximately 1,000 square degrees per night. The survey strategy will be described. The survey will soon be augmented by the addition of the Pan-STARRS2 telescope, which has similar optics and an improved camera, and which will roughly double the survey power. A sample of the important recent solar system discoveries made by the Pan-STARRS survey will be summarized.

The Mission Accessible Near-Earth Object Survey (MANOS): Project Overview

NASA Astrophysics Data System (ADS)

Moskovitz, Nicholas; Polishook, David; Thomas, Cristina; Willman, Mark; DeMeo, Francesca; Mommert, Michael; Endicott, Thomas; Trilling, David; Binzel, Richard; Hinkle, Mary; Siu, Hosea; Neugent, Kathryn; Christensen, Eric; Person, Michael; Burt, Brian; Grundy, Will; Roe, Henry; Abell, Paul; Busch, Michael

2014-11-01

The Mission Accessible Near-Earth Object Survey (MANOS) began in August 2013 as a multi-year physical characterization survey that was awarded survey status by NOAO. MANOS will target several hundred mission-accessible NEOs across visible and near-infrared wavelengths, ultimately providing a comprehensive catalog of physical properties (astrometry, light curves, spectra). Particular focus is paid to sub-km NEOs, for which little data currently exists. These small bodies are essential to understanding the link between meteorites and asteroids, pose the most immediate impact hazard to the Earth, and are highly relevant to a variety of planetary mission scenarios. Accessing these targets is enabled through a combination of classical, queue, and target-of-opportunity observations carried out at 1- to 8-meter class facilities in both the northern and southern hemispheres. The MANOS observing strategy is specifically designed to rapidly characterize newly discovered NEOs before they fade beyond observational limits. MANOS will provide major advances in our understanding of the NEO population as a whole and for specific objects of interest. Here we present an overview of the survey, progress to date, and early science highlights including: (1) an estimate of the taxonomic distribution of spectral types for NEOs smaller than ~100 meters, (2) the distribution of rotational properties for approximately 100 previously unstudied objects, (3) models for the dynamical evolution of the overall NEO population over the past 0.5 Myr, and (4) progress in developing a new set of online tools at asteroid.lowell.edu that will enable near realtime public dissemination of our data while providing a portal to facilitate coordination efforts within the small body observer community.MANOS is supported through telescope allocations from NOAO and Lowell Observatory. We acknowledge funding support from an NSF Astronomy and Astrophysics Postdoctoral Fellowship to N. Moskovitz and NASA NEOO grant

The search for Near Earth Objects - why dark skies are critically important

NASA Astrophysics Data System (ADS)

Wainscoat, Richard

2015-08-01

Impact of Earth by asteroids is perhaps the only natural disaster that can be prevented. If an asteroid that will impact Earth can be identified sufficiently early, it is possible to modify its orbit to eliminate the impact. As a consequence, a major effort is presently underway to identify Near Earth Objects (NEOs) that may present a threat to Earth. The impact of a 20-meter diameter object near Chelyabinsk, Russia, provided a spectacular reminder of the threat that these objects present. Although no deaths were caused, injuries and a large amount of property damage were caused.The search for NEOs is mostly funded by NASA. The principal search telescopes are the Pan-STARRS telescopes, located on Haleakala, Maui, Hawaii, and the Catalina Sky Survey, located near Tucson, Arizona. Both of these locations are seriously threatened by light pollution. A new survey, ATLAS, will commence shortly, with one telescope located on Haleakala, Maui, and the other telescope located on Mauna Loa, Hawaii (which is less threatened).Artificial light (i.e., light pollution) at these observing sites raises the sky background, and makes faint objects harder or impossible to see.Searches for Near Earth Objects typically use very broad passbands in order to obtain the maximum amount of light. These passbands typically stretch from 400 to 820 nm. As such, they are very vulnerable to the changes in lighting that are occurring across the globe, with widespread introduction of blue-rich white lighting. It is critically important in all of these locations to limit the amount of blue light that is so readily scattered by the atmosphere.A network of followup telescopes, spread across the planet, play a crucial role in the discovery of NEOs. After a new NEO is identified by the survey telescopes such as Pan-STARRS and Catalina, additional observations must be secured to establish its orbit, and in order to determine whether it poses a threat to Earth. The majority of these followup telescopes are

Scientific Exploration of Near-Earth Objects via the Crew Exploration Vehicle

NASA Technical Reports Server (NTRS)

Abell, P. A.; Korsmeyer, D. J.; Landis, R. R.; Lu, E.; Adamo, D.; Jones, T.; Lemke, L.; Gonzales, A.; Gershman, B.; Morrison, D.;

The Large Synoptic Survey Telescope: Projected Near-Earth Object Discovery Performance

NASA Technical Reports Server (NTRS)

Chesley, Steven R.; Veres, Peter

2016-01-01

The Large Synoptic Survey Telescope (LSST) is a large-aperture, wide-field survey that has the potential to detect millions of asteroids. LSST is under construction with survey operations slated to begin in 2022. We describe an independent study to assess the performance of LSST for detecting and cataloging near-Earth objects (NEOs). A significant component of the study will be to assess the survey's ability to link observations of a single object from among the large numbers of false detections and detections of other objects. We also will explore the survey's basic performance in terms of fraction of NEOs discovered and cataloged, both for the planned baseline survey, but also for enhanced surveys that are more carefully tuned for NEO search, generally at the expense of other science drivers. Preliminary results indicate that with successful linkage under the current baseline survey LSST would discover approximately 65% of NEOs with absolute magnitude H is less than 22, which corresponds approximately to 140m diameter.

The global impact distribution of Near-Earth objects

NASA Astrophysics Data System (ADS)

Rumpf, Clemens; Lewis, Hugh G.; Atkinson, Peter M.

2016-02-01

Asteroids that could collide with the Earth are listed on the publicly available Near-Earth object (NEO) hazard web sites maintained by the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). The impact probability distribution of 69 potentially threatening NEOs from these lists that produce 261 dynamically distinct impact instances, or Virtual Impactors (VIs), were calculated using the Asteroid Risk Mitigation and Optimization Research (ARMOR) tool in conjunction with OrbFit. ARMOR projected the impact probability of each VI onto the surface of the Earth as a spatial probability distribution. The projection considers orbit solution accuracy and the global impact probability. The method of ARMOR is introduced and the tool is validated against two asteroid-Earth collision cases with objects 2008 TC3 and 2014 AA. In the analysis, the natural distribution of impact corridors is contrasted against the impact probability distribution to evaluate the distributions' conformity with the uniform impact distribution assumption. The distribution of impact corridors is based on the NEO population and orbital mechanics. The analysis shows that the distribution of impact corridors matches the common assumption of uniform impact distribution and the result extends the evidence base for the uniform assumption from qualitative analysis of historic impact events into the future in a quantitative way. This finding is confirmed in a parallel analysis of impact points belonging to a synthetic population of 10,006 VIs. Taking into account the impact probabilities introduced significant variation into the results and the impact probability distribution, consequently, deviates markedly from uniformity. The concept of impact probabilities is a product of the asteroid observation and orbit determination technique and, thus, represents a man-made component that is largely disconnected from natural processes. It is important to consider impact

How Many Ultra-Low Delta-v Near Earth Objects Remain Undiscovered? Implications for missions.

NASA Astrophysics Data System (ADS)

Elvis, Martin; Ranjan, Sukrit; Galache, Jose Luis; Murphy, Max

2015-08-01

The past decade has witnessed considerable growth of interest in missions to Near-Earth Objects (NEOs). NEOs are considered prime targets for manned and robotic missions, for both scientific objectives as well as in-situ resource utilization including harvesting of water for propellant and life support and mining of high-value elements for sale on Earth. Appropriate targets are crucial to such missions. Hence, ultra-low delta-v mission targets are strongly favored. Some mission architectures rely on the discovery of more ultra-low delta-v NEOs. In fact the approved and executed NEO missions have all targeted asteroids with ultra-low LEO to asteroid rendezvous delta-v <5.5 km/s.In this paper, we estimate the total NEO population as a function of delta-v, and how many remain to be discovered in various size ranges down to ~100m. We couple the NEOSSat-1 model (Greenstreet et al., 2012) to the NEO size distribution derived from the NEOWISE survey (Mainzer et al., 2011b) to compute an absolute NEO population model. We compare the Minor Planet Center (MPC) catalog of known NEOs to this NEO population model. We compute the delta-v from LEO to asteroid rendezvous orbits using a modified Shoemaker-Helin (S-H) formalism that empirically removes biases found comparing S-H with the results from NHATS. The median delta-v of the known NEOs is 7.3 km/s, the median delta-v predicted by our NEO model is 9.8 km/s, suggesting that undiscovered objects are biased to higher delta-v. The survey of delta-v <10.3 km/s NEOs is essentially complete for objects with diameter D >300 m. However, there are tens of thousands of objects with delta-v <10.3 km/s to be discovered in the D = 50 - 300 m size class (H = 20.4 - 24.3). Our work suggests that there are 100 yet-undiscovered NEOs with delta-v < 5:8 km/s, and 1000 undiscovered NEOs with v < 6.3 km/s. We conclude that, even with complete NEO surveys, the selection of good (i.e. ultra-low delta-v) mission targets is limited given current

Near-Earth Objects: Targets for Future Human Exploration, Solar System Science, and Planetary Defense

NASA Technical Reports Server (NTRS)

Abell, Paul A.

2011-01-01

Human exploration of near-Earth objects (NEOs) beginning circa 2025 - 2030 is one of the stated objectives of U.S. National Space Policy. Piloted missions to these bodies would further development of deep space mission systems and technologies, obtain better understanding of the origin and evolution of our Solar System, and support research for asteroid deflection and hazard mitigation strategies. This presentation will discuss some of the physical characteristics of NEOs and review some of the current plans for NEO research and exploration from both a human and robotic mission perspective.

Near-Earth-Object identification over apparitions using n-body ranging

NASA Astrophysics Data System (ADS)

Granvik, Mikael; Muinonen, Karri

2007-05-01

Earth-based telescopes can observe Near-Earth objects (NEOs) continuously for a few weeks or months during each apparition. Due to the usually complicated dynamics of the Sun-Earth-NEO triplet, the time interval between consecutive apparitions typically ranges from months to several years. On these timescales single-apparition sets of observations (SASs) having reasonably small observational time-intervals lead to substantial orbital uncertainties. The linking of SASs over apparitions thus becomes a nontrivial task. Of a total of roughly 4,100 NEO observation sets, or orbits, currently known, some 500 are SASs for which the observational time interval is less than 7 days. Either these SASs have not been observed at an apparition following the discovery apparition (some 40% of the above NEO SASs have been obtained in 2005 or later), or the linkage of SASs has failed, an option which should preferably be eliminated. As a continuation to our work on the short-arc linking problem at the discovery moment (Granvik and Muinonen, 2005, Icarus 179, p. 109), we have investigated the possibility of using a similar method for the linking of SASs over apparitions. Assuming that the observational time-interval for SASs of NEOs is typically at least one day (minimum requirement set by the Minor Planet Center), the orbital-element probability density function is constrained as compared to the typical short-arc case with an observational time interval of only a few tens of minutes. Because of the smaller orbital-element uncertainty, we can use the short-arc method (comparison in ephemeris space) for longer time spans, or even do the comparison directly in orbital-element space (Keplerian, equinoctial, etc.), thus allowing us to assess the problem of linking SASs of NEOs. We will present linking results by using both simulated and real NEO SASs.

The LCOGT near-Earth-object follow-up network

NASA Astrophysics Data System (ADS)

Lister, T.

2014-07-01

Las Cumbres Observatory Global Telescope (LCOGT) network is a planned homogeneous network that will eventually consist of over 35 telescopes at 6 locations in the northern and southern hemispheres [1]. This network is versatile and designed to respond rapidly to target of opportunity events and also to do long term monitoring of slowly changing astronomical phenomena. The global coverage of the network and the apertures of telescope available make the LCOGT network ideal for follow-up and characterization of a wide range of solar-system objects (e.g. asteroids, Kuiper-belt objects, comets) and in particular near-Earth objects (NEOs). There are 3 classes to the telescope resources: 2-meter aperture, 1-meter aperture and 0.4-meter aperture. We have been operating our two 2-meter telescopes since 2005 and began a specific program of NEO follow-up for the Pan-STARRS survey in October 2010. The combination of all-sky access, large aperture, rapid response, robotic operation and good site conditions allows us to provide time-critical follow-up astrometry and photometry on newly discovered objects and faint objects as they recede from the Earth, allowing the orbital arc to be extended and preventing loss of objects. These telescope resources have greatly increased as LCOGT has completed the first phase of the deployment, designated as ''Version 1.0'', with the installation, commissioning and ongoing operation of nine 1-meter telescopes. These are distributed among four sites with one 1-meter at McDonald Observatory (Texas), three telescopes at Cerro Tololo (Chile), three telescopes at SAAO (South Africa) and the final two telescope at Siding Spring Observatory (Australia). In addition to the 1-meter network, the scheduling and control system for the two 2-meter telescopes have been upgraded and unified with that of the 1-meter network to provide a coherent robotic telescopic network. The telescope network is now operating and observations are being executed remotely and

Strategy for NEO follow-up observations

NASA Astrophysics Data System (ADS)

Tichy, Milos; Honkova, Michaela; Ticha, Jana; Kocer, Michal

2015-03-01

The Near-Earth Objects (NEOs) belong to the most important small bodies in the solar system, having the capability of close approaches to the Earth and even possibility to collide with the Earth. In fact, it is impossible to calculate reliable orbit of an object from a single night observations. Therefore it is necessary to extend astrometry dataset by early follow-up astrometry. Follow-up observations of the newly discovered NEO candidate should be done over an arc of several hours after the discovery and should be repeated over several following nights. The basic service used for planning of the follow-up observations is the NEO Confirmation Page (NEOCP) maintained by the Minor Planet Center of the IAU. This service provides on-line tool for calculating geocentric and topocentic ephemerides and sky-plane uncertainty maps of these objects at the specific date and time. Uncertainty map is one of the most important information used for planning of follow-up observation strategy for given time, indicating also the estimated distance of the newly discovered object and including possibility of the impact. Moreover, observatories dealing with NEO follow-up regularly have prepared their special tools and systems for follow-up work. The system and strategy for the NEO follow-up observation used at the Klet Observatory are described here. Methods and techniques used at the Klet NEO follow-up CCD astrometric programme, using 1.06-m and 0.57-m telescopes, are also discussed.

How to Communicate Near Earth Objects with the Public - Klet Observatory Experience

NASA Astrophysics Data System (ADS)

Ticha, Jana; Tichy, Milos; Kocer, Michal

2015-08-01

Near-Earth Object (NEO) research is counted among the most popular parts of communicating astronomy with the public. Increasing research results in the field of Near-Earth Objects as well as impact hazard investigations cause growing interest among general public and media. Furthermore NEO related issues have outstanding educational value. So thus communicating NEO detection, NEO characterization, possible impact effects, space missions to NEOs, ways of mitigation and impact warnings with the public and media belong to the most important tasks of scientists and research institutions.Our institution represents an unique liaison of the small professional research institution devoted especially to NEO studies (the Klet Observatory, Czech Republic) and the educational and public outreach branch (the Observatory and Planetarium Ceske Budejovice, Czech Republic). This all has been giving us an excellent opportunity for bringing NEO information to wider audience. We have been obtaining a wide experience in communicating NEOs with the public more than twenty years.There is a wide spectrum of public outreach tools aimed to NEO research and hazard. As the most useful ones we consider two special on-line magazines (e-zins) devoted to asteroids (www.planetky.cz) and comets (www.komety.cz) in Czech language, educational multimedia presentations for schools at different levels in planetarium, summer excursions for wide public just at the Klet Observatory on the top of the Klet mountain, public lectures, meetings and exhibitions. It seems to be very contributing and favoured by public to have opportunities for more or less informal meetings just with NEO researchers from time to time. Very important part of NEO public outreach consists of continuous contact with journalists and media including press releases, interviews, news, periodical programs. An increasing role of social media is taken into account through Facebook and Twitter profiles.The essential goal of all mentioned NEO

Projected Near-Earth Object Discovery Performance of the Large Synoptic Survey Telescope

NASA Technical Reports Server (NTRS)

Chesley, Steven R.; Veres, Peter

2017-01-01

This report describes the methodology and results of an assessment study of the performance of the Large Synoptic Survey Telescope (LSST) in its planned efforts to detect and catalog near-Earth objects (NEOs).

The Size Distribution of Near-Earth Objects Larger Than 10 m

NASA Astrophysics Data System (ADS)

Trilling, D. E.; Valdes, F.; Allen, L.; James, D.; Fuentes, C.; Herrera, D.; Axelrod, T.; Rajagopal, J.

2017-10-01

We analyzed data from the first year of a survey for Near-Earth Objects (NEOs) that we are carrying out with the Dark Energy Camera (DECam) on the 4 m Blanco telescope at the Cerro Tololo Inter-American Observatory. We implanted synthetic NEOs into the data stream to derive our nightly detection efficiency as a function of magnitude and rate of motion. Using these measured efficiencies and the solar system absolute magnitudes derived by the Minor Planet Center for the 1377 measurements of 235 unique NEOs detected, we directly derive, for the first time from a single observational data set, the NEO size distribution from 1 km down to 10 m. We find that there are {10}6.6 NEOs larger than 10 m. This result implies a factor of 10 fewer small NEOs than some previous results, though our derived size distribution is in good agreement with several other estimates.

Feasibility study for near-earth-object tracking by a piggybacked micro-satellite with penetrators

NASA Astrophysics Data System (ADS)

Weiss, P.; Leung, W.; Yung, K. L.

2010-05-01

As of August 2007, over 5000 near-earth-objects (NEO) have been discovered. Some already represent a potential danger to the Earth while others might become hazards in the future. The Planetary Society organised in 2007 the "Apophis Mission Design Competition" in response to this potential threat with the objective to identify promising concepts to track NEOs; the asteroid 99942 Apophis was taken as the study case. This paper describes the "Houyi" proposal which was evaluated by the competition jury as an innovative approach to this problem. Instead of launching a large satellite for NEO tracking, this novel concept proposes a miniaturized satellite that is piggybacked onto a larger (scientific) mission. Such mission design would drastically reduce the costs for NEO surveillance. The presented scenario uses the ESA's SOLO mission as a design baseline for the piggyback option. This paper summarizes the architecture of this CubeSat towards Apophis and extends the previous study by focusing on the feasibility of a piggybacked mission in terms of propulsion requirements.

A Low Risk Strategy for the Exploration of Near-Earth Objects

NASA Technical Reports Server (NTRS)

Landis, Rob R.

2011-01-01

The impetus for asteroid exploration is scientific, political, and pragmatic. The notion of sending human explorers to asteroids is not new. Piloted missions to these primitive bodies were first discussed in the 1960s, pairing Saturn V rockets with enhanced Apollo spacecraft to explore what were then called "Earth-approaching asteroids." Two decades ago, NASA's Space Exploration Initiative (SEI) also briefly examined the possibility of visiting these small celestial bodies. Most recently, the U.S. Human Space Flight Review Committee (the second Augustine Commission) suggested that near-Earth objects (NEOs) represent a target-rich environment for exploration via the "Flexible Path" option. However, prior to seriously considering human missions to NEOs, it has become clear that we currently lack a robust catalog of human accessible targets. The majority of the NEOs identified by a study team across several NASA centers as "human-accessible" are probably too small and have orbits that are too uncertain to consider mounting piloted expeditions to these small worlds. The first step in developing such a catalog is, therefore, to complete a space-based NEO survey. The resulting catalog of candidate NEOs would then be transformed into a matrix of opportunities for robotic and human missions for the next several decades. This initial step of a space-based NEO survey first is the linchpin to laying the foundation of a low-risk architecture to venture out and explore these primitive bodies. We suggest such a minimalist framework architecture from 1) extensive ground-based and precursor spacecraft investigations (while applying operational knowledge from science-driven robotic missions), 2) astronaut servicing of spacecraft operating at geosynchronous Earth orbit to retain essential skills and experience, and 3) applying the sum of these skills, knowledge and experience to piloted missions to NEOs.

NASA Space Missions to Asteroids: Protecting the Earth from NEO Impacts

NASA Technical Reports Server (NTRS)

Morrison, David; Berry, William E. (Technical Monitor)

1996-01-01

There is now a general recognition of the hazard of impacts on Earth by comets and asteroids, but there is yet no consensus concerning international actions that should be taken to protect the planet from such impacts. An essential step in the analysis of the situation involves estimating the relative hazard posed by comets and asteroids of different sizes and orbits. All recent studies agree that the larger impacts pose the greater danger, and that our primary concern from the perspective of total risk should be on impacts that are large enough to cause global ecological catastrophe. These global catastrophes are also of special interest, since they (alone among natural disasters) have the potential to destroy civilization. Studies of the sensitivity of the Earth's environment suggest that the energy threshold energy for causing a global catastrophe is at about 1 million megatons, corresponding to impactor diameters of 1.5 to 2 km. This information leads naturally to a strategy of concentrating on the larger NEOs, say those 1 km or more in diameter. This is the rationale for the Spaceguard Survey, which must be the highest priority in mitigation efforts. The second question concerns the value of developing standing defensive systems that could deflect or destroy an incoming NEO. In the case of the asteroids larger than 1 km in diameter, no such system is needed, since there will be ample time (at least several decades) between the discovery of the threatening object by Spaceguard and the requirement to take action against it. In the case of objects smaller than 1 km diameter, development of defensive systems is not cost-effective; there are many greater dangers to persons and property that are much more urgent. Only in the case of large long-period comets is there a rationale for standing defense systems. The question is also raised whether the risks inherent in developing and maintaining a defense system might be greater than the impact risks it is intended to

NEOview: Near Earth Object Data Discovery and Query

NASA Astrophysics Data System (ADS)

Tibbetts, M.; Elvis, M.; Galache, J. L.; Harbo, P.; McDowell, J. C.; Rudenko, M.; Van Stone, D.; Zografou, P.

2013-10-01

Missions to Near Earth Objects (NEOs) figure prominently in NASA's Flexible Path approach to human space exploration. NEOs offer insight into both the origins of the Solar System and of life, as well as a source of materials for future missions. With NEOview scientists can locate NEO datasets, explore metadata provided by the archives, and query or combine disparate NEO datasets in the search for NEO candidates for exploration. NEOview is a software system that illustrates how standards-based interfaces facilitate NEO data discovery and research. NEOview software follows a client-server architecture. The server is a configurable implementation of the International Virtual Observatory Alliance (IVOA) Table Access Protocol (TAP), a general interface for tabular data access, that can be deployed as a front end to existing NEO datasets. The TAP client, seleste, is a graphical interface that provides intuitive means of discovering NEO providers, exploring dataset metadata to identify fields of interest, and constructing queries to retrieve or combine data. It features a powerful, graphical query builder capable of easing the user's introduction to table searches. Through science use cases, NEOview demonstrates how potential targets for NEO rendezvous could be identified by combining data from complementary sources. Through deployment and operations, it has been shown that the software components are data independent and configurable to many different data servers. As such, NEOview's TAP server and seleste TAP client can be used to create a seamless environment for data discovery and exploration for tabular data in any astronomical archive.

Near-Earth Objects: Targets for Future Human Exploration, Solar System Science, Resource Utilization, and Planetary Defense

NASA Technical Reports Server (NTRS)

Abell, Paul A.

2011-01-01

U.S. President Obama stated on April 15, 2010 that the next goal for human spaceflight will be to send human beings to a near-Earth asteroid by 2025. Given this direction from the White House, NASA has been involved in studying various strategies for near-Earth object (NEO) exploration in order to follow U.S. Space Exploration Policy. This mission would be the first human expedition to an interplanetary body beyond the Earth-Moon system and would prove useful for testing technologies required for human missions to Mars and other Solar System destinations. Missions to NEOs would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific investigations of these primitive objects. In addition, the resulting scientific investigations would refine designs for future extraterrestrial resource extraction and utilization, and assist in the development of hazard mitigation techniques for planetary defense. This presentation will discuss some of the physical characteristics of NEOs and review some of the current plans for NEO research and exploration from both a human and robotic mission perspective.

Small Solar Electric Propulsion Spacecraft Concept for Near Earth Object and Inner Solar System Missions

NASA Technical Reports Server (NTRS)

Lang, Jared J.; Randolph, Thomas M.; McElrath, Timothy P.; Baker, John D.; Strange, Nathan J.; Landau, Damon; Wallace, Mark S.; Snyder, J. Steve; Piacentine, Jamie S.; Malone, Shane;

The Mission Accessible Near-Earth Object Survey (MANOS) -- Science Highlights

NASA Astrophysics Data System (ADS)

Moskovitz, Nicholas; Thirouin, Audrey; Binzel, Richard; Burt, Brian; Christensen, Eric; DeMeo, Francesca; Endicott, Thomas; Hinkle, Mary; Mommert, Michael; Person, Michael; Polishook, David; Siu, Hosea; Thomas, Cristina; Trilling, David; Willman, Mark

2015-08-01

Near-Earth objects (NEOs) are essential to understanding the origin of the Solar System through their compositional links to meteorites. As tracers of other parts of the Solar System they provide insight to more distant populations. Their small sizes and complex dynamical histories make them ideal laboratories for studying ongoing processes of planetary evolution. Knowledge of their physical properties is essential to impact hazard assessment. And the proximity of NEOs to Earth make them favorable targets for a variety of planetary mission scenarios. However, in spite of their importance, only the largest NEOs are well studied and a representative sample of physical properties for sub-km NEOs does not exist.MANOS is a multi-year physical characterization survey, originally awarded survey status by NOAO. MANOS is targeting several hundred mission-accessible, sub-km NEOs across visible and near-infrared wavelengths to provide a comprehensive catalog of physical properties (astrometry, light curves, spectra). Accessing these targets is enabled through classical, queue, and target-of-opportunity observations carried out at 1- to 8-meter class facilities in the northern and southern hemispheres. Our observing strategy is designed to rapidly characterize newly discovered NEOs before they fade beyond observational limits.Early progress from MANOS includes: (1) the de-biased taxonomic distribution of spectral types for NEOs smaller than ~100 meters, (2) the distribution of rotational properties for approximately 100 previously unstudied NEOs, (3) detection of the fastest known rotation period of any minor planet in the Solar System, (4) an investigation of the influence of planetary encounters on the rotational properties of NEOs, (5) dynamical models for the evolution of the overall NEO population over the past 0.5 Myr, and (6) development of a new set of online tools at asteroid.lowell.edu that will enable near realtime public dissemination of our data products while

Physical Characterization of Warm Spitzer-observed Near-Earth Objects

NASA Technical Reports Server (NTRS)

Thomas, Cristina A.; Emery, Joshua P.; Trilling, David E.; Delbo, Marco; Hora, Joseph L.; Mueller, Michael

2014-01-01

Near-infrared spectroscopy of Near-Earth Objects (NEOs) connects diagnostic spectral features to specific surface mineralogies. The combination of spectroscopy with albedos and diameters derived from thermal infrared observations can increase the scientific return beyond that of the individual datasets. For instance, some taxonomic classes can be separated into distinct compositional groupings with albedo and different mineralogies with similar albedos can be distinguished with spectroscopy. To that end, we have completed a spectroscopic observing campaign to complement the ExploreNEOs Warm Spitzer program that obtained albedos and diameters of nearly 600 NEOs (Trilling et al., 2010). The spectroscopy campaign included visible and near-infrared observations of ExploreNEOs targets from various observatories. Here we present the results of observations using the low-resolution prism mode (approx. 0.7-2.5 microns) of the SpeX instrument on the NASA Infrared Telescope Facility (IRTF). We also include near-infrared observations of Explore-NEOs targets from the MIT-UH-IRTF Joint Campaign for Spectral Reconnaissance. Our dataset includes near-infrared spectra of 187 ExploreNEOs targets (125 observations of 92 objects from our survey and 213 observations of 154 objects from the MIT survey). We identify a taxonomic class for each spectrum and use band parameter analysis to investigate the mineralogies for the S-, Q-, and V-complex objects. Our analysis suggests that for spectra that contain near-infrared data but lack the visible wavelength region, the Bus-DeMeo system misidentifies some S-types as Q-types. We find no correlation between spectral band parameters and ExploreNEOs albedos and diameters. We investigate the correlations of phase angle with band area ratio and near-infrared spectral slope. We find slightly negative Band Area Ratio (BAR) correlations with phase angle for Eros and Ivar, but a positive BAR correlation with phase angle for Ganymed.The results of our

Astrometric and Photometric Follow-Up of Faint Near Earth Objects

NASA Technical Reports Server (NTRS)

Spahr, Timothy

2004-01-01

During the last year, the Near-Earth Object (NEO) follow-up program at Mt. Hopkins funded by the Near-Earth Object Observations (NEOO) program continued to improve. The Principal Investigator was again granted all the requested observing time. In addition to the requested time on the 4 8 in. telescope, 2 nights were also granted on the MMT for observations of extremely faint main-belt asteroids and NEOs. It is expected that the MMT can easily reach V = 25 over a 24 X 24 arcminute field of view. Improvements in the last year included more tweaks to the automatic astrometric routine for higher-quality astrometric fits. Use of the new USNO-B1.0 reference catalog has allowed the PI to push the average RMS of reference star solutions below 0.2 in.. Shift-and- stack techniques are used to improve the signal-to-noise ratio of the target objects. The 48 in. telescope at Mt. Hopkins is completely automated, and can be run remotely from either the Principal Investigator's office at SAO, or even his study at home. Most observing runs are now done remotely.

Low Cost Multiple Near Earth Object Missions

NASA Astrophysics Data System (ADS)

Smith, D. B.; Klaus, K.; Kaplan, M.

2009-12-01

Commercial spacecraft are available with efficient high power solar arrays and hybrid propulsion systems (Chemical and Solar Electric) that make possible multiple Near Earth Object Missions within Discovery budget limits. Our analysis is based on the Geosynchronous Transfer Orbit Capability (GTOC-3) solution. GTOC-3 assumptions: - Escape from Earth, rendezvous with 3 asteroids, then rendezvous with Earth - Departure velocity below 0.5 km/s - Launch between 2016 and 2025 - Total trip time less than 10 years - Minimum stay time of 60 days at each asteroid - Initial spacecraft mass of 2,000 kg - Thrust of 0.15 N and Isp of 3,000 s - Only Earth GAMs allowed (Rmin = 6,871 km) Preliminary results indicate that for mission objectives we can visit Apophis and any other 2 asteroids on this list or any other 3 asteroids listed. We have considered two spacecraft approaches to accomplish mission objectives: - Case 1: Chemical engine burn to the 1st target, and then solar electric to the 2nd and 3rd targets, or - Case 2: Solar electric propulsion to all 3 targets For both Cases, we assumed an instrument mass of up to 100 kg, power up to 100 W, and s/c bus pointing as good as 12 arc sec.Multi-NEO Mission Candidates

Multiple NEO Rendezvous Using Solar Sails

NASA Technical Reports Server (NTRS)

Johnson, Les; Alexander, Leslie; Fabisinski, Leo; Heaton, Andy; Miernik, Janie; Stough, Rob; Wright, Roosevelt; Young, Roy

2012-01-01

Mission concept is to assess the feasibility of using solar sail propulsion to enable a robotic precursor that would survey multiple Near Earth Objects (NEOs) for potential future human visits. Single spacecraft will rendezvous with and image 3 NEOs within 6 years of launch

FIRST RESULTS FROM THE RAPID-RESPONSE SPECTROPHOTOMETRIC CHARACTERIZATION OF NEAR-EARTH OBJECTS USING UKIRT

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

Mommert, M.; Trilling, D. E.; Petersen, E.

2016-04-15

Using the Wide Field Camera for the United Kingdom Infrared Telescope (UKIRT), we measure the near-infrared colors of near-Earth objects (NEOs) in order to put constraints on their taxonomic classifications. The rapid-response character of our observations allows us to observe NEOs when they are close to the Earth and bright. Here we present near-infrared color measurements of 86 NEOs, most of which were observed within a few days of their discovery, allowing us to characterize NEOs with diameters of only a few meters. Using machine-learning methods, we compare our measurements to existing asteroid spectral data and provide probabilistic taxonomic classificationsmore » for our targets. Our observations allow us to distinguish between S-complex, C/X-complex, D-type, and V-type asteroids. Our results suggest that the fraction of S-complex asteroids in the whole NEO population is lower than the fraction of ordinary chondrites in the meteorite fall statistics. Future data obtained with UKIRT will be used to investigate the significance of this discrepancy.« less

A Space-Based Near-Earth Object Survey Telescope in Support of Human Exploration, Solar System Science, and Planetary Defense

NASA Technical Reports Server (NTRS)

Abell, Paul A.

2011-01-01

Human exploration of near-Earth objects (NEOs) beginning in 2025 is one of the stated objectives of U.S. National Space Policy. Piloted missions to these bodies would further development of deep space mission systems and technologies, obtain better understanding of the origin and evolution of our Solar System, and support research for asteroid deflection and hazard mitigation strategies. As such, mission concepts have received much interest from the exploration, science, and planetary defense communities. One particular system that has been suggested by all three of these communities is a space-based NEO survey telescope. Such an asset is crucial for enabling affordable human missions to NEOs circa 2025 and learning about the primordial population of objects that could present a hazard to the Earth in the future.

Planetary Defense: Options for Deflection of Near Earth Objects

NASA Technical Reports Server (NTRS)

Adams, R. B.; Statham, G.; Hopkins, R.; Chapman, J.; White, S.; Bonometti, J.; Alexander, R.; Fincher, S.; Polsgrove, T.; Kalkstein, M.

2003-01-01

Several recent near-miss encounters with asteroids and comets have focused attention on the threat of a catastrophic impact with the Earth. This document reviews the historical impact record and current understanding of the number and location of Near Earth Objects (NEO's) to address their impact probability. Various ongoing projects intended to survey and catalog the NEO population are also reviewed. Details are then given of an MSFC-led study, intended to develop and assess various candidate systems for protection of the Earth against NEOs. An existing program, used to model the NE0 threat, was extensively modified and is presented here. Details of various analytical tools, developed to evaluate the performance of proposed technologies for protection against the NEO threat, are also presented. Trajectory tools, developed to model the outbound path a vehicle would take to intercept or rendezvous with a target asteroid or comet, are described. Also, details are given of a tool that was created to model both the un-deflected inbound path of an NE0 as well as the modified, post-deflection, path. The number of possible options available for protection against the NE0 threat was too numerous for them to all be addressed within the study; instead, a representative selection were modeled and evaluated. The major output from this work was a novel process by which the relative effectiveness of different threat mitigation concepts can be evaluated during future, more detailed, studies. In addition, several new or modified mathematical models were developed to analyze various proposed protection systems. A summary of the major lessons learned during this study is presented, as are recommendations for future work. It is hoped that this study will serve to raise the level attention about this very real threat and also demonstrate that successful defense is both possible and practicable, provided appropriate steps are taken.

Klenot Project - Near Earth Objects Follow-Up Program

NASA Astrophysics Data System (ADS)

Tichý, Miloš; Tichá, Jana; Kočer, Michal

2016-01-01

NEO research is a great challenge just now - for science, for exploration and for planetary defence. Therefore NEO discoveries, astrometric follow-up, orbit computations as well as physical studies are of high interest both to science community and humankind. The KLENOT Project of the Klet Observatory, South Bohemia, Czech Republic pursued the confirmation, early follow-up, long-arc follow-up and recovery of Near Earth Objects since 2002. Tens of thousands astrometric measurements helped to make inventory of NEOs as well as to understand the NEO population. It ranked among the world most prolific professional NEO follow-up programmes during its first phase from 2002 to 2008. The fundamental improvement of the 1.06-m KLENOT Telescope was started in autumn 2008. The new computer controlled paralactic mount was built to substantially increase telescope-time efficiency, the number of observations, their accuracy and limiting magnitude. The testing observations of the KLENOT Telescope Next Generation (NG) were started in October 2011. The new more efficient CCD camera FLI ProLine 230 was installed in summer 2013. The original Klet Software Package has been continually upgraded over the past two decades of operation. Along with huge hardware changes we have decided for essential changes in software and the whole KLENOT work-flow. Using the current higher computing power available, enhancing and updating our databases and astrometry program, the core of our software package, will prove highly beneficial. Moreover, the UCAC4 as the more precise astrometric star catalog was implemented. The modernized KLENOT System was put into full operation in September 2013. This step opens new possibilities for the KLENOT Project, the long-term European Contribution to Monitoring and Cataloging Near Earth Objects. KLENOT Project Goals are confirmatory observations of newly discovered fainter NEO candidates, early follow-up of newly discovered NEOs, long-arc follow-up astrometry of NEOs

The Catalina Sky Survey for Near-Earth Objects

NASA Astrophysics Data System (ADS)

Christensen, E.

The Catalina Sky Survey (CSS) specializes in the detection of the closest transients in our transient universe: near-Earth objects (NEOs). CSS is the leading NEO survey program since 2005, with a discovery rate of 500-600 NEOs per year. This rate is set to substantially increase starting in 2014 with the deployment of wider FOV cameras at both survey telescopes, while a proposed 3-telescope system in Chile would provide a new and significant capability in the Southern Hemisphere beginning as early as 2015. Elements contributing to the success of CSS may be applied to other surveys, and include 1) Real-time processing, identification, and reporting of interesting transients; 2) Human-assisted validation to ensure a clean transient stream that is efficient to the limits of the system (˜ 1σ); 3) an integrated follow-up capability to ensure threshold or high-priority transients are properly confirmed and followed up. Additionally, the open-source nature of the CSS data enables considerable secondary science (i.e. CRTS), and CSS continues to pursue collaborations to maximize the utility of the data.

A decision analysis approach for risk management of near-earth objects

NASA Astrophysics Data System (ADS)

Lee, Robert C.; Jones, Thomas D.; Chapman, Clark R.

2014-10-01

Risk management of near-Earth objects (NEOs; e.g., asteroids and comets) that can potentially impact Earth is an important issue that took on added urgency with the Chelyabinsk event of February 2013. Thousands of NEOs large enough to cause substantial damage are known to exist, although only a small fraction of these have the potential to impact Earth in the next few centuries. The probability and location of a NEO impact are subject to complex physics and great uncertainty, and consequences can range from minimal to devastating, depending upon the size of the NEO and location of impact. Deflecting a potential NEO impactor would be complex and expensive, and inter-agency and international cooperation would be necessary. Such deflection campaigns may be risky in themselves, and mission failure may result in unintended consequences. The benefits, risks, and costs of different potential NEO risk management strategies have not been compared in a systematic fashion. We present a decision analysis framework addressing this hazard. Decision analysis is the science of informing difficult decisions. It is inherently multi-disciplinary, especially with regard to managing catastrophic risks. Note that risk analysis clarifies the nature and magnitude of risks, whereas decision analysis guides rational risk management. Decision analysis can be used to inform strategic, policy, or resource allocation decisions. First, a problem is defined, including the decision situation and context. Second, objectives are defined, based upon what the different decision-makers and stakeholders (i.e., participants in the decision) value as important. Third, quantitative measures or scales for the objectives are determined. Fourth, alternative choices or strategies are defined. Fifth, the problem is then quantitatively modeled, including probabilistic risk analysis, and the alternatives are ranked in terms of how well they satisfy the objectives. Sixth, sensitivity analyses are performed in

Near-Earth Object Orbit Linking with the Large Synoptic Survey Telescope

NASA Astrophysics Data System (ADS)

Vereš, Peter; Chesley, Steven R.

2017-07-01

We have conducted a detailed simulation of the ability of the Large Synoptic Survey Telescope (LSST) to link near-Earth and main belt asteroid detections into orbits. The key elements of the study were a high-fidelity detection model and the presence of false detections in the form of both statistical noise and difference image artifacts. We employed the Moving Object Processing System (MOPS) to generate tracklets, tracks, and orbits with a realistic detection density for one month of the LSST survey. The main goals of the study were to understand whether (a) the linking of near-Earth objects (NEOs) into orbits can succeed in a realistic survey, (b) the number of false tracks and orbits will be manageable, and (c) the accuracy of linked orbits would be sufficient for automated processing of discoveries and attributions. We found that the overall density of asteroids was more than 5000 per LSST field near opposition on the ecliptic, plus up to 3000 false detections per field in good seeing. We achieved 93.6% NEO linking efficiency for H< 22 on tracks composed of tracklets from at least three distinct nights within a 12 day interval. The derived NEO catalog was comprised of 96% correct linkages. Less than 0.1% of orbits included false detections, and the remainder of false linkages stemmed from main belt confusion, which was an artifact of the short time span of the simulation. The MOPS linking efficiency can be improved by refined attribution of detections to known objects and by improved tuning of the internal kd-tree linking algorithms.

Physical characterization of Warm Spitzer-observed near-Earth objects

NASA Astrophysics Data System (ADS)

Thomas, Cristina A.; Emery, Joshua P.; Trilling, David E.; Delbó, Marco; Hora, Joseph L.; Mueller, Michael

2014-01-01

Near-infrared spectroscopy of Near-Earth Objects (NEOs) connects diagnostic spectral features to specific surface mineralogies. The combination of spectroscopy with albedos and diameters derived from thermal infrared observations can increase the scientific return beyond that of the individual datasets. For instance, some taxonomic classes can be separated into distinct compositional groupings with albedo and different mineralogies with similar albedos can be distinguished with spectroscopy. To that end, we have completed a spectroscopic observing campaign to complement the ExploreNEOs Warm Spitzer program that obtained albedos and diameters of nearly 600 NEOs (Trilling, D.E. et al. [2010]. Astron. J. 140, 770-784. http://dx.doi.org/10.1088/0004-6256/140/3/770). The spectroscopy campaign included visible and near-infrared observations of ExploreNEOs targets from various observatories. Here we present the results of observations using the low-resolution prism mode (˜0.7-2.5 μm) of the SpeX instrument on the NASA Infrared Telescope Facility (IRTF). We also include near-infrared observations of ExploreNEOs targets from the MIT-UH-IRTF Joint Campaign for Spectral Reconnaissance. Our dataset includes near-infrared spectra of 187 ExploreNEOs targets (125 observations of 92 objects from our survey and 213 observations of 154 objects from the MIT survey). We identify a taxonomic class for each spectrum and use band parameter analysis to investigate the mineralogies for the S-, Q-, and V-complex objects. Our analysis suggests that for spectra that contain near-infrared data but lack the visible wavelength region, the Bus-DeMeo system misidentifies some S-types as Q-types. We find no correlation between spectral band parameters and ExploreNEOs albedos and diameters. We investigate the correlations of phase angle with Band Area Ratio and near-infrared spectral slope. We find slightly negative Band Area Ratio (BAR) correlations with phase angle for Eros and Ivar, but a

Characterization of the Interior Density Structure of Near Earth Objects with Muons

NASA Astrophysics Data System (ADS)

Prettyman, T. H.; Sykes, M. V.; Miller, R. S.; Pinsky, L. S.; Empl, A.; Nolan, M. C.; Koontz, S. L.; Lawrence, D. J.; Mittlefehldt, D. W.; Reddell, B. D.

2015-12-01

Near Earth Objects (NEOs) are a diverse population of short-lived asteroids originating from the main belt and Jupiter family comets. Some have orbits that are easy to access from Earth, making them attractive as targets for science and exploration as well as a potential resource. Some pose a potential impact threat. NEOs have undergone extensive collisional processing, fragmenting and re-accreting to form rubble piles, which may be compositionally heterogeneous (e.g., like 2008 TC3, the precursor to Almahata Sitta). At present, little is known about their interior structure or how these objects are held together. The wide range of inferred NEO macroporosities hint at complex interiors. Information about their density structure would aid in understanding their formation and collisional histories, the risks they pose to human interactions with their surfaces, the constraints on industrial processing of NEO resources, and the selection of hazard mitigation strategies (e.g., kinetic impactor vs nuclear burst). Several methods have been proposed to characterize asteroid interiors, including radar imaging, seismic tomography, and muon imaging (muon radiography and tomography). Of these, only muon imaging has the potential to determine interior density structure, including the relative density of constituent fragments. Muons are produced by galactic cosmic ray showers within the top meter of asteroid surfaces. High-energy muons can traverse large distances through rock with little deflection. Muons transmitted through an Itokawa-sized asteroid can be imaged using a compact hodoscope placed on or near the surface. Challenges include background rejection and correction for variations in muon production with surface density. The former is being addressed by hodoscope design. Surface density variations can be determined via radar or muon limb imaging. The performance of muon imaging is evaluated for prospective NEO interior-mapping missions.

The Large Synoptic Survey Telescope as a Near-Earth Object discovery machine

NASA Astrophysics Data System (ADS)

Jones, R. Lynne; Slater, Colin T.; Moeyens, Joachim; Allen, Lori; Axelrod, Tim; Cook, Kem; Ivezić, Željko; Jurić, Mario; Myers, Jonathan; Petry, Catherine E.

2018-03-01

Using the most recent prototypes, design, and as-built system information, we test and quantify the capability of the Large Synoptic Survey Telescope (LSST) to discover Potentially Hazardous Asteroids (PHAs) and Near-Earth Objects (NEOs). We empirically estimate an expected upper limit to the false detection rate in LSST image differencing, using measurements on DECam data and prototype LSST software and find it to be about 450 deg-2. We show that this rate is already tractable with current prototype of the LSST Moving Object Processing System (MOPS) by processing a 30-day simulation consistent with measured false detection rates. We proceed to evaluate the performance of the LSST baseline survey strategy for PHAs and NEOs using a high-fidelity simulated survey pointing history. We find that LSST alone, using its baseline survey strategy, will detect 66% of the PHA and 61% of the NEO population objects brighter than H = 22 , with the uncertainty in the estimate of ± 5 percentage points. By generating and examining variations on the baseline survey strategy, we show it is possible to further improve the discovery yields. In particular, we find that extending the LSST survey by two additional years and doubling the MOPS search window increases the completeness for PHAs to 86% (including those discovered by contemporaneous surveys) without jeopardizing other LSST science goals (77% for NEOs). This equates to reducing the undiscovered population of PHAs by additional 26% (15% for NEOs), relative to the baseline survey.

KLENOT Project - Near Earth Objects Follow-up Program

NASA Astrophysics Data System (ADS)

Tichy, Milos; Ticha, Jana; Kocer, Michal; Tichy, Milos

2015-08-01

Near Earth Object (NEO) research is important not only as a great challenge for science but also as an important challenge for planetary defense. Therefore NEO discoveries, astrometric follow-up, orbit computations as well as physical studies are of high interest both to science community and humankind.The KLENOT Project of the Klet Observatory, South Bohemia, Czech Republic pursued the confirmation, early follow-up, long-arc follow-up and recovery of NEOs since 2002. Tens of thousands astrometric measurements helped to make inventory of NEOs as well as to understand the NEO distribution. It ranked among the world most prolific professional NEO follow-up programmes during its first phase from 2002 to 2008.The fundamental improvement of the 1.06-m KLENOT Telescope was started in autumn 2008. The new computer controlled paralactic mount was built to substantially increase telescope-time efficiency, the number of observations, their accuracy and limiting magnitude. The testing observations of the KLENOT Telescope Next Generation were started in October 2011. The new more efficient CCD camera FLI ProLine 230 was installed in summer 2013.The original Klet Software Package has been continually upgraded over the past two decades of operation.Both the system and strategy for the NEO follow-up observation used in the framework of the KLENOT Project are described here, including methods for selecting useful and important targets for NEO follow-up astrometry.The modernized KLENOT System was put into full operation in September 2013. More than 8000 of minor planet and comet astrometric positions including NEA measurements were published from September 2013 to February 2015.The 1.06-m KLENOT telescope is still the largest telescope in continental Europe used exclusively for observations of asteroids and comets. Full observing time is dedicated to the KLENOT team. Considering our results and long-time experience obtained at the Klet Observatory, we have the large potential to

NASA Earth Observations (NEO): Data Access for Informal Education and Outreach

NASA Technical Reports Server (NTRS)

Ward, Kevin; Herring, David

2005-01-01

The NEO (NASA Earth Observations) web space is currently under development with the goal of significantly increasing the demand for NASA remote sensing data while dramatically simplifying public access to georeferenced images. NEO will target the unsophisticated, nontraditional data users who are currently underserved by the existing data ordering systems. These users will include formal and informal educators, museum and science center personnel, professional communicators, and citizen scientists and amateur Earth observers. Users will be able to view and manipulate georeferenced browse imagery and, if they desire, download directly or order the source HDF data from the data provider (e.g., NASA DAAC or science team) via a single, integrated interface. NE0 will accomplish this goal by anticipating users expectations and knowledge level, thus providing an interface that presents material to users in a more simplified manner, without relying upon the jargon/technical terminology that make even the identification of the appropriate data set a significant hurdle. NEO will also act as a gateway that manages users expectations by providing specific details about images and data formats, developing tutorials regarding the manipulation of georeferenced imagery and raw data, links to software tools and ensuring that users are able to get the image they want in the format they want as easily as possible.

Debiased orbit and absolute-magnitude distributions for near-Earth objects

NASA Astrophysics Data System (ADS)

Granvik, Mikael; Morbidelli, Alessandro; Jedicke, Robert; Bolin, Bryce; Bottke, William F.; Beshore, Edward; Vokrouhlický, David; Nesvorný, David; Michel, Patrick

2018-09-01

The debiased absolute-magnitude and orbit distributions as well as source regions for near-Earth objects (NEOs) provide a fundamental frame of reference for studies of individual NEOs and more complex population-level questions. We present a new four-dimensional model of the NEO population that describes debiased steady-state distributions of semimajor axis, eccentricity, inclination, and absolute magnitude H in the range 17 < H < 25. The modeling approach improves upon the methodology originally developed by Bottke et al. (2000, Science 288, 2190-2194) in that it is, for example, based on more realistic orbit distributions and uses source-specific absolute-magnitude distributions that allow for a power-law slope that varies with H. We divide the main asteroid belt into six different entrance routes or regions (ER) to the NEO region: the ν6, 3:1J, 5:2J and 2:1J resonance complexes as well as Hungarias and Phocaeas. In addition we include the Jupiter-family comets as the primary cometary source of NEOs. We calibrate the model against NEO detections by Catalina Sky Surveys' stations 703 and G96 during 2005-2012, and utilize the complementary nature of these two systems to quantify the systematic uncertainties associated to the resulting model. We find that the (fitted) H distributions have significant differences, although most of them show a minimum power-law slope at H ∼ 20. As a consequence of the differences between the ER-specific H distributions we find significant variations in, for example, the NEO orbit distribution, average lifetime, and the relative contribution of different ERs as a function of H. The most important ERs are the ν6 and 3:1J resonance complexes with JFCs contributing a few percent of NEOs on average. A significant contribution from the Hungaria group leads to notable changes compared to the predictions by Bottke et al. in, for example, the orbit distribution and average lifetime of NEOs. We predict that there are 962-56+52 (802-42+48 �

The LCOGT NEO Follow-up Network

NASA Astrophysics Data System (ADS)

Lister, Tim; Gomez, Edward; Greenstreet, Sarah

2015-08-01

Las Cumbres Observatory Global Telescope Network (LCOGT) has deployed a homogeneous telescope network of nine 1-meter telescopes to four locations in the northern and southern hemispheres, with a planned network of twelve 1-meter telescopes at 6 locations. This network is very versatile and is designed to respond rapidly to target of opportunity events and also to perform long term monitoring of slowly changing astronomical phenomena. The global coverage of the network and the apertures of telescope available make LCOGT ideal for follow-up and characterization of Solar System objects (e.g. asteroids, Kuiper Belt Objects, comets, Near-Earth Objects (NEOs)) and ultimately for the discovery of new objects.LCOGT has completed the first phase of the deployment with the installation and commissioning of the nine 1-meter telescopes at McDonald Observatory (Texas), Cerro Tololo (Chile), SAAO (South Africa) and Siding Spring Observatory (Australia). The telescope network has been fully operational since 2014 May, and observations are being executed remotely and robotically. Future expansion to sites in the Canary Islands and Tibet is planned for 2016.I am using the LCOGT network to confirm newly detected NEO candidates produced by the major sky surveys such as Catalina Sky Survey (CSS) and PanSTARRS (PS1) and several hundred targets are now being followed-up per year. An increasing amount of time is being spent to obtain follow-up astrometry and photometry for radar-targeted objects and those on the Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) or Asteroid Retrieval Mission (ARM) lists in order to improve the orbits, determine the light curves and rotation periods and improve the characterization. This will be extended to obtain more light curves of other NEOs which could be targets. Recent results have included the first period determinations for several of the Goldstone-targeted NEOs. We are in the process of building a NEO Portal which will allow

A New and Improved Model of the Near-Earth Object Population

NASA Astrophysics Data System (ADS)

Bottke, W. F., Jr.; Granvik, M.; Morbidelli, A.; Jedicke, R.; Bolin, B.; Beshore, E. C.; Vokrouhlicky, D.; Nesvorny, D.; Michel, P.

2014-12-01

This is a golden age for near-Earth Object (NEO) research. We have discovered some 90% of the most threatening NEOs, while ongoing surveys are finding many sub-km NEOs as well. NEO physical characterization studies by missions, space- and ground-based observatories are also revolutionizing our ideas about what NEOs are like. President Obama announced on April 15, 2010 that NASA would send astronauts to an NEA by 2025; this remains Administration policy. The Feb. 15, 2013 explosion of an NEO over Chelyabinsk, Russia, has further boosted interest in NEOs. This increasing interest, and a vast array of new data, have led us to re-investigate the debiased orbital and absolute magnitude distribution of the NEO population. Such models are asboluetly needed to make accurate predictions about NEOs that are likely exploration targets for human and robotic spacecraft. Using the methods of Bottke et al. (2002), we numerically tracked a large unbiased sample of asteroids escaping the main belt and TNO populations in order to locate all possible NEO source regions. From here, we recorded the orbital evolution of the bodies that entering the NEO region; their evolutionary pathways were used to create so-called NEO residence-time distributions. They were combined with the calculated observational selection effects for the Catalina Sky Survey, with the model fit to 4,550 NEOs (15 < H < 25) detected by the Catalina Sky Survey's Mt. Lemmon (G96) and Catalina (703) stations between 2005-2012. Our best fit case beautifully reproduces observations and provides us with a new and improved NEO model population. We find our results are in good agreement with the Bottke et al. (2002) model, but we also find many intriguing differences as well: (i) There is an increasing preference for small NEOs to come from the central main belt; (ii) Many low-perihelion-distance NEOs are apparently missing -- we suspect many were removed by a physical destruction mechanism; (iii) We are largely complete in

Optimal Fragmentation and Dispersion of Hazardous Near-Earth Objects

NASA Technical Reports Server (NTRS)

Wie, Bong

2012-01-01

The complex problem of protecting the Earth from the possibility of a catastrophic impact by a hazardous near-Earth object (NEO) has been recently reassessed in [1]. In a letter on NEOs from the White House Office of Science and Technology Policy (OSTP) to the U.S. Senate and Congress in 2010, the White House OSTP strongly recommended that NASA take the lead in conducting research activities for NEO detection, characterization, and deflection technologies. Furthermore, President Obama's new National Space Policy specifically directs NASA to "pursue capabilities, in cooperation with other departments, agencies, and commercial partners, to detect, track, catalog, and characterize NEOs to reduce the risk of harm to humans from an unexpected impact on our planet." The Planetary Defense Task Force of the NASA Advisory Council also recommended that the NASA Office of the Chief Technologist (OCT) begin efforts to investigate asteroid deflection techniques. With national interest growing in the United States, the NEO threat detection and mitigation problem was recently identified as one of NASA's Space Technology Grand Challenges. An innovative solution to NASA's NEO Impact Threat Mitigation Grand Challenge problem was developed through a NIAC Phase I study (9/16/11 - 9/15/12), and it will be further investigated for a NIAC Phase II study (9/10/12 - 9/9/14). Various NEO deflection technologies, including nuclear explosions, kinetic impactors, and slow-pull gravity tractors, have been proposed and examined during the past two decades. Still, there is no consensus on how to reliably deflect or disrupt hazardous NEOs in a timely manner. It is expected that the most probable mission scenarios will have a mission lead time much shorter than 10 years, so the use of nuclear explosives becomes the most feasible method for planetary defense. Direct intercept missions with a short warning time will result in arrival closing velocities of 10-30 kilometers per second with respect to

Near Earth Objects and Cascading Effects from the Policy Perspective: Implications from Problem and Solution Definition

NASA Astrophysics Data System (ADS)

Lindquist, Eric

2016-04-01

The characterization of near-Earth-objects (NEOs) in regard to physical attributes and potential risk and impact factors presents a complex and complicates scientific and engineering challenge. The societal and policy risks and impacts are no less complex, yet are rarely considered in the same context as material properties or related factors. Further, NEO impacts are typically considered as discrete events, not as initial events in a dynamic cascading system. The objective of this contribution is to position the characterization of NEOs within the public policy process domain as a means to reflect on the science-policy nexus in regard to risks and multi-hazard impacts associated with these hazards. This will be accomplished through, first, a brief overview of the science-policy nexus, followed by a discussion of policy process frameworks, such as agenda setting and the multiple streams model, focusing events, and punctuated equilibrium, and their application and appropriateness to the problem of NEOs. How, too, for example, does NEO hazard and risk compare with other low probability, high risk, hazards in regard to public policy? Finally, we will reflect on the implications of alternative NEO "solutions" and the characterization of the NEO "problem," and the political and public acceptance of policy alternatives as a way to link NEO science and policy in the context of the overall NH9.12 panel.

NEO-LISP: Deflecting near-Earth objects using high average power, repetitively pulsed lasers

NASA Astrophysics Data System (ADS)

Phipps, C. R.; Michaelis, M. M.

Several kinds of Near-Earth objects exist for which one would like to cause modest orbit perturbations, but which are inaccessible to normal means of interception because of their number, distance or the lack of early warning. For these objects, LISP (Laser Impulse Space Propulsion) is an appropriate technique for rapidly applying the required mechanical impulse from a ground-based station. In order of increasing laser energy required, examples are: (1) repositioning specially prepared geosynchronous satellites for an enhanced lifetime; (2) causing selected items of space junk to re-enter and burn up in the atmosphere on a computed trajectory; and (3) safely deflecting Earth-directed comet nuclei and earth-crossing asteroids (ECA's) a few tens of meters in size (the most hazardous size). They will discuss each of these problems in turn and show that each application is best matched by its own matrix of LISP laser pulse width, pulse repetition rate, wavelength and average power. The latter ranges from 100W to 3GW for the cases considered. They will also discuss means of achieving the active beam phase error correction during passage through the atmosphere and very large exit pupil in the optical system which are required in each of these cases.

NEO follow-up, recovery and precovery campaigns at the ESA NEO Coordination Centre

NASA Astrophysics Data System (ADS)

Micheli, Marco; Koschny, Detlef; Drolshagen, Gerhard; Perozzi, Ettore; Borgia, Barbara

2016-01-01

The NEO Coordination Centre (NEOCC) has been established within the framework of the ESA Space Situational Awareness (SSA) Programme. Among its tasks are the coordination of observational activities and the distribution of up-to-date information on NEOs through its web portal. The Centre is directly involved in observational campaigns with various telescopes, including ESO's VLT and ESA's OGS telescope. We are also developing a network of collaborating observatories, with a variety of capabilities, which are alerted when an important observational opportunity arises. From a service perspective, the system hosted at the NEOCC collects information on NEOs produced by European services and makes it available to users, with a focus on objects with possible collisions with the Earth. Among the tools provided via our portal are the Risk List of all known NEOs with impact solutions, and the Priority List, which allows observers to identify NEOs in most urgent need of observations.

Introducing the Benson Prize for Discovery Methods of Near Earth Objects by Amateurs

NASA Astrophysics Data System (ADS)

Benson, J. W.

1997-05-01

The Benson Prize Sponsored by Space Development Corporation The Benson Prize for Discovery Methods of Near Earth Objects by Amateurs is an annual competition which awards prizes to the best proposed methods by which amateur astronomers may discover such near earth objects as asteroids and comet cores. The purpose of the Benson Prize is to encourage the discovery of near earth objects by amateur astronomers. The utilization of valuable near earth resources can provide many new jobs and economic activities on earth, while also creating many new opportunities for opening up the space frontier. The utilization of near earth resources will significantly contribute to the lessening of environmental degradation on the Earth caused by mining and chemical leaching operations required to exploit the low grade ores now remaining on Earth. In addition, near earth objects pose grave dangers for life on earth. Discovering and plotting the orbits of all potentially dangerous near earth objects is the first and necessary step in protecting ourselves against the enormous potential damage possible from near earth objects. With the high quality, large size and low cost of todays consumer telescopes, the rapid development of powerful, high resolution and inexpensive CCD cameras, and the proliferation of inexpensive software for todays powerful home computers, the discovery of near earth objects by amateur astronomers is more attainable than ever. The Benson Prize is sponsored by the Space Development Corporation, a space resource exploration and utilization company. In 1997 one prize of \\500 will be awarded to the best proposed method for the amateur discovery of NEOs, and in each of the four following years, Prizes of \\500, \\250 and \\100 will be awarded. Prizes for the actual discovery of Near Earth Asteroids will be added in later years.

Physical Characterization of the Near-Earth Object Population

NASA Technical Reports Server (NTRS)

Binzel, Richard P.

2004-01-01

Many pieces of the puzzle must be brought together in order to have a clear picture of the near-Earth object (NEO) population. Four of the pieces that can be described include: i) the taxonomic distribution of the population as measured by observational sampling, ii) the determination of albedos that can be associated with the taxonomic distribution, iii) discovery statistics for the NE0 population, and iv) the debiasing of the discovery statistics using the taxonomic and albedo information. Support from this grant enables us to address three of these four pieces. Binzel et al. (2004, submitted) presents the first piece, detailing the observations and observed characteristics of the NE0 and Mars-crossing (MC) population. For the second piece, a complementary program of albedo measurements is pursued at the Keck Observatory (Binzel, P. I.) with first results published in Delbo et al. (2003). For the third piece, the most extensive NE0 discovery statistics are provided by the LINEAR survey. Binzel has supervised the MIT Ph. D. thesis work of Stuart (2003) to bring the fourth piece, submitted for publication by Stuart and Binzel (2004). Our results provide new constraints for the NE0 population and progress for the Spaceguard Survey, illuminate asteroid and comet source regions for the NEOs, and provide new evidence for space weathering processes linking asteroids and meteorites. Further, we are identifying top priority near-Earth spacecraft mission candidates based on their spectral properties and inferred compositions.

The Undiscovered Country: How Many Low-Delta-V Near-Earth Objects Remain to be Found?

NASA Astrophysics Data System (ADS)

Elvis, Martin; Ranjan, Sukrit; Galache, Jose Luis

2014-11-01

Low delta-v near-Earth objects (NEOs) are of great interest as targets for science and human missions, for possible retrieval to cis-lunar space and as potential resource targets for both exploration and commercial uses. This interest stems from the exponential nature of the rocket equation that imposes a harsh mass penalty on any mission to a higher delta-v. We have compared the known NEO population from the IAU Minor Planet Center (MPC) with the NEOSSat-1 model residence times for the NEO population (Greenstreet & Gladman, 2012) to assess how many undiscovered NEOs there are as a function of H magnitude and delta-v. We find that the median of known NEOs is at lower delta-v (7.3 km/s) than the model population (9.8 km/s), suggesting a bias toward detecting lower delta-v NEOs. To the precision of our data, which is as low as 40% for the 300-500 m diameter (D) objects, the bulk of the larger D>300 m NEOs have been found from delta-v<10.3 km/s. However in the 50 < D < 300 m range there are tens of thousands of delta-v < 10.3 km/s to be found. We examine the total number of undiscovered NEOs as a function of delta-v and find that to find at least 100 now unknown NEOs requires a threshold delta-v of 5.7 km/s, while to find at least 1000 of them requires a threshold delta-v of 6.2 km/s. These numbers can be used to determine mission delta-v requirements for a given number of suitable targets, that will likely be restricted by other criteria (size, composition, spin state) to a few percent of the total population.

Sky-plane discovery rates for Near Earth Object discoveries from Pan-STARRS1 - implications for future search strategies

NASA Astrophysics Data System (ADS)

Wainscoat, Richard J.; Chambers, Kenneth C.; Chastel, Serge; Denneau, Larry; Lilly Schunova, Eva; Micheli, Marco; Weryk, Robert J.

2016-10-01

The Pan-STARRS1 telescope has been spending most of its time for the last 2.5 years searching the sky for Near Earth Objects (NEOs). The surveyed area covers the entire northern sky and extends south to -49 degrees declination. Because Pan-STARRS1 has a large field-of-view, it has been able survey large areas of the sky, and we are now able to examine NEO discovery rates relative to ecliptic latitude.Most contemporary searches, including Pan-STARRS1, have been spending large amounts of their observing time during the dark moon period searching for NEOs close to the ecliptic. The rationale for this is that many objects have low inclination, and all objects in orbit around the Sun must cross the ecliptic. New search capabilities are now available, including Pan-STARRS2, and the upgraded camera in Catalina Sky Survey's G96 telescope. These allow NEO searches to be conducted over wider areas of the sky, and to extend further from the ecliptic.We have examined the discovery rates relative to location on the sky for new NEOs from Pan-STARRS1, and find that the new NEO discoveries are less concentrated on the ecliptic than might be expected. This finding also holds for larger objects. The southern sky has proven to be very productive in new NEO discoveries - this is a direct consequence of the major NEO surveys being located in the northern hemisphere.Our preliminary findings suggest that NEO searches should extend to at least 30 degrees from the ecliptic during the more sensitive dark moon period. At least 6,000 deg2 should therefore be searched each lunation. This is possible with the newly augmented NEO search assets, and repeat coverage will be needed in order to recover most of the NEO candidates found. However, weather challenges will likely make full and repeated coverage of such a large area of sky difficult to achieve. Some simple coordination between observing sites will likely lead to improvement in efficiency.

Granular Simulation of NEO Anchoring

NASA Technical Reports Server (NTRS)

Mazhar, Hammad

2011-01-01

NASA is interested in designing a spacecraft capable of visiting a Near Earth Object (NEO), performing experiments, and then returning safely. Certain periods of this mission will require the spacecraft to remain stationary relative to the NEO. Such situations require an anchoring mechanism that is compact, easy to deploy and upon mission completion, easily removed. The design philosophy used in the project relies on the simulation capability of a multibody dynamics physics engine. On Earth it is difficult to create low gravity conditions and testing in low gravity environments, whether artificial or in space is costly and therefore not feasible. Through simulation, gravity can be controlled with great accuracy, making it ideally suited to analyze the problem at hand. Using Chrono::Engine [1], a simulation package capable of utilizing massively parallel GPU hardware, several validation experiments will be performed. Once there is sufficient confidence, modeling of the NEO regolith interaction will begin after which the anchor tests will be performed and analyzed. The outcome of this task is a study with an analysis of several different anchor designs, along with a recommendation on which anchor is better suited to the task of anchoring. With the anchors tested against a range of parameters relating to soil, environment and anchor penetration angles/velocities on a NEO.

Methodology and Results of the Near-Earth Object (NEO) Human Space Flight (HSF) Accessible Targets Study (NHATS)

NASA Technical Reports Server (NTRS)

Barbee, Brent; Mink, Ronald; Adamo, Daniel

2011-01-01

Near-Earth Asteroids (NEAs) have been identified by the current administration as potential destinations for human explorers during the mid-2020s. While the close proximity of these objects' orbits to Earth's orbit creates a risk of highly damaging or catastrophic impacts, it also makes some of these objects particularly accessible to spacecraft departing Earth, and this presents unique opportunities for solar system science and humanity's first ventures beyond cislunar space. Planning such ambitious missions first requires the selection of potentially accessible targets from the growing population of nearly 7,800 NEAs. To accomplish this, NASA is conducting the Near-Earth Object (NEO) Human Space Flight (HSF) Accessible Targets Study (NHATS). Phase I of the NHATS was executed during September of 2010, and Phase II was completed by early March of 2011. The study is ongoing because previously undetected NEAs are being discovered constantly, which has motivated an effort to automate the analysis algorithms in order to provide continuous monitoring of NEA accessibility. The NHATS analysis process consists of a trajectory filter and a minimum maximum estimated size criterion. The trajectory filter employs the method of embedded trajectory grids to compute all possible ballistic round-trip mission trajectories to every NEA in the Jet Propulsion Laboratory (JPL) Small-Body Database (SBDB) and stores all solutions that satisfy the trajectory filter criteria. An NEA must offer at least one qualifying trajectory solution to pass the trajectory filter. The Phase II NHATS filter criteria were purposely chosen to be highly inclusive, requiring Earth departure date between January 1st, 2015 and December 31st, 2040, total round-trip flight time <= 450 days, stay time at the NEA >= 8 days, Earth departure C(sub 3) energy <= 60 km(exp 2)/s(exp 2), total mission delta-v <= 12 km/s (including an Earth departure maneuver from a 400 km altitude circular parking orbit), and a maximum

Comparing NEO Search Telescopes

NASA Astrophysics Data System (ADS)

Myhrvold, Nathan

2016-04-01

Multiple terrestrial and space-based telescopes have been proposed for detecting and tracking near-Earth objects (NEOs). Detailed simulations of the search performance of these systems have used complex computer codes that are not widely available, which hinders accurate cross-comparison of the proposals and obscures whether they have consistent assumptions. Moreover, some proposed instruments would survey infrared (IR) bands, whereas others would operate in the visible band, and differences among asteroid thermal and visible-light models used in the simulations further complicate like-to-like comparisons. I use simple physical principles to estimate basic performance metrics for the ground-based Large Synoptic Survey Telescope and three space-based instruments—Sentinel, NEOCam, and a Cubesat constellation. The performance is measured against two different NEO distributions, the Bottke et al. distribution of general NEOs, and the Veres et al. distribution of Earth-impacting NEO. The results of the comparison show simplified relative performance metrics, including the expected number of NEOs visible in the search volumes and the initial detection rates expected for each system. Although these simplified comparisons do not capture all of the details, they give considerable insight into the physical factors limiting performance. Multiple asteroid thermal models are considered, including FRM, NEATM, and a new generalized form of FRM. I describe issues with how IR albedo and emissivity have been estimated in previous studies, which may render them inaccurate. A thermal model for tumbling asteroids is also developed and suggests that tumbling asteroids may be surprisingly difficult for IR telescopes to observe.

A powerful new southern hemisphere survey for near-Earth objects

NASA Astrophysics Data System (ADS)

Christensen, E.; Lister, T.; Larson, S.; Gibbs, A.; Grauer, A.; Hill, R.; Johnson, J.; Kowalski, R.; Sanders, R.; Shelly, F.

2014-07-01

For nearly a decade, the Catalina Sky Survey (CSS) operated the Siding Spring Survey (SSS) in partnership with the Australian National University. The SSS was the only professional, full-time NEO survey in the Southern Hemisphere during this period. The SSS ceased operations in July of 2013, and the lack of a full-time, state-of-the-art survey in the Southern Hemisphere leaves a significant blind spot in NASA's ongoing effort to identify and track near-Earth objects (NEOs) that may pose a hazard to the Earth, or that may be appropriate destinations for robotic or human missions. The CSS and the Las Cumbres Observatory Global Telescope Network (LCOGT) are partnering to fill this gap, by rapidly building, deploying and operating a network of three dedicated 1.0-meter survey telescopes at Cerro Tololo, one of the premiere astronomical sites in the Southern Hemisphere. The partnership between CSS and LCOGT provides a fast-track, low-risk, and cost-effective survey capability that will be fully dedicated to the NEO discovery effort. The first of three survey telescopes will be operational ˜18 months after the start of funding, with the second and third telescopes coming online within an additional ˜12 months. Our joint survey will be a powerful new NEO survey capability. The telescopes are based on the field-tested LCOGT 1.0-m design, modified to feature a faster f/1.8 primary and a prime focus camera that will deliver an 8.6 deg^2 field of view (FOV), with a resolution of 1.0 arcseconds per pixel. The three co-located telescopes will offer the operational flexibility to survey together (acting as a 1.7-m telescope), or separately (effectively delivering a 25+ deg^2 FOV), and will have no competing science goals to compromise from the primary mission of NEO discovery. The telescopes will be robotically operated, and the data will be processed, validated, and reported in near real-time from the CSS headquarters in Tucson. Same-night and subsequent night astrometric

The Economics OF NEOS

NASA Technical Reports Server (NTRS)

Schalkwyk, James D.

2014-01-01

NASA's Ames Research Center, in its role as partnerships lead for NASA asteroid redirect robotic missions and as a supporting Center for the Asteroid Grand Challenge, responded to increasing interest in near-Earth objects (NEOs) by holding a workshop entitled 'The Economics of NEOs' on the 6th and 7th of September 2014. The workshop was intended to serve as a catalyst for discussions and to foster collaborations between industry, academia and government. This document serves as a summary of the discussions which took place within three sessions and their respective table discussions; Session One: Background and Motivation; Session Two: Economics of NEOs; and Session Three: Policy and Legal Frameworks. This document is a collection of observations by individuals and does not express the consensus view of all participants; it does not express US Government or NASA policy.

NEOPROP: A NEO Propagator for Space Situational Awareness

NASA Astrophysics Data System (ADS)

Zuccarelli, Valentino; Bancelin, David; Weikert, Sven; Thuillot, William; Hestroffer, Daniel; Yabar Valle, Celia; Koschny, Detlef

2013-09-01

The overall aim of the Space Situational Awareness (SSA) Preparatory Programme is to support the European independent utilisation of and access to space for research or services, through providing timely and quality data, information, services and knowledge regarding the environment, the threats and the sustainable exploitation of the outer space surrounding our planet Earth. The SSA system will comprise three main segments:• Space Weather (SWE) monitoring and forecast• Near-Earth Objects (NEO) survey and follow-up• Space Surveillance and Tracking (SST) of man-made space objectsCurrently, there are over 600.000 asteroids known in our Solar System, where more than 9.500 of these are NEOs. These could potentially hit our planet and depending on their size could produce considerable damage. For this reason NEOs deserve active detection and tracking efforts.The role of the SSA programme is to provide warning services against potential asteroid impact hazards, including discovery, identification, orbit prediction and civil alert capabilities. ESA is now working to develop a NEO Coordination Centre which will later evolve into a SSA-NEO Small Bodies Data Centre (SBDC), located at ESA/ESRIN, Italy. The Software prototype developed in the frame of this activity may be later implemented as a part of the SSA-NEO programme simulators aimed at assessing the trajectory of asteroids. There already exist different algorithms to predict orbits for NEOs. The objective of this activity is to come up with a different trajectory prediction algorithm, which allows an independent validation of the current algorithms within the SSA-NEO segment (e.g. NEODyS, JPL Sentry System).The key objective of this activity was to design, develop, test, verify, and validate trajectory prediction algorithm of NEOs in order to be able to computeanalytically and numerically the minimum orbital intersection distances (MOIDs).The NEOPROP software consists of two separate modules/tools:1. The

On the existence of near-Earth-object meteoroid complexes producing meteorites

NASA Astrophysics Data System (ADS)

Trigo-Rodriguez, J.; Madiedo, J.; Williams, I.

2014-07-01

It is generally thought that meteorites are formed as a result of collisions within the main belt of asteroids [1]. They are delivered onto Earth-crossing orbits because of the effects of orbital resonances, primarily with Jupiter. About 15 meteorites are known where their passage through the atmosphere was observed and recorded, allowing the parameters of the pre-encounter orbit to be derived [2]. The cosmic-ray-exposure ages (CREAs) are suggesting that most meteorites have been exposed to cosmic rays for tens of millions of years (Myrs) [3], re-enforcing the belief that the process of modifying the orbit from being near-circular in the main belt to highly elliptical as an Earth-crossing orbit was a gradual process like the effects of resonance. However, there is growing evidence that some meteorite could originate directly from the near-Earth-object (NEO) population. A good example of this is the recent discovery of rare primitive groups in the Antarctic, an example being Elephant Moraine (EET) 96026: a C4/5 carbonaceous chondrite with a measured cosmic ray exposure age of only 0.28 Ma [4]. Here, we focus on recent dynamic links that have been established between meteorite-dropping bolides and NEOs that support the idea of short-life meteoroid streams that can generate meteoroids on Earth. The fact that such streams can exist allows rocky material from potentially-hazardous asteroids (PHA) to be sampled and investigated in the laboratory. The existence of meteoroid streams capable of producing meteorites has been proposed following the determination of accurate meteoroid orbits of fireballs obtained by the Canadian Meteorite Observation and Recovery Project (MORP) [5]. Some asteroids in the Earth's vicinity are undergoing both dynamical and collisional evolution on very short timescales [6]. Many of these objects are crumbly bodies that originated from the collisions between main-belt asteroids during their life-time. An obvious method of forming these complexes

The ESA SSA NEO Coordination Centre contribution to NEO hazard monitoring and observational campaigns

NASA Astrophysics Data System (ADS)

Micheli, Marco; Borgia, Barbara; Drolshagen, Gerhard; Koschny, Detlef; Perozzi, Ettore

2015-08-01

The NEO Coordination Centre (NEOCC) has recently been established in Frascati, near Rome, within the framework of the ESA Space Situational Awareness (SSA) Programme. Among its tasks is the coordination of observational activities related to the NEO hazard, and the distribution of relevant and up-to-date information on NEOs to both the scientific community and general users through its web portal (http://neo.ssa.esa.int).On the observational side, the NEOCC is linked to an increasingly large worldwide network of collaborating observatories, ranging from amateurs observers to large professional telescopes. The Centre organizes observation campaigns, alerting the network to suggest urgent or high-priority observations, and providing them with observational support.The NEOCC is also directly obtaining astrometric observations of high-priority targets, especially Virtual Impactors (VIs), on challenging objects as faint as magnitude 26.5, thanks to successful collaborations with ESO VLT in Chile and the INAF-sponsored LBT in Arizona. In addition, the Centre carries out regular monthly runs dedicated to NEO follow-up, recovery and survey activities with the 1-meter ESA OGS telescope in Tenerife.From a service perspective, the NEO System hosted at the NEOCC collects data and information on NEOs produced by various European services (e.g. NEODyS, EARN) and makes them available to a variety of users, with a particular focus on objects with possible collision solutions with the Earth. Among the tools provided through the web portal are the Risk List (a table of all known NEOs with impact solutions), a table of recent and upcoming close approaches, a database of physical properties of NEOs and the so-called Priority List, which allows observers to identify NEOs in most urgent need of observations, and prioritise their observational activities accordingly.The results of our recent observation campaigns and some major recent improvements to the NEO System will presented and

Search for Near-Earth Objects with Small Aphelion Distances

NASA Technical Reports Server (NTRS)

Tholen, David J.

2004-01-01

Progress for the period 13 July 2003 through 11 August 2004 is reported. Report topics include personnel, NEO follow-up astrometry, and the continued search for near-Earth asteroids with small aphelion distances.

The population of natural Earth satellites

NASA Astrophysics Data System (ADS)

Granvik, Mikael; Vaubaillon, Jeremie; Jedicke, Robert

2012-03-01

We have for the first time calculated the population characteristics of the Earth’s irregular natural satellites (NESs) that are temporarily captured from the near-Earth-object (NEO) population. The steady-state NES size-frequency and residence-time distributions were determined under the dynamical influence of all the massive bodies in the Solar System (but mainly the Sun, Earth, and Moon) for NEOs of negligible mass. To this end, we compute the NES capture probability from the NEO population as a function of the latter’s heliocentric orbital elements and combine those results with the current best estimates for the NEO size-frequency and orbital distribution. At any given time there should be at least one NES of 1-m diameter orbiting the Earth. The average temporarily-captured orbiter (TCO; an object that makes at least one revolution around the Earth in a co-rotating coordinate system) completes (2.88 ± 0.82) rev around the Earth during a capture event that lasts (286 ± 18) d. We find a small preference for capture events starting in either January or July. Our results are consistent with the single known natural TCO, 2006 RH120, a few-meter diameter object that was captured for about a year starting in June 2006. We estimate that about 0.1% of all meteors impacting the Earth were TCOs.

Planetary Defense. Department of Defense Cost for the Detection, Exploration, and Rendezvous Mission of Near-Earth Objects

DTIC Science & Technology

1997-01-01

or even impact the Earth. In the past 15 years, research on NEOs has dra­ mati cally increased as astrono mers and ge­ olo gists real ize the Earth...fig. 7). In 1989, astrono mers discov ered an aster­ oid labeled 1989FC after its closest approach to Earth. This illus trates a disturb ing fact...Cur rently only astrono mers on shoestring, aca demic budgets are trying to locate and track NEOs, making esti mates of NEO popu­ la tions very impre

Optimization of deflection of a big NEO through impact with a small one.

PubMed

Zhu, Kaijian; Huang, Weiping; Wang, Yuncai; Niu, Wei; Wu, Gongyou

2014-01-01

Using a small near-Earth object (NEO) to impact a larger and potentially threatening NEO has been suggested as an effective method to avert a collision with Earth. This paper develops a procedure for analysis of the technique for specific NEOs. First, an optimization method is used to select a proper small body from the database. Some principles of optimality are achieved with the optimization process. Then, the orbit of the small body is changed to guarantee that it flies toward and impacts the big threatening NEO. Kinetic impact by a spacecraft is chosen as the strategy of deflecting the small body. The efficiency of this method is compared with that of a direct kinetic impact to the big NEO by a spacecraft. Finally, a case study is performed for the deflection of the Apophis NEO, and the efficiency of the method is assessed.

Optimization of Deflection of a Big NEO through Impact with a Small One

PubMed Central

Zhu, Kaijian; Huang, Weiping; Wang, Yuncai; Niu, Wei; Wu, Gongyou

2014-01-01

Using a small near-Earth object (NEO) to impact a larger and potentially threatening NEO has been suggested as an effective method to avert a collision with Earth. This paper develops a procedure for analysis of the technique for specific NEOs. First, an optimization method is used to select a proper small body from the database. Some principles of optimality are achieved with the optimization process. Then, the orbit of the small body is changed to guarantee that it flies toward and impacts the big threatening NEO. Kinetic impact by a spacecraft is chosen as the strategy of deflecting the small body. The efficiency of this method is compared with that of a direct kinetic impact to the big NEO by a spacecraft. Finally, a case study is performed for the deflection of the Apophis NEO, and the efficiency of the method is assessed. PMID:25525627

Exploration-driven NEO Detection Requirements

NASA Astrophysics Data System (ADS)

Head, J. N.; Sykes, M. V.

2005-12-01

The Vision for Space Exploration calls for use of in situ resources to support human solar system exploration goals. Focus has been on potential lunar polar ice, Martian subsurface water and resource extraction from Phobos. Near-earth objects (NEOs) offer easily accessible targets that may represent a critical component to achieving sustainable human operations, in particular small, newly discovered asteroids within a specified dynamical range having requisite composition and frequency. A minimum size requirement is estimated assuming CONOPs has an NEO harvester on station at L1. When the NEO launch window opens, the vehicle departs, rendezvousing within 30 days. Mining and processing operations ( 60 days) produces dirty water for the return trip ( 30 days) to L1 for final refinement into propellants. A market for propellant at L1 is estimated to be 700 mT /year: 250 mT for Mars missions, 100 mT for GTO services (Blair et al. 2002), 50 mT for L1 to lunar surface services, and 300 mT for bringing NEO-derived propellants to L1. Assuming an appropriate NEO has 5% recoverable water, exploited with 50% efficiency, 23000 mT/year must be processed. At 1500 kg/m3, this corresponds to one object per year with a radius of 15 meters, or two 5 m radius objects per month, of which it is estimated there are 10000 having delta-v < 4.2 km/s and 200/year of these available for short roundtrip missions to meet resource requirements (Jones et al. 2002). The importance of these potential resource objects should drive a requirement that next generation NEO detection systems (e.g., Pan-STARRS/LSST) be capable by 2010 of detecting dark NEOs fainter than V=24, allowing for identification 3 months before closest approach. Blair et al. 2002. Final Report to NASA Exploration Team, December 20, 2002. Jones et al. 2002. ASP Conf. Series Vol. 202 (M. Sykes, Ed.), pp. 141-154.

Space weathering on near-Earth objects investigated by neutral-particle detection

NASA Astrophysics Data System (ADS)

Plainaki, C.; Milillo, A.; Orsini, S.; Mura, A.; De Angelis, E.; Di Lellis, A. M.; Dotto, E.; Livi, S.; Mangano, V.; Massetti, S.; Palumbo, M. E.

2009-03-01

The ion-sputtering (IS) process is active in many planetary environments in the solar system where plasma precipitates directly on the surface (for instance, Mercury, Moon and Europa). In particular, solar wind sputtering is one of the most important agents for the surface erosion of a near-Earth object (NEO), acting together with other surface release processes, such as photon stimulated desorption (PSD), thermal desorption (TD) and micrometeoroid impact vaporization (MIV). The energy distribution of the IS-released neutrals peaks at a few eVs and extends up to hundreds of eVs. Since all other release processes produce particles of lower energies, the presence of neutral atoms in the energy range above 10 eV and below a few keVs (sputtered high-energy atoms (SHEA)) identifies the IS process. SHEA easily escape from the NEO, due to NEO's extremely weak gravity. Detection and analysis of SHEA will give important information on surface-loss processes as well as on surface elemental composition. The investigation of the active release processes, as a function of the external conditions and the NEO surface properties, is crucial for obtaining a clear view of the body's present loss rate as well as for getting clues on its evolution, which depends significantly on space weather. In this work, an attempt to analyze processes that take place on the surface of these small airless bodies, as a result of their exposure to the space environment, has been realized. For this reason, a new space weathering model (space weathering on NEO-SPAWN) is presented. Moreover, an instrument concept of a neutral-particle analyzer specifically designed for the measurement of neutral density and the detection of SHEA from a NEO is proposed.

Space weathering on near-Earth objects investigated by neutral-particle detection

NASA Astrophysics Data System (ADS)

Plainaki, C.; Milillo, A.; Orsini, S.; Mura, A.; de Angelis, E.; di Lellis, A. M.; Dotto, E.; Livi, S.; Mangano, V.; Palumbo, M. E.

2009-04-01

The ion-sputtering (IS) process is active in many planetary environments in the solar system where plasma precipitates directly on the surface (for instance, Mercury, Moon and Europa). In particular, solar wind sputtering is one of the most important agents for the surface erosion of a near-Earth object (NEO), acting together with other surface release processes, such as photon stimulated desorption (PSD), thermal desorption (TD) and micrometeoroid impact vaporization (MIV). The energy distribution of the IS-released neutrals peaks at a few eVs and extends up to hundreds of eVs. Since all other release processes produce particles of lower energies, the presence of neutral atoms in the energy range above 10 eV and below a few keVs (sputtered high-energy atoms (SHEA)) identifies the IS process. SHEA easily escape from the NEO, due to NEO's extremely weak gravity. Detection and analysis of SHEA will give important information on surface-loss processes as well as on surface elemental composition. The investigation of the active release processes, as a function of the external conditions and the NEO surface properties, is crucial for obtaining a clear view of the body's present loss rate as well as for getting clues on its evolution, which depends significantly on space weather. In this work, an attempt to analyze processes that take place on the surface of these small airless bodies, as a result of their exposure to the space environment, has been realized. For this reason, a new space weathering model (space weathering on NEO-SPAWN) is presented. Moreover, an instrument concept of a neutral-particle analyzer specifically designed for the measurement of neutral density and the detection of SHEA from a NEO is proposed.

The Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) List of Near-Earth Asteroids: Identifying Potential Targets for Future Exploration

NASA Astrophysics Data System (ADS)

Abell, Paul; Barbee, B. W.; Mink, R. G.; Adamo, D. R.; Alberding, C. M.; Mazanek, D. D.; Johnson, L. N.; Yeomans, D. K.; Chodas, P. W.; Chamberlin, A. B.; Benner, L. A. M.; Drake, B. G.; Friedensen, V. P.

2012-10-01

Introduction: Much attention has recently been focused on human exploration of near-Earth asteroids (NEAs). Detailed planning for deep space exploration and identification of potential NEA targets for human space flight requires selecting objects from the growing list of known NEAs. NASA therefore initiated the Near-Earth Object Human Space Flight Accessible Target Study (NHATS), which uses dynamical trajectory performance constraints to identify potentially accessible NEAs. Accessibility Criteria: Future NASA human space flight capability is being defined while the Orion Multi-Purpose Crew Vehicle and Space Launch System are under development. Velocity change and mission duration are two of the most critical factors in any human spaceflight endeavor, so the most accessible NEAs tend to be those with orbits similar to Earth’s. To be classified as NHATS-compliant, a NEA must offer at least one round-trip trajectory solution satisfying purposely inclusive constraints, including total mission change in velocity ≤ 12 km/s, mission duration ≤ 450 days (with at least 8 days at the NEA), Earth departure between Jan 1, 2015 and Dec 31, 2040, Earth departure C3 ≤ 60 km2/s2, and Earth return atmospheric entry speed ≤ 12 km/s. Monitoring and Updates: The NHATS list of potentially accessible targets is continuously updated as NEAs are discovered and orbit solutions for known NEAs are improved. The current list of accessible NEAs identified as potentially viable for future human exploration under the NHATS criteria is available to the international community via a website maintained by NASA’s NEO Program Office (http://neo.jpl.nasa.gov/nhats/). This website also lists predicted optical and radar observing opportunities for each NHATS-compliant NEA to facilitate acquisition of follow-up observations. Conclusions: This list of NEAs will be useful for analyzing robotic mission opportunities, identifying optimal round trip human space flight trajectories, and

Physical Characterization of Near-Earth Object 3988 (1986 LA)

NASA Astrophysics Data System (ADS)

Truong, Thien-Tin; Hicks, M.; Strojia, C.; Teague, S.; Gerhart, C.; McCormack, M.

2012-01-01

The Near-Earth Object (NEO) 3988 (1986 LA) was discovered photographically by Glo Helin and colleagues with the 1.2-m Schmidt at Palomar (Helin et al. 1986: IAU Circ. 4228). With a perihelion distance q = 1.055 AU, 1986 LA is an Amor-type NEO. The spacecraft rendezvous potential of any small solar system body can be quantified, to first order, by the dV required to match the target's orbit. Using the method described by Shoemaker & Helin (1978; N7829022) and assuming a massless rendezvous target, a dV of 6.29 km/s is required to reach the orbit of Mars. Objects with dV < 6.29 km/s can therefor be considered low-dV targets: 1791 NEOs meet this criteria. 1986 LA has a dV of 5.84 km/s. With an absolute magnitude H = 17.7 (Lowell Astorb Database), the object is in the top 0.985 percentile in terms of expected size. We obtained four nights of Bessel BVRI on 2011 June 14, 15, 16, and 18 at the JPL Table Mountain 0.6-m telescope. Our analysis was hampered by the high density of background stars, the low lunar elongation, and an intermittent tracking error. The rotationally averaged colors were found most consistent with an Ld-type spectral classification (Bus taxonomy), an association obtained through a comparison of our colors with the 1341 asteroid spectra in the SMASS II database (Bus & Binzel 2002). Despite the large error bars in our photometry we are confident that 1986 LA belongs to the S-family of asteroids (Tholen Taxonomy). Assuming a phase parameter G=0.15 and our V-R color, we measured an absolute magnitude HV = 17.97 +/- 0.15 mag, intermediate between the HV = 17.7 mag (Lowell) and HV = 18.2 mag (JPL) database listings. We observed for 21 additional nights. The pole positions are currently unresolved based on the further observations.

Preparing for LSST with the LCOGT NEO Follow-up Network

NASA Astrophysics Data System (ADS)

Greenstreet, Sarah; Lister, Tim; Gomez, Edward

2016-10-01

The Las Cumbres Observatory Global Telescope Network (LCOGT) provides an ideal platform for follow-up and characterization of Solar System objects (e.g. asteroids, Kuiper Belt Objects, comets, Near-Earth Objects (NEOs)) and ultimately for the discovery of new objects. The LCOGT NEO Follow-up Network is using the LCOGT telescope network in addition to a web-based system developed to perform prioritized target selection, scheduling, and data reduction to confirm NEO candidates and characterize radar-targeted known NEOs.In order to determine how to maximize our NEO follow-up efforts, we must first define our goals for the LCOGT NEO Follow-up Network. This means answering the following questions. Should we follow-up all objects brighter than some magnitude limit? Should we only focus on the brightest objects or push to the limits of our capabilities by observing the faintest objects we think we can see and risk not finding the objects in our data? Do we (and how do we) prioritize objects somewhere in the middle of our observable magnitude range? If we want to push to faint objects, how do we minimize the amount of data in which the signal-to-noise ratio is too low to see the object? And how do we find a balance between performing follow-up and characterization observations?To help answer these questions, we have developed a LCOGT NEO Follow-up Network simulator that allows us to test our prioritization algorithms for target selection, confirm signal-to-noise predictions, and determine ideal block lengths and exposure times for observing NEO candidates. We will present our results from the simulator and progress on our NEO follow-up efforts.In the era of LSST, developing/utilizing infrastructure, such as the LCOGT NEO Follow-up Network and our web-based platform for selecting, scheduling, and reducing NEO observations, capable of handling the large number of detections expected to be produced on a daily basis by LSST will be critical to follow-up efforts. We hope our

Power and Propulsion System Design for Near-Earth Object Robotic Exploration

NASA Technical Reports Server (NTRS)

Snyder, John Steven; Randolph, Thomas M.; Landau, Damon F.; Bury, Kristen M.; Malone, Shane P.; Hickman, Tyler A.

2011-01-01

Near-Earth Objects (NEOs) are exciting targets for exploration; they are relatively easy to reach but relatively little is known about them. With solar electric propulsion, a vast number of interesting NEOs can be reached within a few years and with extensive flexibility in launch date. An additional advantage of electric propulsion for these missions is that a spacecraft can be small, enabling a fleet of explorers launched on a single vehicle or as secondary payloads. Commercial, flight-proven Hall thruster systems have great appeal based on their performance and low cost risk, but one issue with these systems is that the power processing units (PPUs) are designed for regulated spacecraft power architectures which are not attractive for small NEO missions. In this study we consider the integrated design of power and propulsion systems that utilize the capabilities of existing PPUs in an unregulated power architecture. Models for solar array and engine performance are combined with low-thrust trajectory analyses to bound spacecraft design parameters for a large class of NEO missions, then detailed array performance models are used to examine the array output voltage and current over a bounded mission set. Operational relationships between the power and electric propulsion systems are discussed, and it is shown that both the SPT-100 and BPT-4000 PPUs can perform missions over a solar range of 0.7 AU to 1.5 AU - encompassing NEOs, Venus, and Mars - within their operable input voltage ranges. A number of design trades to control the array voltage are available, including cell string layout, array offpointing during mission operations, and power draw by the Hall thruster system.

The Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) List of Near-Earth Asteroids: Identifying Potential Targets for Future Exploration

NASA Technical Reports Server (NTRS)

Abell, Paul A.; Barbee, B. W.; Mink, R. G.; Alberding, C. M.; Adamo, D. R.; Mazanek, D. D.; Johnson, L. N.; Yeomans, D. K.; Chodas, P. W.; Chamberlin, A. B.;

Neo: an object model for handling electrophysiology data in multiple formats

PubMed Central

Garcia, Samuel; Guarino, Domenico; Jaillet, Florent; Jennings, Todd; Pröpper, Robert; Rautenberg, Philipp L.; Rodgers, Chris C.; Sobolev, Andrey; Wachtler, Thomas; Yger, Pierre; Davison, Andrew P.

2014-01-01

Neuroscientists use many different software tools to acquire, analyze and visualize electrophysiological signals. However, incompatible data models and file formats make it difficult to exchange data between these tools. This reduces scientific productivity, renders potentially useful analysis methods inaccessible and impedes collaboration between labs. A common representation of the core data would improve interoperability and facilitate data-sharing. To that end, we propose here a language-independent object model, named “Neo,” suitable for representing data acquired from electroencephalographic, intracellular, or extracellular recordings, or generated from simulations. As a concrete instantiation of this object model we have developed an open source implementation in the Python programming language. In addition to representing electrophysiology data in memory for the purposes of analysis and visualization, the Python implementation provides a set of input/output (IO) modules for reading/writing the data from/to a variety of commonly used file formats. Support is included for formats produced by most of the major manufacturers of electrophysiology recording equipment and also for more generic formats such as MATLAB. Data representation and data analysis are conceptually separate: it is easier to write robust analysis code if it is focused on analysis and relies on an underlying package to handle data representation. For that reason, and also to be as lightweight as possible, the Neo object model and the associated Python package are deliberately limited to representation of data, with no functions for data analysis or visualization. Software for neurophysiology data analysis and visualization built on top of Neo automatically gains the benefits of interoperability, easier data sharing and automatic format conversion; there is already a burgeoning ecosystem of such tools. We intend that Neo should become the standard basis for Python tools in neurophysiology

Neo: an object model for handling electrophysiology data in multiple formats.

PubMed

Garcia, Samuel; Guarino, Domenico; Jaillet, Florent; Jennings, Todd; Pröpper, Robert; Rautenberg, Philipp L; Rodgers, Chris C; Sobolev, Andrey; Wachtler, Thomas; Yger, Pierre; Davison, Andrew P

2014-01-01

Neuroscientists use many different software tools to acquire, analyze and visualize electrophysiological signals. However, incompatible data models and file formats make it difficult to exchange data between these tools. This reduces scientific productivity, renders potentially useful analysis methods inaccessible and impedes collaboration between labs. A common representation of the core data would improve interoperability and facilitate data-sharing. To that end, we propose here a language-independent object model, named "Neo," suitable for representing data acquired from electroencephalographic, intracellular, or extracellular recordings, or generated from simulations. As a concrete instantiation of this object model we have developed an open source implementation in the Python programming language. In addition to representing electrophysiology data in memory for the purposes of analysis and visualization, the Python implementation provides a set of input/output (IO) modules for reading/writing the data from/to a variety of commonly used file formats. Support is included for formats produced by most of the major manufacturers of electrophysiology recording equipment and also for more generic formats such as MATLAB. Data representation and data analysis are conceptually separate: it is easier to write robust analysis code if it is focused on analysis and relies on an underlying package to handle data representation. For that reason, and also to be as lightweight as possible, the Neo object model and the associated Python package are deliberately limited to representation of data, with no functions for data analysis or visualization. Software for neurophysiology data analysis and visualization built on top of Neo automatically gains the benefits of interoperability, easier data sharing and automatic format conversion; there is already a burgeoning ecosystem of such tools. We intend that Neo should become the standard basis for Python tools in neurophysiology.

Follow-up and Characterization of NEOs with the LCOGT Network

NASA Astrophysics Data System (ADS)

Lister, Tim

2013-10-01

Las Cumbres Observatory Global Telescope (LCOGT) network is a planned homogeneous network of over 35 telescopes at 6 locations in the northern and southern hemispheres. This network is versatile and designed to respond rapidly to target of opportunity events and also to do long term monitoring of slowly changing astronomical phenomena. The global coverage of the network and the apertures of telescope available make LCOGT ideal for follow-up and characterization of Solar System objects (e.g. asteroids, Kuiper Belt Objects, comets, Near-Earth Objects (NEOs)) and ultimately for the discovery of new objects. LCOGT has completed the first phase of the deployment with the installation and commissioning of nine 1-meter telescopes at McDonald Observatory (Texas), Cerro Tololo (Chile), SAAO (South Africa) and Siding Spring Observatory (Australia). The telescope network is now operating and observations are being executed remotely and robotically. I am using the LCOGT network to confirm newly detected NEO candidates produced by the major sky surveys such as Catalina Sky Survey (CSS) and PanSTARRS (PS1). An increasing amount of time is being spent to obtain follow-up astrometry and photometry for radar-targeted objects in order to improve the orbits and determine the rotation periods. This will be extended to obtain more light curves of other NEOs which could be Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) or Asteroid Retrieval Mission (ARM) targets. Recent results have included the first period determination for the Apollo 2002 NV16 and our first NEO spectrum from the FLOYDS spectrographs on the LCOGT 2m telescopes obtained for 2012 DA14 during the February 2013 closepass.

Near-Earth Asteroids 2006 RH120 And 2009 BD: Proxies For Maximally Accessible Objects?

NASA Technical Reports Server (NTRS)

Barbee, Brent W.; Chodas, Paul W.

2015-01-01

Near-Earth Object Human Space Flight Accessible Targets Study(NHATS): http://neo.jpl.nasa.govnhats/. As of mid-July 2015: 1,434 of the 12,778 currently known NEAs are more astrodynamically accessible than is Mars (requiring less Delta v and or less flight time for round-trip missions). Within those 1,434 NEAs: 605 NEAs can be visited round-trip for less Delta v (9 km/s) than the lunar surface. 51 NEAs can be visited round-trip for less v (5 km/s) than low circular lunar orbit. NEO population statistical models:Tens of thousands of NEAs greater than 100 m yet to be discovered. At least several million NEAs less than or equal to100 m in size (down to approximately 3 m in size) yet to be discovered. How accessible are the NEAs that haven't yet been discovered?

Multiple NEO Rendezvous, Reconnaissance and In Situ Exploration

NASA Astrophysics Data System (ADS)

Klaus, K.; Elsperman, M. S.; Cook, T.; Smith, D.

2010-12-01

We propose a two spacecraft mission (Mother Ship and Small Body Lander) rendezvous with multiple Near Earth Objects (NEO). This two spacecraft mission mimics the likely architecture approach that human explorers will use: a “mother ship”(MS) designed to get from Earth to the NEO and a “Small Body Lander”(SBL) that performs in situ investigation on or close to the NEO’s surface. The MS carries the SBL to the target NEO. Once at the target NEO, the MS conducts an initial reconnaissance in order to produce a high resolution map of the surface. This map is used to identify coordinates of interest which are sent to the SBL. The SBL un-docks from the MS to rendezvous with the NEO and collect data. Landings are possible, though the challenges of anchoring to the NEO surface are significant. The SBL design is flexible and adaptable, enabling science data collection on or near the surface. After surface investigations are completed on the first NEO, the SBL will return and autonomously rendezvous and dock with the MS. The MS then goes to the next NEO target. During transit to the next NEO, the SBL could be refueled by the MS, a TRL8 capability demonstrated on the DARPA/NASA Orbital Express mission in 2007, or alternately sized to operate without requiring refueling depending on the mission profile. The mission goals are to identify surface hazards; quantify engineering boundary conditions for future human visits, and identify resources for future exploitation. The mission goals will be accomplished through the execution of key mission objectives: (1) high-resolution surface topography; (2) surface composition and mineralogy; (3) radiation environment near NEO; and (4) mechanical properties of the surface. Essential SBL instruments include: a) LIDAR (Obj. 1); b) 3D, high- resolution hyperspectral imaging cameras (Obj. 2); c) radiation sensor package (Obj. 3); and d) strain gauges (Obj. 4). Additional or alternative instruments could include: e) x-ray fluorescence

Relative 2-color Photometry Of Neo's

NASA Astrophysics Data System (ADS)

Shelus, P.; Gyorgyey-Ries, J.; Ricklefs, R.; Barker, E.

We have been making Solar System small body positional observations at McDon- ald Observatory since the early 1970's. In 1994 we moved to a CCD-based, almost totally automated, astrometry system (Whipple et al, 1996, Astron. J., Vol. 112, p. 316). Our present observational effort is focussed upon Near Earth Objects (NEOs) as part of NASA's mission to discover and catalogue 90 percent of NEOs with diameters larger than 1 km by 2008. Observing 4 nights per lunation, we conduct observations to confirm newly discovered NEOs, filling in the night on a target-of-opportunnity basis, with observations of under-observed NEOs. Our major intent is to understand the overall hazard that these objects pose to Earth and their dynamical and physical characterization. We recently adopted the USNO-A2.0 catalogue to improve astromet- ric results and a number of up-grades to the end-to-end system have been developed (Barker et al, 2001, Bull. AAS, Vol. 33, p. 1116). The USNO catalog also provides stellar magnitudes in the standard Johnson R and B photometric bands. We have thus taken the opportunity to expand our observational efforts to regularly provide R mag- nitudes, in addition to astrometric positions. Our limiting magnitude in R is near 22. We are now furthering our photometric efforts by including B exposures as part of our standard observation triplet. We have already confirmed that switching filters between exposures on standard fields does not compromise the astrometric accurary. Thus, we plan to provide two color, sequential, relative photometry, (B-R), of newly discov- ered or under observed asteroids, as part of our routine observation process. The time interval between exposures is always less than 20 minutes, short compared to most asteroid rotation times. Consequently, a meaningful color index can be obtained in parallel with the astrometric positions. Although (B-R) is not the usual color index used in asteroid classification studies, we are testing whether we can

Analysis of ejecta fate from proposed man-made impactors into near-Earth objects --- a NEOShield study

NASA Astrophysics Data System (ADS)

Schwartz, S.; Michel, P.; Jutzi, M.

2014-07-01

Asteroids measuring 100 meters across tend to impact the Earth once every 5,000 years on average [1]. Smaller bodies enter into the Earth's atmosphere more frequently, but may detonate before reaching the surface. Conversely, impacts from larger bodies are more rare [2], but can come with devastating global consequences to living species. In 2005, a United States Congressional mandate called for NASA to detect, by 2020, 90 percent of near-Earth objects (NEOs) having diameters of 140 meters or greater [3]. One year prior, ESA's Near-Earth Object Mission Advisory Panel (NEOMAP) recommended the study of a kinetic impactor mission as a priority in the framework of NEO risk assessment [4]. A ''Phase-A'' study of such a mission, Don Quixote, took place at ESA until 2007. In accordance with NEOMAP and with the Target NEO Global Community's recommendations in 2011 [5], the NEOShield Project is being funded for 3.5 years by the European Commission in its FP7 program. NEOShield began in 2012 and is primarily, but not exclusively, a European consortium of research institutions and engineering industries that aims to analyze promising mitigation options and provide solutions to the critical scientific and technical obstacles involved in confronting threats posed by the small bodies in the neighborhood of the Earth's orbit [6]. To further explore the NEO threat mitigation via the strategy of kinetic impact, building upon the Don Quixote study, the idea is to target a specific NEO for impact and attempt to quantify the response. How long do ejecta remain aloft and where do they end up? Fragments that are ejected at high speeds escape, but what about material moving at or near the escape speed of the NEO or that suffer energy-dissipating collisions after being ejected? Where would be a ''safe'' location for an observing spacecraft during and subsequent to the impact? Here, we outline the early phases of an ongoing numerical investigation of the fate of the material ejected from a

A NEO population generation and observation simulation software tool

NASA Astrophysics Data System (ADS)

Müller, Sven; Gelhaus, Johannes; Hahn, Gerhard; Franco, Raffaella

One of the main targets of ESA's Space Situational Awareness (SSA) program is to build a wide knowledge base about objects that can potentially harm Earth (Near-Earth Objects, NEOs). An important part of this effort is to create the Small Bodies Data Centre (SBDC) which is going to aggregate measurement data from a fully-integrated NEO observation sensor network. Until this network is developed, artificial NEO measurement data is needed in order to validate SBDC algorithms. Moreover, to establish a functioning NEO observation sensor network, it has to be determined where to place sensors, what technical requirements have to be met in order to be able to detect NEOs and which observation strategies work the best. Because of this, a sensor simulation software was needed. This paper presents a software tool which allows users to create and analyse NEO populations and to simulate and analyse population observations. It is a console program written in Fortran and comes with a Graphical User Interface (GUI) written in Java and C. The tool can be distinguished into the components ``Population Generator'' and ``Observation Simulator''. The Population Generator component is responsible for generating and analysing a NEO population. Users can choose between creating fictitious (random) and synthetic populations. The latter are based on one of two models describing the orbital and size distribution of observed NEOs: The existing socalled ``Bottke Model'' (Bottke et al. 2000, 2002) and the new ``Granvik Model'' (Granvik et al. 2014, in preparation) which has been developed in parallel to the tool. Generated populations can be analysed by defining 2D, 3D and scatter plots using various NEO attributes. As a result, the tool creates the appropiate files for the plotting tool ``gnuplot''. The tool's Observation Simulator component yields the Observation Simulation and Observation Analysis functions. Users can define sensor systems using ground- or space-based locations as well as

A feasibility study on the implementation of satellite-to-satellite tracking around a small near-Earth object

NASA Astrophysics Data System (ADS)

Church, Christopher J.

Near-earth objects (NEOs) are asteroids and comets that have a perihelion distance of less than 1.3 astronomical units (AU). There are currently more than 10,000 known NEOs. The majority of these objects are less than 1 km in diameter. Despite the number of NEOs, little is known about most of them. Characterizing these objects is a crucial component in developing a thorough understanding of solar system evolution, human exploration, exploitation of asteroid resources, and threat mitigation. Of particular interest is characterizing the internal structure of NEOs. While ground-based methods exist for characterizing the internal structure of NEOs, the information that can be gleaned from such studies is limited and often accompanied by large uncertainty. An alternative is to use in situ studies to examine an NEO's shape and gravity field, which can be used to assess its internal structure. This thesis investigates the use of satellite-to-satellite tracking (SST) to map the gravity field of a small NEO on the order of 500 m or less. An analysis of the mission requirements of two previously flown SST missions, GRACE and GRAIL, is conducted. Additionally, a simulation is developed to investigate the dynamics of SST in the vicinity of a small NEO. This simulation is then used to simulate range and range-rate data in the strongly perturbed environment of the small NEO. These data are used in conjunction with the analysis of the GRACE and GRAIL missions to establish a range of orbital parameters that can be used to execute a SST mission around a small NEO. Preliminary mission requirements for data collection and orbital correction maneuvers are also established. Additionally, the data are used to determine whether or not proven technology can be used to resolve the expected range and range-rate measurements. It is determined that the orbit semi-major axis for each spacecraft should be approximately 100% to 200% of the NEO's mean diameter and the two spacecraft should be in

NEOs in the mid-infrared: from Spitzer to JWST

NASA Astrophysics Data System (ADS)

Mueller, Michael; Thomas, Cristina A.

2016-10-01

Near-Earth Objects (NEOs) account for a surprisingly large fraction of the Spitzer observing time devoted to Solar System science. As a community, we should think of ways to repeat that success with JWST. JWST is planning an open Early Release Science Program, with the expected deadline for letters of intent in early 2017. We can't wait for next year's DPS to develop ideas. The time is now!In order to stir up the discussion, we will present ideas for NEO observing programs that are well adapted to JWST's capabilities and limitations, based on our recent PASP paper (Thomas et al., 2016). Obvious measurement objectives would include* size and albedo from thermal continuum (MIRI photometry)* thermal inertia for objects with well-known shape and spin state (MIRI)* taxonomy through reflection spectroscopy and emission spectroscopy in the NIR and MIR; NIR colors for faint objects.In all cases, JWST's sensitivity will allow us to go deeper than currently possible by at least an order of magnitude. Meter-sized NEOs similar to 2009 BD or 2011 MD are easy targets for MIRI spectrophotometry!The following limitations must be kept in mind, however: JWST's large size makes it slow to move. Most problematic for NEOs is probably the resulting 'speed limit': non-sidereal tracking is supported up to a rate of 30 mas/s, NEOs can easily move faster than that (ways to relax this constraint are under discussion). The average slew to a new target is budgeted to take 30 min, effectively ruling out programs many-target programs like ExploreNEOs or NEOSurvey (see D. Trilling's paper). Additionally, JWST will only observe close to quadrature, translating to large solar phase angles for NEO observations; this is familiar from other space-based IR facilities.

The orbit and size distribution of small Solar System objects orbiting the Sun interior to the Earth's orbit

NASA Astrophysics Data System (ADS)

Zavodny, Maximilian; Jedicke, Robert; Beshore, Edward C.; Bernardi, Fabrizio; Larson, Stephen

2008-12-01

We present the first observational measurement of the orbit and size distribution of small Solar System objects whose orbits are wholly interior to the Earth's (Inner Earth Objects, IEOs, with aphelion <0.983 AU). We show that we are able to model the detections of near-Earth objects (NEO) by the Catalina Sky Survey (CSS) using a detailed parameterization of the CSS survey cadence and detection efficiencies as implemented within the Jedicke et al. [Jedicke, R., Morbidelli, A., Spahr, T., Petit, J.M., Bottke, W.F., 2003. Icarus 161, 17-33] survey simulator and utilizing the Bottke et al. [Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H.F., Michel, P., Metcalfe, T.S., 2002. Icarus 156, 399-433] model of the NEO population's size and orbit distribution. We then show that the CSS detections of 4 IEOs are consistent with the Bottke et al. [Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H.F., Michel, P., Metcalfe, T.S., 2002. Icarus 156, 399-433] IEO model. Observational selection effects for the IEOs discovered by the CSS were then determined using the survey simulator in order to calculate the corrected number and H distribution of the IEOs. The actual number of IEOs with H<18 (21) is 36±26 ( 530±240) and the slope of the H magnitude distribution ( ∝10) for the IEOs is α=0.44-0.22+0.23. The slope is consistent with previous measurements for the NEO population of α=0.35±0.02 [Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H.F., Michel, P., Metcalfe, T.S., 2002. Icarus 156, 399-433] and α=0.39±0.013 [Stuart, J.S., Binzel, R.P., 2004. Icarus 170, 295-311]. Based on the agreement between the predicted and observed IEO orbit and absolute magnitude distributions there is no indication of any non-gravitational effects (e.g. Yarkovsky, tidal disruption) affecting the known IEO population.

Towards Designing an Integrated Architecture for NEO Characterization, Mitigation, Scientific Evaluation, and Resource Utilization

NASA Technical Reports Server (NTRS)

Adams, Robert B.; LaPointe, Michael; Wilks, Rod; Allen, Brian

2009-01-01

This poster reviews the planning and design for an integrated architecture for characterization, mitigation, scientific evaluation and resource utilization of near earth objects. This includes tracks to observe and characterize the nature of the threat posed by a NEO, and deflect if a significant threat is posed. The observation stack can also be used for a more complete scientific analysis of the NEO.

NEOCAM: Near Earth Object Chemical Analysis Mission: Bridging the Gulf between Telescopic Observations and the Chemical and Mineralogical Compositions of Asteroids or Diogenes A: Diagnostic Observation of the Geology of Near Earth Spectrally-Classified Asteroids

NASA Technical Reports Server (NTRS)

Nuth, Joseph A.

2009-01-01

Studies of meteorites have yielded a wealth of scientific information based on highly detailed chemical and isotopic studies possible only in sophisticated terrestrial laboratories. Telescopic studies have revealed an enormous (greater than 10(exp 5)) number of physical objects ranging in size from a few tens of meters to several hundred kilometers, orbiting not only in the traditional asteroid belt between Mars and Jupiter but also throughout the inner solar system. Many of the largest asteroids are classed into taxonomic groups based on their observed spectral properties and are designated as C, D. X, S or V types (as well as a wide range in sub-types). These objects are certainly the sources far the meteorites in our laboratories, but which asteroids are the sources for which meteorites? Spectral classes are nominally correlated to the chemical composition and physical characteristics of the asteroid itself based on studies of the spectral changes induced in meteorites due to exposure to a simulated space environment. While laboratory studies have produced some notable successes (e.g. the identification of the asteroid Vesta as the source of the H, E and D meteorite classes), it is unlikely that we have samples of each asteroidal spectral type in our meteorite collection. The correlation of spectral type and composition for many objects will therefore remain uncertain until we can return samples of specific asteroid types to Earth for analyses. The best candidates for sample return are asteroids that already come close to the Earth. Asteroids in orbit near 1 A.U. have been classified into three groups (Aten, Apollo & Amor) based on their orbital characteristics. These Near Earth Objects (NEOs) contain representatives of virtually all spectral types and sub-types of the asteroid population identified to date. Because of their close proximity to Earth, NEOs are prime targets for asteroid missions such as the NEAR-Shoemaker NASA Discovery Mission to Eros and the

Infrared near-Earth-object survey modeling for observatories interior to the Earth's orbit

NASA Astrophysics Data System (ADS)

Buie, M.

2014-07-01

The search for and dynamical characterization of the near-Earth population of objects (NEOs) has been a busy topic for surveys for many years. Most of the work thus far has been from ground-based optical surveys such as the Catalina Sky Survey and LINEAR. These surveys have essentially reached a complete inventory of objects down to 1 km diameter and have shown that the known objects do not pose any significant impact threat. Smaller objects are correspondingly smaller threats but there are more of them and fewer of them have so far been discovered. The next generation of surveys is looking to extend their reach down to much smaller sizes. From an impact risk perspective, those objects as small as 30--40 m are still of interest (similar in size to the Tunguska bolide). Smaller objects than this are largely of interest from a space resource or in-situ analysis efforts. A recent mission concept promoted by the B612 Foundation and Ball Aerospace calls for an infrared survey telescope in a Venus-like orbit, known as the Sentinel Mission. This wide-field facility has been designed to complete the inventory down to a 140 m diameter while also providing substantial constraints on the NEO population down to a Tunguska-sized object. I have been working to develop a suite of tools to provide survey modeling for this class of survey telescope. The purpose of the tool is to uncover hidden complexities that govern mission design and operation while also working to quantitatively understand the orbit quality provided on its catalog of objects without additional followup assets. The baseline mission design calls for a 6.5 year survey lifetime. This survey model is a statistically based tool for establishing completeness as a function of object size and survey duration. Effects modeled include the ability to adjust the field-of-regard (includes all pointing restrictions), field-of-view, focal plane array fill factor, and the observatory orbit. Consequences tracked include time

The DLR AsteroidFinder for NEOs

NASA Astrophysics Data System (ADS)

Mottola, Stefano; Kuehrt, Ekkehard; Michaelis, Harald; Hoffmann, Harald; Spietz, Peter; Jansen, Frank; Thimo Grundmann, Jan; Hahn, Gerhard; Montenegro, Sergio; Findlay, Ross; Boerner, Anko; Messina, Gabriele; Behnke, Thomas; Tschentscher, Matthias; Scheibe, Karsten; Mertens, Volker; Heidecke, Ansgar

Potential Earth-impacting asteroids that spend most of their time interior to Earth's orbit are extremely difficult to be observed from the ground and remain largely undetected. Firstly, they are mostly located at small solar elongations, where the sky brightness and their faintness due to the large phase angle prevents their discovery. Secondly, these objects tend to have very long synodic orbital periods, which makes observation opportunities rare and impact warning times short. Because of these limitations, even the advent of next generation ground-based asteroid surveys is not likely to radically improve the situation (Veres et al. Icarus 203, p472, 2009). On the other hand, a small satellite with a suitable design can observe close to the Sun and detect these objects efficiently against a dark sky background. For this reason, DLR, the German Aerospace Center, has selected AsteroidFinder as the first experiment to be launched under its new compact satellite national program. The primary goal of the mission is to detect and characterize Near Earth Objects (NEOs), with a particular focus on the population of objects completely contained within Earth's orbit (IEOs or Inner Earth Objects). Current dynamical models predict the existence of more than 1000 such objects down to a size of 100m, of which, due to the abovementioned observation difficulties, only 10 have been discovered to date. Benefitting from the vantage point of a Low Earth Orbit (LEO), AsteroidFinder makes use of a small optical telescope to scan those regions of the sky that are close to the Sun, and therefore beyond the reach of ground based observatories. By estimating the population, the size and the orbital distribution of IEOs, AsteroidFinder will contribute to our knowledge of the inner Solar System, and to the assessment of the impact hazard for the Earth. A secondary goal of the mission is to demonstrate techniques that enable the space-based detection of space debris in the cm size range

Initial Considerations for Navigation and Flight Dynamics of a Crewed Near-Earth Object Mission

NASA Technical Reports Server (NTRS)

Holt, Greg N.; Getchius, Joel; Tracy, William H.

2011-01-01

A crewed mission to a Near-Earth Object (NEO) was recently identified as a NASA Space Policy goal and priority. In support of this goal, a study was conducted to identify the initial considerations for performing the navigation and flight dynamics tasks of this mission class. Although missions to a NEO are not new, the unique factors involved in human spaceflight present challenges that warrant special examination. During the cruise phase of the mission, one of the most challenging factors is the noisy acceleration environment associated with a crewed vehicle. Additionally, the presence of a human crew necessitates a timely return trip, which may need to be expedited in an emergency situation where the mission is aborted. Tracking, navigation, and targeting results are shown for sample human-class trajectories to NEOs. Additionally, the benefit of in-situ navigation beacons on robotic precursor missions is presented. This mission class will require a longer duration flight than Apollo and, unlike previous human missions, there will likely be limited communication and tracking availability. This will necessitate the use of more onboard navigation and targeting capabilities. Finally, the rendezvous and proximity operations near an asteroid will be unlike anything previously attempted in a crewed spaceflight. The unknown gravitational environment and physical surface properties of the NEO may cause the rendezvous to behave differently than expected. Symbiosis of the human pilot and onboard navigation/targeting are presented which give additional robustness to unforeseen perturbations.

Update on Spacewatch Observations of Near-Earth Objects

NASA Astrophysics Data System (ADS)

Brucker, Melissa; McMillan, Robert S.; Bressi, Terry; Larsen, Jeff; Mastaler, Ron; Read, Mike; Scotti, Jim; Tubbiolo, Andrew

2017-10-01

Spacewatch performs targeted astrometric follow-up of near-Earth objects, primarily asteroids (NEAs), to improve knowledge of their orbits. We have a noteworthy history of asteroid and comet observations beginning in 1984 as the first survey to use CCDs to scan the sky for asteroids and comets. Currently, we measure simultaneous astrometry and photometry of observations during an average of 24 nights per lunation (dark and gray time) as the exclusive users of a 1.8-m telescope and a 0.9-m telescope on Kitt Peak. In addition, we use bright time on the 2.3-m Bok Telescope and the 4-m Mayall Telescope on Kitt Peak to chase fainter targets. Continued astrometric follow-up helps to prevent potentially hazardous objects and scientifically interesting NEAs from becoming lost.We prioritize virtual impactors, MPC confirmation page objects, potentially hazardous asteroids (PHAs) with close approaches within 0.03 AU in the next 30 years, upcoming radar targets with astrometry requests, Yarkovsky effect candidates, NEAs with existing characterization data (WISE, Spitzer, SMASS, MANOS), possible spacecraft destinations (NHATS), and requests from the community.In mid October 2015, we switched from survey mode to targeted astrometry on the 0.9-m telescope. From 2015 October 15 through 2017 June 29 (1.7yr), Spacewatch (observatory codes 291, 691, and ^695) had 20951 MPC-accepted NEO lines of astrometry corresponding to measurements of 2647 different NEOs. This includes 4801 PHA lines of astrometry corresponding to 426 different PHAs, of which 223 lines were at apparent magnitudes V>=22.5. We observed 43% of all NEAs and 52% of all unnumbered NEAs that were observed by any observatory during that period. We observed 50% of all PHAs and 64% of all unnumbered PHAs observed during that period. These statistics do not include submitted measurements of confirmation page objects that were not confirmed as NEAs.Support of Spacewatch is from NASA/NEOO grants, the Lunar and Planetary

Characterization of NEOs from the Policy Perspective: Implications from Problem and Solution Definitions

NASA Astrophysics Data System (ADS)

Lindquist, E.

2015-12-01

The characterization of near-Earth-objects (NEOs) in regard to physical attributes and potential risk and impact factors presents a complex and complicates scientific and engineering challenge. The societal and policy risks and impacts are no less complex, yet are rarely considered in the same context as material properties or related factors. The objective of this contribution is to position the characterization of NEOs within the public policy process domain as a means to reflect on the science-policy nexus in regard to risks associated with NEOs. This will be accomplished through, first, a brief overview of the science-policy nexus, followed by a discussion of several policy process frameworks, such as agenda setting and the multiple streams model, focusing events, and punctuated equilibrium, and their application and appropriateness to the problem of NEOs. How, too, for example, does NEO hazard and risk compare with other low probability, high risk, hazards in regard to public policy? Finally, we will reflect on the implications of alternative NEO "solutions" and the characterization of the NEO "problem," and the political and public acceptance of policy alternatives as a way to link NEO science and policy in the context of the overall NH004 panel.

Fast rotation of a subkilometer-sized near-Earth object 2011 XA{sub 3}

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

Urakawa, Seitaro; Ohtsuka, Katsuhito; Abe, Shinsuke

2014-05-01

We present light curve observations and their multiband photometry for near-Earth object (NEO) 2011 XA{sub 3}. The light curve has shown a periodicity of 0.0304 ± 0.0003 days (= 43.8 ± 0.4 minutes). The fast rotation shows that 2011 XA{sub 3} is in a state of tension (i.e., a monolithic asteroid) and cannot be held together by self-gravitation. Moreover, the multiband photometric analysis indicates that the taxonomic class of 2011 XA{sub 3} is S-complex, or V-type. Its estimated effective diameter is 225 ± 97 m (S-complex) and 166 ± 63 m (V-type), respectively. Therefore, 2011 XA{sub 3} is a candidatemore » for the second-largest, fast-rotating, monolithic asteroid. Moreover, the orbital parameters of 2011 XA{sub 3} are apparently similar to those of NEO (3200) Phaethon, but F/B-type. We computed the orbital evolutions of 2011 XA{sub 3} and Phaethon. However, the results of the computation and distinct taxonomy indicate that neither of the asteroids is of common origin.« less

Capture of near-Earth objects with low-thrust propulsion and invariant manifolds

NASA Astrophysics Data System (ADS)

Tang, Gao; Jiang, Fanghua

2016-01-01

In this paper, a mission incorporating low-thrust propulsion and invariant manifolds to capture near-Earth objects (NEOs) is investigated. The initial condition has the spacecraft rendezvousing with the NEO. The mission terminates once it is inserted into a libration point orbit (LPO). The spacecraft takes advantage of stable invariant manifolds for low-energy ballistic capture. Low-thrust propulsion is employed to retrieve the joint spacecraft-asteroid system. Global optimization methods are proposed for the preliminary design. Local direct and indirect methods are applied to optimize the two-impulse transfers. Indirect methods are implemented to optimize the low-thrust trajectory and estimate the largest retrievable mass. To overcome the difficulty that arises from bang-bang control, a homotopic approach is applied to find an approximate solution. By detecting the switching moments of the bang-bang control the efficiency and accuracy of numerical integration are guaranteed. By using the homotopic approach as the initial guess the shooting function is easy to solve. The relationship between the maximum thrust and the retrieval mass is investigated. We find that both numerically and theoretically a larger thrust is preferred.

Mapping Near-Earth Hazards

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-06-01

How can we hunt down all the near-Earth asteroids that are capable of posing a threat to us? A new study looks at whether the upcoming Large Synoptic Survey Telescope (LSST) is up to the job.Charting Nearby ThreatsLSST is an 8.4-m wide-survey telescope currently being built in Chile. When it goes online in 2022, it will spend the next ten years surveying our sky, mapping tens of billions of stars and galaxies, searching for signatures of dark energy and dark matter, and hunting for transient optical events like novae and supernovae. But in its scanning, LSST will also be looking for asteroids that approach near Earth.Cumulative number of near-Earth asteroids discovered over time, as of June 16, 2016. [NASA/JPL/Chamberlin]Near-Earth objects (NEOs) have the potential to be hazardous if they cross Earths path and are large enough to do significant damage when they impact Earth. Earths history is riddled with dangerous asteroid encounters, including the recent Chelyabinsk airburst in 2013, the encounter that caused the kilometer-sized Meteor Crater in Arizona, and the impact thought to contribute to the extinction of the dinosaurs.Recognizing the potential danger that NEOs can pose to Earth, Congress has tasked NASA with tracking down 90% of NEOs larger than 140 meters in diameter. With our current survey capabilities, we believe weve discovered roughly 25% of these NEOs thus far. Now a new study led by Tommy Grav (Planetary Science Institute) examines whether LSST will be able to complete this task.Absolute magnitude, H, of asynthetic NEO population. Though these NEOs are all larger than 140 m, they have a large spread in albedos. [Grav et al. 2016]Can LSST Help?Based on previous observations of NEOs and resulting predictions for NEO properties and orbits, Grav and collaborators simulate a synthetic population of NEOs all above 140 m in size. With these improved population models, they demonstrate that the common tactic of using an asteroids absolute magnitude as a

NEOSURVEY 1: INITIAL RESULTS FROM THE WARM SPITZER EXPLORATION SCIENCE SURVEY OF NEAR-EARTH OBJECT PROPERTIES

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

Trilling, David E.; Mommert, Michael; Hora, Joseph

Near-Earth objects (NEOs) are small solar system bodies whose orbits bring them close to the Earth’s orbit. We are carrying out a Warm Spitzer Cycle 11 Exploration Science program entitled NEOSurvey—a fast and efficient flux-limited survey of 597 known NEOs in which we derive a diameter and albedo for each target. The vast majority of our targets are too faint to be observed by NEOWISE, though a small sample has been or will be observed by both observatories, which allows for a cross-check of our mutual results. Our primary goal is to create a large and uniform catalog of NEO properties. Wemore » present here the first results from this new program: fluxes and derived diameters and albedos for 80 NEOs, together with a description of the overall program and approach, including several updates to our thermal model. The largest source of error in our diameter and albedo solutions, which derive from our single-band thermal emission measurements, is uncertainty in η , the beaming parameter used in our thermal modeling; for albedos, improvements in solar system absolute magnitudes would also help significantly. All data and derived diameters and albedos from this entire program are being posted on a publicly accessible Web page at nearearthobjects.nau.edu.« less

Dangerous Near-Earth Asteroids and Meteorites

NASA Astrophysics Data System (ADS)

Mickaelian, A. M.; Grigoryan, A. E.

2015-07-01

The problem of Near-Earth Objects (NEOs; Astreoids and Meteorites) is discussed. To have an understanding on the probablity of encounters with such objects, one may use two different approaches: 1) historical, based on the statistics of existing large meteorite craters on the Earth, estimation of the source meteorites size and the age of these craters to derive the frequency of encounters with a given size of meteorites and 2) astronomical, based on the study and cataloging of all medium-size and large bodies in the Earth's neighbourhood and their orbits to estimate the probability, angles and other parameters of encounters. Therefore, we discuss both aspects and give our present knowledge on both phenomena. Though dangerous NEOs are one of the main source for cosmic catastrophes, we also focus on other possible dangers, such as even slight changes of Solar irradiance or Earth's orbit, change of Moon's impact on Earth, Solar flares or other manifestations of Solar activity, transit of comets (with impact on Earth's atmosphere), global climate change, dilution of Earth's atmosphere, damage of ozone layer, explosion of nearby Supernovae, and even an attack by extraterrestrial intelligence.

Dynamical features of hazardous near-Earth objects

NASA Astrophysics Data System (ADS)

Emel'yanenko, V. V.; Naroenkov, S. A.

2015-07-01

We discuss the dynamical features of near-Earth objects moving in dangerous proximity to Earth. We report the computation results for the motions of all observed near-Earth objects over a 600-year-long time period: 300 years in the past and 300 years in the future. We analyze the dynamical features of Earth-approaching objects. In particular, we established that the observed distribution of geocentric velocities of dangerous objects depends on their size. No bodies with geocentric velocities smaller that 5 kms-1 have been found among hazardous objects with absolute magnitudes H <18, whereas 9% of observed objects with H <27 pass near Earth moving at such velocities. On the other hand, we found a tendency for geocentric velocities to increase at H >29. We estimated the distribution of absolute magnitudes of hazardous objects based on our analysis of the data for the asteroids that have passed close to Earth. We inferred the Earth-impact frequencies for objects of different sizes. Impacts of objects with H <18 with Earth occur on average once every 0.53 Myr, and impacts of objects with H <27—once every 130-240 years. We show that currently about 0.1% of all near-Earth objects with diameters greater than 10 m have been discovered. We point out the discrepancies between the estimates of impact rates of Chelyabinsk-type objects, determined from fireball observations and from the data of telescopic asteroid tracking surveys. These estimates can be reconciled assuming that Chelyabinsk-sized asteroids have very low albedos (about 0.02 on average).

Finding Long Lost Lexell's Comet: The Fate of the First Discovered Near-Earth Object

NASA Astrophysics Data System (ADS)

Ye, Quan-Zhi; Wiegert, Paul A.; Hui, Man-To

2018-04-01

Jupiter-family Comet D/1770 L1 (Lexell) was the first discovered Near-Earth Object (NEO) and passed the Earth on 1770 July 1 at a recorded distance of 0.015 au. The comet was subsequently lost due to unfavorable observing circumstances during its next apparition followed by a close encounter with Jupiter in 1779. Since then, the fate of D/Lexell has attracted interest from the scientific community, and now we revisit this long-standing question. We investigate the dynamical evolution of D/Lexell based on a set of orbits recalculated using the observations made by Charles Messier, the comet’s discoverer, and find that there is a 98% chance that D/Lexell remains in the solar system by the year of 2000. This finding remains valid even if a moderate non-gravitational effect is imposed. Messier’s observations also suggest that the comet is one of the largest known near-Earth comets, with a nucleus of ≳10 km in diameter. This implies that the comet should have been detected by contemporary NEO surveys regardless of its activity level if it has remained in the inner solar system. We identify asteroid 2010 JL33 as a possible descendant of D/Lexell, with a 0.8% probability of chance alignment, but a direct orbital linkage of the two bodies has not been successfully accomplished. We also use the recalculated orbit to investigate the meteors potentially originating from D/Lexell. While no associated meteors have been unambiguously detected, we show that meteor observations can be used to better constrain the orbit of D/Lexell despite the comet being long lost.

Visible Wavelength Reflectance Spectra and Taxonomies of Near-Earth Objects from Apache Point Observatory

NASA Astrophysics Data System (ADS)

Hammergren, Mark; Brucker, Melissa J.; Nault, Kristie A.; Gyuk, Geza; Solontoi, Michael R.

2015-11-01

Near-Earth Objects (NEOs) are interesting to scientists and the general public for diverse reasons: their impacts pose a threat to life and property; they present important albeit biased records of the formation and evolution of the Solar System; and their materials may provide in situ resources for future space exploration and habitation.In January 2015 we began a program of NEO astrometric follow-up and physical characterization using a 17% share of time on the Astrophysical Research Consortium (ARC) 3.5-meter telescope at Apache Point Observatory (APO). Our 500 hours of annual observing time are split into frequent, short astrometric runs (see poster by K. A. Nault et. al), and half-night runs devoted to physical characterization (see poster by M. J. Brucker et. al for preliminary rotational lightcurve results). NEO surface compositions are investigated with 0.36-1.0 μm reflectance spectroscopy using the Dual Imaging Spectrograph (DIS) instrument. As of August 25, 2015, including testing runs during fourth quarter 2014, we have obtained reflectance spectra of 68 unique NEOs, ranging in diameter from approximately 5m to 8km.In addition to investigating the compositions of individual NEOs to inform impact hazard and space resource evaluations, we may examine the distribution of taxonomic types and potential trends with other physical and orbital properties. For example, the Yarkovsky effect, which is dependent on asteroid shape, mass, rotation, and thermal characteristics, is believed to dominate other dynamical effects in driving the delivery of small NEOs from the main asteroid belt. Studies of the taxonomic distribution of a large sample of NEOs of a wide range of sizes will test this hypothesis.We present a preliminary analysis of the reflectance spectra obtained in our survey to date, including taxonomic classifications and potential trends with size.Acknowledgements: Based on observations obtained with the Apache Point Observatory 3.5-meter telescope, which

Flagstaff Robotic Survey Telescope (FRoST): Rapid Response for NEOs

NASA Astrophysics Data System (ADS)

Avner, Louis Daniel; Trilling, David E.; Dunham, Edward W.

2016-10-01

The Flagstaff Robotic Survey Telescope (FRoST) is a robotic 0.6m Schmidt telescope that will be used for instant follow-up observations of newly discovered Near Earth Objects (NEOs). Here, we present the progress being made on FRoST as well as the remaining tasks until the telescope is fully operational. With more than one thousand NEOs being found yearly, more telescopes are needed to carry out follow-up observations. Most NEOs are found at their peak brightness, meaning that these observations need to happen quickly before they fade. By using the Catalina Sky Survey Queue Manager, FRoST will be able to accept interruptions during the night and prioritize observations automatically, allowing instant follow-up observations. FRoST will help refine the orbit of these newly discovered objects while providing optical colors. We will ingest information from the NEOCP and JPL's Scout program at five minute intervals and observe newly discovered targets robotically, process the data automatically, and autonomously generate astrometry and colors. We estimate that will we provide essentially 100% recovery of objects brighter than V~20. This work was supported by the NSF MRI program as well as by NAU and Lowell Observatory.

TMAP: A NEO follow-up program utilizing undergraduate observers

NASA Astrophysics Data System (ADS)

Ramirez, C.; Deaver, D.; Martinez, R.; Foster, J.; Kuang, L.; Ates, A.; Anderson, M.; Mijac, M.; Gillam, S.; Hicks, M. D.

2000-10-01

In the spring of 2000 we began TMAP (Table Mountain Astrometry Project), a program designed to provide timely astrometric followup of newly discovered near-Earth asteroids. Relying on undergraduate observers from the local California State Universities, we have to date been involved with the over 50 NEO and new comet discoveries. This is a significant fraction of all near-Earth asteroids discovered over the time period. All observations are performed at JPL's Table Mountain Facility near Wrightwood California using the 0.6-meter telescope equipped with a Photometrics LN cooled 1k CCD mounted at the cassegrain focus. With this system we can routinely detect objects to R=20.5. We have typically scheduled two runs per month on weekends bracketing the new moon. The student observers man the telescope are trained to select and obtain R-band images of candidates from the Minor Planet Center's NEO Confirmation Page (http://cfa-www.harvard.edu/cfa/ps/NEO/TheNEOPage.html). The astrometry is then reduced and submitted to the Minor Planet Center the following day. TMAP has proven to be an efficient way both to obtain much needed astrometric measurements of newly discovered small bodies as well as to involve undergraduate researchers in planetary research. The limiting magnitudes provided by the 0.6-meter partially fills the gap between the extremely helpful and dedicated amateur astromitrists and the followup that the NEO detection programs do themselves. This work is supported by NASA.

Dynamical evolution of near-Earth asteroid 1991 VG

NASA Astrophysics Data System (ADS)

de la Fuente Marcos, C.; de la Fuente Marcos, R.

2018-01-01

The discovery of 1991 VG on 1991 November 6 attracted an unprecedented amount of attention as it was the first near-Earth object (NEO) ever found on an Earth-like orbit. At that time, it was considered by some as the first representative of a new dynamical class of asteroids, while others argued that an artificial (terrestrial or extraterrestrial) origin was more likely. Over a quarter of a century later, this peculiar NEO has been recently recovered and the new data may help in confirming or ruling out early theories about its origin. Here, we use the latest data to perform an independent assessment of its current dynamical status and short-term orbital evolution. Extensive N-body simulations show that its orbit is chaotic on time-scales longer than a few decades. We confirm that 1991 VG was briefly captured by Earth's gravity as a minimoon during its previous fly-by in 1991-1992; although it has been a recurrent transient co-orbital of the horseshoe type in the past and it will return as such in the future, it is not a present-day co-orbital companion of the Earth. A realistic NEO orbital model predicts that objects like 1991 VG must exist and, consistently, we have found three other NEOs - 2001 GP2, 2008 UA202 and 2014 WA366 - which are dynamically similar to 1991 VG. All this evidence confirms that there is no compelling reason to believe that 1991 VG is not natural.

Small D-type asteroids in the NEO population: new targets for space missions

NASA Astrophysics Data System (ADS)

Barucci, Maria Antonietta; Perna, D.; Popescu, M.; Fornasier, S.; Doressoundiram, A.; Lantz, C.; Merlin, F.; Fulchignoni, M.; Dotto, E.; Kanuchova, S.

2018-06-01

In the framework of the Near Earth Objects (NEOs) observational campaign carried out within the NEOShield-2 project, we identify nine new small D-type asteroids with estimated diameter less than 600 m. The link with meteorites for this class of asteroids is weak and the best fit obtained is with the Tagish Lake meteorite for seven of them. D-type asteroids are believed to contain the most pristine material of the Solar system and could have delivered the pre-biotic material to the Earth. Our results double the known sample of the D-types in the NEO population and triple the candidates of this class for a sample-return mission (at very low ΔV). Our finding increases considerably the number of targets for sample-return mission. A sample-return mission to a D-type asteroid will provide a major progress in understanding the early history of the Solar system and to investigate the origin of life on the Earth.

Debiased estimates for NEO orbits, absolute magnitudes, and source regions

NASA Astrophysics Data System (ADS)

Granvik, Mikael; Morbidelli, Alessandro; Jedicke, Robert; Bolin, Bryce T.; Bottke, William; Beshore, Edward C.; Vokrouhlicky, David; Nesvorny, David; Michel, Patrick

2017-10-01

The debiased absolute-magnitude and orbit distributions as well as source regions for near-Earth objects (NEOs) provide a fundamental frame of reference for studies on individual NEOs as well as on more complex population-level questions. We present a new four-dimensional model of the NEO population that describes debiased steady-state distributions of semimajor axis (a), eccentricity (e), inclination (i), and absolute magnitude (H). We calibrate the model using NEO detections by the 703 and G96 stations of the Catalina Sky Survey (CSS) during 2005-2012 corresponding to objects with 17NEOs and the predicted numbers, particularly for the larger NEOs, are in agreement with other contemporary estimates. Our model also provides updated estimates for the likelihood of the various source regions and escape routes as a function of NEO (a,e,i,H) parameters. We present the model and its predictions, and discuss them in the context of other contemporary estimates.

Astrometric and Photometric Follow-up of Faint Near Earth Objects

NASA Technical Reports Server (NTRS)

Morgan, T. (Technical Monitor); Spahr, Timothy

2005-01-01

During the period April 2003 - April 2005, roughly 150 different faint NEO's were observed using the 1.2-m telescope at Mt. Hopkins. Among these were a couple of spacecraft/radar targets, including support observations in support of the Deep Impact mission. While not strictly an NEO target, comet P/Tempel 1 was nonetheless observed as an object of very high importance. During this time and independent contractor, Kyle Smalley, was trained in the use of the telescope and provided some basic software support for the project.

Determining the Location, Number Density and Temporal Evolution of Streams of Hazardous Near-Earth Objects Using the Magnetic Signatures Produced in Destructive Collisions

NASA Astrophysics Data System (ADS)

Lai, H.; Russell, C. T.; Wei, H.; Delzanno, G. L.; Connors, M. G.

2014-12-01

Near-Earth objects (NEOs) of tens of meters in diameter are difficult to detect by optical methods from the Earth but they result in the most damage per year. Many of these bodies are produced in non-destructive collisions with larger well-characterized NEOs. After generation, the debris spreads forward and backward in a cocoon around the orbit of the parent body. Thereafter, scattering will occur due to gravitational perturbations when the debris stream passes near a planet even when the parent body has no such close approaches. Therefore "safe" NEOs which have no close encounters to the Earth for thousands of years may be accompanied by potentially hazardous co-orbiting debris. We have developed a technique to identify co-orbiting debris by detecting the magnetic signature produced when some of the debris suffers destructive collisions with meteoroids, which are numerous and can be as small as tens of centimeters in diameter. Clouds of nanoscale dust/gas particles released in such collisions can interact coherently with the solar wind electromagnetically. The resultant magnetic perturbations are readily identified when they pass spacecraft equipped with magnetometers. We can use such observations to obtain the spatial and size distribution as well as temporal variation of the debris streams. A test of this technique has been performed and debris streams both leading and trailing asteroid 138175 have been identified. There is a finite spread across the original orbit and most of the co-orbitals were tens of meters in diameter before the disruptive collisions. We estimate that there were tens of thousands of such co-orbiting objects, comprising only 1% of the original mass of the parent asteroid but greatly increasing the impact hazard. A loss of the co-orbitals since 1970s has been inferred from observations with a decay time consistent with that calculated from the existing collisional model [Grün et al., 1985]. Therefore disruptive collisions are the main loss

A concept for providing warning of earth impacts by small asteroids

NASA Astrophysics Data System (ADS)

Dunham, D. W.; Reitsema, H. J.; Lu, E.; Arentz, R.; Linfield, R.; Chapman, C.; Farquhar, R.; Ledkov, A. A.; Eismont, N. A.; Chumachenko, E.

2013-07-01

The atmospheric detonation of a 17 m-asteroid above Chelyabinsk, Russia on 2013 February 15 shows that even small asteroids can cause extensive damage. Earth-based telescopes have found smaller harmless objects, such as 2008 TC3, a 4 m-asteroid that was discovered 20h before it exploded over northeastern Sudan (Jenniskens, 2009). 2008 TC3 remains the only asteroid discovered before it hit Earth because it approached Earth from the night side, where it was observed by large telescopes searching for near-Earth objects (NEO's). The larger object that exploded over Chelyabinsk approached Earth from the day side, from too close to the Sun to be detected from Earth. A sizeable telescope in an orbit about the Sun-Earth L1 (SE-L1) libration point could find objects like the "Chelyabinsk" asteroid approaching approximately from the line of sight to the Sun about a day before Earth closest approach. Such a system would have the astrometric accuracy needed to determine the time and impact zone for a NEO on a collision course. This would give at least several hours, and usually 2-4 days, to take protective measures, rather than the approximately two-minute interval between the flash and shock wave arrival that occurred in Chelyabinsk. A perhaps even more important reason for providing warning of these events, even smaller harmless ones that explode high in the atmosphere with the force of an atomic bomb, is to prevent mistaking such an event for a nuclear attack that could trigger a devastating nuclear war. A concept using a space telescope similar to that needed for an SE-L1 monitoring satellite, is already conceived by the B612 Foundation, whose planned Sentinel Space Telescope could find nearly all 140 m and larger NEO's, including those in orbits mostly inside the Earth's orbit that are hard to find with Earth-based telescopes, from a Venus-like orbit (Lu, 2013). Few modifications would be needed to the Sentinel Space Telescope to operate in a SE-L1 orbit, 0.01 AU from

A photometric survey of Near-Earth Objects in support of the NEOShield-2 project

NASA Astrophysics Data System (ADS)

Ieva, S.; Dotto, E.; Mazzotta Epifani, E.; Perna, D.; Barucci, M. A.; Di Paola, A.; Micheli, M.; Perozzi, E.; Speziali, R.; Lazzarin, M.; Bertini, I.; Giunta, A.; Lazzaro, D.; Arcoverde, P.

2017-09-01

More than 85% of the 16,000 NEOs discovered up to now lack a physical characterization. The study of their physical properties is essential to define a proper mitigation scenario. One of the main aims of the NEOShield-2 project (2015-2017), financed by the European Community in the framework of the Horizon 2020 program, is therefore to retrieve physical properties of a wide number of NEOs, in order to design impact mitigation missions and assess the consequences of an impact on Earth. We present the results obtained during a 2-year Long-Term Program at the Telescopio Nazionale Galileo (TNG, La Palma, Spain), where we carried out BVRI photometry of about 150 NEOs, and the analysis of the phase curves obtained at the Campo Imperatore telescope (L'Aquila, Italy) and the Observatório Astronômico do Sertão de Itaparica (Nova Itacuruba, Brazil).

Near-Earth asteroids: Observer alert network and physical observations

NASA Technical Reports Server (NTRS)

Davis, Donald R.; Chapman, Clark R.

1992-01-01

This project strives to obtain physical observations on newly discovered Near-Earth Objects (NEO's) in order to provide fundamental data needed to assess the resources available in the population. The goal is acquiring data on all objects brighter than magnitude V= 17.0. To accomplish this, an electronic mail alert and observer information service that informs observers around the world as to the status of physical observations on currently observable NEO's was established. Such data is also acquired ourselves through a cooperative program with European colleagues that uses telescopes on La Palma to obtain spectra of NEO's and through observations made from a local telescope on Tumamoc Hill. This latter telescope has the advantage that large amounts of observing time are available, so that whenever a new NEO's discovered, we can be assured of getting time to observe it.

Physical characterization of Near Earth Objects with Spitzer

NASA Astrophysics Data System (ADS)

Trilling, David; Hora, Joseph; Mommert, Michael; Chesley, Steve; Emery, Joshua; Fazio, Giovanni; Harris, Alan; Mueller, Migo; Smith, Howard

2018-05-01

We propose here an efficient, flux-limited survey of 426 optically discovered NEOs in order to measure their diameters and albedos. We include only targets not previously detected by Spitzer or NEOWISE and includes all NEOs available to Spitzer in Cycle 14. This program will maintain the fraction of all known NEOs with measured diameters and albedos at around 20% even in the face of increasingly successful NEO discovery surveys. By the conclusion of this program nearly 3500 NEOs will have measured diameters and albedos, with nearly 3000 of those observations being made by Spitzer and our team. We will determine an independent size distribution of NEOs at 100 meters that is free from albedo assumptions, addressing a current controversy. We will also derive, through our albedo measurements, the compositional distribution of NEOs as a function of size. We will measure or constrain lightcurves for more than 400 NEOs, thus constraining their shapes in addition to sizes and compositions. This catalog will enable a number of other science cases to be pursued by us and other researchers. Our team has unmatched experience observing NEOs with Spitzer.

Survey and Risk Assessment of Near Earth Asteroids

NASA Astrophysics Data System (ADS)

Zhao, H. B.

2010-07-01

In 1994, 21 fragments of comet Shoemaker-Levy 9 impacted Jupiter with a velocity of about 60 km/s, which is the first grand collision between celestial bodies observed by human beings. The impact makes us informed definitely that the earth is faced with the small but serious threat of Near Earth Objects (NEOs). Chinese scientists of Purple Mountain Observatory proposed a plan of Chinese Near Earth Object Survey (CNEOS) in the conference on NEOs held in the building of the World Headquarters of United Nations, New York in 1995. This project started in 1998. During the past 7 years, CNEOS proceeded in selecting observational site, manufacturing telescope and CCD detector, carrying out observation, reducing mass data, and assessing impact risk from NEOs. Will those so-called potential hazardous asteroids be the terminator of mankind? In 2007, NASA proposed the Spaceguard goal to detect, track, catalogue and characterize 90% of the potentially hazardous objects with diameters greater than 140 m. This dissertation reviews the current situation of research on asteroids and NEOs, which will greatly enhance our understanding of the planetary sciences. The project of CNEOS, including selecting observational site, manufacturing telescope and CCD detector, had been put in practice since 1998. The telescope of CNEOS is a 1.04/1.20/1.80 m Schmidt telescope, equipped with a 4096 by 4096 CCD detector which has drift-scanning function. In this dissertation, the advantage and disadvantage of drift-scanning and corresponding observational method are discussed. This dissertation discusses residential district of asteroids and distribution of visual magnitudes of asteroids. As a result, we draw three principles of observational plan. This dissertation also develops algorithms of pretreatment of astronomical image, extracting objects, and cross-identification, then discusses the methods of identifying and classifying of move objects, establishes software to realize the reduction of the

Phase-Angle Dependence of Determinations of Diameter, Albedo, and Taxonomy: A Case Study of NEO 3691 Bede

NASA Technical Reports Server (NTRS)

Wooden, Diane H.; Lederer, Susan M.; Jehin, Emmanuel; Howell, Ellen S.; Fernandez, Yan; Harker, David E.; Ryan, Erin; Lovell, Amy; Woodward, Charles E.; Benner, Lance A.

2015-01-01

Parameters important for NEO risk assessment and mitigation include Near-Earth Object diameter and taxonomic classification, which translates to surface composition. Diameters of NEOs are derived from the thermal fluxes measured by WISE, NEOWISE, Spitzer Warm Mission and ground-based telescopes including the IRTF and UKIRT. Diameter and its coupled parameters Albedo and IR beaming parameter (a proxy for thermal inertia and/or surface roughness) are dependent upon the phase angle, which is the Sun-target-observer angle. Orbit geometries of NEOs, however, typically provide for observations at phase angles greater than 20 degrees. At higher phase angles, the observed thermal emission is sampling both the day and night sides of the NEO. We compare thermal models for NEOs that exclude (NEATM) and include (NESTM) night-side emission. We present a case study of NEO 3691 Bede, which is a higher albedo object, X (Ec) or Cgh taxonomy, to highlight the range of H magnitudes for this object (depending on the albedo and phase function slope parameter G), and to examine at different phase angles the taxonomy and thermal model fits for this NEO. Observations of 3691 Bede include our observations with IRTF+SpeX and with the 10 micrometer UKIRT+Michelle instrument, as well as WISE and Spitzer Warm mission data. By examining 3691 Bede as a case study, we highlight the interplay between the derivation of basic physical parameters and observing geometry, and we discuss the uncertainties in H magnitude, taxonomy assignment amongst the X-class (P, M, E), and diameter determinations. Systematic dependencies in the derivation of basic characterization parameters of H-magnitude, diameter, albedo and taxonomy with observing geometry are important to understand. These basic characterization parameters affect the statistical assessments of the NEO population, which in turn, affects the assignment of statistically-assessed basic parameters to discovered but yet-to-be-fully-characterized NEOs.

Near-Earth object 2012XJ112 as a source of bright bolides of achondritic nature

NASA Astrophysics Data System (ADS)

Madiedo, José M.; Trigo-Rodríguez, Josep M.; Williams, Iwan P.; Konovalova, Natalia; Ortiz, José L.; Castro-Tirado, Alberto J.; Pastor, Sensi; de los Reyes, José A.; Cabrera-Caño, Jesús

2014-04-01

We analyse the likely link between the recently discovered near-Earth object 2012XJ112 and a bright fireball observed over the south of Spain on 2012 December 27. The bolide, with an absolute magnitude of -9 ± 1, was simultaneously imaged during the morning twilight from two meteor stations operated by the SPanish Meteor Network (SPMN). It was also observed by several casual witnesses. The emission spectrum produced during the ablation of the meteoroid in the atmosphere was also recorded. From its analysis, the chemical nature of this particle was inferred. Although our orbital association software identified several potential parent bodies for this meteoroid, the analysis of the evolution of the orbital elements performed with the MERCURY 6 symplectic integrator supports the idea that NEO 2012XJ112 is the source of this meteoroid. The implications of this potential association are discussed here. In particular, the meteoroid bulk chemistry is consistent with a basaltic achondrite, and this emphasizes the importance to deduce from future Earth approaches the reflectance spectrum and taxonomic nature of 2012XJ112.

Target selection and mass estimation for manned NEO exploration using a baseline mission design

NASA Astrophysics Data System (ADS)

Boden, Ralf C.; Hein, Andreas M.; Kawaguchi, Junichiro

2015-06-01

In recent years Near-Earth Objects (NEOs) have received an increased amount of interest as a target for human exploration. NEOs offer scientifically interesting targets, and at the same time function as a stepping stone for achieving future Mars missions. The aim of this research is to identify promising targets from the large number of known NEOs that qualify for a manned sample-return mission with a maximum duration of one year. By developing a baseline mission design and a mass estimation model, mission opportunities are evaluated based on on-orbit mass requirements, safety considerations, and the properties of the potential targets. A selection of promising NEOs is presented and the effects of mission requirements and restrictions are discussed. Regarding safety aspects, the use of free-return trajectories provides the lowest on-orbit mass, when compared to an alternative design that uses system redundancies to ensure return of the spacecraft to Earth. It is discovered that, although a number of targets are accessible within the analysed time frame, no NEO offers both easy access and high incentive for its exploration. Under the discussed aspects a first human exploration mission going beyond the vicinity of Earth will require a trade off between targets that provide easy access and those that are of scientific interest. This lack of optimal mission opportunities can be seen in the small number of only 4 NEOs that meet all requirements for a sample-return mission and remain below an on-orbit mass of 500 metric Tons (mT). All of them require a mass between 315 and 492 mT. Even less ideal, smaller asteroids that are better accessible require an on-orbit mass that exceeds the launch capability of future heavy lift vehicles (HLV) such as SLS by at least 30 mT. These mass requirements show that additional efforts are necessary to increase the number of available targets and reduce on-orbit mass requirements through advanced mission architectures. The need for on

Catalog based two-color, relative photometry of NEOs at McDonald Observatory

NASA Astrophysics Data System (ADS)

Barker, E. S.; Györgyey Ries, J.; Shelus, P. J.; Ricklefs, R. L.

2001-11-01

The McDonald Observatory astrometry group has been involved in Solar System positional observations since the early 1970's. Since 1995, it has evolved to a CCD-based, almost totally automated, astrometry package. We are focusing our observational program on Near Earth Objects (NEOs) as part of NASA's mission to discover and catalogue 90 percent of NEOs with diameters larger than 1 km by 2008. We carry out confirmation observations of newly discovered objects and contribute to orbit improvements of under-observed objects. Understanding the overall hazard that these objects pose to Earth requires their dynamical and physical characterization. We recently adopted the USNO-A2.0 catalogue to improve our astrometric results. The catalog, however, also provides stellar magnitudes in the standard Johnson R and B photometric bands. After completing the night’s observing program, we now regularly provide the IAU with R magnitudes in addition to astrometric positions. Our limiting magnitude in R is near 22 in a 15 minute exposure over a 46 arcmin field on the 0.8m prime focus camera. Typically, we are scheduled for 4 nights each lunation, but our semi-automated, IRAF/ICE based program can be used by other 0.8m users. We are testing procedures that will include B and V exposures as part of our standard confirmation triplet. We have confirmed that switching filters between exposures on standard fields does not compromise the astrometric accurary. Thus, we should be able to provide two color, sequential, relative photometry of any newly discovered asteroid, as part of the confirmation process. The time interval between exposures is less than 20 minutes, short compared to most asteroid rotation times. Consequently, a meaningful color index can be obtained in parallel with the astrometric positions. Although B-R is not the usual color index used in asteroid classification studies, we are testing whether we can use it as a quick diagnostic tool to roughly classify newly

A resonant family of dynamically cold small bodies in the near-Earth asteroid belt

NASA Astrophysics Data System (ADS)

de la Fuente Marcos, C.; de la Fuente Marcos, R.

2013-07-01

Near-Earth objects (NEOs) moving in resonant, Earth-like orbits are potentially important. On the positive side, they are the ideal targets for robotic and human low-cost sample return missions and a much cheaper alternative to using the Moon as an astronomical observatory. On the negative side and even if small in size (2-50 m), they have an enhanced probability of colliding with the Earth causing local but still significant property damage and loss of life. Here, we show that the recently discovered asteroid 2013 BS45 is an Earth co-orbital, the sixth horseshoe librator to our planet. In contrast with other Earth's co-orbitals, its orbit is strikingly similar to that of the Earth yet at an absolute magnitude of 25.8, an artificial origin seems implausible. The study of the dynamics of 2013 BS45 coupled with the analysis of NEO data show that it is one of the largest and most stable members of a previously undiscussed dynamically cold group of small NEOs experiencing repeated trappings in the 1:1 commensurability with the Earth. This new resonant family is well constrained in orbital parameter space and it includes at least 10 other transient members: 2003 YN107, 2006 JY26, 2009 SH2 and 2012 FC71 among them. 2012 FC71 represents the best of both worlds as it is locked in a Kozai resonance and is unlikely to impact the Earth. These objects are not primordial and may have originated within the Venus-Earth-Mars region or in the main-belt, then transition to Amor-class asteroid before entering Earth's co-orbital region. Objects in this group could be responsible for the production of Earth's transient irregular natural satellites.

New Technologies and Strategies to Exploit Near Earth Asteroids for Breakthrough Space Development

NASA Astrophysics Data System (ADS)

Rather, John; Powell, James; Maise, George

2010-01-01

The past two decades have brought a profound expansion of knowledge of near earth objects (NEO). If creatively exploited, NEOs can significantly increase human safety while reducing costs of exploration and development of the moon, Mars and the solar system. Synergistically, the ability to defend the Earth from devastating impacts will become very effective. A spherical volume having a radius equivalent to the moon's orbit, 400,000 km, is visited every day by approximately ten NEOs having diameters of ~10 meters, while ~30 meter diameter encounters occur about once per month. Because these objects are usually very faint and only within detectable range for a few days, they require specialized equipment to discover them with high probability of detection and to enable accurate determination of orbital parameters. Survey systems are now being implemented that are cataloging many thousands of objects larger than 30 meters, but numerous advantages will result from extending the complete NEO census down to 10 meter diameters. The typical compositions of such NEOs will range from ~80% that are low density dust & rock ``rubble piles'' to perhaps 2% containing heavy metals-properties well known from meteorite samples. It is quite possible that there will also be some fragments of short period comets that are rich in water ice and other volatile components. In this paper we will propose a set of new technologies and strategies for exploiting NEO resources that can yield important space development breakthroughs at much lower costs than existing concepts. Solar powered ``Tugboats'' deployed at the space station can rendezvous with carefully selected NEOs and steer them into captured orbits in the lunar L4 & L5 regions. Robotic equipment will then modify them for a plethora of benefits. Notably, the problem of radiation shielding against the Van Allen belts, solar flares and cosmic rays will be solved. Free transportation from low earth orbit to the moon and beyond will be

An Innovative Solution to NASA's NEO Impact Threat Mitigation Grand Challenge and Flight Validation Mission Architecture Development

NASA Technical Reports Server (NTRS)

Wie, Bong; Barbee, Brent W.

2015-01-01

This paper presents the results of a NASA Innovative Advanced Concept (NIAC) Phase 2 study entitled "An Innovative Solution to NASA's Near-Earth Object (NEO) Impact Threat Mitigation Grand Challenge and Flight Validation Mission Architecture Development." This NIAC Phase 2 study was conducted at the Asteroid Deflection Research Center (ADRC) of Iowa State University in 2012-2014. The study objective was to develop an innovative yet practically implementable mitigation strategy for the most probable impact threat of an asteroid or comet with short warning time (< 5 years). The mitigation strategy described in this paper is intended to optimally reduce the severity and catastrophic damage of the NEO impact event, especially when we don't have sufficient warning times for non-disruptive deflection of a hazardous NEO. This paper provides an executive summary of the NIAC Phase 2 study results. Detailed technical descriptions of the study results are provided in a separate final technical report, which can be downloaded from the ADRC website (www.adrc.iastate.edu).

NEOShield-2 Project: Final Results on Compositional Characterization of small NEOs

NASA Astrophysics Data System (ADS)

Barucci, Maria Antonieta; Perna, Davide; Fornasier, Sonia; Doressoundiram, Alain; Lantz, Cateline; Popescu, Marcel; Merlin, Frederic; Fulchignoni, Marcello

2017-10-01

NEOShield-2 project was selected in the framework of the European Commission H2020 program in answer to the call for “Access technologies and characterisation for Near Earth Objects (NEOs)”. NEOShield-2 project (2015-2017) is a follow-up of the first NEOShield (2012-2015) and includes 11 European Institutions and Industries. The main objectives of NEOShield-2 project are: i) technological development on techniques and instruments needed for GNC for possible asteroid missions and ii) characterization of NEOs of small sizes.Our team at LESIA is the leader of the entire observational program which involved complementary techniques to provide physical and compositional characterization of NEOs. Priority has been given to potential space-mission targets, optimized for mitigation or exploration missions. In this framework an agreement with the European Southern Observatory was signed to obtain Guaranteed Time Observations at the 3.6-meter NTT with an allocation of 30 nights to characterize by spectroscopy the composition of the smaller asteroids. The objects with an absolute magnitude larger than 20 were selected, with a priority for the very small newly discovered objects.We obtained more than 170 new spectra of NEOs. The observations were performed with EFOSC2 instrument. We covered the wavelength interval 0.4-0.92 microns, with a resolution of R=~200. The observed asteroids include 29 asteroids with diameters smaller than 100 meters and 71 with diameters between 100 and 300 m.The taxonomic type has been assigned for 137 individual objects. Our results on NEO mineralogical compositions provide a body of reference data directly applicable to the design and development of mitigation-relevant space missions. Within our survey, we found eight D-types with ΔV < 7 km/s, four of which with ΔV < 6 km/s. Among these, 2009 DL46 and (52381) 1993 HA, with a ΔV below 5.5 km/s and a diameter large enough to allow spacecraft operations in their proximity, represent the best

A sample return mission to a pristine NEO submitted to ESA CV 2015-2025

NASA Astrophysics Data System (ADS)

Michel, P.; Barucci, A.

2007-08-01

ESA Cosmic Vision 2015-2025 aims at furthering Europe's achievements in space science, for the benefit of all mankind. ESA' multinational Space Science Advisory Committee prepared the final plan, which contains a selection of themes and priorities. In the theme concerning how the Solar System works, a Near-Earth Object (NEO) sample return mission is indicated among the priorities. Indeed, small bodies, as primitive leftover building blocks of the Solar System formation process, offer clues to the chemical mixture from which the planets formed some 4.6 billion years ago. The Near Earth Objects (NEOs) are representative of the population of asteroids and dead comets and are thought to be similar in many ways to the ancient planetesimal swarms that accreted to form the planets. NEOs are thus fundamentally interesting and highly accessible targets for scientific research and space missions. A sample return space mission to a pristine NEO has thus been proposed in partnership with the Japanese Space Agency JAXA, involving a large European community of scientists. The principal objectives are to obtained crucial information about 1) the properties of the building blocks of the terrestrial planets; 2) the major events (e.g. agglomeration, heating, ... .) which ruled the history of planetesimals; 3) the properties of primitive asteroids which may contain presolar material unknown in meteoritic samples; 4) the organics in primitive materials; 5) the initial conditions and evolution history of the solar nebula; and 6) on the potential origin of molecules necessary for life. This project appears clearly to have the potential to revolutionize our understanding of primitive materials. It involves a main spacescraft which will allow the determination of important physical properties of the target (shape, mass, crater distribution . . . ) and which will take samples by a touch-and-go procedure, a Lander for in-situ investigation of the sampling site, and sampling depending on

Quantifying the risk posed by potential Earth impacts

NASA Technical Reports Server (NTRS)

Chesley, S. R.; Chodas, P. W.; Harris, A. W.; Milani, A.; Valsecchi, G. B.; Yeomans, D. K.

2001-01-01

Predictions of future potential Earth impacts by near-Earth objects (NEOs) have become commonplace in recent years, and the rate of these detections is likely to accelerate as asteroid survey efforts continue to mature. In this paper we describe the metrics introduced, and we give numerous examples of their application. This enables us to establish in rough terms the levels at which events become interesting to various parties.

A New Approach on the Long Term Dynamics of NEO's Under Yarkovsky Effect.

NASA Astrophysics Data System (ADS)

Peláez, Jesús; Urrutxua, Hodei; Bombardelli, Claudio; Perez-Grande, Isabel

2011-12-01

A classical approach to the many-body problem is that of using special perturbation methods. Nowadays and due to the availability of high-speed computers is an essential tool in Space Dynamics which exhibits a great advantage: it is applicable to any orbit involving any number of bodies and all sorts of astrodynamical problems, especially when these problems fall into regions in which general perturbation theories are absent. One such case is, for example, that Near Earth Objects (NEO's) dynamics. In this field, the Group of Tether Dynamics of UPM (GDT) has developed a new regularisation scheme - called DROMO - which is characterised by only 8 ODE. This new regularisation scheme allows a new approach to the dynamics of NEO's in the long term, specially appropriated to consider the influence of the anisotropic thermal emission (Yarkovsky and YORP effects) on the dynamics. A new project, called NEODROMO, has been started in GDT that aims to provide a reliable tool for the long term dynamics of NEO's.

Search for Dormant Comets in Near-Earth Space

NASA Astrophysics Data System (ADS)

Kim, Yoonyoung

2013-06-01

It is considered that comets have been injected into near-Earth space from outer region (e.g. Kuiper-belt region), providing rich volatile and organic compounds to the earth. Some comets are still active while most of them are dormant with no detectable tails and comae. Here we propose to make a multi-band photometric observation of near-Earth objects (NEOs) with comet-like orbits. We select our targets out of infrared asteroidal catalogs based on AKARI and WISE observations. With a combination of taxonomic types by Subaru observation and albedos by AKARI or WISE, we aim to dig out dormant comet candidates among NEOs. Our results will provide valuable information to figure out the dynamical evolution and fate of comets. We would like to emphasize that this is the first taxonomic survey of dormant comets to utilize the infrared data archive with AKARI and WISE.

Space-based infrared near-Earth asteroid survey simulation

NASA Astrophysics Data System (ADS)

Tedesco, Edward F.; Muinonen, Karri; Price, Stephan D.

2000-08-01

We demonstrate the efficiency and effectiveness of using a satellite-based sensor with visual and infrared focal plane arrays to search for that subclass of Near-Earth Objects (NEOs) with orbits largely interior to the Earth's orbit. A space-based visual-infrared system could detect approximately 97% of the Atens and 64% of the IEOs (the, as yet hypothetical, objects with orbits entirely Interior to Earth's Orbit) with diameters greater than 1 km in a 5-year mission and obtain orbits, albedos and diameters for all of them; the respective percentages with diameters greater than 500 m are 90% and 60%. Incidental to the search for Atens and IEOs, we found that 70% of all Earth-Crossing Asteroids (ECAs) with diameters greater than 1 km, and 50% of those with diameters greater than 500 m, would also be detected. These are the results of a feasibility study; optimizing the concept presented would result in greater levels of completion. The cost of such a space-based system is estimated to be within a factor of two of the cost of a ground-based system capable of about 21st magnitude, which would provide only orbits and absolute magnitudes and require decades to reach these completeness levels. In addition to obtaining albedos and diameters for the asteroids discovered in the space-based survey, a space-based visual-infrared system would obtain the same information on virtually all NEOs of interest. A combined space-based and ground-based survey would be highly synergistic in that each can concentrate on what it does best and each complements the strengths of the other. The ground-based system would discover the majority of Amors and Apollos and provide long-term follow-up on all the NEOs discovered in both surveys. The space-based system would discover the majority of Atens and IEOs and provide albedos and diameters on all the NEOs discovered in both surveys and most previously discovered NEOs as well. Thus, an integrated ground- and space-based system could accomplish

Next Gen NEAR: Near Earth Asteroid Human Robotic Precursor Mission Concept

NASA Technical Reports Server (NTRS)

Rivkin, Andrew S.; Kirby, Karen; Cheng, Andrew F.; Gold, Robert; Kelly, Daniel; Reed, Cheryl; Abell, Paul; Garvin, James; Landis, Rob

2012-01-01

Asteroids have long held the attention of the planetary science community. In particular, asteroids that evolve into orbits near that of Earth, called near-Earth objects (NEO), are of high interest as potential targets for exploration due to the relative ease (in terms of delta V) to reach them. NASA's Flexible Path calls for missions and experiments to be conducted as intermediate steps towards the eventual goal of human exploration of Mars; piloted missions to NEOs are such example. A human NEO mission is a valuable exploratory step beyond the Earth-Moon system enhancing capabilities that surpass our current experience, while also developing infrastructure for future mars exploration capabilities. To prepare for a human rendezvous with an NEO, NASA is interested in pursuing a responsible program of robotic NEO precursor missions. Next Gen NEAR is such a mission, building on the NEAR Shoemaker mission experience at the JHU/APL Space Department, to provide an affordable, low risk solution with quick data return. Next Gen NEAR proposes to make measurements needed for human exploration to asteroids: to demonstrate proximity operations, to quantify hazards for human exploration and to characterize an environment at a near-Earth asteroid representative of those that may be future human destinations. The Johns Hopkins University Applied Physics Laboratory has demonstrated exploration-driven mission feasibility by developing a versatile spacecraft design concept using conventional technologies that satisfies a set of science, exploration and mission objectives defined by a concept development team in the summer of 2010. We will describe the mission concept and spacecraft architecture in detail. Configuration options were compared with the mission goals and objectives in order to select the spacecraft design concept that provides the lowest cost, lowest implementation risk, simplest operation and the most benefit for the mission implementation. The Next Gen NEAR

The LCOGT NEO Follow-up Network

NASA Astrophysics Data System (ADS)

Lister, Tim; Greenstreet, Sarah; Gomez, Edward; Christensen, Eric J.; Larson, Stephen M.

2016-10-01

The LCOGT NEO Follow-up Network is using the telescopes of the Las Cumbres Observatory Global Telescope Network (LCOGT) and a web-based target selection, scheduling and data reduction system to confirm NEO candidates and characterize radar-targeted known NEOs. Starting in July 2014, the LCOGT NEO Follow-up Network has observed over 3,500 targets and reported more than 16,000 astrometric and photometric measurements to the Minor Planet Center (MPC).The LCOGT NEO Follow-up Network's main aims are to perform confirming follow-up of the large number of NEO candidates and to perform characterization measurements of radar targets to obtain light curves and rotation rates. The NEO candidates come from the NEO surveys such as Catalina, PanSTARRS, ATLAS, NEOWISE and others. In particular, we are targeting objects in the Southern Hemisphere, where the LCOGT NEO Follow-up Network is the largest resource for NEO observations.LCOGT has completed the first phase of the deployment with the installation and commissioning of the nine 1-meter telescopes at McDonald Observatory (Texas), Cerro Tololo (Chile), SAAO (South Africa) and Siding Spring Observatory (Australia). The telescope network has been fully operational since 2014 May, and observations are being executed remotely and robotically. Future expansion to a site at Ali Observatory, Tibet is planned for 2017-2018.We have developed web-based software called NEOexchange which automatically downloads and aggregates NEO candidates from the Minor Planet Center's NEO Confirmation Page, the Arecibo and Goldstone radar target lists and the NASA ARM list. NEOexchange allows the planning and scheduling of observations on the LCOGT Telescope Network and the tracking of the resulting blocks and generated data. We have recently extended the NEOexchange software to include automated data reduction to re-compute the astrometric solution, determine the photometric zeropoint and find moving objects and present these results to the user via

Properties of Earth's temporarily-captured flybys

NASA Astrophysics Data System (ADS)

Fedorets, Grigori; Granvik, Mikael

2014-11-01

In addition to the Moon, a population of small temporarily-captured NEOs is predicted to orbit the Earth. The definition of a natural Earth satellite is that it is on an elliptic geocentric orbit within 0.03 au from the Earth. The population is further divided into temporarily-captured orbiters (TCOs, or minimoons, making at least one full revolution around the Earth in a coordinate system co-rotating with the Sun) and temporarily-captured flybys (TCFs) which fail to make a full revolution, but are temporarily on an elliptic orbit around the Earth. Only one minimoon has been discovered to date, but it is expected that next generation surveys will be able to detect these objects regularly.Granvik et al. (2012) performed an extensive analysis of the behaviour of these temporarily-captured objects. One of the main results was that at any given moment there is at least one 1-meter-diameter minimoon in orbit around the Earth. However, the results of Granvik et al. (2012) raised questions considering the NES population such as the bimodality of the capture duration distribution and a distinctive lack of test particles within Earth's Hill sphere, which requires investigating the statistical properties also of the TCF population.In this work we confirm the population characteristics for minimoons described by Granvik et al. (2012), and extend the analysis to TCFs. For the calculations we use a Bulirsch-Stoer integrator implemented in the OpenOrb software package (Granvik et al. 2009). We study, e.g., the capture statistics, residence-time distributions, and steady-state properties of TCFs. Our preliminary results indicate that TCFs may be suitable targets for asteroid-redirect missions. More detailed knowledge of the TCF population will also improve our understanding of the link between temporarily-captured objects and NEOs in general.References: Granvik et al. (2009) MPS 44(12), 1853-1861; Granvik et al. (2012) Icarus 218, 262-277.

Finding Near-Earth Asteroid (NEA) Destinations for Human Exploration: Implications for Astrobiology

NASA Technical Reports Server (NTRS)

Landis, Rob; Abell, Paul; Barbee, Brent; Johnson, Lindley

2012-01-01

The current number of known potential NEA targets for HSF is limited to those objects whose orbital characteristics are similar to that of the Earth. This is due to the projected capabilities of the exploration systems currently under consideration and development at NASA. However, NEAs with such orbital characteristics often have viewing geometries that place them at low solar elongations and thus are difficult to detect from the vicinity of Earth. While ongoing ground-based surveys and data archives maintained by the NEO Program Observation Program Office and the Minor Planet Center (MPC) have provided a solid basis upon which to build, a more complete catalog of the NEO population is required to inform a robust and sustainable HSF exploration program. Since all the present NEO observing assets are currently confined to the vicinity of the Earth, additional effort must be made to provide capabilities for detection of additional HSF targets via assets beyond Earth orbit. A space-based NEO survey telescope located beyond the vicinity of the Earth, has considerable implications for planetary science and astrobiology. Such a telescope will provide foundational knowledge of our Solar System small body population and detect targets of interest for both the HSF and scientific communities. Data from this asset will yield basic characterization data on the NEOs observed (i.e., albedo, size determination, potential for volatiles and organics, etc.) and help down select targets for future HSF missions. Ideally, the most attractive targets from both HSF and astrobiology perspectives are those NEAs that may contain organic and volatile materials, and which could be effectively sampled at a variety of locations and depths. Presented here is an overview of four space-based survey concepts; any one of which after just a few years of operation will discover many highly accessible NEO targets suitable for robotic and human exploration. Such a space-based survey mission will reveal

Ground-based Characterization of Earth Quasi Satellite (469219) 2016 HO3

NASA Astrophysics Data System (ADS)

Reddy, Vishnu; Kuhn, Olga; Thirouin, Audrey; Conrad, Al; Malhotra, Renu; Sanchez, Juan A.; Veillet, Christian

2017-10-01

(469219) 2016 HO3 is a small, <100 meter-size, near-Earth object (NEO) that while orbiting the Sun, also appears to circle around the Earth just beyond the Hill sphere as a Earth quasi-satellite. Only five quasi-satellites have been discovered so far, but 2016 HO3 is the most stable of them. The provenance of this object is unknown. On timescales of many centuries, 2016 HO3 remains within 38-100 lunar distance from us making it a prime target for future robotic and human exploration, provided it can be established it is indeed a natural object. In an effort to constrain its rotation period and surface composition, we observed 2016 HO3 on April 14 and 18 2017 (UTC) with the Large Binocular Telescope (LBT) and the Discovery Channel Telescope (DCT). We derive a rotation period of about 28 minutes based on our lightcurve observations. We obtained low-resolution (R ˜ 150 - 500) spectra of 2016 HO3 on 2017 April 14 (UTC) using the pair of MODS spectrographs mounted at the direct Gregorian foci of the LBT, obtaining the entire spectrum from 0.39-0.97 microns simultaneously. The visible wavelength spectrum shows a sharp rise in reflectance between 0.4-0.65 microns with a broad plateau beyond. The scatter near 0.8 microns makes it challenging to confirm the presence of a silicate absorption band at ~1 micron. Color ratios derived from the spectrum all suggest an S taxonomic type. We also derive an updated diameter of 36 meters for 2016 HO3 using an absolute magnitude of 24.3 and S-type albedo of 0.25. The derived rotation period and the spectrum are not uncommon amongst small NEOs, suggesting that 2016 HO3 is a natural object of similar provenance to other small NEOs. NASA Near-Earth Object Observations Program Grant NNX17AJ19G (PI: Reddy) funded parts of this work.

2P/Encke, the Taurid complex NEOs and the Maribo and Sutter's Mill meteorites

NASA Astrophysics Data System (ADS)

Tubiana, C.; Snodgrass, C.; Michelsen, R.; Haack, H.; Böhnhardt, H.; Fitzsimmons, A.; Williams, I. P.

2015-12-01

Aims: 2P/Encke is a short period comet that was discovered in 1786 and has been extensively observed and studied for more than 200 years. The Taurid meteoroid stream has long been linked with 2P/Encke owing to a good match of their orbital elements, even though the comet's activity is not strong enough to explain the number of observed meteors. Various small near-Earth objects (NEOs) have been discovered with orbits that can be linked to 2P/Encke and the Taurid meteoroid stream. Maribo and Sutter's Mill are CM type carbonaceous chondrite that fell in Denmark on January 17, 2009 and April 22, 2012, respectively. Their pre-atmospheric orbits place them in the middle of the Taurid meteoroid stream, which raises the intriguing possibility that comet 2P/Encke could be the parent body of CM chondrites. Methods: To investigate whether a relationship between comet 2P/Encke, the Taurid complex associated NEOs, and CM chondrites exists, we performed photometric and spectroscopic studies of these objects in the visible wavelength range. We observed 2P/Encke and 10 NEOs on August 2, 2011 with the FORS instrument at the 8.2 m Very Large Telescope on Cerro Paranal (Chile). Results: Images in the R filter, used to investigate the possible presence of cometary activity around the nucleus of 2P/Encke and the NEOs, show that no resolved coma is present. None of the FORS spectra show the 700 nm absorption feature due to hydrated minerals that is seen in the CM chondrite meteorites. All objects show featureless spectra with moderate reddening slopes at λ< 800 nm. Apart for 2003 QC10 and 1999 VT25, which show a flatter spectrum, the spectral slope of the observed NEOs is compatible with that of 2P/Encke. However, most of the NEOs show evidence of a silicate absorption in lower S/N data at λ> 800 nm, which is not seen in 2P/Encke, which suggests that they are not related. Conclusions: Despite similar orbits, we find no spectroscopic evidence for a link between 2P/Encke, the Taurid

To measure the chemical composition of a Near Earth Object

NASA Astrophysics Data System (ADS)

Gasnault, 0.; Ball, A.; Biele, J.; D'Uston, C.; Forni, O.; Klingelhofer, G.; Maurice, S.; Ulamec, S.

Introduction. Scenarios for a Near Earth Object (NEO) rendezvous mission were discussed recently in Europe. Such a mission would address scientific questions about the initial conditions and evolutionary history of the solar nebula, as well as mitigation considerations to prevent impact with the Earth. In our opinion the measurement of the elemental composition and the distribution of volatiles in the shallow sub-surface are two of the key observations to be conducted, either from an orbiter or a lander. These measurements are also valuable for documentation (landing site candidates and sample context). This report is limited to the chemical composition, but we assume that remote and/or in-situ observations of physical characteristics, interior, morphology, mineralogy, and organic compounds will also be made as essential complements to achieve the mission scientific objectives. Scientific Interest. The analysis of the bulk composition addresses three fundamental aspects of the scientific mission: (1) the formation of the asteroid or the comet; (2) the evolution of the object; (3) the relation between the parent body and collected meteorites on Earth. Classification of an asteroid/comet can be based on its global composition (abundances of Mg, Si, Fe, Al, Ca, etc. along with its mineralogy), which bears the signature of the feeding zone where it formed. For example the K/U and K/Th ratios seem to increase with distance from the Sun (decreasing temperature). The hydrogen content is another measurable to study the distribution of volatiles in the Solar System. The surface composition is also the result of the degree of evolution of the object and of the interactions with its environment. Building a compositional map of the major elements is necessary to identify and characterize the processes that influenced the asteroid along its history. Finally, knowing the chemical composition will obviously help to relate the parent 1 body to meteorites. Ideally the measurement

Cost-Effective NEO Characterization Using Solar Electric Propulsion (SEP)

NASA Astrophysics Data System (ADS)

Dissly, R. W.; Reinert, R.; Mitchell, S.

2003-05-01

We present a cost-effective multiple NEO rendezvous mission design optimized around the capabilities of Ball's 200-kg NEOX Solar Electric Propelled microsatellite. The NEOX spacecraft is 3-axis stabilized with better-than 1 milliradian pointing accuracy to serve as an excellent imaging platform; its DSN compatible telecommunications subsystem can support a 6.4-kbps downlink rate at 3 AU earth range. The spacecraft mass is <200kg at launch to allow launch as a cost-effective secondary payload. It uses proven SEP technology to provide 12km/s of Delta-V, which enables multiple rendezvous' in a single mission. Cost-effectiveness is optimized by launch as a secondary payload (e.g., Ariane-5 ASAP) or as a multiple manifest on a single dedicated launch vehicle (e.g., 4 on a Delta-II 2925). Following separation from the LV, we describe a candidate mission profile that minimizes cost by using the spacecraft's 12km/s of SEP Delta-V to allow orbiting up to 4 separate NEO's. Orbiting as opposed to flying by augments the mission's science return by providing the NEO mass and by allowing multiple phase angle imaging. The NEOX Spacecraft has the capability to support a 20kg payload drawing 100W average during SEP cruise, with >1kW available during the NEO orbital phase when the SEP thrusters are not powered. We will present a candidate payload suite that includes a visible/NIR imager, a laser altimeter, and a set of small, self-righting surface probes that can be used to assess the geophysical state of the object surface and near-surface environments. The surface probe payload notionally includes a set of cameras for imaging the body surface at mm-scale resolution, an accelerometer package to measure surface mechanical properties upon probe impact, a Langmuir probe to measure the electrostatic gradient immediately above the object surface, and an explosive charge that can be remotely detonated at the end of the surface mission to excavate an artificial crater that can be remotely

Scout: orbit analysis and hazard assessment for NEOCP objects

NASA Astrophysics Data System (ADS)

Farnocchia, Davide; Chesley, Steven R.; Chamberlin, Alan B.

2016-10-01

It typically takes a few days for a newly discovered asteroid to be officially recognized as a real object. During this time, the tentative discovery is published on the Minor Planet Center's Near-Earth Object Confirmation Page (NEOCP) until additional observations confirm that the object is a real asteroid rather than an observational artifact or an artificial object. Also, NEOCP objects could have a limited observability window and yet be scientifically interesting, e.g., radar and lightcurve targets, mini-moons (temporary Earth captures), mission accessible targets, close approachers or even impactors. For instance, the only two asteroids discovered before an impact, 2008 TC3 and 2014 AA, both reached the Earth less than a day after discovery. For these reasons we developed Scout, an automated system that provides an orbital and hazard assessment for NEOCP objects within minutes after the observations are available. Scout's rapid analysis increases the chances of securing the trajectory of interesting NEOCP objects before the ephemeris uncertainty grows too large or the observing geometry becomes unfavorable. The generally short observation arcs, perhaps only a few hours or even less, lead severe degeneracies in the orbit estimation process. To overcome these degeneracies Scout relies on systematic ranging, a technique that derives possible orbits by scanning a grid in the poorly constrained space of topocentric range and range rate, while the plane-of-sky position and motion are directly tied to the recorded observations. This scan allows us to derive a distribution of the possible orbits and in turn identify the NEOCP objects of most interest to prioritize followup efforts. In particular, Scout ranks objects according to the likelihood of an impact, estimates the close approach distance, the Earth-relative minimum orbit intersection distance and v-infinity, and computes scores to identify objects more likely to be an NEO, a km-sized NEO, a Potentially

Multi-objective optimization of chromatographic rare earth element separation.

PubMed

Knutson, Hans-Kristian; Holmqvist, Anders; Nilsson, Bernt

2015-10-16

The importance of rare earth elements in modern technological industry grows, and as a result the interest for developing separation processes increases. This work is a part of developing chromatography as a rare earth element processing method. Process optimization is an important step in process development, and there are several competing objectives that need to be considered in a chromatographic separation process. Most studies are limited to evaluating the two competing objectives productivity and yield, and studies of scenarios with tri-objective optimizations are scarce. Tri-objective optimizations are much needed when evaluating the chromatographic separation of rare earth elements due to the importance of product pool concentration along with productivity and yield as process objectives. In this work, a multi-objective optimization strategy considering productivity, yield and pool concentration is proposed. This was carried out in the frame of a model based optimization study on a batch chromatography separation of the rare earth elements samarium, europium and gadolinium. The findings from the multi-objective optimization were used to provide with a general strategy for achieving desirable operation points, resulting in a productivity ranging between 0.61 and 0.75 kgEu/mcolumn(3), h(-1) and a pool concentration between 0.52 and 0.79 kgEu/m(3), while maintaining a purity above 99% and never falling below an 80% yield for the main target component europium. Copyright © 2015 Elsevier B.V. All rights reserved.

The Next Giant Leap: Human Exploration and Utilization of NEOs

NASA Astrophysics Data System (ADS)

Jones, T. D.; Vilas, F.; Love, S.; Hack, K.; Gefert, L.; Sykes, M. V.; Lewis, J. S.; Jedicke, R.; Davis, D.; Hartmann, W. K.; Farquhar, R.; McFadden, L.; Durda, D.

2001-11-01

Planetary science plays a unique role as the pathfinder for future human space activities beyond the International Space Station. It can also provide the rationale for the first human departure from LEO since the Apollo program. We are examining the potential for human missions to small near-Earth objects (typically tens of meters), passing close by the Earth-Moon system with very low delta-v. A preliminary estimate suggests there may be many thousands of these objects, raising the possibility of number of launch opportunities each year. To demonstrate feasibility, we have simulated a mission to 1991 VG during 1991/1992 when it passed within 0.004 AU of the Earth. This mission takes a total of 60 days, including a 30 day stay time at the asteroid. The accessibility of these targets may provide an opportunity to develop and test systems needed for longer duration interplanetary missions to Mars, and to engage in precursor space resource utilization activities. Early discovery, orbit determination, and target characterization should be pursued and spacebased and groundbased systems that would be needed assessed. Crewed missions would be preceded by robotic probes to test acquisition, rendezvous, and local operations while returning significant new science from target objects. As we look beyond ISS over the next decade, we must reinvigorate a mutually supportive relationship between our human space and solar system exploration goals. The scientific and exploration rationale for sending humans to NEOs must be mature to meet NASA's decision making window, now opening, for operations beyond near-Earth space.

Geophysics-based method of locating a stationary earth object

DOEpatents

Daily, Michael R [Albuquerque, NM; Rohde, Steven B [Corrales, NM; Novak, James L [Albuquerque, NM

2008-05-20

A geophysics-based method for determining the position of a stationary earth object uses the periodic changes in the gravity vector of the earth caused by the sun- and moon-orbits. Because the local gravity field is highly irregular over a global scale, a model of local tidal accelerations can be compared to actual accelerometer measurements to determine the latitude and longitude of the stationary object.

LINNAEUS: BOOSTING NEAR EARTH ASTEROID CHARACTERIZATION RATES

NASA Astrophysics Data System (ADS)

Elvis, Martin; Beeson, C.; Galache, J.; DeMeo, F.; Evans, I.; Evans, J.; Konidaris, N.; Najita, J.; Allen, L.; Christensen, E.; Spahr, T.

2013-10-01

Near Earth objects (NEOs) are being discovered at a rate of about 1000 per year, and this rate is set to double by 2015. However, the physical characterization of NEOs is only ~100 per year for each type of follow-up observation. We have proposed the LINNAEUS program to NASA to raise the characterization rate of NEOs to the rate of their discovery. This rate matching is necessary as any given NEO is only available for a relatively short time (days to weeks), and they are usually fainter on subsequent apparitions. Hence follow-up observations must be initiated rapidly, without time to cherry-pick the optimum objects. LINNAEUS concentrates on NEO composition. Optical spectra, preferably extending into the near-infrared, provide compositions that can distinguish major compositional classes of NEOs with reasonable confidence (Bus and Binzel 2002, DeMeo et al. 2009). Armed with a taxonomic type the albedo, pV, of an NEO is better constrained, leading to more accurate sizes and masses. Time-resolved spectroscopy can give indications of period, axial ratio and surface homogeneity. A reasonable program of spectroscopy could keep pace with the NEO discovery rate. A ground-based telescope can observe faint NEOs about 210 nights a year, due to time lost due to weather, bright time, and equipment downtime (e.g. Gemini), for a total of ~2000 hours/year. At 1 hour per NEO spectrum, a well-run, dedicated, telescope could obtain almost 2000 spectra per year, about the rate required. If near-IR spectra are required then a 4 m or larger telescope is necessary to reach 20. However, if the Bus-Binzel taxomonmy suffices then only optical spectra are needed and a 2 meter class telescope is sufficient. LINNAEUS would use 50% of the KPNO 2.1 m telescope with an IFU spectrometer, the SED-machine (Ben-Ami et al. 2013), to obtain time-resolved optical spectra of 1200-2000 NEOs/year, or 4200-7000 in 3.5 years observing in an NEOO program. Robust pipeline analysis will release taxonomic types

Unconfirmed Near-Earth Objects

NASA Astrophysics Data System (ADS)

Vereš, Peter; Payne, Matthew J.; Holman, Matthew J.; Farnocchia, Davide; Williams, Gareth V.; Keys, Sonia; Boardman, Ian

2018-07-01

We studied the Near-Earth Asteroid (NEA) candidates posted on the Minor Planet Center’s Near-Earth Object Confirmation Page (NEOCP) between years 2013 and 2016. Out of more than 17000 NEA candidates, while the majority became either new discoveries or were associated with previously known objects, about 11% were unable to be followed-up or confirmed. We further demonstrate that of the unconfirmed candidates, 926 ± 50 are likely to be NEAs, representing 18% of discovered NEAs in that period. Only 11% (∼93) of the unconfirmed NEA candidates were large (having absolute magnitude H < 22). To identify the reasons why these NEAs were not recovered, we analyzed those from the most prolific asteroid surveys: Pan-STARRS, the Catalina Sky Survey, the Dark Energy Survey, and the Space Surveillance Telescope. We examined the influence of plane-of-sky positions and rates of motion, brightnesses, submission delays, and computed absolute magnitudes, as well as correlations with the phase of the moon and seasonal effects. We find that delayed submission of newly discovered NEA candidate to the NEOCP drove a large fraction of the unconfirmed NEA candidates. A high rate of motion was another significant contributing factor. We suggest that prompt submission of suspected NEA discoveries and rapid response to fast-moving targets and targets with fast growing ephemeris uncertainty would allow better coordination among dedicated follow-up observers, decrease the number of unconfirmed NEA candidates, and increase the discovery rate of NEAs.

Proceedings of the Near-Earth-Object Interception Workshop

NASA Technical Reports Server (NTRS)

Canavan, G. J. (Editor); Solem, J. C. (Editor); Rather, John D. G. (Editor)

1993-01-01

The National Aeronautics and Space Administration Headquarters sponsored the Near-Earth-Object Interception Workshop hosted by the Los Alamos National Laboratory on 14-16 Jan. 1992 at the J. Robert Oppenheimer Study Center in Los Alamos, New Mexico. The Workshop evaluated the issues involved in intercepting celestial objects that could hit the Earth. It covered the technologies for acquiring, tracking, and homing, as well as those for sending interceptors to inspect, rendezvous with, land on, irradiate, deflect, or destroy them. This report records the presentations and technical options reviewed.

The flux of small near-Earth objects colliding with the Earth.

PubMed

Brown, P; Spalding, R E; ReVelle, D O; Tagliaferri, E; Worden, S P

2002-11-21

Asteroids with diameters smaller than approximately 50-100 m that collide with the Earth usually do not hit the ground as a single body; rather, they detonate in the atmosphere. These small objects can still cause considerable damage, such as occurred near Tunguska, Siberia, in 1908. The flux of small bodies is poorly constrained, however, in part because ground-based observational searches pursue strategies that lead them preferentially to find larger objects. A Tunguska-class event-the energy of which we take to be equivalent to 10 megatons of TNT-was previously estimated to occur every 200-300 years, with the largest annual airburst calculated to be approximately 20 kilotons (kton) TNT equivalent (ref. 4). Here we report satellite records of bolide detonations in the atmosphere over the past 8.5 years. We find that the flux of objects in the 1-10-m size range has the same power-law distribution as bodies with diameters >50 m. From this we estimate that the Earth is hit on average annually by an object with approximately 5 kton equivalent energy, and that Tunguska-like events occur about once every 1,000 years.

Identifying Potentially Hazardous Co-orbiting Material of Known NEOs Using Magnetic Signatures Produced in Destructive Collisions

NASA Astrophysics Data System (ADS)

Lai, Hairong; Russell, Christopher; Jia, Yingdong; Wei, Hanying; Connors, Martin

2015-04-01

It is estimated that over 99% of near-Earth objects (NEOs) with diameters of about tens of meters are undiscovered. However, simulations show that they result in the most damage per year. Many of these bodies, produced in non-destructive collisions with larger well-characterized NEOs, are co-orbiting with their parent objects. Thereafter, scattering will occur due to gravitational perturbations when the co-orbiters have close encounters to any planets. Such gravitational scattering may not affect the orbits of the parent body. Therefore "safe" NEOs which have negligible impact probability with the Earth may be accompanied by potentially hazardous co-orbiting material. Those co-orbitals do reveal their existence in collisions with meteoroids, which are numerous and can be as small as tens of centimeters in diameter. Clouds of fine dust/gas particles released in such collisions become charged after generation and interact coherently with the solar wind electromagnetically. The interplanetary magnetic field is then perturbed. The resultant structures have been called interplanetary field enhancements (IFEs). They are readily identified when they pass spacecraft equipped with magnetometers. Although the co-orbitals responsible for the IFEs were disrupted in collisions, they are valid samples of the remaining co-orbiting material. Therefore, we can use IFEs to identify the spatial and mass distribution of such co-orbitals. With statistical studies of IFE occurrence, we identified asteroid 2201 Oljato and asteroid 138175 to have such co-orbiting material. The mass of the co-orbitals can be inferred by combining the results from observations and MHD simulations. Multi-spacecraft simultaneous observations measure the dimensions of the magnetic perturbations and the forces lifting them away from the Sun, while multi-fluid simulations give the accelerations of the perturbations. In summary, our technique not only helps us to identify which NEOs are accompanied by hazardous

NEOShield - A global approach to NEO Impact Threat Mitigation

NASA Astrophysics Data System (ADS)

Michel, Patrick

2015-03-01

NEOShield is a European-Union funded project coordinated by the German Aero-space Center, DLR, to address near-Earth object (NEO) impact hazard mitigation issues. The NEOShield consortium consists of 13 research institutes, universities, and industrial partners from 6 countries and includes leading US and Russian space organizations. The project is funded for a period of 3.5 years from January 2012 with a total of 5.8 million euros. The primary aim of the project is to investigate in detail promising mitigation techniques, such as the kinetic impactor, blast deflection, and the gravity tractor, and devise feasible demonstration missions. Options for an international strategy for implementation when an actual impact threat arises will also be investigated. The NEOShield work plan consists of scientific investigations into the nature of the impact hazard and the physical properties of NEOs, and technical and engineering studies of practical means of deflecting NEOs. There exist many ideas for asteroid deflection techniques, many of which would require considerable scientific and technological development. The emphasis of NEOShield is on techniques that are feasible with current technology, requiring a minimum of research and development work. NEOShield aims to provide detailed designs of feasible mitigation demonstration missions, targeting NEOs of the kind most likely to trigger the first space-based mitigation action. Most of the asteroid deflection techniques proposed to date require physical contact with the threatening object, an example being the kinetic impactor. NEOShield includes research into the mitigation-relevant physical properties of NEOs on the basis of remotely-sensed astronomical data and the results of rendezvous missions, the observational techniques required to efficiently gather mitigation-relevant data on the dynamical state and physical properties of a threatening NEO, and laboratory investigations using gas guns to fire projectiles into

PôDET: A Centre for Earth Dynamical Environment

NASA Astrophysics Data System (ADS)

Hestroffer, D.; Deleflie, F.

2013-11-01

The monitoring of the Earth space environment has gained some importance these last decades, in particular at the European level, partly because the phenomenon which origin come from space can have socio-economic consequences; and also because our understanding of those phenomenon - their associated prediction and risks - is still limited. For instance, the Space Situational Awareness programme (SSA) at ESA has set up in 2013 a centre and network for aspects connected to space debris (SST), to space weather (SW), and to near-Earth objects (NEO). At IMCCE, the Pôle sur la dynamique de l'environnement terrestre} (PODET, \\url{podet.imcce.fr}) for the Earth dynamical environment is studying effects and prediction for natural and artificial objects gravitating in the Earth vicinity. These studies englobe near-Earth objects, asteroids, comets, meteoroids, meteorite streams, and space debris. For all object types that are concerned, a general scheme of a functional analysis has been developed. It encompasses data acquisition with dedicated observations--essentially astrometric--or database queries, orbit determination or adjustment, prediction and ephemerides, and eventually impact probability computation and data dissemination. We develop here the general context of this action, the PôDET project, its scientific objectives, interaction with other disciplines, and the development in progress for dedicated tools.

VizieR Online Data Catalog: NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)

NASA Astrophysics Data System (ADS)

Mainzer, A.; Bauer, J.; Cutri, R. M.; Grav, T.; Masiero, J.; Beck, R.; Clarkson, P.; Conrow, T.; Dailey, J.; Eisenhardt, P.; Fabinsky, B.; Fajardo-Acosta, S.; Fowler, J.; Gelino, C.; Grillmair, C.; Heinrichsen, I.; Kendall, M.; Kirkpatrick, J. D.; Liu, F.; Masci, F.; McCallon, H.; Nugent, C. R.; Papin, M.; Rice, E.; Royer, D.; Ryan, T.; Sevilla, P.; Sonnett, S.; Stevenson, R.; Thompson, D. B.; Wheelock, S.; Wiemer, D.; Wittman, M.; Wright, E.; Yan, L.

2017-04-01

Regular survey operations, including the moving object processing pipeline, began on 2013 December 23; the first new NEO was discovered 6 days later. The NEOWISE operational cadence remains identical to that employed during the prime mission (Wright et al. 2010AJ....140.1868W; Heinrichsen & Wright 2006SPIE.6270E..1CH). The telescope scans continuously along great circles with approximately constant ecliptic longitude, while a scan mirror freezes the sky on the focal planes for 9.9 s and returns to its starting position 1.1 s later. While the sky is fixed on the focal planes, simultaneous exposures are collected in the W1 and W2 bands through the use of beamsplitters every 11 s with an exposure time of 7.7 s. Based on its present rate of NEO observations, over the course of its three year mission, NEOWISE is expected to observe ~2000 NEOs, roughly 700-800 of which will be detected in single-exposure images, with the remainder being recoverable through stacking. (1 data file).

Astrometric Results of NEOs from the Characterization and Astrometric Follow-up Program at Adler Planetarium

NASA Astrophysics Data System (ADS)

Nault, Kristie A.; Brucker, Melissa J.; Hammergren, Mark; Gyuk, Geza; Solontoi, Mike R.

2015-11-01

We present astrometric results of near-Earth objects (NEOs) targeted in fourth quarter 2014 and in 2015. This is part of Adler Planetarium’s NEO characterization and astrometric follow-up program, which uses the Astrophysical Research Consortium (ARC) 3.5-m telescope at Apache Point Observatory (APO). The program utilizes a 17% share of telescope time, amounting to a total of 500 hours per year. This time is divided up into two hour observing runs approximately every other night for astrometry and frequent half-night runs approximately several times a month for spectroscopy (see poster by M. Hammergren et. al.) and light curve studies (see poster by M. J. Brucker et. al.).Observations were made using Seaver Prototype Imaging Camera (SPIcam), a visible-wavelength, direct imaging CCD camera with 2048 x 2048 pixels and a field of view of 4.78’ x 4.78’. Observations were made using 2 x 2 binning.Special emphasis has been made to focus on the smallest NEOs, particularly around 140m in diameter. Targets were selected based on absolute magnitude (prioritizing for those with H > 25 mag to select small objects) and a 3σ uncertainty less than 400” to ensure that the target is in the FOV. Targets were drawn from the Minor Planet Center (MPC) NEA Observing Planning Aid, the JPL What’s Observable tool, and the Spaceguard priority list and faint NEO list.As of August 2015, we have detected 670 NEOs for astrometric follow-up, on point with our goal of providing astrometry on a thousand NEOs per year. Astrometric calculations were done using the interactive software tool Astrometrica, which is used for data reduction focusing on the minor bodies of the solar system. The program includes automatic reference star identification from new-generation star catalogs, access to the complete MPC database of orbital elements, and automatic moving object detection and identification.This work is based on observations done using the 3.5-m telescope at Apache Point Observatory

Circumlunar Free-Return Cycler Orbits for a Manned Earth-Moon Space Station

NASA Technical Reports Server (NTRS)

Genova, Anthony L.; Aldrin, Buzz

2015-01-01

Multiple free-return circumlunar cycler orbits were designed to allow regular travel between the Earth and Moon by a manned space station. The presented cycler orbits contain circumlunar free-return "figure-8" segments and yield lunar encounters every month. Smaller space "taxi" vehicles can rendezvous with (and depart from) the cycling Earth-Moon space station to enter lunar orbit (and/or land on the lunar surface), return to Earth, or reach destinations including Earth-Moon L1 and L2 halo orbits, near-Earth objects (NEOs), Venus, and Mars. To assess the practicality of the selected orbits, relevant cycler characteristics (including (Delta)V maintenance requirements) are presented and compared.

Lunar impact flashes - tracing the NEO size distribution

NASA Astrophysics Data System (ADS)

Avdellidou, Chrysa; Koschny, Detlef; NELIOTA Team

2017-10-01

Almost 20 years ago, we started to monitor the lunar surface with small telescopes to detect light flashes resulting from the hypervelocity collisions of meteoroids. The initial purpose was to understand the flux of impactors on Earth. The estimation of the flux of near Earth Objects (NEOs) is important not only for the protection of the human civilisation (meter-sized, see Chelyabinsk event in 2013), but also for the protection of the space assets (cm-sized objects). Apart from the NEO flux, the lunar surface helps the study of the impact events per se. The European Space Agency (ESA) is directing and funding lunar observations at 1.2 m Kryoneri telescope in Peloponnese, Greece. This telescope is equipped with a dichroic beam-splitter that directs the light onto two sCMOS cameras, that observe in visible and infrared wavelengths, using Rc and Ic Cousin filters respectively. Currently it is the largest telescope in the world that performs dedicated lunar impact flashes observations. We present the first flash observations in two bands, allowing us to measure flash temperatures for the first time. We find that the temperatures have a range that agrees with the theoretical approaches. Since the temperature can now be calculated, we have a more accurate estimation of the impactor’s mass and the size of the radiated ejecta plume.Having the Moon as a large-scale laboratory, new horizons are set towards the understanding of the nature of impacts, the impactor's material type and the energy partitioning, that is a constant puzzle in impact studies. This can now happen as more impact parameters can be determined and combined, such as the impactor’s mass and speed, flash luminosity, radiating volume, crater size when applicable etc. Future statistics can determine the different lunar regolith properties at different impact sites, especially during a meteoroid stream where the impactors share a common origin and possibly composition.

cyNeo4j: connecting Neo4j and Cytoscape

PubMed Central

Summer, Georg; Kelder, Thomas; Ono, Keiichiro; Radonjic, Marijana; Heymans, Stephane; Demchak, Barry

2015-01-01

Summary: We developed cyNeo4j, a Cytoscape App to link Cytoscape and Neo4j databases to utilize the performance and storage capacities Neo4j offers. We implemented a Neo4j NetworkAnalyzer, ForceAtlas2 layout and Cypher component to demonstrate the possibilities a distributed setup of Cytoscape and Neo4j have. Availability and implementation: The app is available from the Cytoscape App Store at http://apps.cytoscape.org/apps/cyneo4j, the Neo4j plugins at www.github.com/gsummer/cyneo4j-parent and the community and commercial editions of Neo4j can be found at http://www.neo4j.com. Contact: georg.summer@gmail.com PMID:26272981

Current NEO surveys

NASA Astrophysics Data System (ADS)

Larson, Stephen

2007-05-01

The state and discovery rate of current NEO surveys reflects incremental improvements in a number of areas, such as detector size and sensitivity, computing capacity and availability of larger apertures. The result has been an increased discovery rate even with the expected reduction of objects left to discover. There are currently about 10 telescopes ranging in size from 0.5 - 1.5-meters carrying out full or part-time, regular surveying in both hemispheres. The sky is covered between 1-2 times per lunation to V~19, with a band near the ecliptic to V~20.5. We review the current survey programs and their contribution towards the Spaceguard goal of discovering at least 90% of the NEOs larger than 1 km.

Near-Earth Asteroids Astrometry with Gaia and Beyond

NASA Astrophysics Data System (ADS)

Bancelin, D.; Hestroffer, D.; Thuillot, W.

2010-05-01

Gaia is an astrometric mission from the European Space Agency (ESA) that will be launched in Spring 2012. The Gaia telescope and spectrometer will operate in the visible wavelength scanning the whole sky during 5 years (nominal mission duration). It will observe about one billion stars and QSOs but also a large number of solar system bodies, mainly asteroids, and a few comets and planetary satellites. The unprecedented accuracy of the measures both astrometric and photometric (note that the spectroscopic observations are of little scientific value for Solar System objects science) will enable to significantly improve the knowledge of the dynamics and physical properties for a large number of asteroids. With a relatively limiting magnitude somewhat reduced to V≤20 (compared to other future or ongoing surveys) Gaia will mainly oserve main-belt asteroids (MBAs), and very few TNOs or Centaurs. The Gaia telescope will also be able to observe several thousands of Near- Earth Objects (NEOs) down to low solar elongation (observation of solar system objects are performed with elongation 45° ≤ L ≤ 135°). Gaia will not be a ''big'' NEO discover, however it can possibly discover inner-Earth orbiting objects (IEOs) or sub-Atens, from atmosphereless low solar-elongation observations. In the case of discovering a new NEO target, ground-based observations in network could be needed to avoid confusion in identifying the object in the database, or loss of the target. We are aiming to generate VO-alert for such eventuality. Ground-based observations of NEOs would also more generally enter into the operational centre in construction at the IMCCE that will deal with data mining, astrometric reduction, orbit computation, alerts, etc. On the other hand, in the framework of ESA Space Situational Awareness (SSA), ground-based astrometry, possibly complemented by Gaia data, is needed to refine the orbits and collision assessment of PHAs. High accuracy astrometric and colour

ESA's Earth observation priority research objectives and satellite instrument requirements

NASA Astrophysics Data System (ADS)

Reynolds, M. L.

2018-04-01

Since 1996 the European Space Agency has been pursuing an Earth Observation strategy based on a resolution endorsed by European Minister at a meeting in Toulouse. This resolution recognised a broad distinction between purely research objectives, on the one hand, and purely application objectives on the other. However, this is not to be understood as an absolute separation, but rather as an identification of the major driving emphasis for the definition of mission requirement. Indeed, application satellites can provide a wealth of data for research objectives and scientific earth observation programmes can equally provide an important source of data to develop and demonstrate new applications. It is sufficient to look at the data utilisation of Meteosat and ERS to find very many examples of this. This paper identifies the priority research objectives defined for scientific Earth Explorer missions and the resulting instrument needs. It then outlines the requirements for optical instruments.

An international program to protect the earth from impact catastrophe - Initial steps

NASA Technical Reports Server (NTRS)

Morrison, David

1992-01-01

Risks posed by impacting objects of various sizes are analyzed using the Spaceguard Survey, the 1992 NASA report of International Near-Earth-Object (NEO) Detection workshop. The state-of-the-art technology makes it possible to discover and track nearly all earth-crossing asteroids and short-period comets large enough to threaten global catastrophe. To deal with this hazard a long-term telescopic search is required that reaches stellar magnitude 22 in order to achieve a nearly complete census of objects 1 km or larger. A program can be performed on the basis of an international network of six telescopes of 2-3 m aperture equipped with modern CCD detectors and automatic signal processing capability.

Numerical Modeling in Problems of Near-Earth Object Dynamics

NASA Astrophysics Data System (ADS)

Aleksandrova, A. G.; Bordovitsyna, T. V.; Chuvashov, I. N.

2017-05-01

A method of numerical modeling is used to solve three most interesting problems of artificial Earth satellite (AES) dynamics. Orbital evolution of an ensemble of near-Earth objects at altitudes in the range from 1 500 to 60 000 km is considered, chaoticity of motion of objects in the geosynchronous zone is studied by the MEGNOanalysis, the parameters of AES motion are determined, and the models of forces are considered from measurements for GLONASS satellites. The recent versions of algorithms and programs used to perform investigations are briefly described.

Multiple NEO Rendezvous Using Solar Sail Propulsion

NASA Technical Reports Server (NTRS)

Johnson, Les; Alexander, Leslie; Fabisinski, Leo; Heaton, Andy; Miernik, Janie; Stough, Rob; Wright, Roosevelt; Young, Roy

2012-01-01

The NASA Marshall Space Flight Center (MSFC) Advanced Concepts Office performed an assessment of the feasibility of using a near-term solar sail propulsion system to enable a single spacecraft to perform serial rendezvous operations at multiple Near Earth Objects (NEOs) within six years of launch on a small-to-moderate launch vehicle. The study baselined the use of the sail technology demonstrated in the mid-2000 s by the NASA In-Space Propulsion Technology Project and is scheduled to be demonstrated in space by 2014 as part of the NASA Technology Demonstration Mission Program. The study ground rules required that the solar sail be the only new technology on the flight; all other spacecraft systems and instruments must have had previous space test and qualification. The resulting mission concept uses an 80-m X 80-m 3-axis stabilized solar sail launched by an Athena-II rocket in 2017 to rendezvous with 1999 AO10, Apophis and 2001 QJ142. In each rendezvous, the spacecraft will perform proximity operations for approximately 30 days. The spacecraft science payload is simple and lightweight; it will consist of only the multispectral imager flown on the Near Earth Asteroid Rendezvous (NEAR) mission to 433 Eros and 253 Mathilde. Most non-sail spacecraft systems are based on the Messenger mission spacecraft. This paper will describe the objectives of the proposed mission, the solar sail technology to be employed, the spacecraft system and subsystems, as well as the overall mission profile.

The observing campaign on the deep-space debris WT1190F as a test case for short-warning NEO impacts

NASA Astrophysics Data System (ADS)

Micheli, Marco; Buzzoni, Alberto; Koschny, Detlef; Drolshagen, Gerhard; Perozzi, Ettore; Hainaut, Olivier; Lemmens, Stijn; Altavilla, Giuseppe; Foppiani, Italo; Nomen, Jaime; Sánchez-Ortiz, Noelia; Marinello, Wladimiro; Pizzetti, Gianpaolo; Soffiantini, Andrea; Fan, Siwei; Frueh, Carolin

2018-04-01

On 2015 November 13, the small artificial object designated WT1190F entered the Earth atmosphere above the Indian Ocean offshore Sri Lanka after being discovered as a possible new asteroid only a few weeks earlier. At ESA's SSA-NEO Coordination Centre we took advantage of this opportunity to organize a ground-based observational campaign, using WT1190F as a test case for a possible similar future event involving a natural asteroidal body.

A Free-Return Earth-Moon Cycler Orbit for an Interplanetary Cruise Ship

NASA Technical Reports Server (NTRS)

Genova, Anthony L.; Aldrin, Buzz

2015-01-01

A periodic circumlunar orbit is presented that can be used by an interplanetary cruise ship for regular travel between Earth and the Moon. This Earth-Moon cycler orbit was revealed by introducing solar gravity and modest phasing maneuvers (average of 39 m/s per month) which yields close-Earth encounters every 7 or 10 days. Lunar encounters occur every 26 days and offer the chance for a smaller craft to depart the cycler and enter lunar orbit, or head for a Lagrange point (e.g., EM-L2 halo orbit), distant retrograde orbit (DRO), or interplanetary destination such as a near-Earth object (NEO) or Mars. Additionally, return-to-Earth abort options are available from many points along the cycling trajectory.

Physical characterization of fast rotator NEOs

NASA Astrophysics Data System (ADS)

Kikwaya Eluo, Jean-Baptiste; Hergenrother, Carl W.

2015-08-01

Understanding the physical characteristics of fast rotator NEOs (sub-km sizes with H > 22) is important for two reasons: to establish properties that can constraint models of their potential hazard, and to learn about the origin and the evolution of the solar system. Technically it is difficult to cover different ranges of wavelengths using one telescope with one instrument. Setting up a network of telescopes with different instruments observing simultaneously the same object will efficiently contribute to the characterization of NEOs.ART (Arizona Robotic Telescope) is a University of Arizona initiative whose goal is to use local 2-m size telescopes to provide near real-time observations of Target of Opportunity objects covering the visible and the near- infrared wavelengths. We plan to use three telescopes of the ART project to observe fast rotator NEOs: 1) VATT (Vatican Advanced Technology Telescope) at Mount Graham (longitude: -109.8719, latitude: 32.7016, elevation: 10469 feet) with VATT-4K optical imager for photometry to estimate colors, lightcurves to get the rotation rate, and estimate the phase angle function of NEOs, 2) Bok 2.3 m at Kitt Peak (longitude: -111.6004, latitude: 31.9629, elevation: 6795 feet) with BCSpec (Boller & Chivens Spectrograph) for visible spectroscopy, and 3) Kuiper 1.5-m at Mount Bigelow (longitude: -110.7345, latitude: 32.4165, elevation: 8235 feet) with a near-infrared instrument.We report here the preliminary results of several NEOs whose rotation rate, color, and type have been estimated using photometry with images recorded with VATT-4K. 2009 SQ104 has a rotation rate of 6.85+/- 0.03 h, 2014 AY28 has a rotation rate of 0.91 +/- 0.02 h, 2014 EC of 0.54 +/-0.04 h, 2014 FA44 of 3.45 +/- 0.05 h, 2014 KS40 of 1.11 +/- 0.06 h, 2011 PT of 0.17 +/- 0.05 h, 2014 SC324 of 0.36 +/- 0.43 h, 2014 WF201 of 1.00 +/- 0.03 h. Of these objects, 2014 HM2, 2014 FA, 2014 SB145, 2011 PT fall among X-type asteroids; 2014 KS, 2014 WF are likely to be

The complex of robotic telescopes for observation of Earth's artificial satellites and near-Earth objects

NASA Astrophysics Data System (ADS)

Shulga, A. V.; Kozyrev, E. S.; Kovalchuk, A. N.; Chernozub, V. M.; Sibiryakova, E. S.; Bochkarev, A. B.; Lopachenko, V. V.; Ryhalsky, V. V.

2010-05-01

Modern tasks for orbit control of the Earth artificial satellites and objects approaching the Earth define high requirements to ground-based telescopes, which have to be equipped with fast objectives, CCD cameras with a chip size not less than two inches. The CCD camera has to work in different modes. The telescopes must be fully robotized, and have a control system with remote operation and alert mode. In cooperation between RI NAO and NSFCTC, the upgrade of the AZT-8 classical telescope, belonging to NSFCTC, was made. Two telescopes of original design, namely the Fast Robotic Telescope (FRT) and the Mobile Telescope (MobiTel) were made in RI NAO. The telescopes are equipped with absolute angle encoders, CCD cameras with Kodak KAF-09000 chips, GPS time service, robotic drives and an automatic control system. The telescope features, such as a telescope name, f-number, chip name and operating modes, pixel numbers, field of view, pixel sizes, pixel scale, limiting magnitude, the standard deviation are given in the following list: 1) AZT-8(NSFCTC), 0.7/2.8 m, FLI PL09000 stare, 3056x3056, 45x45', 12x12 μm, 0.9"/pix, 20m, 0.05"/0.15"; 2) FRT (NAO), 0.3/1.5 m, Alta U9000stare and drift-scan, 3056x3056, 1°24'x1°24', 12x12 μm, 1.6"/pix, 18m, 0.15"/0.40"; 3) MobiTel-0.5(NAO), 0.5/3.0 m, Alta U9000stare and drift-scan,3056x3056, 42x42, 12x12μm, 0.8"/pix, 19m,0.0"05"/0".15"; 4) MobiTel-0.3(NAO), 0.3/0.75 m, Alta U9000 stare and drift-scan, 3056x3056, 2°48x2°48', 12x12 μm, 3.2"/pix, 18 m, 0.20"/0.45". The telescopes are actively used for control of the near-Earth space as well as for the solution of problems connected with thepotentially hazardous asteroids and comets approaching the Earth. Combination of classical and original methods of observations allows us to carry out virtually any observing programme. Considering objects at geostationary orbits and at highly elliptical orbits, we are able to carry out the following types of observations: massive

Multi-objective optimization of GENIE Earth system models.

PubMed

Price, Andrew R; Myerscough, Richard J; Voutchkov, Ivan I; Marsh, Robert; Cox, Simon J

2009-07-13

The tuning of parameters in climate models is essential to provide reliable long-term forecasts of Earth system behaviour. We apply a multi-objective optimization algorithm to the problem of parameter estimation in climate models. This optimization process involves the iterative evaluation of response surface models (RSMs), followed by the execution of multiple Earth system simulations. These computations require an infrastructure that provides high-performance computing for building and searching the RSMs and high-throughput computing for the concurrent evaluation of a large number of models. Grid computing technology is therefore essential to make this algorithm practical for members of the GENIE project.

Monitoring objects orbiting earth using satellite-based telescopes

DOEpatents

Olivier, Scot S.; Pertica, Alexander J.; Riot, Vincent J.; De Vries, Willem H.; Bauman, Brian J.; Nikolaev, Sergei; Henderson, John R.; Phillion, Donald W.

2015-06-30

An ephemeris refinement system includes satellites with imaging devices in earth orbit to make observations of space-based objects ("target objects") and a ground-based controller that controls the scheduling of the satellites to make the observations of the target objects and refines orbital models of the target objects. The ground-based controller determines when the target objects of interest will be near enough to a satellite for that satellite to collect an image of the target object based on an initial orbital model for the target objects. The ground-based controller directs the schedules to be uploaded to the satellites, and the satellites make observations as scheduled and download the observations to the ground-based controller. The ground-based controller then refines the initial orbital models of the target objects based on the locations of the target objects that are derived from the observations.

The Near-Earth Object Camera: A Next-Generation Minor Planet Survey

NASA Astrophysics Data System (ADS)

Mainzer, Amy K.; Wright, Edward L.; Bauer, James; Grav, Tommy; Cutri, Roc M.; Masiero, Joseph; Nugent, Carolyn R.

2015-11-01

The Near-Earth Object Camera (NEOCam) is a next-generation asteroid and comet survey designed to discover, characterize, and track large numbers of minor planets using a 50 cm infrared telescope located at the Sun-Earth L1 Lagrange point. Proposed to NASA's Discovery program, NEOCam is designed to carry out a comprehensive inventory of the small bodies in the inner regions of our solar system. It address three themes: 1) quantify the potential hazard that near-Earth objects may pose to Earth; 2) study the origins and evolution of our solar system as revealed by its small body populations; and 3) identify the best destinations for future robotic and human exploration. With a dual channel infrared imager that observes at 4-5 and 6-10 micron bands simultaneously through the use of a beamsplitter, NEOCam enables measurements of asteroid diameters and thermal inertia. NEOCam complements existing and planned visible light surveys in terms of orbital element phase space and wavelengths, since albedos can be determined for objects with both visible and infrared flux measurements. NEOCam was awarded technology development funding in 2011 to mature the necessary megapixel infrared detectors.

Neo-Darwinists and Neo-Aristotelians: how to talk about natural purpose.

PubMed

Woodford, Peter

2016-12-01

This paper examines the points of disagreement between Neo-Darwinian and recent Neo-Aristotelian discussions of the status of purposive language in biology. I discuss recent Neo-Darwinian "evolutionary" treatments and distinguish three ways to deal with the philosophical status of teleological language of purpose: teleological error theory, methodological teleology, and Darwinian teleological realism. I then show how "non-evolutionary" Neo-Aristotelian approaches in the work of Michael Thompson and Philippa Foot differ from these by offering a view of purposiveness grounded in life-cycle patterns, rather than in long-term evolutionary processes or natural selection. Finally, I argue that the crucial difference between Neo-Darwinian and Neo-Aristotelian approaches regards the question of whether or not reproduction deserves the status of an "ultimate" aim of organisms. I offer reasons to reject the concept of an "ultimate" aim in evolutionary biology and to reject the notion that reproduction serves a purpose. I argue that evolutionary biology is not in the position to determine what the "ultimate" explanation of natural purpose is.

Assessing the U.S. presidents using the Revised NEO Personality Inventory.

PubMed

Rubenzer, S J; Faschingbauer, T R; Ones, D S

2000-12-01

This article describes the use of objective psychological instruments, including the Revised NEO Personality Inventory (NEO PI-R), to assess the personalities of all 41 U.S. presidents to date. We briefly report our findings pertaining to the average profile of chief executives on the NEO PI-R and summarize data on two of our most illustrious presidents, Washington and Lincoln. We review a typology of presidents based on our data. Finally, we summarize the results of our investigation of the Big Five personality dimensions and facets that are related to presidential success (i.e., historical greatness). The project and findings are discussed in terms of the use of the NEO PI-R in psychohistorical research and assessment.

The LCO Follow-up and Characterization Network and AgentNEO Citizen Science Project

NASA Astrophysics Data System (ADS)

Lister, Tim; Greenstreet, Sarah; Gomez, Edward; Christensen, Eric J.; Larson, Stephen M.

2017-10-01

The LCO NEO Follow-up Network is using the telescopes of the Las Cumbres Observatory (LCO) and a web-based target selection, scheduling and data reduction system to confirm NEO candidates and characterize radar-targeted known NEOs. Starting in July 2014, the LCO NEO Follow-up Network has observed over 4,500 targets and reported more than 25,000 astrometric and photometric measurements to the Minor Planet Center.The LCO NEO Follow-up Network's main aims are to perform confirming follow-up of the large number of NEO candidates and to perform characterization measurements of radar targets to obtain light curves and rotation rates. The NEO candidates come from the NEO surveys such as Catalina, PanSTARRS, ATLAS, NEOWISE and others. In particular, we are targeting objects in the Southern Hemisphere, where the LCO NEO Follow-up Network is the largest resource for NEO observations.The first phase of the LCO Network comprises nine 1-meter and seven 0.4-meter telescopes at site at McDonald Observatory (Texas), Cerro Tololo (Chile), SAAO (South Africa) and Siding Spring Observatory (Australia). The network has been fully operational since 2014 May, and observations are being executed remotely and robotically. Additional 0.4-meter telescopes will be deployed in 2017 and 2x1-meter telescopes for a site at Ali Observatory, Tibet are planned for 2018-2019.We have developed web-based software called NEOexchange which automatically downloads and aggregates NEO candidates from the Minor Planet Center's NEO Confirmation Page, the Arecibo and Goldstone radar target lists and the NASA lists. NEOexchange allows the planning and scheduling of observations on the LCO Telescope Network and the tracking of the resulting blocks and generated data. We have extended the NEOexchange software to include automated scheduling and moving object detection, with the results presented to the user via the website.We will present results from the LCO NEO Follow-up Network and from the development of the

Are we producing PHAs? On the target selection for a proposed mitigation demo-mission within the NEO-Shield project

NASA Astrophysics Data System (ADS)

Eggl, S.; Hestroffer, D.; Thuillot, W.

2013-09-01

The Chelyabinsk event on February 15th, 2013 has shown once again that even small near earth objects (NEOs) can become a real safety concern. Eventhough we believe to have the capabilities to avert larger potentially disastrous asteroid impacts, only the realization of mitigation demonstration missions can confirm this claim. The target selection process for such deflection demonstrations is a demanding task, as physical, dynamical and engineering aspects have to be considered in great detail. One of the top priorities of such a demonstration mission is, of course, that a harmless asteroid should not be turned into a potentially hazardous object (PHO). Given the potentially large uncertainties in the asteroid's physical parameters as well as the additional uncertainties introduced during the deflection attempt, an in depth analysis of the impact probabilities over the next century becomes necessary, in order to exclude an augmentation of potential risks. Assuming worst case scenarios regard- ing the orbital, physical and mitigation induced uncertainties, we provide a keyhole and impact risk analysis of a list of potential targets for the mitigation demomission proposed in the framework of the NEO-Shield project.

Spacecraft formation flying for Earth-crossing object deflections using a power limited laser ablating

NASA Astrophysics Data System (ADS)

Yoo, Sung-Moon; Song, Young-Joo; Park, Sang-Young; Choi, Kyu-Hong

2009-06-01

A formation flying strategy with an Earth-crossing object (ECO) is proposed to avoid the Earth collision. Assuming that a future conceptual spacecraft equipped with a powerful laser ablation tool already rendezvoused with a fictitious Earth collision object, the optimal required laser operating duration and direction histories are accurately derived to miss the Earth. Based on these results, the concept of formation flying between the object and the spacecraft is applied and analyzed as to establish the spacecraft's orbital motion design strategy. A fictitious "Apophis"-like object is established to impact with the Earth and two major deflection scenarios are designed and analyzed. These scenarios include the cases for the both short and long laser operating duration to avoid the Earth impact. Also, requirement of onboard laser tool's for both cases are discussed. As a result, the optimal initial conditions for the spacecraft to maintain its relative trajectory to the object are discovered. Additionally, the discovered optimal initial conditions also satisfied the optimal required laser operating conditions with no additional spacecraft's own fuel expenditure to achieve the spacecraft formation flying with the ECO. The initial conditions founded in the current research can be used as a spacecraft's initial rendezvous points with the ECO when designing the future deflection missions with laser ablation tools. The results with proposed strategy are expected to make more advances in the fields of the conceptual studies, especially for the future deflection missions using powerful laser ablation tools.

Newtonian-Machian analysis of the neo-Tychonian model of planetary motions

NASA Astrophysics Data System (ADS)

Popov, Luka

2013-03-01

The calculation of the trajectories in the Sun-Earth-Mars system is performed using two different models, both in the framework of Newtonian mechanics. The first model is the well-known Copernican system, which assumes that the Sun is at rest and that all the planets orbit around it. The second is a less well-known model, developed by Tycho Brahe (1546-1601), according to which the Earth stands still, the Sun orbits around the Earth, and the other planets orbit around the Sun. The term ‘neo-Tychonian system’ refers to the assumption that orbits of distant masses around the Earth are synchronized with the Sun's orbit. It is the aim of this paper to show the kinematical and dynamical equivalence of these systems, under the assumption of Mach's principle.

Tracking target objects orbiting earth using satellite-based telescopes

DOEpatents

De Vries, Willem H; Olivier, Scot S; Pertica, Alexander J

2014-10-14

A system for tracking objects that are in earth orbit via a constellation or network of satellites having imaging devices is provided. An object tracking system includes a ground controller and, for each satellite in the constellation, an onboard controller. The ground controller receives ephemeris information for a target object and directs that ephemeris information be transmitted to the satellites. Each onboard controller receives ephemeris information for a target object, collects images of the target object based on the expected location of the target object at an expected time, identifies actual locations of the target object from the collected images, and identifies a next expected location at a next expected time based on the identified actual locations of the target object. The onboard controller processes the collected image to identify the actual location of the target object and transmits the actual location information to the ground controller.

Integrated Instrument Simulator Suites for Earth Science

NASA Technical Reports Server (NTRS)

Tanelli, Simone; Tao, Wei-Kuo; Matsui, Toshihisa; Hostetler, Chris; Hair, Johnathan; Butler, Carolyn; Kuo, Kwo-Sen; Niamsuwan, Noppasin; Johnson, Michael P.; Jacob, Joseph C.;

Orbital and Physical Characteristics of Meter-sized Earth Impactors

NASA Astrophysics Data System (ADS)

Brown, Peter G.; Wiegert, Paul; Clark, David; Tagliaferri, Edward

2015-11-01

We have analysed the orbits and ablation characteristics in the atmosphere of more than 60 earth-impacting meteoroids of one meter in diameter or larger. Using heights at peak luminosity as a proxy for strength, we find that there is roughly an order of magnitude spread in the apparent strength of the population of meter-sized impactors at the Earth. The orbits and physical strength of these objects are consistent with the majority being asteroidal bodies originating from the inner main asteroid belt. We find ~10-15% of our objects have a probable cometary (Jupiter-Family comet and/or Halley-type comet) origin based on orbital characteristics alone. Only half this number, however, show evidence for the expected weaker than average structure compared to asteroidal bodies. Almost all impactors show peak brightness between 20-40 km altitude. Several events have exceptionally high (relative to the remainder of the population) heights of peak brightness. These are physically most consistent with high microporosity objects, though all were on asteroidal-type orbits. We also find three events, including the Oct 8, 2009 airburst near Sulawesi, Indonesia, which display comparatively low heights of peak brightness, consistent with strong monolithic stones or iron meteoroids. Based on orbital similarity, we find a probable connection among several NEOs in our population with the Taurid meteoroid complex. No other major meteoroid streams show linkages with the pre-atmospheric orbits of our meter-class impactors. Our events cover almost four orders of magnitude in mass, but no trend in height of peak brightness is evident, suggesting no strong trend in strength with size for small NEOs, a finding consistent with the results of Popova et al (2011).

Are 2P/Encke, the Taurid complex NEOs and CM chondrites related?

NASA Astrophysics Data System (ADS)

Tubiana, C.; Snodgrass, C.; Michelsen, R.; Haack, H.; Fitzsimmons, A.; Williams, I.; Boehnhardt, H.

2013-09-01

Comet 2P/Encke is a short-period comet that was discovered in 1786 and has been extensively observed and studied for more than 200 years. It has an orbital period of 3.3 years and its orbit is dynamically decoupled from Jupiter's control due to gravitational interaction with terrestrial planets [6]. It is the only comet known on such an orbit, making it unique. Capture from the outer solar system onto its current orbit is very unlikely and even a continuous smooth dynamical evolution has a low probability as this requires a continuous period when it is dormant in order to avoid the volatiles from the nucleus becoming exhausted and making the current observed activity impossible. An origin in the asteroid belt is a possibility especially in view of the recently discovered main belt comets. The nucleus of 2P/Encke is dark (geometric albedo of 0.047 ± 0.023 [3]), has an effective radius of 2.4 ± 0.3 km [3] and it has polarimetric properties that are unique compared to other measured types of solar system objects, such as asteroids, TNOs, cometary dust, Centaurs [2]. The colors of 2P/Encke's nucleus are typical for comets, but no spectra of the nucleus in the visible wavelength range exist so far. The Taurid meteoroid stream has long been linked with 2P/Encke, but the activity of the comet is not strong enough to explain the number of observed meteors. It has been suggested that the meteoroid stream was caused by the break up of a larger parent body, which left comet 2P/Encke and other various small bodies along with a stream of dust. Various small near-Earth objects (NEOs) have been discovered with orbits that can be linked with 2P/Encke and the Taurid meteoroid stream [1]. Though many of the associations are spurious due to the low inclination of 2P/Encke's orbit, many NEO's have evolved in a similar way to 2P/Encke overa period of 5000 years [8] suggesting some relationship. In addition to dynamical properties, common taxonomic properties can also provide an

What do the data show? Fostering physical intuition with ClimateBits and NASA Earth Observations

NASA Astrophysics Data System (ADS)

Schollaert Uz, S.; Ward, K.

2017-12-01

Through data visualizations using global satellite imagery available in NASA Earth Observations (NEO), we explain Earth science concepts (e.g. albedo, urban heat island effect, phytoplankton). We also provide examples of ways to explore the satellite data in NEO within a new blog series. This is an ideal tool for scientists and non-scientists alike who want to quickly check satellite imagery for large scale features or patterns. NEO analysis requires no software or plug-ins; only a browser and an internet connection. You can even check imagery and perform simple analyses from your smart phone. NEO can be used to create graphics for presentations and papers or as a first step before acquiring data for more rigorous analysis. NEO has potential application to easily explore large scale environmental and climate patterns that impact operations and infrastructure. This is something we are currently exploring with end user groups.

Earth Observing System: Science Objectives and Challenges

NASA Technical Reports Server (NTRS)

King, Michael D.

1999-01-01

The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. In this presentation we review the key areas of scientific uncertainty in understanding climate and global change, and follow that with a description of the EOS goals, objectives, and scientific research elements that comprise the program (instrument science teams and interdisciplinary investigations). Finally, I will describe how scientists and policy makers intend to use EOS data improve our understanding of key global change uncertainties, such as: (i) clouds and radiation, including fossil fuel and natural emissions of sulfate aerosol and its potential impact on cloud feedback, (ii) man's impact on ozone depletion, with examples of ClO and O3 obtained from the UARS satellite during the Austral Spring, and (iii) volcanic eruptions and their impact on climate, with examples from the eruption of Mt. Pinatubo.

Earth Observing System: Science Objectives and Challenges

NASA Technical Reports Server (NTRS)

King, Michael D.

1998-01-01

The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. In this presentation I will describe the key areas of scientific uncertainty in understanding climate and global change, and follow that with a description of the EOS goals, objectives, and scientific research elements that comprise the program (instrument science teams and interdisciplinary investigations). Finally, I will describe how scientists and policy makers intend to use EOS data to improve our understanding of key global change uncertainties, such as: (i) clouds and radiation, including fossil fuel and natural emissions of sulfate aerosol and its potential impact on cloud feedback, (ii) man's impact on ozone depletion, with examples of ClO and O3 obtained from the UARS satellite during the Austral Spring, and (iii) volcanic eruptions and their impact on climate, with examples from the eruption of Mt. Pinatubo.

The detection of earth orbiting objects by IRAS

NASA Technical Reports Server (NTRS)

Dow, Kimberly L.; Sykes, Mark V.; Low, Frank J.; Vilas, Faith

1990-01-01

A systematic examination of 1836 images of the sky constructed from scans made by the Infrared Astronomical Satellite has resulted in the detection of 466 objects which are shown to be in earth orbit. Analysis of the spatial and size distribution and thermal properties of these objets, which may include payloads, rocket bodies and debris particles, is being conducted as one step in a feasibility study for space-based debris detection technologies.

Human Exploration of Near-Earth Asteroids

NASA Technical Reports Server (NTRS)

Abell, Paul

2013-01-01

A major goal for NASA's human spaceflight program is to send astronauts to near-Earth asteroids (NEA) in the coming decades. Missions to NEAs would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific examinations of these primitive objects. However, before sending human explorers to NEAs, robotic investigations of these bodies would be required to maximize operational efficiency and reduce mission risk. These precursor missions to NEAs would fill crucial strategic knowledge gaps concerning their physical characteristics that are relevant for human exploration of these relatively unknown destinations. Dr. Paul Abell discussed some of the physical characteristics of NEOs that will be relevant for EVA considerations, reviewed the current data from previous NEA missions (e.g., Near-Earth Asteroid Rendezvous (NEAR) Shoemaker and Hayabusa), and discussed why future robotic and human missions to NEAs are important from space exploration and planetary defense perspectives.

The σ-Capricornids complex of near-Earth objects

NASA Astrophysics Data System (ADS)

Babadzhanov, P. B.; Kokhirova, G. I.; Khamroev, U. Kh.

2015-04-01

The Earth-crossing asteroids 2008BO16, 2011EC41, and 2013CT36 have very similar orbits according to the Southworth and Hawkins DSH criterion. Their orbits are additionally classified as comet-like based on using the Tisserand parameter which is a standard tool used to distinction between asteroids and comets. The orbital evolution research shows that they cross the Earth's orbit four times over one cycle of the perihelion argument variations. Consequently, a meteoroid stream, possibly associated with them, may produce four meteor showers. Theoretic parameters of the predicted showers were calculated and identified with the observable nighttime σ-Capricornids and χ-Sagittariids, and daytime χ-Capricornids and Capricornids-Sagittariids meteor showers. The similar comet-like orbits and the linkage with the same meteoroid stream producing four active showers provide strong evidence that these asteroids have a common cometary origin. Earlier, it was demonstrated that the Earth-crossing asteroids (2101) Adonis and 1995CS, being a potentially hazardous asteroid (PHA), were recognized as dormant comets because of their linkage with the σ-Capricornids meteoroid stream. Thus, a conclusion was made, that either the considered objects are large pieces of the Adonis, or all five objects are extinct or dormant fragments of a larger comet that was the parent body of the σ-Capricornids meteoroid stream, and whose break-up occurred several tens of thousands years ago. During 2010-2011, three σ-Capricornids fireballs were captured by the Tajikistan fireball network. Taking into account the observations in Canada and the USA, the dynamic and physical properties of the σ-Capricornid meteoroids were identified. According to the estimated meteoroids bulk density a non-homogeneous compound of the σ-Capricornids shower comet-progenitor was suggested.

The discovery of cometary activity in near-Earth asteroid (3552) Don Quixote

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

Mommert, Michael; Harris, Alan W.; Hora, Joseph L.

The near-Earth object (NEO) population, which mainly consists of fragments from collisions between asteroids in the main asteroid belt, is thought to include contributions from short-period comets as well. One of the most promising NEO candidates for a cometary origin is near-Earth asteroid (3552) Don Quixote, which has never been reported to show activity. Here we present the discovery of cometary activity in Don Quixote based on thermal-infrared observations made with the Spitzer Space Telescope in its 3.6 and 4.5 μm bands. Our observations clearly show the presence of a coma and a tail in the 4.5 μm but notmore » in the 3.6 μm band, which is consistent with molecular band emission from CO{sub 2}. Thermal modeling of the combined photometric data on Don Quixote reveals a diameter of 18.4{sub −0.4}{sup +0.3} km and an albedo of 0.03{sub −0.01}{sup +0.02}, which confirms Don Quixote to be the third-largest known NEO. We derive an upper limit on the dust production rate of 1.9 kg s{sup –1} and derive a CO{sub 2} gas production rate of (1.1 ± 0.1) × 10{sup 26} molecules s{sup –1}. Spitzer Infrared Spectrograph spectroscopic observations indicate the presence of fine-grained silicates, perhaps pyroxene rich, on the surface of Don Quixote. Our discovery suggests that CO{sub 2} can be present in near-Earth space over a long time. The presence of CO{sub 2} might also explain that Don Quixote's cometary nature remained hidden for nearly three decades.« less

Scheduler for monitoring objects orbiting earth using satellite-based telescopes

DOEpatents

Olivier, Scot S; Pertica, Alexander J; Riot, Vincent J; De Vries, Willem H; Bauman, Brian J; Nikolaev, Sergei; Henderson, John R; Phillion, Donald W

2015-04-28

An ephemeris refinement system includes satellites with imaging devices in earth orbit to make observations of space-based objects ("target objects") and a ground-based controller that controls the scheduling of the satellites to make the observations of the target objects and refines orbital models of the target objects. The ground-based controller determines when the target objects of interest will be near enough to a satellite for that satellite to collect an image of the target object based on an initial orbital model for the target objects. The ground-based controller directs the schedules to be uploaded to the satellites, and the satellites make observations as scheduled and download the observations to the ground-based controller. The ground-based controller then refines the initial orbital models of the target objects based on the locations of the target objects that are derived from the observations.

Dropped objects and other motions relative to the noninertial earth

NASA Astrophysics Data System (ADS)

Tiersten, Martin S.; Soodak, Harry

2000-02-01

Earth is a noninertial frame of reference due to its spin and its orbital free-fall acceleration in the gravity fields of the sun, moon, and other external attractors. Three particularly interesting aspects of motion relative to the earth are discussed: (a) the effect of the sun and the moon and other external gravitational attractors; (b) the Foucault pendulum at middle latitudes; (c) the venerable and surprising problem of the deviation of the path of a dropped object away from the plumb line. A selective review of the twentieth century physics literature on motion relative to the earth demonstrates that errors and omissions abound. A fourth example is also presented, the interesting textbook problem of the free motion of a particle on a frictionless horizontal plane, as a simple illustration of carelessly incorrect treatment in much of the literature.

Free to Manage? A Neo-Liberal Defence of Academic Freedom in British Higher Education

ERIC Educational Resources Information Center

Miller, Brian

2014-01-01

Much of the rhetoric opposing managerialism in higher education can be ascribed to philosophical and political objections to the neo-liberal ideology which is alleged to underlie the phenomenon. This paper approaches managerialism from a different direction, addressing it within a neo-liberal framework. The paper argues that there is no intrinsic…

Understanding Interdependencies between Heterogeneous Earth Observation Systems When Applied to Federal Objectives

NASA Astrophysics Data System (ADS)

Gallo, J.; Sylak-Glassman, E.

2017-12-01

We will present a method for assessing interdependencies between heterogeneous Earth observation (EO) systems when applied to key Federal objectives. Using data from the National Earth Observation Assessment (EOA), we present a case study that examines the frequency that measurements from each of the Landsat 8 sensors are used in conjunction with heterogeneous measurements from other Earth observation sensors to develop data and information products. This EOA data allows us to map the most frequent interactions between Landsat measurements and measurements from other sensors, identify high-impact data and information products where these interdependencies occur, and identify where these combined measurements contribute most to meeting a key Federal objective within one of the 13 Societal Benefit Areas used in the EOA study. Using a value-tree framework to trace the application of data from EO systems to weighted key Federal objectives within the EOA study, we are able to estimate relative contribution of individual EO systems to meeting those objectives, as well as the interdependencies between measurements from all EO systems within the EOA study. The analysis relies on a modified Delphi method to elicit relative levels of reliance on individual measurements from EO systems, including combinations of measurements, from subject matter experts. This results in the identification of a representative portfolio of all EO systems used to meet key Federal objectives. Understanding the interdependencies among a heterogeneous set of measurements that modify the impact of any one individual measurement on meeting a key Federal objective, especially if the measurements originate from multiple agencies or state/local/tribal, international, academic, and commercial sources, can impact agency decision-making regarding mission requirements and inform understanding of user needs.

Meteorite Source Regions as Revealed by the Near-Earth Object Population

NASA Astrophysics Data System (ADS)

Binzel, Richard P.; DeMeo, Francesca E.; Burt, Brian J.; Polishook, David; Burbine, Thomas H.; Bus, Schelte J.; Tokunaga, Alan; Birlan, Mirel

2014-11-01

Spectroscopic and taxonomic information is now available for 1000 near-Earth objects, having been obtained through both targeted surveys (e.g. [1], [2], [3]) or resulting from all-sky surveys (e.g. [4]). We determine their taxonomic types in the Bus-DeMeo system [5] [6] and subsequently examine meteorite correlations based on spectral analysis (e.g. [7],[8]). We correlate our spectral findings with the source region probabilities calculated using the methods of Bottke et al. [9]. In terms of taxonomy, very clear sources are indicated: Q-, Sq-, and S-types most strongly associated with ordinary chondrite meteorites show clear source signatures through the inner main-belt. V-types are relatively equally balanced between nu6 and 3:1 resonance sources, consistent with the orbital dispersion of the Vesta family. B- and C-types show distinct source region preferences for the outer belt and for Jupiter family comets. A Jupiter family comet source predominates for the D-type near-Earth objects, implying these "asteroidal" bodies may be extinct or dormant comets [10]. Similarly, near-Earth objects falling in the spectrally featureless "X-type" category also show a strong outer belt and Jupiter family comet source region preference. Finally the Xe-class near-Earth objects, which most closely match the spectral properties of enstatite achondrite (aubrite) meteorites seen in the Hungaria region[11], show a source region preference consistent with a Hungaria origin by entering near-Earth space through the Mars crossing and nu6 resonance pathways. This work supported by the National Science Foundation Grant 0907766 and NASA Grant NNX10AG27G.[1] Lazzarin, M. et al. (2004), Mem. S. A. It. Suppl. 5, 21. [2] Thomas, C. A. et al. (2014), Icarus 228, 217. [3] Tokunaga, A. et al. (2006) BAAS 38, 59.07. [4] Hasselmann, P. H., Carvano, J. M., Lazzaro, D. (2011) NASA PDS, EAR-A-I0035-5-SDSSTAX-V1.0. [5] Bus, S.J., Binzel, R.P. (2002). Icarus 158, 146. [6] DeMeo, F.E. et al. (2009), Icarus

78 FR 38430 - Culturally Significant Objects Imported for Exhibition; Determinations: “Of Heaven and Earth: 500...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-26

... DEPARTMENT OF STATE [Public Notice 8359] Culturally Significant Objects Imported for Exhibition; Determinations: ``Of Heaven and Earth: 500 Years of Italian Painting From Glasgow Museums'' SUMMARY: Notice is... objects to be included in the exhibition ``Of Heaven and Earth: 500 Years of Italian Painting from Glasgow...

78 FR 48216 - Culturally Significant Objects Imported for Exhibition Determinations: “Heaven and Earth: Art of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-07

... DEPARTMENT OF STATE [Public Notice 8412] Culturally Significant Objects Imported for Exhibition Determinations: ``Heaven and Earth: Art of Byzantium from Greek Collections'' SUMMARY: Notice is hereby given of... determine that the objects to be included in the exhibition ``Heaven and Earth: Art of Byzantium from Greek...

The Main-belt Asteroid and NEO Tour with Imaging and Spectroscopy (MANTIS)

NASA Astrophysics Data System (ADS)

Rivkin, A.; Cohen, B. A.; Barnouin, O. S.; Chabot, N. L.; Ernst, C. M.; Klima, R. L.; Helbert, J.; Sternovsky, Z.

2015-12-01

The asteroids preserve information from the earliest times in solar system history, with compositions in the population reflecting the material in the solar nebula and experiencing a wide range of temperatures. Today they experience ongoing processes, some of which are shared with larger bodies but some of which are unique to their size regime. They are critical to humanity's future as potential threats, resource sites, and targets for human visitation. However, over twenty years since the first spacecraft encounters with asteroids, they remain poorly understood. The mission we propose here, the Main-belt Asteroid and NEO Tour with Imaging and Spectroscopy (MANTIS), explores the diversity of asteroids to understand our solar system's past history, its present processes, and future opportunities and hazards. MANTIS addresses many of NASA's highest priorities as laid out in its 2014 Science Plan and provides additional benefit to the Planetary Defense and Human Exploration communities via a low-risk, cost-effective tour of the near-Earth and inner asteroid belt. MANTIS visits the materials that witnessed solar system formation and its earliest history, addressing the NASA goal of exploring and observing the objects in the solar system to understand how they formed and evolve. MANTIS measures OH, water, and organic materials via several complementary techniques, visiting and sampling objects known to have hydrated minerals and addressing the NASA goal of improving our understanding of the origin and evolution of life on Earth. MANTIS studies the geology and geophysics of nine diverse asteroids, with compositions ranging from water-rich to metallic, representatives of both binary and non-binary asteroids, and sizes covering over two orders of magnitude, providing unique information about the chemical and physical processes shaping the asteroids, addressing the NASA goal of advancing the understanding of how the chemical and physical processes in our solar system

Perspectives on the Near-Earth Object Impact Hazard After Chelyabinsk

NASA Astrophysics Data System (ADS)

Chapman, C. R.

2013-12-01

Until this year, the NEO impact hazard had been regarded as a theoretical example of a very low probability high consequence natural disaster. There had been no confirmed examples of fatalities directly due to asteroid or meteoroid strikes. (There still aren't.) The several megaton Tunguska event in 1908 was in a remote, unpopulated place. So human beings have been witnessing only the tiniest analogs of asteroid strikes, the night-sky meteors and occasional bolides, which - on rare occasions - yield meteoritic fragments that puncture holes in roofs. Though the NEO impact hazard has occasionally been treated in the natural hazards literature, interest primarily remained in the planetary science and aerospace communities. The Chelyabinsk asteroid impact on 15 February 2013 was a real disaster, occurring near a city with a population exceeding a million. Well over a thousand people were injured, thousands of buildings suffered at least superficial damage (mainly to windows), schools and sports facilities were closed, and emergency responders swarmed across the city and surrounding rural areas. While the consequences were very small compared with larger natural disasters, which kill tens of thousands of people annually worldwide, this specific case - for the first time - has permitted a calibration of the consequences of the rare impacts asteroid astronomers have been predicting. There now are reasons to expect that impacts by bodies tens of meters in diameter are several times more frequent than had been thought and each impact is more damaging than previously estimated. The Chelyabinsk event, produced by a 20 meter diameter asteroid, specifically suggests that asteroids just 15 meters diameter, or even smaller, could be very dangerous and damaging; indeed, a more common steeper impact angle would have produced more consequential damage on the ground. This contrasts with estimates a decade earlier [NASA NEO Science Definition Team report, 2003] that asteroids smaller

The contribution of comets in Near-Earth Object and Main Belt populations and the role of collisions in the physical properties of members of these populations.

NASA Astrophysics Data System (ADS)

Michel, P.

2008-09-01

The population of Near-Earth Objects (NEOs) is composed of small bodies of various origins. Groundbased observational programs have been developed to perform their inventory and to determine their physical properties. However, these observations contain many biases and the total population of NEOs with diameters down to a few hundreds of meters has not been identified yet. In recent years, the main sources of NEOs have been characterized [1]. Most of these bodies come from the asteroid main belt and the Jupiter-family comets and their source regions are linked to transport mechanisms (mean motion and secular resonances, slow diffusion mechanisms) to the NEO-space. It has then been possible to construct a complete model of the steady-state orbital, size and albedo distribution of NEOs and to determine the level of contribution of each of their sources, including the contribution of Jupiter-family comets. However, nothing is known regarding the contribution of longperiod comets. Physical observations have been conducted in order to identify potential dormant or extinct comets among small bodies in the NEO population and to determine the fraction of "comet candidates within the total NEO population. Combining the results of these observations with our model of NEO population to evaluate source region probabilities [1], it was found that 8 +/- 5% of the total asteroid-like NEO population may have originated as comets from the outer Solar System [2]. In the population of Main Belt (MB) asteroids, three members are known to display transient comet-like physical characteristics, including prolonged periods of dust emission leading to the formation of radiation pressure-swept tails [3]. These physical properties are most naturally explained as the result of sub-limation of near-surface ice from what are, dynamically, mainbelt asteroids (hence the name "main-belt comets" (MBCs) or, equivalently "icy asteroids"). No pausible dynamical path to the asteroid belt from the

Discovery of M class objects among the near-earth asteroid population

NASA Technical Reports Server (NTRS)

Tedesco, Edward F.; Gradie, Jonathan

1987-01-01

Broadband colorimetry, visual photometry, near-infrared photometry, and 10 and 20 micron radiometry of the near-earth asteroids (NEAs) 1986 DA and 1986 EB are used to show that these objects belong to the M class of asteroids. The similarity among the distributions of taxonomic classes among the 38 NEAs to the abundances found in the inner astoroid belt between the 3:1 and 5:2 resonances suggests that NEAs have their origins among asteroids in the vicinity of these resonances. The implied mineralogy of 1986 DA and 1986 EB is mostly nickel-iron metal; if this is indeed the case, then current models for meteorite production based on strength-related collisional processes on asteroidal surfaces predict that these two objects alone should produce about one percent of all meteorite falls. Iron meteorites derived from these near-earth asteroids should have low cosmic-ray exposure ages.

Assessing the Universal Structure of Personality in Early Adolescence: The NEO-PI-R and NEO-PI-3 in 24 Cultures

ERIC Educational Resources Information Center

De Fruyt, Filip; De Bolle, Marleen; McCrae, Robert R.; Terracciano, Antonio; Costa, Paul T., Jr.

2009-01-01

The structure and psychometric characteristics of the NEO Personality Inventory-3 (NEO-PI-3), a more readable version of the Revised NEO Personality Inventory (NEO-PI-R), are examined and compared with NEO-PI-R characteristics using data from college student observer ratings of 5,109 adolescents aged 12 to 17 years from 24 cultures. Replacement…

A Neo-Cognitive Dimension.

ERIC Educational Resources Information Center

Suarez, E. M.

1988-01-01

Responds to Mahoney and Lyddon's review of constructivism in previous article by focusing on developments emerged from work with Neo-Cognitive Psychotherapy that add new and necessary dimension to issues of agency and constructivism. Presents neo-cognitive view of thought and discusses the evolution of understanding. (NB)

The Spaceguard Survey: Report of the NASA International Near-Earth-Object Detection Workshop

NASA Technical Reports Server (NTRS)

Morrison, David (Editor)

1992-01-01

Impacts by Earth-approaching asteroids and comets pose a significant hazard to life and property. Although the annual probability of the Earth being struck by a large asteroid or comet is extremely small, the consequences of such a collision are so catastrophic that it is prudent to assess the nature of the threat and to prepare to deal with it. The first step in any program for the prevention or mitigation of impact catastrophes must involve a comprehensive search for Earth-crossing asteroids and comets and a detailed analysis of their orbits. At the request of the U.S. Congress, NASA has carried out a preliminary study to define a program for dramatically increasing the detection rate of Earth-crossing objects, as documented in this workshop report.

On NEO Threat Mitigation (Preprint)

DTIC Science & Technology

2007-10-15

Yucatan event is at least a major contributor, if not the direct cause of the extinction of the dinosaurs . Moreover, it is clear that NEO impacts can... extinction of the human race. The probability of these events decreases with the severity of the impact, and size (mass) of the NEO. Figure 1 and Table 1...thus, it is more reasonable to infer that all the large NEOs can be catalogued within a reasonable time, while smaller and less consequential

Exploration Roadmap Working Group (ERWG) Data Collection, NASA's Inputs

NASA Technical Reports Server (NTRS)

Drake, Bret; Landis, Rob; Thomas, Andrew; Mauzy, Susan; Graham, Lee; Culbert, Chris; Troutman, Pat

2010-01-01

This slide presentation reviews four areas for further space exploration: (1) Human Exploration of Mars Design Reference Architecture (DRA) 5.0, (2) Robotic Precursors targeting Near Earth Objects (NEO) for Human Exploration, (3) Notional Human Exploration of Near Earth Objects and (4) Low Earth Orbit (LEO) Refueling to Augment Human Exploration. The first presentation reviews the goals and objectives of the Mars DRA, presents a possible mission profile, innovation requirements for the mission and key risks and challenges for human exploration of Mars. The second presentation reviews the objective and goals of the robotic precursors to the NEO and the mission profile of such robotic exploration. The third presentation reviews the mission scenario of human exploration of NEO, the objectives and goals, the mission operational drivers, the key technology needs and a mission profile. The fourth and last presentation reviews the examples of possible refueling in low earth orbit prior to lunar orbit insertion, to allow for larger delivered payloads for a lunar mission.

Evolution of NASA's Earth Science Digital Object Identifier Registration System

NASA Technical Reports Server (NTRS)

Wanchoo, Lalit; James, Nathan

2017-01-01

NASA's Earth Science Data and Information System (ESDIS) Project has implemented a fully automated system for assigning Digital Object Identifiers (DOIs) to Earth Science data products being managed by its network of 12 distributed active archive centers (DAACs). A key factor in the successful evolution of the DOI registration system over last 7 years has been the incorporation of community input from three focus groups under the NASA's Earth Science Data System Working Group (ESDSWG). These groups were largely composed of DOI submitters and data curators from the 12 data centers serving the user communities of various science disciplines. The suggestions from these groups were formulated into recommendations for ESDIS consideration and implementation. The ESDIS DOI registration system has evolved to be fully functional with over 5,000 publicly accessible DOIs and over 200 DOIs being held in reserve status until the information required for registration is obtained. The goal is to assign DOIs to the entire 8000+ data collections under ESDIS management via its network of discipline-oriented data centers. DOIs make it easier for researchers to discover and use earth science data and they enable users to provide valid citations for the data they use in research. Also for the researcher wishing to reproduce the results presented in science publications, the DOI can be used to locate the exact data or data products being cited.

Exploration of Near-Earth Objects from the Deep Space Gateway

NASA Astrophysics Data System (ADS)

Dunham, D. W.; Stakkestad, K.; Vedder, P.; McAdams, J.; Horsewood, J.; Genova, A. L.

2018-02-01

The paper will show how clever use of orbital dynamics can lower delta-V costs to enable scientifically interesting missions. The high-energy Deep Space Gateway orbits can be used to reach NEOs, a trans node for crews, or to deploy small sats. Examples are given.

High-Performance Modeling and Simulation of Anchoring in Granular Media for NEO Applications

NASA Technical Reports Server (NTRS)

Quadrelli, Marco B.; Jain, Abhinandan; Negrut, Dan; Mazhar, Hammad

2012-01-01

NASA is interested in designing a spacecraft capable of visiting a near-Earth object (NEO), performing experiments, and then returning safely. Certain periods of this mission would require the spacecraft to remain stationary relative to the NEO, in an environment characterized by very low gravity levels; such situations require an anchoring mechanism that is compact, easy to deploy, and upon mission completion, easy to remove. The design philosophy used in this task relies on the simulation capability of a high-performance multibody dynamics physics engine. On Earth, it is difficult to create low-gravity conditions, and testing in low-gravity environments, whether artificial or in space, can be costly and very difficult to achieve. Through simulation, the effect of gravity can be controlled with great accuracy, making it ideally suited to analyze the problem at hand. Using Chrono::Engine, a simulation pack age capable of utilizing massively parallel Graphic Processing Unit (GPU) hardware, several validation experiments were performed. Modeling of the regolith interaction has been carried out, after which the anchor penetration tests were performed and analyzed. The regolith was modeled by a granular medium composed of very large numbers of convex three-dimensional rigid bodies, subject to microgravity levels and interacting with each other with contact, friction, and cohesional forces. The multibody dynamics simulation approach used for simulating anchors penetrating a soil uses a differential variational inequality (DVI) methodology to solve the contact problem posed as a linear complementarity method (LCP). Implemented within a GPU processing environment, collision detection is greatly accelerated compared to traditional CPU (central processing unit)- based collision detection. Hence, systems of millions of particles interacting with complex dynamic systems can be efficiently analyzed, and design recommendations can be made in a much shorter time. The figure

Neo-oogenesis in mammals.

PubMed

Porras-Gómez, Tania Janeth; Moreno-Mendoza, Norma

2017-08-01

Recently, the existence of a mechanism for neo-oogenesis in the ovaries of adult mammals has generated much controversy within reproductive biology. This mechanism, which proposes that the ovary has cells capable of renewing the follicular reserve, has been described for various species of mammals. The first evidence was found in prosimians and humans. However, these findings were not considered relevant because the predominant dogma for reproductive biology at the time was that of Zuckerman. This dogma states that female mammals are born with finite numbers of oocytes that decline throughout postnatal life. Currently, the concept of neo-oogenesis has gained momentum due to the discovery of cells with mitotic activity in adult ovaries of various mammalian species (mice, humans, rhesus monkeys, domestic animals such as pigs, and wild animals such as bats). Despite these reports, the concept of neo-oogenesis has not been widely accepted by the scientific community, generating much criticism and speculation about its accuracy because it has been impossible to reproduce some evidence. This controversy has led to the creation of two positions: one in favour of neo-oogenesis and the other against it. Various animal models have been used in support of both camps, including both classic laboratory animals and domestic and wild animals. The aim of this review is to critically present the current literature on the subject and to evaluate the arguments pro and contra neo-oogenesis in mammals.

A Piloted Flight to a Near-Earth Object: A Feasibility Study

NASA Technical Reports Server (NTRS)

Landis, Rob; Korsmeyer, Dave; Abell, Paul; Adamo, Dan; Morrison, Dave; Lu, Ed; Lemke, Larry; Gonzales, Andy; Jones, Tom; Gershman, Bob;

Dormant Comets in the Near-Earth Asteroid Population

NASA Astrophysics Data System (ADS)

Mommert, Michael; Harris, Alan W.; Mueller, Michael; Hora, Joseph L.; Trilling, David E.; Knight, Matthew; Bottke, William F.; Thomas, Cristina; Delbo', Marco; Emery, Josh P.; Fazio, Giovanni; Smith, Howard A.

2015-11-01

The population of near-Earth objects comprises active comets and asteroids, covering a wide range of dynamical parameters and physical properties. Dormant (or extinct) comets, masquerading as asteroids, have long been suspected of supplementing the near-Earth asteroid (NEA) population. We present a search for asteroidal objects of cometary origin based on dynamical and physical considerations. Our study is based on albedos derived within the ExploreNEOs program and is extended by adding data from NEOWISE and the Akari asteroid catalog. We use a statistical approach to identify asteroids on orbits that resemble those of short-period near-Earth comets using the Tisserand parameter with respect to Jupiter, the aphelion distance, and the minimum orbital intersection distance with respect to Jupiter. We identify a total of 23 near-Earth asteroids from our sample that are likely to be dormant short-period near-Earth comets and, based on a de-biasing procedure applied to the cryogenic NEOWISE survey, estimate both magnitude-limited and size-limited fractions of the NEA population that are dormant short-period comets. We find that 0.3-3.3% of the NEA population with H <= 21, and 9(+2/-5)% of the population with diameters d >= 1 km, are dormant short-period near-Earth comets. We also present an observation program that utilizes the 1.8m Vatican Advanced Technology Telescope (VATT) on Mt. Graham, AZ, to identify dormant comet candidates and search for activity in these objects. Our targets are NEAs on comet-like orbits, based on the dynamical criteria derived in the above study, that are accessible with the VATT (V <= 22). We identify dormant comets based on their optical spectral slope, represented by V-R color measurements, as albedo measurements for most of these objects are not available. For each target we measure and monitor its V magnitude in order to reveal activity outbreaks. We also search for extended emission around our targets using deep imaging and a point

Assessing the universal structure of personality in early adolescence: The NEO-PI-R and NEO-PI-3 in 24 cultures.

PubMed

De Fruyt, Filip; De Bolle, Marleen; McCrae, Robert R; Terracciano, Antonio; Costa, Paul T

2009-09-01

The structure and psychometric characteristics of the NEO Personality Inventory-3 (NEO-PI-3), a more readable version of the Revised NEO Personality Inventory (NEO-PI-R), are examined and compared with NEO-PI-R characteristics using data from college student observer ratings of 5,109 adolescents aged 12 to 17 years from 24 cultures. Replacement items in the PI-3 showed on average stronger item-total correlations and slightly improved facet reliabilities compared with the NEO-PI-R in both English- and non-English-speaking samples. NEO-PI-3 replacement items did not substantially affect scale means compared with the original scales. Analyses across and within cultures confirmed the intended factor structure of both versions when used to describe young adolescents. The authors discuss implications of these cross-cultural findings for the advancement of studies in adolescence and personality development across the lifespan.

Near-Earth Asteroids Astrometry with Gaia

NASA Astrophysics Data System (ADS)

Bancelin, D.; Hestroffer, D.; Thuillot, W.

2011-05-01

Potentially Hazardous Asteroids (PHAs) are Near-Earth Asteroids caraterised by a Minimum Orbital Intersection Distance (MOID) with Earth less to 0.05 A.U and an absolute magnitude H<22. Those objects have sometimes a so significant close approach with Earth that they can be put on a chaotic orbit. This kind of orbit is very sensitive for exemple to the initial conditions, to the planetary theory used (for instance JPL's model versus IMCCE's model) or even to the numerical integrator used (Lie Series, Bulirsch-Stoer or Radau). New observations (optical, radar, flyby or satellite mission) can improve those orbits and reduce the uncertainties on the Keplerian elements.The Gaia mission is an astrometric mission that will be launched in 2012 and will observe a large number of Solar System Objects down to magnitude V≤20. During the 5-year mission, Gaia will continuously scan the sky with a specific strategy: objects will be observed from two lines of sight separated with a constant basic angle. Five constants already fixed determinate the nominal scanning law of Gaia: The inertial spin rate (1°/min) that describe the rotation of the spacecraft around an axis perpendicular to those of the two fields of view, the solar-aspect angle (45°) that is the angle between the Sun and the spacecraft rotation axis, the precession period (63.12 days) which is the precession of the spin axis around the Sun-Earth direction. Two other constants are still free parameters: the initial spin phase, and the initial precession angle that will be fixed at the start of the nominal science operations. These latter are constraint by scientific outcome (e.g. possibility of performing test of fundamental physics) together with operational requirements (downlink to Earth windows). Several sets of observations of specific NEOs will hence be provided according to the initial precession angle. The purpose here is to study the statistical impact of the initial precession angle on the error

Asteroid Redirect Mission - Next Major stepping-stone to Human Exploration of NEOs and beyond

NASA Astrophysics Data System (ADS)

Sanchez, Natalia

2016-07-01

In response to NASA's Asteroid Initiative, an Asteroid Redirect and Robotic Mission (ARRM) is being studied by a NASA cohort, led by JPL, to enable the capture a multi-ton boulder from the surface of a Near-Earth Asteroid and return it to cislunar space for subsequent human and robotic exploration. The mission would boost our understanding of NEOs and develop technological capabilities for Planetary Defense, shall a NEO come up on a collision course. The benefits of this mission can extend our capabilities to explore farther into space, as well as create a new commercial sector in Space Mining, which would make materials in Space available for our use. ARRM would leverage and advance current knowledge of higher-efficiency propulsion systems with a new Solar Electric Propulsion demonstration (similar to that on the Dawn spacecraft) to be incorporated into future Mars Missions.

Project NEO Specific Impulse Testing Solutions

NASA Technical Reports Server (NTRS)

Baffa, Bill

2018-01-01

The Neo test stand is currently configured to fire a horizontally mounted rocket motor with up to 6500 lbf thrust. Currently, the Neo test stand can measure flow of liquid propellant and oxidizer, pressures residing in the closed system up to the combustion chamber. The current configuration does not have the ability to provide all data needed to compute specific impulse. This presents three methods to outfit the NEO test fixture with instrumentation allowing for calculation of specific impulse.

77 FR 27533 - Culturally Significant Objects Imported for Exhibition Determinations: “Ends of the Earth: Land...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-10

... DEPARTMENT OF STATE [Public Notice 7877] Culturally Significant Objects Imported for Exhibition Determinations: ``Ends of the Earth: Land Art to 1974'' SUMMARY: Notice is hereby given of the following... ``Ends of the Earth: Land Art to 1974'' imported from abroad for temporary exhibition within the United...

Cohesion, granular solids, granular liquids, and their connection to small near-Earth objects

NASA Astrophysics Data System (ADS)

Sánchez, P.; Scheeres, D.

2014-07-01

During the last 15 years or so, the Planetary Sciences community has been using Discrete Element Method (DEM) simulation codes to study small near-Earth objects (NEOs). In general, these codes treat gravitational aggregates as conglomerates of spherical particles; a good approximation given that many asteroids are self-gravitating granular media. Unfortunately, the degree of sophistication of these codes, and our own understanding, has not been high enough as to appropriately represent realistic physical properties of granular matter. In particular, angles of friction (θ) and cohesive strength (σ_c) of the aggregates were rarely taken in consideration and this could have led to unrealistic dynamics, and therefore, unrealistic conclusions about the dynamical evolution of small NEOs. In our research, we explore the failure mechanics of spherical (r=71 m) and ellipsoidal (r_1=92 m) self-gravitating aggregates with different angles of friction and values for their cohesive strength, in order to better understand the geophysics of rubble-pile asteroids. In particular we focused on the deformation and different disruption modes provoked by an always increasing angular velocity (spin rate). Scaling arguments allow us to regard simulations with the same aggregate size and different σ_c as equivalent to simulations of aggregates of different size and the same σ_c. We use a computational code that implements a Soft-Sphere DEM. The aggregates are composed by 3,000 spherical solid spheres (7--10 m) with 6 degrees of freedom. The code calculates normal, as well as, frictional (tangential) contact forces by means of soft potentials and the aggregate as a whole mimics the effect of non- spherical particles through the implementation of rolling friction. Cohesive forces, and a cohesive stress, are calculated as the net effect of the sum of the van der Waals forces between the smaller regolith, sand and dust (powder) that are present in real asteroids [1]. These finer materials

Orbit and size distributions for asteroids temporarily captured by the Earth-Moon system

NASA Astrophysics Data System (ADS)

Fedorets, Grigori; Granvik, Mikael; Jedicke, Robert

2017-03-01

As a continuation of the work by Granvik et al. (2012), we expand the statistical treatment of Earth's temporarily-captured natural satellites from temporarily-captured orbiters (TCOs, i.e., objects which make at least one orbit around the Earth) to the newly redefined subpopulation of temporarily-captured flybys (TCFs). TCFs are objects that while being gravitationally bound fail to make a complete orbit around the Earth while on a geocentric orbit, but nevertheless approach the Earth within its Hill radius. We follow the trajectories of massless test asteroids through the Earth-Moon system and record the orbital characteristics of those that are temporarily captured. We then carry out a steady-state analysis utilizing the novel NEO population model by Granvik et al. (2016). We also investigate how an quadratic distribution at very small values of e⊙ and i⊙ affects the predicted population statistics of Earth's temporarily-captured natural satellites. The steady-state population in both cases (constant and quadratic number distributions inside the e and i bins) is predicted to contain a slightly reduced number of meter-sized asteroids compared to the values of the previous paper. For the combined TCO/TCF population, we find the largest body constantly present on a geocentric orbit to be on the order of 80 cm in diameter. In the phase space, where the capture is possible, the capture efficiency of TCOs and TCFs is O(10-6 -10-4) . We also find that kilometer-scale asteroids are captured once every 10 Myr.

On the possibility of space objects invasion observations into the Earth's atmosphere with the help of a multifunctional polarimeter

NASA Astrophysics Data System (ADS)

Nevodovskyi, P. V.; Steklov, A. F.; Vidmachenko, A. P.

2018-05-01

Relevance of the tasks associated with the observation of the invasion of space objects into the Earth's atmosphere increases with each passing year. We used astronomical panoramic polarimeter for carrying out of polarimetric observations of objects, that flying into the atmosphere of the Earth from the surrounding outer space.

Patterns of molecular evolution of an avian neo-sex chromosome.

PubMed

Pala, Irene; Hasselquist, Dennis; Bensch, Staffan; Hansson, Bengt

2012-12-01

Newer parts of sex chromosomes, neo-sex chromosomes, offer unique possibilities for studying gene degeneration and sequence evolution in response to loss of recombination and population size decrease. We have recently described a neo-sex chromosome system in Sylvioidea passerines that has resulted from a fusion between the first half (10 Mb) of chromosome 4a and the ancestral sex chromosomes. In this study, we report the results of molecular analyses of neo-Z and neo-W gametologs and intronic parts of neo-Z and autosomal genes on the second half of chromosome 4a in three species within different Sylvioidea lineages (Acrocephalidea, Timaliidae, and Alaudidae). In line with hypotheses of neo-sex chromosome evolution, we observe 1) lower genetic diversity of neo-Z genes compared with autosomal genes, 2) moderate synonymous and weak nonsynonymous sequence divergence between neo-Z and neo-W gametologs, and 3) lower GC content on neo-W than neo-Z gametologs. Phylogenetic reconstruction of eight neo-Z and neo-W gametologs suggests that recombination continued after the split of Alaudidae from the rest of the Sylvioidea lineages (i.e., after ~42.2 Ma) and with some exceptions also after the split of Acrocephalidea and Timaliidae (i.e., after ~39.4 Ma). The Sylvioidea neo-sex chromosome shares classical evolutionary features with the ancestral sex chromosomes but, as expected from its more recent origin, shows weaker divergence between gametologs.

Reconnaissance of Near-Earth Objects

NASA Technical Reports Server (NTRS)

Binzel, Richard P.

2002-01-01

NASA sponsorship of asteroid research for this grant has resulted in 30 publications and major new results relating near-Earth asteroids to known meteorite groups, most especially ordinary chondrites. Analysis of observations continues.

Near-Earth Object Interception Using Nuclear Thermal Rock Propulsion

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

X-L. Zhang; E. Ball; L. Kochmanski

Planetary defense has drawn wide study: despite the low probability of a large-scale impact, its consequences would be disastrous. The study presented here evaluates available protection strategies to identify bottlenecks limiting the scale of near-Earth object that could be deflected, using cutting-edge and near-future technologies. It discusses the use of a nuclear thermal rocket (NTR) as a propulsion device for delivery of thermonuclear payloads to deflect or destroy a long-period comet on a collision course with Earth. A ‘worst plausible scenario’ for the available warning time (10 months) and comet approach trajectory are determined, and empirical data are used tomore » make an estimate of the payload necessary to deflect such a comet. Optimizing the tradeoff between early interception and large deflection payload establishes the ideal trajectory for an interception mission to follow. The study also examines the potential for multiple rocket launch dates. Comparison of propulsion technologies for this mission shows that NTR outperforms other options substantially. The discussion concludes with an estimate of the comet size (5 km) that could be deflected usingNTRpropulsion, given current launch capabilities.« less

The Near-Earth Space Surveillance (NESS) Mission: Discovery, Tracking, and Characterization of Asteroids, Comets, and Artificial Satellites with a Microsatellite

NASA Technical Reports Server (NTRS)

Hildebrand, A. R.; Carroll, K. A.; Balam, D. D.; Cardinal, R. D.; Matthews, J. M.; Kuschnig, R.; Walker, G. A. H.; Brown, P. G.; Tedesco, E. F.; Worden, S. P.

2001-01-01

The Near-Earth Space Surveillance (NESS) Mission, a microsatellite dedicated to observing near-Earth (NEO) and interior-to-the-Earth (IEO)asteroids and comets plus artificial satellites, is currently being studied under contract to the Canadian Space Agency. Additional information is contained in the original extended abstract.

Determining characteristics of artificial near-Earth objects using observability analysis

NASA Astrophysics Data System (ADS)

Friedman, Alex M.; Frueh, Carolin

2018-03-01

Observability analysis is a method for determining whether a chosen state of a system can be determined from the output or measurements. Knowledge of state information availability resulting from observability analysis leads to improved sensor tasking for observation of orbital debris and better control of active spacecraft. This research performs numerical observability analysis of artificial near-Earth objects. Analysis of linearization methods and state transition matrices is performed to determine the viability of applying linear observability methods to the nonlinear orbit problem. Furthermore, pre-whitening is implemented to reformulate classical observability analysis. In addition, the state in observability analysis is typically composed of position and velocity; however, including object characteristics beyond position and velocity can be crucial for precise orbit propagation. For example, solar radiation pressure has a significant impact on the orbit of high area-to-mass ratio objects in geosynchronous orbit. Therefore, determining the time required for solar radiation pressure parameters to become observable is important for understanding debris objects. In order to compare observability analysis results with and without measurement noise and an extended state, quantitative measures of observability are investigated and implemented.

Physical Properties of Near-Earth Objects: Optical and Infrared Astronomical Observations

DTIC Science & Technology

2003-04-30

caused the extinction of over 75% of the Earth’s living organisms, including the dinosaurs (e.g., Grieve & Shoemaker 1994). Many mammals then were...bluer wavelengths. This is the same reason why the sky appears blue during the day. 25 Spacewatch also utilized an extinction curve, but for an...Ironically, these objects that may have provided much of the materials needed for life on Earth may also upon occasion have caused the extinction of

Assessing the Universal Structure of Personality in Early Adolescence: The NEO-PI-R and NEO-PI-3 in 24 Cultures

PubMed Central

De Fruyt, Filip; De Bolle, Marleen; McCrae, Robert R.; Terracciano, Antonio; Costa, Paul T.

2010-01-01

The structure and psychometric characteristics of the NEO-PI-3, a more readable version of the NEO-PI-R, are examined and compared with NEO-PI-R characteristics using data from college student observer ratings of 5,109 adolescents aged 12 to 17 from 24 cultures. Replacement items in the PI-3 showed on average stronger item/total correlations and slightly improved facet reliabilities compared with the NEO-PI-R in both English- and non-English-speaking samples. NEO-PI-3 replacement items did not substantially affect scale means compared with the original scales. Analyses across and within cultures confirmed the intended factor structure of both versions when used to describe young adolescents. We discuss implications of these cross-cultural findings for the advancement of studies in adolescence and personality development across the lifespan. PMID:19419953

Comet/Asteroid Protection System (CAPS): A Space-Based System Concept for Revolutionizing Earth Protection and Utilization of Near-Earth Objects

NASA Technical Reports Server (NTRS)

Mazanek, Daniel D.; Roithmayr, Carlos M.; Antol, Jeffrey; Kay-Bunnell, Linda; Werner, Martin R.; Park, Sang-Young; Kumar, Renjith R.

2002-01-01

There exists an infrequent, but significant hazard to life and property due to impacting asteroids and comets. There is currently no specific search for long-period comets, smaller near-Earth asteroids, or smaller short-period comets. These objects represent a threat with potentially little or no warning time using conventional ground-based telescopes. These planetary bodies also represent a significant resource for commercial exploitation, long-term sustained space exploration, and scientific research. The Comet/Asteroid Protection System (CAPS) would expand the current detection effort to include long-period comets, as well as small asteroids and short-period comets capable of regional destruction. A space-based detection system, despite being more costly and complex than Earth-based initiatives, is the most promising way of expanding the range of detectable objects, and surveying the entire celestial sky on a regular basis. CAPS is a future spacebased system concept that provides permanent, continuous asteroid and comet monitoring, and rapid, controlled modification of the orbital trajectories of selected bodies. CAPS would provide an orbit modification system capable of diverting kilometer class objects, and modifying the orbits of smaller asteroids for impact defense and resource utilization. This paper provides a summary of CAPS and discusses several key areas and technologies that are being investigated.

Synoptic Observations for Physical Characterization of Fast Rotator NEOs

NASA Astrophysics Data System (ADS)

Kikwaya Eluo, Jean-Baptiste; Hergenrother, Carl W.

2014-11-01

NEOs can be studied not only dynamically, to learn about their impact hazard, but also physically, to establish various properties important both to better address their potential hazard and also to understand what they can tell us about the origin of the solar system and its ongoing processes.Taking advantage of the two-meter-class telescopes around Tucson, we plan to observe NEOs synoptically using telescopes at three different locations: VATT (Vatican Advanced Technology Telescope) at Mount Graham (longitude: -109.8719, latitude: 32.7016, elevation: 10469 feet), Bok 2.3 m at Kitt Peak (longitude: -111.6004, latitude: 31.9629, elevation: 6795 feet) and Kuiper 1.5-m at Mount Bigelow (longitude: -110.7345, latitude: 32.4165, elevation: 8235 feet). All three telescopes will aim simultaneously at the same object, each with a different instrument. The three telescopes will be part of the Arizona Robotic Telescope (ART) network, a University of Arizona initiative to provide near real-time observations of Target of Opportunity objects across the visible and near-infrared wavelengths. The VATT-4K optical imager mounted on the VATT has already been used for photometry. In the future we plan to utilize the BCSpec (Boller & Chivens Spectrograph) for visible spectroscopy on Bok 2.3 meter and a near-infrared instrument on Kuiper 1.5 meter. We report here the preliminary results of several NEOs whose rotation rate and color have been estimated using photometry with images recorded with VATT-4K. 2009 SQ104 has a rotation rate of 6.85+/- 0.03 h, 2014 AY28 has a rotation rate of 0.91 +/- 0.02 h, 2014 EC of 0.54 +/-0.04 h, 2014 FA44 of 3.45 +/- 0.05 h, and 2014 KS40 of 1.11 +/- 0.06 h.

Suborbital Asteroid Intercept and Fragmentation for Very Short Warning Time Scenarios

NASA Technical Reports Server (NTRS)

Hupp, Ryan; Dewald, Spencer; Wie, Bong; Barbee, Brent W.

2015-01-01

Small near-Earth objects (NEOs) 50150 m in size are far more numerous (hundreds of thousands to millions yet to be discovered) than larger NEOs. Small NEOs, which are mostly asteroids rather than comets, are very faint in the night sky due to their small sizes, and are, therefore, difficult to discover far in advance of Earth impact. However, even small NEOs are capable of creating explosions with energies on the order of tens or hundreds of megatons (Mt).We are, therefore, motivated to prepare to respond effectively to short warning time, small NEO impact scenarios. In this paper we explore the lower bound on actionable warning time by investigating the performance of notional upgraded Intercontinental Ballistic Missiles (ICBMs) to carry Nuclear Explosive Device (NED) payloads to intercept and disrupt a fictitious incoming NEO at high altitudes (generally, at least 2500 km above Earth). We conduct this investigation by developing optimal NEO intercept trajectories for a range of cases and comparing their performances.Our results show that suborbital NEO intercepts using Minuteman III or SM-3 IIA launch vehicles could achieve NEO intercept a few minutes prior to when the NEOwould strike Earth. We also find that more powerful versions of the launch vehicles (e.g., total V 9.511 kms) could intercept incoming NEOs over a day prior to when the NEO would strike Earth, if launched at least several days prior to the time of NEO intercept. Finally, we discuss a number of limiting factors and practicalities that affect whether the notional systems we describe could become feasible.

Low cost missions to explore the diversity of near Earth objects

NASA Technical Reports Server (NTRS)

Belton, Michael J. S.; Delamere, Alan

1992-01-01

We propose a series of low-cost flyby missions to perform a reconnaissance of near-Earth cometary nuclei and asteroids. The primary scientific goal is to study the physical and chemical diversity in these objects. The mission concept is based on the Pegasus launch vehicle. Mission costs, inclusive of launch, development, mission operations, and analysis are expected to be near $50 M per mission. Launch opportunities occur in all years. The benefits of this reconnaissance to society are stressed.

Energetic Techniques For Planetary Defense

NASA Astrophysics Data System (ADS)

Barbee, B.; Bambacus, M.; Bruck Syal, M.; Greenaugh, K. C.; Leung, R. Y.; Plesko, C. S.

2017-12-01

Near-Earth Objects (NEOs) are asteroids and comets whose heliocentric orbits tend to approach or cross Earth's heliocentric orbit. NEOs of various sizes periodically collide with Earth, and efforts are currently underway to discover, track, and characterize NEOs so that those on Earth-impacting trajectories are discovered far enough in advance that we would have opportunities to deflect or destroy them prior to Earth impact, if warranted. We will describe current efforts by the National Aeronautics and Space Administration (NASA) and the National Nuclear Security Administration (NNSA) to assess options for energetic methods of deflecting or destroying hazardous NEOs. These methods include kinetic impactors, which are spacecraft designed to collide with an NEO and thereby alter the NEO's trajectory, and nuclear engineering devices, which are used to rapidly vaporize a layer of NEO surface material. Depending on the amount of energy imparted, this can result in either deflection of the NEO via alteration of its trajectory, or robust disruption of the NEO and dispersal of the remaining fragments. We have studied the efficacies and limitations of these techniques in simulations, and have combined the techniques with corresponding spacecraft designs and mission designs. From those results we have generalized planetary defense mission design strategies and drawn conclusions that are applicable to a range of plausible scenarios. We will present and summarize our research efforts to date, and describe approaches to carrying out planetary defense missions with energetic NEO deflection or disruption techniques.

Neo-Liberalism in Crisis? Educational Dimensions

ERIC Educational Resources Information Center

Small, David

2011-01-01

Until the global financial crisis, neo-liberalism had appeared invincible. This article examines the global rise of neo-liberalism and its impact on education, particularly its treatment of the social democratic ideal of equality. Drawing on examples from education and other socio-political factors, it considers whether the financial crisis is…

Using Item Response Theory to Develop a 60-Item Representation of the NEO PI-R Using the International Personality Item Pool: Development of the IPIP-NEO-60.

PubMed

Maples-Keller, Jessica L; Williamson, Rachel L; Sleep, Chelsea E; Carter, Nathan T; Campbell, W Keith; Miller, Joshua D

2017-10-31

Given advantages of freely available and modifiable measures, an increase in the use of measures developed from the International Personality Item Pool (IPIP), including the 300-item representation of the Revised NEO Personality Inventory (NEO PI-R; Costa & McCrae, 1992a ) has occurred. The focus of this study was to use item response theory to develop a 60-item, IPIP-based measure of the Five-Factor Model (FFM) that provides equal representation of the FFM facets and to test the reliability and convergent and criterion validity of this measure compared to the NEO Five Factor Inventory (NEO-FFI). In an undergraduate sample (n = 359), scores from the NEO-FFI and IPIP-NEO-60 demonstrated good reliability and convergent validity with the NEO PI-R and IPIP-NEO-300. Additionally, across criterion variables in the undergraduate sample as well as a community-based sample (n = 757), the NEO-FFI and IPIP-NEO-60 demonstrated similar nomological networks across a wide range of external variables (r ICC = .96). Finally, as expected, in an MTurk sample the IPIP-NEO-60 demonstrated advantages over the Big Five Inventory-2 (Soto & John, 2017 ; n = 342) with regard to the Agreeableness domain content. The results suggest strong reliability and validity of the IPIP-NEO-60 scores.

Search for Near-Earth Objects with Small Aphelion Distances

NASA Technical Reports Server (NTRS)

Tholen, David J.

2003-01-01

An essential component of our ability to efficiently find NEOs at small solar elongation is a focal reducer, whose construction is being separately funded by a grant from NSF. This focal reducer will increase the field of view of the 8k CCD mosaic camera from 19 arc min to about 32 arc min at the Cassegrain focus of the University of Hawaii 2.24-m telescope. As of January, all but one of the lenses for the focal reducer were in hand. The final lens had been delayed due to problems with the availability of the rather exotic material out of which the manufacturer was to fabricate the lens. Perhaps as a result of their rush to deliver that final lens, it developed a crack during the annealing process at the manufacturer, thus they had to start over. The total delay in delivery of that last lens was nearly ten months, and therefore the focal reducer was not completed on schedule and could not be used on the telescope this semester. A postdoctoral research associate was recruited to handle the day-to-day operations. The closing date for applications was 2002 December 3 1, and seven were received. One applicant was not qualified, and two were marginal. Of the four qualified candidates, Fabrizio Bernardi stood out as being best qualified. He was a student of Andrea Carusi and had worked on the CINEOS project in Italy, which includes a component of searching for NEOs at small solar elongations.

Earth's gravity gradient and eddy currents effects on the rotational dynamics of space debris objects: Envisat case study

NASA Astrophysics Data System (ADS)

Gómez, Natalia Ortiz; Walker, Scott J. I.

2015-08-01

The space debris population has grown rapidly over the last few decades with the consequent growth of impact risk between current objects in orbit. Active Debris Removal (ADR) has been recommended to be put into practice by several National Agencies in order to remove objects that pose the biggest risk for the space community. The most immediate target that is being considered for ADR by the European Space Agency is the Earth-observing satellite Envisat. In order to safely remove such a massive object from its orbit, a capturing process followed by a controlled reentry is necessary. However, current ADR methods that require physical contact with the target have limitations on the maximum angular momentum that can be absorbed and a de-tumbling phase prior to the capturing process may be required. Therefore, it is of utmost importance for the ADR mission design to be able to predict accurately how the target will be rotating at the time of capture. This article analyses two perturbations that affect an object in Low Earth Orbit (LEO), the Earth's gravity gradient and the eddy currents induced by the Earth's magnetic field. The gravity gradient is analysed using the equation of conservation of total energy and a graphical method is presented to understand the expected behaviour of any object under the effect of this perturbation. The eddy currents are also analysed by studying the total energy of the system. The induced torque and the characteristic time of decay are presented as a function of the object's magnetic tensor. In addition, simulations were carried out for the Envisat spacecraft including the gravity gradient perturbation as well as the eddy currents effect using the International Geomagnetic Reference Field IGRF-11 to model the Earth's magnetic field. These simulations show that the combined effect of these two perturbations is a plausible explanation for the rotational speed decay observed between April 2013 and September 2013.

Coordination of NEO Observers in South-America

NASA Astrophysics Data System (ADS)

Tancredi, G.

At present the discovery of NEOs is concentrated in the Northern Hemisphere. None of the 6 existing survey programs can reach declinations below -30deg. Nevertheless, there are two small surveys ready to start in the near future in the southern hemisphere: an extension of the Catalina Sky Survey using the Uppsala Schmidt in Siding Spring and the Project BUSCA in Uruguay. Many of the NEOs discovered by the northern surveys could reach the southern sky, with declinations unreachable for a northern observer. Furthermore, the recovery of an asteroid in subsequent oppositions could come indistinctly in the northern and southern sky. A network of well-equipped observers in the southern region is then a must in a campaign to catalog the NEO population. In view of this situation, the Planetary Society, through its NEO grant, have already supported many observers in the Southern Hemisphere. The planetary science community in South America has considerably grown in the last 10 years. We have well-known research groups in Argentina, Brazil and Uruguay. Those groups have established many scientific links by exchanging graduate students and through several meetings. In particular, we have already hold two Workshop in Planetary Science in South America in 1999 (La Plata, Argentina) and 2000 (Montevideo, Uruguay) with more than 25 participants each. Recently, in February 2002, we organized a Workshop of NEO observers in Montevideo with the participation of more than 20 professional and amateurs observers from: Argentina: Obs. Ast. Felix Aguilar - Yale University (San Juan) and CRICYT (Mendoza); Brazil: Obs. Abraes de Moraes (San Pablo), Obs. Wykrota (Belo Horizonte) and Observatorio Nacional (Rio de Janeiro); Paraguay: Obs. Nacional de Asuncion and Sociedad de Estudios Astronómicos (Asunción) Uruguay: Depto. Astronomía - Fac. Ciencias, Obs. Ast. Los Molinos and Obs. Kappa Crucis (Montevideo). Among the resolutions of the Workshop, we highlight: * Creation of the "Asociaci

Design Guide for Earth System Science Education: Common Student Learning Objectives and Special Pedagogical Approaches

NASA Astrophysics Data System (ADS)

Baker, D.

2006-12-01

As part of the NASA-supported undergraduate Earth System Science Education (ESSE) program, fifty-seven institutions have developed and implemented a wide range of Earth system science (ESS) courses, pedagogies, and evaluation tools. The Teaching, Learning, and Evaluation section of USRA's online ESSE Design Guide showcases these ESS learning environments. This Design Guide section also provides resources for faculty who wish to develop ESS courses. It addresses important course design issues including prior student knowledge and interests, student learning objectives, learning resources, pedagogical approaches, and assessments tied to student learning objectives. The ESSE Design Guide provides links to over 130 ESS course syllabi at introductory, senior, and graduate levels. ESS courses over the past 15 years exhibit common student learning objectives and unique pedagogical approaches. From analysis of ESS course syllabi, seven common student learning objectives emerged: 1) demonstrate systems thinking, 2) develop an ESS knowledge base, 3) apply ESS to the human dimension, 4) expand and apply analytical skills, 5) improve critical thinking skills, 6) build professional/career skills, and 7) acquire an enjoyment and appreciation for science. To meet these objectives, ESSE often requires different ways of teaching than in traditional scientific disciplines. This presentation will highlight some especially successful pedagogical approaches for creating positive and engaging ESS learning environments.

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

Thirouin, A.; Moskovitz, N.; Burt, B.

The Mission Accessible Near-Earth Objects Survey aims to physically characterize sub-km near-Earth objects (NEOs). We report the first photometric results from the survey that began in 2013 August. Photometric observations were performed using 1–4 m class telescopes around the world. We present rotational periods and light curve amplitudes for 86 sub-km NEOs, though in some cases only lower limits are provided. Our main goal is to obtain light curves for small NEOs (typically, sub-km objects) and estimate their rotational periods, light curve amplitudes, and shapes. These properties are used for a statistical study to constrain overall properties of the NEOmore » population. A weak correlation seems to indicate that smaller objects are more spherical than larger ones. We also report seven NEOs that are fully characterized (light curve and visible spectra) as the most suitable candidates for a future human or robotic mission. Viable mission targets are objects fully characterized, with Δ v {sup NHATS} ≤ 12 km s{sup −1}, and a rotational period P  > 1 hr. Assuming a similar rate of object characterization as reported in this paper, approximately 1230 NEOs need to be characterized in order to find 100 viable mission targets.« less

Suborbital Intercept and Fragmentation of an Asteroid with Very Short Warning Time Scenario

NASA Technical Reports Server (NTRS)

Hupp, Ryan; DeWald, Spencer; Wie, Bong; Barbee, Brent W.

2015-01-01

Small near-Earth objects (NEOs) is approx. 50-150 m in size are far more numerous (hundreds of thousands to millions yet to be discovered) than larger NEOs. Small NEOs, which are mostly asteroids rather than comets, are very faint in the night sky due to their small sizes, and are, therefore, difficult to discover far in advance of Earth impact. Furthermore, even small NEOs are capable of creating explosions with energies on the order of tens or hundreds of megatons (Mt). We are, therefore, motivated to prepare to respond effectively to short warning time, small NEO impact scenarios. In this paper we explore the lower bound on actionable warning time by investigating the performance of notional upgraded Intercontinental Ballistic Missiles (ICBMs) to carry Nuclear Explosive Device (NED) payloads to intercept and disrupt a hypothetical incoming NEO at high altitudes (generally at least 2500 km above Earth). We conduct this investigation by developing optimal NEO intercept trajectories for a range of cases and comparing their performances. Our results show that suborbital NEO intercepts using Minuteman III or SM-3 IIA launch vehicles could achieve NEO intercept a few minutes prior to when the NEO would strike Earth. We also find that more powerful versions of the launch vehicles (e.g., total deltaV is approx. 9.5-11 km/s) could intercept incoming NEOs several hours prior to when the NEO would strike Earth, if launched at least several days prior to the time of intercept. Finally, we discuss a number of limiting factors and practicalities that affect whether the notional systems we describe could become feasible.

Mission Design and Analysis for Suborbital Intercept and Fragmentation of an Asteroid with Very Short Warning Time

NASA Technical Reports Server (NTRS)

Hupp, Ryan; DeWald, Spencer; Wie, Bong; Barbee, Brent W.

2014-01-01

Small near-Earth objects (NEOs) approximately 50-150 m in size are far more numerous (hundreds of thousands to millions yet to be discovered) than larger NEOs. Small NEOs, which are mostly asteroids rather than comets, are very faint in the night sky due to their small sizes, and are, therefore, difficult to discover far in advance of Earth impact. Furthermore, even small NEOs are capable of creating explosions with energies on the order of tens or hundreds of megatons (Mt). We are, therefore, motivated to prepare to respond effectively to short warning time, small NEO impact scenarios. In this paper we explore the lower bound on actionable warning time by investigating the performance of notional upgraded Intercontinental Ballistic Missiles (ICBMs) to carry Nuclear Explosive Device (NED) payloads to intercept and disrupt a hypothetical incoming NEO at high altitudes (generally at least 2500 km above Earth). We conduct this investigation by developing optimal NEO intercept trajectories for a range of cases and comparing their performances. Our results show that suborbital NEO intercepts using Minuteman III or SM-3 IIA launch vehicles could achieve NEO intercept a few minutes prior to when the NEO would strike Earth. We also find that more powerful versions of the launch vehicles (e.g., total delta V of approximately 9.5-11 km/s) could intercept incoming NEOs several hours prior to when the NEO would strike Earth, if launched at least several days prior to the time of intercept. Finally, we discuss a number of limiting factors and practicalities that affect whether the notional systems we describe could become feasible.

Revised NEO Personality Inventory normative data for police officer selection.

PubMed

Detrick, Paul; Chibnall, John T

2013-11-01

The Revised NEO Personality Inventory (NEO PI-R) has demonstrated utility in the personnel selection context. Its use in police officer selection has been relatively limited, in part, because there are no published normative data for the NEO PI-R for police officer applicants. The authors present normative data on NEO PI-R domain and facet scores for a large sample (N = 288) of police officer applicants in a large, urban, Midwestern police department who completed the NEO PI-R as part of a preemployment psychological evaluation. Applicants reported low levels of Neuroticism and high levels of Extraversion and Conscientiousness. Neuroticism and Conscientiousness scores were strongly and consistently correlated with the Positive Presentation Management (PPM) research validity scale of the NEO PI-R. Extraversion and Agreeableness scores were moderately and less consistently correlated with PPM. These data may serve as a normative comparison group for professionals and researchers who use or may want to use the NEO PI-R in the police officer selection context.

Assessing adolescents' personality with the NEO PI-R.

PubMed

De Fruyt, F; Mervielde, I; Hoekstra, H A; Rolland, J P

2000-12-01

The suitability of the Revised NEO Personality Inventory (NEO PI-R) to assess adolescents' personality traits was investigated in an unselected heterogeneous sample of 469 adolescents aged 12 to 17 years. They were further administered the Hierarchical Personality Inventory for Children (HiPIC) to allow an examination of convergent and discriminant validity. The adult NEO PI-R factor structure proved to be highly replicable in the sample of adolescents, with all facet scales primarily loading on the expected factors, independent of the age group. Domain and facet internal consistency coefficients were comparable to those obtained in adult samples, with less than 12% of the items showing corrected item-facet correlations below absolute value .20. Although, in general, adolescents reported few difficulties with the comprehensibility of the items, they tend to report more problems with the Openness to Ideas (05) and Openness to Values (06) items. Correlations between NEO PI-R and HiPIC scales underscored the convergent and discriminant validity of the NEO facets and HiPIC scales. It was concluded that the NEO PI-R in its present form is useful for assessing adolescents' traits at the primary level, but additional research is necessary to infer the most appropriate facet level structure.

Noncombatant Evacuation Operations (NEO) Decision-Making Process Effects on Efficiency

DTIC Science & Technology

2012-02-15

the eastern coast of Japan. On 12 March, the Fukushima Daiichi nuclear power plant experienced explosions and fires within four reactors.51 Over... awareness , and understanding the mission objectives.43 The following outlines recent NEO successes and failures. First, a strategic look at the evacuation... Daiichi nuclear power plant. Over the next 30 days, the JTF and embassy worked intensely to develop a comprehensive plan overcoming many of the

Neo-Conservatives as Social Darwinists: Implications for Higher Education.

ERIC Educational Resources Information Center

Sola, Peter; And Others

1986-01-01

Compares the Social Darwinism of the 1890s with neo-conservatism of the 1980s. Discusses the ideologies of fair play versus fair shares, the theory of supply-side economics, and the implications of neo-conservatism for higher education. Argues that neo-conservatism is altering radically our conceptions of democracy, equality, and freedom. (KH)

The NEOShield-2 EU Project - The Italian contribution

NASA Astrophysics Data System (ADS)

Ieva, Simone; Dotto, Elisabetta; Mazzotta Epifani, Elena; Di Paola, Andrea; Speziali, Roberto; Cortese, Matteo; Lazzarin, Monica; Bertini, Ivano; Magrin, Sara; Barucci, Maria Antonietta; Perna, Davide; Perozzi, Ettore; Micheli, Marco

2016-04-01

The Near Earth Object (NEO) population comprehends small bodies that periodically approach or intersect the Earth's orbit. NEOs could have possible impacts with the Earth and, whatever the scenario, their physical characterization is essential to define successful mitigation strategies. Moreover, their study is important per se, since they represent the closest remnants of the planetary formation, 4.5 billion years ago, and the knowledge of their physical properties allows us to put constraints on the formation and early evolution of the Solar System. On the basis of these considerations, the NEO population is an important target for ground-based studies. Unfortunately, less than 15% of the 13500 known NEOs has a physical characterization, showing a great diversity - in sizes, shapes, rotational periods, albedos, and composition - and their increasing discovery rate (currently ˜1500 objects/year) makes the situation progressively worse. At a European level, the European Commission promoted the study on NEOs by approving and financing the NEOShield-2 project (2015-2017) in the framework of the Horizon 2020 program. The aims of NEOShield-2 are: i) to study detailed technologies and instruments to conduct close approach missions to NEOs or to undertake mitigation demonstration, and ii) to retrieve the physical properties of a wide number of NEOs, in order to design impact mitigation missions and assess the consequences of an impact on Earth. The Italian contributors to the NEOShield-2 project (INAF-OAR and Padova University) are responsible for the Task 10.2.1 'Colours and Phase function'. The aim of this task is to acquire photometric measurements for a wide sample of NEOs in order to i) perform phase function analysis, ii) retrieve surface colors and iii) obtain a preliminary taxonomical classification. This activity is developed in close collaboration with the ESA SSA NEO Coordination Centre.

Quantifying the Risk Posed by Potential Earth Impacts

NASA Astrophysics Data System (ADS)

Chesley, Steven R.; Chodas, Paul W.; Milani, Andrea; Valsecchi, Giovanni B.; Yeomans, Donald K.

2002-10-01

Predictions of future potential Earth impacts by near-Earth objects (NEOs) have become commonplace in recent years, and the rate of these detections is likely to accelerate as asteroid survey efforts continue to mature. In order to conveniently compare and categorize the numerous potential impact solutions being discovered we propose a new hazard scale that will describe the risk posed by a particular potential impact in both absolute and relative terms. To this end, we measure each event in two ways, first without any consideration of the event's time proximity or its significance relative to the so-called background threat, and then in the context of the expected risk from other objects over the intervening years until the impact. This approach is designed principally to facilitate communication among astronomers, and it is not intended for public communication of impact risks. The scale characterizes impacts across all impact energies, probabilities and dates, and it is useful, in particular, when dealing with those cases which fall below the threshold of public interest. The scale also reflects the urgency of the situation in a natural way and thus can guide specialists in assessing the computational and observational effort appropriate for a given situation. In this paper we describe the metrics introduced, and we give numerous examples of their application. This enables us to establish in rough terms the levels at which events become interesting to various parties.

Plasma Flowfields Around Low Earth Orbit Objects: Aerodynamics to Underpin Orbit Predictions

NASA Astrophysics Data System (ADS)

Capon, Christopher; Boyce, Russell; Brown, Melrose

2016-07-01

Interactions between orbiting bodies and the charged space environment are complex. The large variation in passive body parameters e.g. size, geometry and materials, makes the plasma-body interaction in Low Earth Orbit (LEO) a region rich in fundamental physical phenomena. The aerodynamic interaction of LEO orbiting bodies with the neutral environment constitutes the largest non-conservative force on the body. However in general, study of the LEO plasma-body interaction has not been concerned with external flow physics, but rather with the effects on surface charging. The impact of ionospheric flow physics on the forces on space debris (and active objects) is not well understood. The work presented here investigates the contribution that plasma-body interactions have on the flow structure and hence on the total atmospheric force vector experienced by a polar orbiting LEO body. This work applies a hybrid Particle-in-Cell (PIC) - Direct Simulation Monte Carlo (DSMC) code, pdFoam, to self-consistently model the electrostatic flowfield about a cylinder with a uniform, fixed surface potential. Flow conditions are representative of the mean conditions experienced by the Earth Observing Satellite (EOS) based on the International Reference Ionosphere model (IRI-86). The electron distribution function is represented by a non-linear Boltzmann electron fluid and ion gas-surface interactions are assumed to be that of a neutralising, conducting, thermally accommodating solid wall with diffuse reflections. The variation in flowfield and aerodynamic properties with surface potential at a fixed flow condition is investigated, and insight into the relative contributions of charged and neutral species to the flow physics experienced by a LEO orbiting body is provided. This in turn is intended to help improve the fidelity of physics-based orbit predictions for space debris and other near-Earth space objects.

Asteroid 1997 XF11 Could Collide with Earth

NASA Astrophysics Data System (ADS)

Marsden, B. G.

1999-09-01

2-km asteroids. The discovery and incorporation of observations from 1990 (IAUC 6839) immediately eliminated the possibility of an impact by 1997 XF11 for several millennia. An object in a short-period orbit destined to strike the earth is likely to make other close approaches beforehand. Important lessons to learn from the 1997 XF11 ``fiasco'' are that considerations of simple dynamics and geometry are at least as important as probabilistic estimates, and that there is a need to ensure that searches are made for prediscovery images and that an aggressive observational follow-up program is carried out for new NEO discoveries that may seem only an indirect threat.

Who is the Scientist-Subject? A Critique of the Neo-Kantian Scientist-Subject in Lorraine Daston and Peter Galison's Objectivity.

PubMed

Shah, Esha

2017-01-01

The main focus of this essay is to closely engage with the role of scientist-subjectivity in the making of objectivity in Lorraine Daston and Peter Galison's book Objectivity, and Daston's later and earlier works On Scientific Observation and The Moral Economy of Science. I have posited four challenges to the neo-Kantian and Foucauldian constructions of the co-implication of psychology and epistemology presented in these texts. Firstly, following Jacques Lacan's work, I have argued that the subject of science constituted by the mode of modern science suffers from paranoia. It is not the fear of subjectivity interfering with objectivity but the impossibility of knowing the truth of the real that causes paranoia. Here, I have argued that it is not the ethos of objectivity that drives epistemology as Daston and Galison suggest, but the pathos of paranoia. The second challenge builds upon Kant's own denial that the perfect correspondence between the human will and the moral law is possible. Kant himself thought that an ethical human act is impossible without the component of "pathology." This questions Daston and Galison's argument that there is always ethical imperative at the core of epistemic virtue. The third challenge contests the way Daston and Galison take appearance for being in their application of the Foucauldian concept of technologies of the self in modeling the master scientist-self. The fourth challenge questions the notion of the psychological and unconscious in the making of epistemology in Daston's later and earlier work. Against this background, I aim to make a claim that understanding and disclosing "entities" in the scientific domain presupposes an understanding of "being" in general. My goal is to open up the discussion for an alternative conception of the scientist-subject and thereby an affective and existential formulation of science.

French roots of French neo-lamarckisms, 1879-1985.

PubMed

Loison, Laurent

2011-01-01

This essay attempts to describe the neo-Lamarckian atmosphere that was dominant in French biology for more than a century. Firstly, we demonstrate that there were not one but at least two French neo-Lamarckian traditions. This implies, therefore, that it is possible to propose a clear definition of a (neo)Lamarckian conception, and by using it, to distinguish these two traditions. We will see that these two conceptions were not dominant at the same time. The first French neo-Lamarckism (1879-1931) was structured by a very mechanic view of natural processes. The main representatives of this first period were scientists such as Alfred Giard (1846-1908), Gaston Bonnier (1853-1922) and Félix Le Dantec (1869-1917). The second Lamarckism - much more vitalist in its inspiration - started to develop under the supervision of people such as Albert Vandel (1894-1980) and Pierre-Paul Grassé (1895-1985). Secondly, this essay suggests that the philosophical inclinations of these neo-Lamarckisms reactivated a very ancient and strong dichotomy of French thought. One part of this dichotomy is a material, physicalist tradition, which started with René Descartes but developed extensively during the 18th and 19th centuries. The other is a spiritual and vitalist reaction to the first one, which also had a very long history, though it is most closely associated with the work of Henri Bergson. Through Claude Bernard, the first neo-Lamarckians tried to construct a mechanical and determinist form of evolutionary theory which was, in effect, a Cartesian theory. The second wave of neo-Lamarckians wanted to reconsider the autonomy and reactivity of life forms, in contrast to purely physical systems.

The Mission Accessibility of Near-Earth Asteroids

NASA Technical Reports Server (NTRS)

Barbee, Brent W.; Abell, Paul A.; Adamo, Daniel R.; Mazanek, Daniel D.; Johnson, Lindley N.; Yeomans, Donald K.; Chodas, Paul W.; Chamberlin, Alan B.; Benner, Lance A. M.; Taylor, Patrick;

Migration of Trans-Neptunian Objects to a Near-Earth Space

NASA Technical Reports Server (NTRS)

Ipatov, S. I.; Mather, J. C.; Oegerle, William (Technical Monitor)

2002-01-01

Our estimates of the migration of trans-Neptunian objects (TNOs) to a near-Earth space are based on the results of investigations of orbital evolution of TNOs and Jupiter-crossing objects (JCOs). The orbital evolution of TNOs was considered in many papers. Recently we investigated the evolution for intervals of at least 5-10 Myr of 2500 JCOs under the gravitational influence of all planets, except for Mercury and Pluto (without dissipative factors). In the first series we considered N=2000 orbits near the orbits of 30 real Jupiter-family comets with period P(sub alpha)less than 10 yr, and in the second series we took N=500 orbits close to the orbit of Comet 10P Tempel 2 (alpha=3.1 AU, e=0.53, i=12 deg). We calculated the probabilities of collisions of objects with the terrestrial planets, using orbital elements obtained with a step equal to 500 yr, and then summarized the results for all time intervals and all bodies, obtaining the total probability P(sub sigma) of collisions with a planet and the total time interval T(sub sigma) during which perihelion distance q of bodies was less than a semimajor axis of the planet.

Integrating Authentic Earth Science Data in Online Visualization Tools and Social Media Networking to Promote Earth Science Education

NASA Astrophysics Data System (ADS)

Carter, B. L.; Campbell, B.; Chambers, L.; Davis, A.; Riebeek, H.; Ward, K.

2008-12-01

The Goddard Space Flight Center (GSFC) is one of the largest Earth Science research-based institutions in the nation. Along with the research comes a dedicated group of people who are tasked with developing Earth science research-based education and public outreach materials to reach the broadest possible range of audiences. The GSFC Earth science education community makes use of a wide variety of platforms in order to reach their goals of communicating science. These platforms include using social media networking such as Twitter and Facebook, as well as geo-spatial tools such as MY NASA DATA, NASA World Wind, NEO, and Google Earth. Using a wide variety of platforms serves the dual purposes of promoting NASA Earth Science research and making authentic data available to educational communities that otherwise might not otherwise be granted access. Making data available to education communities promotes scientific literacy through the investigation of scientific phenomena using the same data that is used by the scientific community. Data from several NASA missions will be used to demonstrate the ways in which Earth science data are made available for the education community.

Identifying Accessible Near-Earth Objects For Crewed Missions With Solar Electric Propulsion

NASA Technical Reports Server (NTRS)

Smet, Stijn De; Parker, Jeffrey S.; Herman, Jonathan F. C.; Aziz, Jonathan; Barbee, Brent W.; Englander, Jacob A.

2015-01-01

This paper discusses the expansion of the Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) with Solar Electric Propulsion (SEP). The research investigates the existence of new launch seasons that would have been impossible to achieve using only chemical propulsion. Furthermore, this paper shows that SEP can be used to significantly reduce the launch mass and in some cases the flight time of potential missions as compared to the current, purely chemical trajectories identified by the NHATS project.

An Urban Neo-Poverty Population-Based Quality of Life and Related Social Characteristics Investigation from Northeast China

PubMed Central

Ou, Fengrong; Li, Kai; Gao, Qian; Liu, Dan; Li, Jinghai; Hu, Liwen; Wu, Xian; Edmiston, E. Kale; Liu, Yang

2012-01-01

Objective To investigate quality of life (QOL) and related characteristics among an urban neo-poverty population in northeast China, and to compare this population with a traditional poverty cohort. Design The research was a cross-sectional survey executed from June 2005 to October 2007, with a sample of 2940 individuals ages 36 to 55 in three different industrial cities of northeast China. Data were collected on QOL status and sociodemographic characteristics. QOL was assessed using the 36-item Short Form Health Survey (Chinese version). Multiple regression analysis was employed to analyze association between sociodemographic variables and QOL. Results The scores for QOL in the neo-poverty group were higher than those in the traditional poverty group, but lower than those in the general population. When the neo-poverty population was divided into two subgroups by age, 36–45 years and 46–55 years, the differences in QOL scores were not significant. However, there were significant differences in several dimensions between two subgroups according to unemployment time (<5 years and >5 years). Additionally, stepwise regression analysis indicated that disease burden, including disease and medical expenditures, was a common risk factor for declining QOL in the neo-poverty group. Conclusions Despite some limitations, this study provides initial evidence that the QOL of the urban neo-poverty population lies between that of the general population and traditional poverty. QOL of the neo-poverty group approached QOL of the traditional poverty group with increased unemployment years. In addition to decreased income, disease burden is the most important factor influencing QOL status in urban neo-poverty. PMID:22719968

Neo-Liberalism, Irish Society and Adult Education

ERIC Educational Resources Information Center

Finnegan, Fergal

2008-01-01

This article offers an overview of recent international scholarship on neo-liberalism in particular the work of the geographer and historian David Harvey and the recent books of the educationalist Henry Giroux. It begins with a brief historical account of neo-liberalism and outlines the main characteristics of the free market era. Irish society…

Near-Earth Asteroids 2006 RH120 AND 2009 BD: Proxies for Maximally Accessible Objects?

NASA Technical Reports Server (NTRS)

Barbee, Brent W.; Chodas, Paul W.

2015-01-01

NASA's Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) has identified over 1,400 of the approximately 12,800 currently known near-Earth asteroids (NEAs) as more astrodynamically accessible, round-trip, than Mars. Hundreds of those approximately 1,400 NEAs can be visited round-trip for less change-in-velocity than the lunar surface, and dozens can be visited round-trip for less change-in-velocity than low lunar orbit. How accessible might the millions of undiscovered NEAs be? We probe that question by investigating the hypothesis that NEAs 2006 RH120 and 2009 BD are proxies for the most accessible NEAs we would expect to find, and describing possible future NEA population model studies.

Near-Earth asteroids orbits using Gaia and ground-based observations

NASA Astrophysics Data System (ADS)

Bancelin, D.; Hestroffer, D.; Thuillot, W.

2011-05-01

Potentially Hazardous Asteroids (PHAs) are Near-Earth Asteroids caraterised by a Minimum Orbital Intersection Distance (MOID) with Earth less to 0.05 A.U and an absolute magnitude H<22. Those objects have sometimes a so significant close approach with Earth that they can be put on a chaotic orbit. This kind of orbit is very sensitive for exemple to the initial conditions, to the planetary theory used (for instance JPL's model versus IMCCE's model) or even to the numerical integrator used (Lie Series, Bulirsch-Stoer or Radau). New observations (optical, radar, flyby or satellite mission) can improve those orbits and reduce the uncertainties on the Keplerian elements.The Gaia mission is an astrometric mission that will be launched in 2012 and will observe a large number of Solar System Objects down to magnitude V≤20. During the 5-year mission, Gaia will continuously scan the sky with a specific strategy: objects will be observed from two lines of sight separated with a constant basic angle. Five constants already fixed determinate the nominal scanning law of Gaia: The inertial spin rate (1°/min) that describe the rotation of the spacecraft around an axis perpendicular to those of the two fields of view, the solar-aspect angle (45°) that is the angle between the Sun and the spacecraft rotation axis, the precession period (63.12 days) which is the precession of the spin axis around the Sun-Earth direction. Two other constants are still free parameters: the initial spin phase, and the initial precession angle that will be fixed at the start of the nominal science operations. These latter are constraint by scientific outcome (e.g. possibility of performing test of fundamental physics) together with operational requirements (downlink to Earth windows). Several sets of observations of specific NEOs will hence be provided according to the initial precession angle. The purpose here is to study the statistical impact of the initial precession angle on the error

Enhancing SAMOS Data Access in DOMS via a Neo4j Property Graph Database.

NASA Astrophysics Data System (ADS)

Stallard, A. P.; Smith, S. R.; Elya, J. L.

2016-12-01

The Shipboard Automated Meteorological and Oceanographic System (SAMOS) initiative provides routine access to high-quality marine meteorological and near-surface oceanographic observations from research vessels. The Distributed Oceanographic Match-Up Service (DOMS) under development is a centralized service that allows researchers to easily match in situ and satellite oceanographic data from distributed sources to facilitate satellite calibration, validation, and retrieval algorithm development. The service currently uses Apache Solr as a backend search engine on each node in the distributed network. While Solr is a high-performance solution that facilitates creation and maintenance of indexed data, it is limited in the sense that its schema is fixed. The property graph model escapes this limitation by creating relationships between data objects. The authors will present the development of the SAMOS Neo4j property graph database including new search possibilities that take advantage of the property graph model, performance comparisons with Apache Solr, and a vision for graph databases as a storage tool for oceanographic data. The integration of the SAMOS Neo4j graph into DOMS will also be described. Currently, Neo4j contains spatial and temporal records from SAMOS which are modeled into a time tree and r-tree using Graph Aware and Spatial plugin tools for Neo4j. These extensions provide callable Java procedures within CYPHER (Neo4j's query language) that generate in-graph structures. Once generated, these structures can be queried using procedures from these libraries, or directly via CYPHER statements. Neo4j excels at performing relationship and path-based queries, which challenge relational-SQL databases because they require memory intensive joins due to the limitation of their design. Consider a user who wants to find records over several years, but only for specific months. If a traditional database only stores timestamps, this type of query would be complex

OUTFLOWS IN SODIUM EXCESS OBJECTS

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

Park, Jongwon; Yi, Sukyoung K.; Jeong, Hyunjin, E-mail: yi@yonsei.ac.kr

2015-08-10

Van Dokkum and Conroy revisited the unexpectedly strong Na i lines at 8200 Å found in some giant elliptical galaxies and interpreted them as evidence for an unusually bottom-heavy initial mass function. Jeong et al. later found a large population of galaxies showing equally extraordinary Na D doublet absorption lines at 5900 Å (Na D excess objects: NEOs) and showed that their origins can be different for different types of galaxies. While a Na D excess seems to be related to the interstellar medium (ISM) in late-type galaxies, smooth-looking early-type NEOs show little or no dust extinction and hence nomore » compelling signs of ISM contributions. To further test this finding, we measured the Doppler components in the Na D lines. We hypothesized that the ISM would have a better (albeit not definite) chance of showing a blueshift Doppler departure from the bulk of the stellar population due to outflow caused by either star formation or AGN activities. Many of the late-type NEOs clearly show blueshift in their Na D lines, which is consistent with the former interpretation that the Na D excess found in them is related to gas outflow caused by star formation. On the contrary, smooth-looking early-type NEOs do not show any notable Doppler components, which is also consistent with the interpretation of Jeong et al. that the Na D excess in early-type NEOs is likely not related to ISM activities but is purely stellar in origin.« less

Planetary Protection Progress of Hayabusa2 and Its Piggyback PROCYON: Launch, Earth Swingby and Outbound Cruising Phases

NASA Astrophysics Data System (ADS)

Yano, Hajime; Yoshikawa, Makoto; Sarli, Bruno; Ozaki, Naoya; Funase, Ryu; Tsuda, Yuichi; Chujo, Toshihiro; Ariu, Kaito

2016-07-01

Hayabusa-2 is Japan's second asteroid sample return mission which was successfully launched into the planned Earth departure trajectory with the H-IIA rocket on December 3rd, 2014, together with a group of its interplanetary piggyback micro- spacecraft, including the PROCYON(Proximate Object Close flYby with Optical Navigation)spacecraft, the world's first 50 kg-class deep space micro-spacecraft developed by the University of Tokyo and the Japan Aerospace Exploration Agency. The Hayabusa-2 spacecraft will go to Rug, a C-type NEO, and attempt surface investigations with daughter rovers (MINERVA-II series and MASCOT), artificial impact cratering experiment (SCI) and both surface and sub-surface sampling (Sampler) in 2018-2019 and plans to return to the Earth in December 2020. The PROCYON mission objective was to demonstrate a micro-spacecraft bus technology for deep space exploration and proximity flyby to asteroids performing optical measurements. Both of the above missions were fully evaluated by the COSPAR Planetary Protection Panel at the dedicated COSPAR colloquium and scientific assembly in 2014 and the COSPAR PPP has endorsed the Category-2 for their outbound trajectories and the non-restricted Earth return for the inbound trajectory of Hayabusa-2. As a part of the fulfillments of the Category-2 classification, both spacecraft must be compliant with the COSPAR PPP requirements of non-impact probability to Mars since they would have enough energy to reach and beyond the orbit of Mars, due to the Earth swing-by and ion engine operations for their outbound cruising. As for the Hayabusa-2 spacecraft, it successfully performed its Earth gravity assist in December 2015, resulting on accurate orbit determination for the post-swing-by orbit to be ready to restart the ion engine operation. Thus the non-impact probability to Mars did not change from the estimate given by Chujo, et al. (2015). As for the PROCYON spacecraft after the completion of the bus system

Roadmap for an EArth Defense Initiative (READI)

NASA Astrophysics Data System (ADS)

Burke, J. D.; Hussain, A.; Soni, A.; Johnson-Freese, J.; Faull, J.; Schmidt, N.; Wilson, T.; Thangavelu, M.

2015-12-01

During the 2015 Space Studies Program of the International Space University, a team of thirty-four participants from seventeen countries carried out a team project on the subject of planetary defense against near-Earth object impacts. The READI Project presents the components of a complete architecture representing practical future strategies and methods for protecting our planet and life as we know it. The findings and recommendations of the project are as follows: for detection and tracking, add infrared instruments in space and radar in Earth's southern hemisphere, as well as dedicated ground telescopes and a program for spectroscopic and other characterization of asteroids and comets; for deflection, develop and space-qualify kinetic and nuclear interceptors, as well as long-range laser ablators; for education and outreach, develop programs aimed at the cohort of children aged 6-15 and their parents; and for evacuation and recovery, provide distributed shelters and increased emergency planning. The project recognizes that the enactment of any deflection strategy would require significant international collaboration; thus, we recommend the formation of a Mitigation Action Group (MAG) in addition to the existing organizations IAWN and SMPAG. The MAG should be chartered to recommend deflection strategies to the UN Security Council in the event of an imminent NEO impact and, upon approval, to lead international deflection action.

Internal and temporal reliability estimates for informant ratings of personality using the NEO PI-R and IAS. NEO Personality Inventory. Interpersonal Adjective Scales.

PubMed

Kurtz, J E; Lee, P A; Sherker, J L

1999-06-01

This study examines the internal consistency and temporal stability of informant ratings from two widely used instruments for normal personality assessment, the revised NEO Personality Inventory (NEO PI-R) and the Interpersonal Adjective Scales (IAS). Well-known adult targets were selected by 109 undergraduate students and rated on two occasions separated by a 6-month interval. With few exceptions, estimates of internal consistency are adequate to good for both instruments. NEO PI-R domain scores yield coefficient alphas ranging from .89 to .96, with a median of .80 for the 30 facet scales. IAS octant scales show coefficient alphas ranging from .83 to .92. Retest Pearson correlations are above .70 for each of the NEO PI-R domain scores and both IAS axis coordinates, and intraclass correlations are above .60 for all scales from both instruments. Score changes were small but statistically significant for three of the five NEO PI-R domains at retest. The retest stability of IAS type classifications varies as a function of the extremity of the associated octant scores.

Collisional fragmentation of asteroids and its implication on the physical properties of Near-Earth Objects

NASA Astrophysics Data System (ADS)

Michel, P.

will show the sensitivity of the resulting family characteristics upon the internal structure of the parent body. According to our current understanding, most NEOs are certainly fragments of larger asteroids of the Main Belt, injected either directly or by diffusion into main resonances that transported them to Earth-crossing orbits. According to our simulations, most NEOs with diameter larger than several hundreds of meters should then correspond to gravitational aggregates. Given the crucial role of the internal structure on the impact outcome, this has important implications in the development of efficient mitigation strategies.

Options and uncertainties in planetary defense: Mission planning and vehicle design for flexible response

NASA Astrophysics Data System (ADS)

Barbee, Brent W.; Syal, Megan Bruck; Dearborn, David; Gisler, Galen; Greenaugh, Kevin; Howley, Kirsten M.; Leung, Ron; Lyzhoft, Josh; Miller, Paul L.; Nuth, Joseph A.; Plesko, Catherine; Seery, Bernard D.; Wasem, Joseph; Weaver, Robert P.; Zebenay, Melak

2018-02-01

This paper is part of an integrated study by NASA and the NNSA to quantitatively understand the response timeframe should a threatening Earth-impacting near-Earth object (NEO) be identified. The two realistic responses considered are the use of a spacecraft functioning as either a kinetic impactor or a nuclear explosive carrier to deflect the approaching NEO. The choice depends on the NEO size and mass, the available response time prior to Earth impact, and the various uncertainties. Whenever practical, the kinetic impactor is the preferred approach, but various factors, such as large uncertainties or short available response time, reduce the kinetic impactor's suitability and, ultimately, eliminate its sufficiency. Herein we examine response time and the activities that occur between the time when an NEO is recognized as being a sufficient threat to require a deflection and the time when the deflection impulse is applied to the NEO. To use a kinetic impactor for successful deflection of an NEO, it is essential to minimize the reaction time and maximize the time available for the impulse delivered to the NEO by the kinetic impactor to integrate forward in time to the eventual deflection of the NEO away from Earth impact. To shorten the response time, we develop tools to survey the profile of needed spacecraft launches and the possible mission payloads. We further present a vehicle design capable of either serving as a kinetic impactor, or, if the need arises, serving as a system to transport a nuclear explosive to the NEO. These results are generated by analyzing a specific case study in which the simulated Earth-impacting NEO is modeled very closely after the real NEO known as 101955 Bennu (1999 RQ36). Bennu was selected for our case study in part because it is the best-studied of the known NEOs. It is also the destination of NASA's OSIRIS-REx sample return mission, which is, at the time of this writing, enroute to Bennu following a September 2016 launch.

Exploration Opportunity Search of Near-earth Objects Based on Analytical Gradients

NASA Astrophysics Data System (ADS)

Ren, Yuan; Cui, Ping-Yuan; Luan, En-Jie

2008-07-01

The problem of search of opportunity for the exploration of near-earth minor objects is investigated. For rendezvous missions, the analytical gradients of the performance index with respect to the free parameters are derived using the variational calculus and the theory of state-transition matrix. After generating randomly some initial guesses in the search space, the performance index is optimized, guided by the analytical gradients, leading to the local minimum points representing the potential launch opportunities. This method not only keeps the global-search property of the traditional method, but also avoids the blindness in the latter, thereby increasing greatly the computing speed. Furthermore, with this method, the searching precision could be controlled effectively.

[Chemical constituents from Neo-Taraxacum siphonathum].

PubMed

Shi, Shuyun; Zhou, Honghao; Zhang, Yuping; Huang, Kelong; Liu, Suqin

2009-04-01

To study the chemical constituents from the antioxidant fraction of Neo-Taraxacum siphonathum. Various chromatographic techniques were used to isolate and purify the constituents. The structures were elucidated on the basis of chemical evidence and spectral analysis. Ten compounds were isolated and identified from Neo-T. siphonathum, caffeic acid (1), chlorogenic acid (2), quercetin (3), luteolin (4), quercetin-3-O-beta-D-glucopyranoside (5), quercetin-3-O-alpha-D-arabinofuranoside (6), quercetin-3-O-alpha-D-arabinopyranoside (7), luteolin-7-O-beta-D-glucopyranoside (8), beta-sitosterol (9) and daucosterol (10). Compounds 1-10 were isolated from this plant for the first time.

Orbit Modification of Earth-Crossing Asteroids/Comets Using Rendezvous Spacecraft and Laser Ablation

NASA Technical Reports Server (NTRS)

Park, Sang-Young; Mazanek, Daniel D.

2005-01-01

This report describes the approach and results of an end-to-end simulation to deflect a long-period comet (LPC) by using a rapid rendezvous spacecraft and laser ablation system. The laser energy required for providing sufficient deflection DELTA V and an analysis of possible intercept/rendezvous spacecraft trajectories are studied in this analysis. These problems minimize a weighted sum of the flight time and required propellant by using an advanced propulsion system. The optimal thrust-vector history and propellant mass to use are found in order to transfer a spacecraft from the Earth to a targeted celestial object. One goal of this analysis is to formulate an optimization problem for intercept/rendezvous spacecraft trajectories. One approach to alter the trajectory of the object in a highly controlled manner is to use pulsed laser ablative propulsion. A sufficiently intense laser pulse ablates the surface of a near-Earth object (NEO) by causing plasma blowoff. The momentum change from a single laser pulse is very small. However, the cumulative effect is very effective because the laser can interact with the object over long periods of time. The laser ablation technique can overcome the mass penalties associated with other nondisruptive approaches because no propellant is required to generate the DELTA V (the material of the celestial object is the propellant source). Additionally, laser ablation is effective against a wide range of surface materials and does not require any landing or physical attachment to the object. For diverting distant asteroids and comets, the power and optical requirements of a laser ablation system on or near the Earth may be too extreme to contemplate in the next few decades. A hybrid solution would be for a spacecraft to carry a laser as a payload to a particular celestial body. The spacecraft would require an advanced propulsion system capable of rapid rendezvous with the object and an extremely powerful electrical generator, which is

Adventures in near-Earth object exploration.

PubMed

Asphaug, Erik

2006-06-02

Asteroids, because of the hazard they pose to Earth, are compelling targets for robotic and human space exploration. Yet because of their exotic low-gravity environment, simply landing on an asteroid appears to be much more challenging than we had appreciated 5 or 10 years ago. Thanks to a bold new mission from Japan that has made the first asteroid sample return attempt, this goal is now within our reach.

Active Asteroids in the NEO Population

NASA Astrophysics Data System (ADS)

Jenniskens, Peter

2016-01-01

Some main-belt asteroids evolve into near-Earth objects. They can then experience the same meteoroid-producing phenomena as active asteroids in the main belt. If so, they would produce meteoroid streams, some of which evolve to intersect Earth's orbit and produce meteor showers at Earth. Only few of those are known. Meteoroid streams that move in orbits with Tisserand parameter well in excess of 3 are the Geminids and Daytime Sextantids of the Phaethon complex and the lesser known epsilon Pegasids. The observed activity appears to be related to nearly whole scale disintegrations, rather than dust ejection from volatile outgassing as observed in active comets. There is only a small population of asteroids with a main-belt origin that recently disintegrated into meteoroid streams.

Historicism and neo-Kantianism.

PubMed

Beiser, Fred

2008-12-01

This article treats the conflict between historicism and neo-Kantianism in the late nineteenth century by a careful examination of the writings of Wilhelm Windelband, the leader of the Southwestern neo-Kantians. Historicism was a profound challenge to the fundamental principles of Kant's philosophy because it seemed to imply that there are no universal and necessary principles of science, ethics or aesthetics. Since all such principles are determined by their social and historical context, they differ with each culture and epoch. Windelband attempted to respond to the challenge of this relativism by either broadening Kantian principles, so that they could accommodate the results of historicism, or by reformulating Kantian principles, so that they were impregnable to historical change. The article examines both aspects of Windelband's strategy in some detail, noting the many changes and different formulations in his views. A final section considers some of the difficulties of Windelband's strategy and concludes that, despite its heroic efforts, it was a failure.

High performance bonded neo magnets using high density compaction

NASA Astrophysics Data System (ADS)

Herchenroeder, J.; Miller, D.; Sheth, N. K.; Foo, M. C.; Nagarathnam, K.

2011-04-01

This paper presents a manufacturing method called Combustion Driven Compaction (CDC) for the manufacture of isotropic bonded NdFeB magnets (bonded Neo). Magnets produced by the CDC method have density up to 6.5 g/cm3 which is 7-10% higher compared to commercially available bonded Neo magnets of the same shape. The performance of an actual seat motor with a representative CDC ring magnet is presented and compared with the seat motor performance with both commercial isotropic bonded Neo and anisotropic NdFeB rings of the same geometry. The comparisons are made at both room and elevated temperatures. The airgap flux for the magnet produced by the proposed method is 6% more compared to the commercial isotropic bonded Neo magnet. After exposure to high temperature due to the superior thermal aging stability of isotropic NdFeB powders the motor performance with this material is comparable to the motor performance with an anisotropic NdFeB magnet.

NEO-P1 Profiles in PTSD as a Function of Trauma Level.

ERIC Educational Resources Information Center

Talbert, F. Suzanne; And Others

1993-01-01

Administered NEO Personality Inventory (NEO-PI) and Combat Exposure Scale to 100 Vietnam veterans with combat-related Posttraumatic Stress Disorder (PTSD) and sorted subjects into three groups based on trauma exposure level. Found no significant differences among personality profiles of three trauma-exposed groups. Revealed normative NEO-PI…

Asteroid Impact Risk: Ground Hazard versus Impactor Size

NASA Technical Reports Server (NTRS)

Mathias, Donovan; Wheeler, Lorien; Dotson, Jessie; Aftosmis, Michael; Tarano, Ana

2017-01-01

We utilized a probabilistic asteroid impact risk (PAIR) model to stochastically assess the impact risk due to an ensemble population of Near-Earth Objects (NEOs). Concretely, we present the variation of risk with impactor size. Results suggest that large impactors dominate the average risk, even when only considering the subset of undiscovered NEOs.

Neo-Nationalism in Higher Education: Case of South Africa

ERIC Educational Resources Information Center

Lee, Jenny J.

2017-01-01

Given the rise of regional hubs, emerging economies are experiencing international student growth as higher education providers in their respective regions. This study examined the neo-national experiences of international students in South Africa. Neo-nationalism refers to a new nationalism based national order in the new global economy. The…

A space mission to detect imminent Earth impactors

NASA Astrophysics Data System (ADS)

Valsecchi, G. B.; Perozzi, E.; Rossi, A.

2015-03-01

One of the goals of NEO surveys is to discover Earth impactors before they hit. How much warning time is desirable depends on the size of the impactors: for the larger ones more time is needed to mount effective mitigation measures. Initially, NEO surveys were aimed at large impactors, that can have significant global effects; however, their typical time scale is orders of magnitude larger than human lifetime. At the other extreme, monthly and annual events, liberating energies of the order of 1 to 10 kilotons, are immaterial as a threat to mankind, not justifying substantial expenditure on them. Intermediate events are of more concern: in the megatons range, timescales are of the order of centuries, and the damage can be substantial. A classical example is the Tunguska event, in which a body with a diameter of about 30 to 50 m liberated about 5 megatons in the atmosphere, devastating 2 000 square kilometers of Siberian forest.

A Dedicated NEO Follow-up Program for the Southern Hemisphere

NASA Astrophysics Data System (ADS)

van Altena, W. F.; Bailyn, C. D.; Girard, T. M.; Rabinowitz, D.; Branham, R. L.; Hicks, M.; Lopez, C. E.

2001-11-01

We describe an ongoing program dedicated to the observation of NEOs found by the northern discovery programs and whose tracks carry them into the Southern Hemisphere. We are observing the NEOs, to determine their positions, compute improved orbits and submit them to the Minor Planet Center over the Internet. Alerts of needed observations are monitored on relevant Web pages and e-mail messages from our collaborators at the northern discovery programs. The observations are made at the Cesco Observatory at El Leoncito, Argentina with the 0.5-meter double astrograph and/or at CTIO with the 1.0-meter YALO telescope, depending on the magnitude of the NEO and the photometric requirements for the specific NEO. The double astrograph at El Leoncito observes simultaneous CCD B and V photometry and astrometry for those NEO's brighter than 20, while the YALO observes those brighter than 21.5. YALO also provides simultaneous V and IR photometry and astrometry. All YALO observations are ftp'd to San Juan for astrometric reduction and then a revised orbit is computed from the new and existing observations in Mendoza and a decision is made to retarget our observations if necessary. If so, the El Leoncito and/or YALO observers are notified and provided with an improved ephemeris. The final positions and photometry are then forwarded to the MPC, MPEC and our collaborators. To date, we have reported the positions of over 2000 asteroids, 61 comets and 142 NEOs.

Post Neo-Liberalism and the Humanities: What the Repressive State Apparatus Means for Universities

ERIC Educational Resources Information Center

Hyslop-Margison, Emery J.; Leonard, Hugh A.

2012-01-01

In this article we explore how neo-liberal and post neo-liberal policies threaten the humanities in post-secondary education as a potential site of democratic dialogue and social transformation. We distinguish between neo-liberalism and post neo-liberalism on the basis of the latter's increased police suppression of democratic dissent. We are…

Neo-Keynesian Economics Today.

ERIC Educational Resources Information Center

Shackleton, J. R.

1987-01-01

Traces the development of post-Keynesian economic theories and examines the arguments which surround current neo-Keynesian thought. Argues for an eclecticism which recognizes that both supply-side and demand-side factors have a role to play in determining levels of output and employment. Useful charts and diagrams are included. (Author/DH)

What Future for Student Engagement in Neo-Liberal Times?

ERIC Educational Resources Information Center

Zepke, Nick

2015-01-01

The paper first examines the context that has given student engagement a very strong profile in higher education. It identifies neo-liberalism as the driving force in the present higher education context and argues that student engagement enjoys an elective affinity with it. While neo-liberalism is dominant, student engagement will be strong. But…

Constraining the Physical Properties of Near-Earth Object 2009 BD

NASA Astrophysics Data System (ADS)

Mommert, M.; Hora, J. L.; Farnocchia, D.; Chesley, S. R.; Vokrouhlický, D.; Trilling, D. E.; Mueller, M.; Harris, A. W.; Smith, H. A.; Fazio, G. G.

2014-05-01

We report on Spitzer Space Telescope Infrared Array Camera observations of near-Earth object 2009 BD that were carried out in support of the NASA Asteroid Robotic Retrieval Mission concept. We did not detect 2009 BD in 25 hr of integration at 4.5 μm. Based on an upper-limit flux density determination from our data, we present a probabilistic derivation of the physical properties of this object. The analysis is based on the combination of a thermophysical model with an orbital model accounting for the non-gravitational forces acting upon the body. We find two physically possible solutions. The first solution shows 2009 BD as a 2.9 ± 0.3 m diameter rocky body (ρ = 2.9 ± 0.5 g cm-3) with an extremely high albedo of 0.85_{-0.10}^{+0.20} that is covered with regolith-like material, causing it to exhibit a low thermal inertia (\\Gamma =30_{-10}^{+20} SI units). The second solution suggests 2009 BD to be a 4 ± 1 m diameter asteroid with p_V=0.45_{-0.15}^{+0.35} that consists of a collection of individual bare rock slabs (Γ = 2000 ± 1000 SI units, \\rho = 1.7_{-0.4}^{+0.7} g cm-3). We are unable to rule out either solution based on physical reasoning. 2009 BD is the smallest asteroid for which physical properties have been constrained, in this case using an indirect method and based on a detection limit, providing unique information on the physical properties of objects in the size range smaller than 10 m.

Astronomical Research Institute Photometric Results

NASA Astrophysics Data System (ADS)

Linder, Tyler R.; Sampson, Ryan; Holmes, Robert

2013-01-01

The Astronomical Research Institute (ARI) conducts astrometric and photometric studies of asteroids with a concentration on near-Earth objects (NEOs). A 0.76-m autoscope was used for photometric studies of seven asteroids of which two were main-belt targets and five were NEOs, including one potentially hazardous asteroid (PHA). These objects are: 3122 Florence, 3960 Chaliubieju, 5143 Heracles, (6455) 1992 HE, (36284) 2000 DM8, (62128) 2000 SO1, and 2010 LF86.

Socially Desirable Responding and the Factorial Stability of the NEO PI-R

ERIC Educational Resources Information Center

Marshall, Margarita B.; De Fruyt, Filip; Rolland, Jean-Pierre; Bagby, R. Michael

2005-01-01

The goal of the present investigation is to compare the factor structure of the revised NEO Personality Inventory (NEO PI-R; P. T. Costa & R. R. McCrae, 1992) in samples of respondents differentially motivated to respond in a socially desirable manner. In the French sample, the authors compared the NEO PI-R structure of job applicants…

Indigenous Knowledge in the Science Curriculum: Avoiding Neo-Colonialism

ERIC Educational Resources Information Center

Ryan, Ann

2008-01-01

Science education in Papua New Guinea has been influenced by neo-colonial practices that have significantly contributed to the silencing of the Papua New Guinea voice. This silencing has led to the production of science curriculum documents that are irrelevant to the students for whom they are written. To avoid being caught up in neo-colonial…

[Proposals for social class classification based on the Spanish National Classification of Occupations 2011 using neo-Weberian and neo-Marxist approaches].

PubMed

Domingo-Salvany, Antònia; Bacigalupe, Amaia; Carrasco, José Miguel; Espelt, Albert; Ferrando, Josep; Borrell, Carme

2013-01-01

In Spain, the new National Classification of Occupations (Clasificación Nacional de Ocupaciones [CNO-2011]) is substantially different to the 1994 edition, and requires adaptation of occupational social classes for use in studies of health inequalities. This article presents two proposals to measure social class: the new classification of occupational social class (CSO-SEE12), based on the CNO-2011 and a neo-Weberian perspective, and a social class classification based on a neo-Marxist approach. The CSO-SEE12 is the result of a detailed review of the CNO-2011 codes. In contrast, the neo-Marxist classification is derived from variables related to capital and organizational and skill assets. The proposed CSO-SEE12 consists of seven classes that can be grouped into a smaller number of categories according to study needs. The neo-Marxist classification consists of 12 categories in which home owners are divided into three categories based on capital goods and employed persons are grouped into nine categories composed of organizational and skill assets. These proposals are complemented by a proposed classification of educational level that integrates the various curricula in Spain and provides correspondences with the International Standard Classification of Education. Copyright © 2012 SESPAS. Published by Elsevier Espana. All rights reserved.

Search of exploration opportunity for near earth objects based on analytical gradients

NASA Astrophysics Data System (ADS)

Ren, Y.; Cui, P. Y.; Luan, E. J.

2008-01-01

The problem of searching for exploration opportunity of near Earth objects is investigated. For rendezvous missions, the analytical gradients of performance index with respect to free parameters are derived by combining the calculus of variation with the theory of state-transition matrix. Then, some initial guesses are generated random in the search space, and the performance index is optimized with the guidance of analytical gradients from these initial guesses. This method not only keeps the property of global search in traditional method, but also avoids the blindness in the traditional exploration opportunity search; hence, the computing speed could be increased greatly. Furthermore, by using this method, the search precision could be controlled effectively.

Exploring patient experiences of neo-adjuvant chemotherapy for breast cancer.

PubMed

Beaver, Kinta; Williamson, Susan; Briggs, Jean

2016-02-01

Neo-adjuvant chemotherapy is recommended for 'inoperable' locally advanced and inflammatory breast cancers. For operable breast cancers, trials indicate no survival differences between chemotherapy given pre or post-surgery. Communicating evidence based information to patients is complex and studies examining patient experiences of neo-adjuvant chemotherapy are lacking. This study aims to explore the experiences of women who received neo-adjuvant chemotherapy for breast cancer. A qualitative approach using in-depth interviews with 20 women who had completed neo-adjuvant chemotherapy for breast cancer. Interview data were analysed using thematic analysis. The sample included a relatively young group of women, with caring responsibilities. Five main themes emerged: coping with the rapid transition from 'well' to 'ill', information needs and decision making, needing support and empathy, impact on family, and creating a new 'normal'. More support was needed towards the end of chemotherapy, when side effects were at their most toxic, and decisions about forthcoming surgery were being made. Some women were referred to psychological services, but usually when a crisis point had been reached. Information and support would have been beneficial at key time points. This information is vital in developing services and interventions to meet the complex needs of these patients and potentially prevent late referral to psychological services. Specialist oncology nurses are able to develop empathetic relationships with patients and have the experience, knowledge and skills to inform and support women experiencing neo-adjuvant chemotherapy. Targeting key time points and maintaining relationship throughout neo-adjuvant chemotherapy would be highly beneficial. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analysis of orbital perturbations acting on objects in orbits near geosynchronous earth orbit

NASA Technical Reports Server (NTRS)

Friesen, Larry J.; Jackson, Albert A., IV; Zook, Herbert A.; Kessler, Donald J.

1992-01-01

The paper presents a numerical investigation of orbital evolution for objects started in GEO or in orbits near GEO in order to study potential orbital debris problems in this region. Perturbations simulated include nonspherical terms in the earth's geopotential field, lunar and solar gravity, and solar radiation pressure. Objects simulated include large satellites, for which solar radiation pressure is insignificant, and small particles, for which solar radiation pressure is an important force. Results for large satellites are largely in agreement with previous GEO studies that used classical perturbation techniques. The orbit plane of GEO satellites placed in a stable plane orbit inclined approximately 7.3 deg to the equator experience very little precession, remaining always within 1.2 percent of their initial orientation. Solar radiation pressure generates two major effects on small particles: an orbital eccentricity oscillation anticipated from previous research, and an oscillation in orbital inclination.

Constraining central Neo-Tethys Ocean reconstructions with mantle convection models

NASA Astrophysics Data System (ADS)

Nerlich, Rainer; Colli, Lorenzo; Ghelichkhan, Siavash; Schuberth, Bernhard; Bunge, Hans-Peter

2017-04-01

A striking feature of the Indian Ocean is a distinct geoid low south of India, pointing to a regionally anomalous mantle density structure. Equally prominent are rapid plate convergence rate variations between India and SE Asia, particularly in Late Cretaceous/Paleocene times. Both observations are linked to the central Neo-Tethys Ocean subduction history, for which competing scenarios have been proposed. Here we evaluate three alternative reconstructions by assimilating their associated time-dependent velocity fields in global high-resolution geodynamic Earth models, allowing us to predict the resulting seismic mantle heterogeneity and geoid signal. Our analysis reveals that a geoid low similar to the one observed develops naturally when a long-lived back-arc basin south of Eurasia's paleomargin is assumed. A quantitative comparison to seismic tomography further supports this model. In contrast, reconstructions assuming a single northward dipping subduction zone along Eurasia's margin or models incorporating a temporary southward dipping intraoceanic subduction zone cannot sufficiently reproduce geoid and seismic observations.

Constraining central Neo-Tethys Ocean reconstructions with mantle convection models

NASA Astrophysics Data System (ADS)

Nerlich, Rainer; Colli, Lorenzo; Ghelichkhan, Siavash; Schuberth, Bernhard; Bunge, Hans-Peter

2016-09-01

A striking feature of the Indian Ocean is a distinct geoid low south of India, pointing to a regionally anomalous mantle density structure. Equally prominent are rapid plate convergence rate variations between India and SE Asia, particularly in Late Cretaceous/Paleocene times. Both observations are linked to the central Neo-Tethys Ocean subduction history, for which competing scenarios have been proposed. Here we evaluate three alternative reconstructions by assimilating their associated time-dependent velocity fields in global high-resolution geodynamic Earth models, allowing us to predict the resulting seismic mantle heterogeneity and geoid signal. Our analysis reveals that a geoid low similar to the one observed develops naturally when a long-lived back-arc basin south of Eurasia's paleomargin is assumed. A quantitative comparison to seismic tomography further supports this model. In contrast, reconstructions assuming a single northward dipping subduction zone along Eurasia's margin or models incorporating a temporary southward dipping intraoceanic subduction zone cannot sufficiently reproduce geoid and seismic observations.

Application of Digital Object Identifiers to data sets at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)

NASA Astrophysics Data System (ADS)

Vollmer, B.; Ostrenga, D.; Johnson, J. E.; Savtchenko, A. K.; Shen, S.; Teng, W. L.; Wei, J. C.

2013-12-01

Digital Object Identifiers (DOIs) are applied to selected data sets at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). The DOI system provides an Internet resolution service for unique and persistent identifiers of digital objects. Products assigned DOIs include data from the NASA MEaSUREs Program, the Earth Observing System (EOS) Aqua Atmospheric Infrared Sounder (AIRS) and EOS Aura High Resolution Dynamics Limb Sounder (HIRDLS). DOIs are acquired and registered through EZID, California Digital Library and DataCite. GES DISC hosts a data set landing page associated with each DOI containing information on and access to the data including a recommended data citation when using the product in research or applications. This work includes participation with the earth science community (e.g., Earth Science Information Partners (ESIP) Federation) and the NASA Earth Science Data and Information System (ESDIS) Project to identify, establish and implement best practices for assigning DOIs and managing supporting information, including metadata, for earth science data sets. Future work includes (1) coordination with NASA mission Science Teams and other data providers on the assignment of DOIs for other GES DISC data holdings, particularly for future missions such as Orbiting Carbon Observatory -2 and -3 (OCO-2, OCO-3) and projects (MEaSUREs 2012), (2) construction of landing pages that are both human and machine readable, and (3) pursuing the linking of data and publications with tools such as the Thomson Reuters Data Citation Index.

MACSAT - A Near Equatorial Earth Observation Mission

NASA Astrophysics Data System (ADS)

Kim, B. J.; Park, S.; Kim, E.-E.; Park, W.; Chang, H.; Seon, J.

MACSAT mission was initiated by Malaysia to launch a high-resolution remote sensing satellite into Near Equatorial Orbit (NEO). Due to its geographical location, Malaysia can have large benefits from NEO satellite operation. From the baseline circular orbit of 685 km altitude with 7 degrees of inclination, the neighboring regions around Malaysian territory can be frequently monitored. The equatorial environment around the globe can also be regularly observed with unique revisit characteristics. The primary mission objective of MACSAT program is to develop and validate technologies for a near equatorial orbit remote sensing satellite system. MACSAT is optimally designed to accommodate an electro-optic Earth observation payload, Medium-sized Aperture Camera (MAC). Malaysian and Korean joint engineering teams are formed for the effective implementation of the satellite system. An integrated team approach is adopted for the joint development for MACSAT. MAC is a pushbroom type camera with 2.5 m of Ground Sampling Distance (GSD) in panchromatic band and 5 m of GSD in four multi-spectral bands. The satellite platform is a mini-class satellite. Including MAC payload, the satellite weighs under 200 kg. Spacecraft bus is designed optimally to support payload operations during 3 years of mission life. The payload has 20 km of swath width with +/- 30 o of tilting capability. 32 Gbits of solid state recorder is implemented as the mass image storage. The ground element is an integrated ground station for mission control and payload operation. It is equipped with S- band up/down link for commanding and telemetry reception as well as 30 Mbps class X-band down link for image reception and processing. The MACSAT system is capable of generating 1:25,000-scale image maps. It is also anticipated to have capability for cross-track stereo imaging for Digital elevation Model (DEM) generation.

Conceptual Design of a Flight Validation Mission for a Hypervelocity Asteroid Intercept Vehicle

NASA Technical Reports Server (NTRS)

Barbee, Brent W.; Wie, Bong; Steiner, Mark; Getzandanner, Kenneth

2013-01-01

Near-Earth Objects (NEOs) are asteroids and comets whose orbits approach or cross Earth s orbit. NEOs have collided with our planet in the past, sometimes to devastating effect, and continue to do so today. Collisions with NEOs large enough to do significant damage to the ground are fortunately infrequent, but such events can occur at any time and we therefore need to develop and validate the techniques and technologies necessary to prevent the Earth impact of an incoming NEO. In this paper we provide background on the hazard posed to Earth by NEOs and present the results of a recent study performed by the NASA/Goddard Space Flight Center s Mission Design Lab (MDL) in collaboration with Iowa State University s Asteroid Deflection Research Center (ADRC) to design a flight validation mission for a Hypervelocity Asteroid Intercept Vehicle (HAIV) as part of a Phase 2 NASA Innovative Advanced Concepts (NIAC) research project. The HAIV is a two-body vehicle consisting of a leading kinetic impactor and trailing follower carrying a Nuclear Explosive Device (NED) payload. The HAIV detonates the NED inside the crater in the NEO s surface created by the lead kinetic impactor portion of the vehicle, effecting a powerful subsurface detonation to disrupt the NEO. For the flight validation mission, only a simple mass proxy for the NED is carried in the HAIV. Ongoing and future research topics are discussed following the presentation of the detailed flight validation mission design results produced in the MDL.

Magnetospheric Effects as a New Aspect of the Asteroid Impact Problem: Necessity and Possibilities of Laboratory Simulation Experiments

NASA Astrophysics Data System (ADS)

Zakharov, Yuri P.; Nikitin, Sergei A.; Ponomarenko, Arnold G.; Minami, Shigeyuki

1997-05-01

This paper discusses the possible consequences to the Earth's magnetosphere, when due to too short an advanced warning, attempts at mitigation of a near-Earth object (NEO) must be made in close proximity to the Earth. The energy Eo, and explosive plasma release during impact may be compared with the kinetic energy Ek of the NEO and with the energy, Ee (Ee approximately Ek), needed for NEO deflection by a strong (protective force) explosive, at distances close to the scale of the magnetosphere. If the energy, Em, of the Earth's dipole field latter is relatively small (Em is less than Eo for a NEO size approximately 1 km), global or even catastrophic disturbances could occur. These ecologically important magnetospheric aspects of the NEO impact problem have been discussed recently; particularly in the context of the comet SL-9/Jupiter impact. In the latter case, the effect on Jupiter's magnetosphere of the 'NEO' explosions was very small (x equals Eo/Em approximately 0.001, where Em is the 'outer' magnetic energy of the planetary dipole field) and the corresponding model of its 'fireball' development could be simulated numerically in 'zero' approximation, with the assumption of an undisturbed magnetospheric media as a whole. However, in general, and, in the rather probable case of NEO impacts with values x approximately 1, the development of such 3D, nonstationary MHD or PIC-models at this time. Such information can be obtained from new kinds of simulation experiments with the laboratory magnetosphere, the so-called 'terrella'.

Mrmc Neo Surgical Ventilating Port and Neo Attic Malleo-Incudal Complex in Endoscopic Management of Limited Attico-Antral Cholesteatoma.

PubMed

Nandyal, C B; Sutrave, Mithun; Kurle, Vinayak; Harsoor, Pallavi A

2018-03-01

To study functional outcome of the endoscopic management of limited attico-antral cholesteatoma in terms of visualization of sac, cholesteatoma disease clearance, ABG closure improvement, preservation of residual anatomy and recurrence of disease. It is a prospective study done during Feb 2016 to March 2017 done on 20 pts with limited attico-antral cholesteatoma with CT confirmation. Endoscopic management of limited attico-antral cholesteatoma with complete removal of sac, infected discharge and granulations along with creation of MRMC Neo surgical ventilating port (joining Anterior & posterior isthmuses) done in cases where residual attic anatomy was present to establish physiological attic ventilation and drainage. Whereas in cases of attic and ossicular erosion, ossiculoplasty along with neo attic malleo-incudal complex (with composite tragal cartilage with perichondrium graft) for lateral attic wall reconstruction was done to prevent attic retraction. Patients had mean pre op ABG of 36.29 ± 6.29 and mean post op ABG closure of 16.33 ± 6.50 with no recurrence of cholesteatoma at 6 months of follow up. Patient showed significant (55%) improvement in hearing with all having graft uptake in which four cases having mild pars tensa retraction which recovered later without any intervention. Thus creation of new MRMC Neo surgical ventilating port or neo attic malleo-incudal complex with endoscopic approach allows better visual access to clear the limited attico-antral disease with sparing of normal residual attic anatomy along with physiological ventilation and drainage having better hearing results and outcome.

Ancient Male Recombination Shaped Genetic Diversity of Neo-Y Chromosome in Drosophila albomicans.

PubMed

Satomura, Kazuhiro; Tamura, Koichiro

2016-02-01

Researchers studying Y chromosome evolution have drawn attention to neo-Y chromosomes in Drosophila species due to their resembling the initial stage of Y chromosome evolution. In the studies of neo-Y chromosome of Drosophila miranda, the extremely low genetic diversity observed suggested various modes of natural selection acting on the nonrecombining genome. However, alternative possibility may come from its peculiar origin from a single chromosomal fusion event with male achiasmy, which potentially caused and maintained the low genetic diversity of the neo-Y chromosome. Here, we report a real case where a neo-Y chromosome is in transition from an autosome to a typical Y chromosome. The neo-Y chromosome of Drosophila albomicans harbored a rich genetic diversity comparable to its gametologous neo-X chromosome and an autosome in the same genome. Analyzing sequence variations in 53 genes and measuring recombination rates between pairs of loci by cross experiments, we elucidated the evolutionary scenario of the neo-Y chromosome of D. albomicans having high genetic diversity without assuming selective force, i.e., it originated from a single chromosomal fusion event, experienced meiotic recombination during the initial stage of evolution and diverged from neo-X chromosome by the suppression of recombination tens or a few hundreds of thousand years ago. Consequently, the observed high genetic diversity on the neo-Y chromosome suggested a strong effect of meiotic recombination to introduce genetic variations into the newly arisen sex chromosome. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Public Pedagogy and the Politics of Neo-Liberalism: Making the Political More Pedagogical

ERIC Educational Resources Information Center

Giroux, Henry A.

2004-01-01

Neo-liberalism has reached a new stage in the United States, buttressed largely by the almost seamless alliances formed among the Bush administration, religious fundamentalists, neo-conservative extremists, the dominant media, and corporate elites. This article explores the various ways in which neo-liberal cultural politics works as a form of…

An objective frequency domain method for subsurface characterisation using Earth and atmospheric tides

NASA Astrophysics Data System (ADS)

Cuthbert, M. O.; Acworth, I. R.; Halloran, L. J. S.; Rau, G. C.; Bernadi, T. L.

2017-12-01

It has long been recognised that hydraulic properties can be derived from the response of piezometric heads to tidal loadings. However, there is a degree of subjectivity in existing graphical approaches most commonly used to calculate barometric efficiency leading to uncertainties in derived values of compressible storage. Here we demonstrate a novel approach to remove these uncertainties by objectively deriving the barometric efficiency from groundwater hydraulic head responses using a frequency domain method. We take advantage of the presence of worldwide and ubiquitous atmospheric tide fluctuations which occur at 2 cycles per day (cpd). First we use a Fourier transform to calculate the amplitudes of the 2 cpd signals from co-located atmospheric pressure and hydraulic head time series measurements. Next we show how the Earth tide response at the same frequency can be quantified and removed so that this effect does not interfere with the calculation of the barometric efficiency. Finally, the ratio of the amplitude of the response at 2 cpd of hydraulic head to atmospheric pressure is used to quantify the barometric efficiency. This new method allows an objective quantification using `passive' in situ monitoring rather than resorting to aquifer pumping or laboratory tests. The minimum data requirements are 15 days duration of 6-hourly hydraulic head and atmospheric pressure measurements, and modelled Earth tide records which are readily conducted using freely available software. The new approach allows for a rapid and cost-effective alternative to traditional methods of estimating aquifer compressible storage properties without the subjectivity of existing approaches, and will be of importance to improving the spatial coverage of subsurface characterisation for groundwater resource evaluation and land subsidence assessment.

Evolution beyond neo-Darwinism: a new conceptual framework.

PubMed

Noble, Denis

2015-01-01

Experimental results in epigenetics and related fields of biological research show that the Modern Synthesis (neo-Darwinist) theory of evolution requires either extension or replacement. This article examines the conceptual framework of neo-Darwinism, including the concepts of 'gene', 'selfish', 'code', 'program', 'blueprint', 'book of life', 'replicator' and 'vehicle'. This form of representation is a barrier to extending or replacing existing theory as it confuses conceptual and empirical matters. These need to be clearly distinguished. In the case of the central concept of 'gene', the definition has moved all the way from describing a necessary cause (defined in terms of the inheritable phenotype itself) to an empirically testable hypothesis (in terms of causation by DNA sequences). Neo-Darwinism also privileges 'genes' in causation, whereas in multi-way networks of interactions there can be no privileged cause. An alternative conceptual framework is proposed that avoids these problems, and which is more favourable to an integrated systems view of evolution. © 2015. Published by The Company of Biologists Ltd.

Standardization of the NEO-PI-3 in the Greek general population.

PubMed

Fountoulakis, Konstantinos N; Siamouli, Melina; Moysidou, Stefania; Pantoula, Eleonora; Moutou, Katerina; Panagiotidis, Panagiotis; Kemeridou, Marina; Mavridou, Eirini; Loli, Efimia; Batsiari, Elena; Preti, Antonio; Tondo, Leonardo; Gonda, Xenia; Mobayed, Nisreen; Akiskal, Kareen; Akiskal, Hagop; Costa, Paul; McCrae, Robert

2014-01-01

The revised NEO Personality Inventory (NEO-PI-3) includes 240 items corresponding to the Big Five personality traits (Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience) and subordinate dimensions (facets). It is suitable for use with adolescents and adults (12 years or older). The aim of the current study was to validate the Greek translation of the NEO-PI-3 in the general Greek population. The study sample included 734 subjects from the general Greek population of whom 59.4% were females and 40.6% males aged 40.80 ± 11.48. The NEO-PI-3 was translated into Greek and back-translated into English, and the accuracy of the translation was confirmed and established. The statistical analysis included descriptive statistics, confirmatory factorial analysis (CFA), the calculation of Cronbach's alpha, and the calculation of Pearson product-moment correlations. Sociodemographics groups were compared by ANOVA. Most facets had Cronbach's alpha above 0.60. Confirmatory factor analysis showed acceptable loading of the facets on their own hypothesized factors and very good estimations of Cronbach's alphas for the hypothesized factors, so it was partially supportive of the five-factor structure of the NEO-PI-3.The factors extracted with Procrustes rotation analysis can be considered reasonably homologous to the factors of the American normative sample. Correlations between dimensions were as expected and similar to those reported in the literature. The literature suggests that overall, the psychometric properties of NEO-PI-3 scales have been found to generalize across ages, cultures, and methods of measurement. In accord with this, the results of the current study confirm the reliability of the Greek translation and adaptation of the NEO-PI-3. The inventory has comparable psychometric properties in its Greek version in comparison to the original and other national translations, and it is suitable for clinical as well as research use.

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

Mainzer, A.; Bauer, J.; Masiero, J.

NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft has been brought out of hibernation and has resumed surveying the sky at 3.4 and 4.6 μm. The scientific objectives of the NEOWISE reactivation mission are to detect, track, and characterize near-Earth asteroids and comets. The search for minor planets resumed on 2013 December 23, and the first new near-Earth object (NEO) was discovered 6 days later. As an infrared survey, NEOWISE detects asteroids based on their thermal emission and is equally sensitive to high and low albedo objects; consequently, NEOWISE-discovered NEOs tend to be large and dark. Over the course of itsmore » three-year mission, NEOWISE will determine radiometrically derived diameters and albedos for ∼2000 NEOs and tens of thousands of Main Belt asteroids. The 32 months of hibernation have had no significant effect on the mission's performance. Image quality, sensitivity, photometric and astrometric accuracy, completeness, and the rate of minor planet detections are all essentially unchanged from the prime mission's post-cryogenic phase.« less

Mathematics in Mind, Brain, and Education: A Neo-Piagetian Approach

ERIC Educational Resources Information Center

Norton, Anderson; Deater-Deckard, Kirby

2014-01-01

Because of their focus on psychological structures and operations, neo-Piagetian approaches to learning lend themselves to neurological hypotheses. Recent advances in neural imaging and educational technology now make it possible to test some of these claims. Here, we take a neo-Piagetian approach to mathematical learning in order to frame two…

Effects of positive impression management on the NEO Personality Inventory--Revised in a clinical population.

PubMed

Ballenger, J F; Caldwell-Andrews, A; Baer, R A

2001-06-01

Sixty adults in outpatient psychotherapy completed the NEO Personality Inventory--Revised (NEO PI-R, P. T. Costa & R. R. McCrae, 1992a). Half were instructed to fake good and half were given standard instructions. All completed the Interpersonal Adjective Scale--Revised, Big Five (J. S. Wiggins & P. D. Trapnell, 1997) under standard instructions, and their therapists completed the observer rating form of the NEO Five-Factor Inventory. A comparison group of 30 students completed the NEO PI-R under standard instructions. Standard and fake-good participants obtained significantly different NEO PI-R domain scores. Correlations between the NEO PI-R and criterion measures were significantly lower for faking than for standard patients. Validity scales for the NEO PI-R (J. A. Schinka, B. N. Kinder, & T. Kremer, 1997) were moderately accurate in discriminating faking from standard patients, but were only marginally accurate in discriminating faking patients from students.

Rapid neo-sex chromosome evolution and incipient speciation in a major forest pest

Treesearch

Ryan R. Bracewell; Barbara J. Bentz; Brian T. Sullivan; Jeffrey M. Good

2017-01-01

Genome evolution is predicted to be rapid following the establishment of new (neo) sex chromosomes, but it is not known if neo-sex chromosome evolution plays an important role in speciation. Here we combine extensive crossing experiments with population and functional genomic data to examine neo-XY chromosome evolution and incipient speciation in the mountain pine...

Reliability of the NEO Five Factor Inventory short form for assessing personality after stroke.

PubMed

Dwan, Toni; Ownsworth, Tamara; Donovan, Caroline; Lo, Ada Ho Yan

2017-07-01

It is well recognized that an individual's personality characteristics influence their psychological adjustment after stroke. However, there is a lack of research on the reliability of personality inventories for stroke. This study primarily aimed to evaluate the reliability of the Neuroticism, Extroversion, Openness to Experience (NEO)-Five Factor Inventory (NEO-FFI) for assessing pre-morbid personality and personality changes after stroke. Further aims were to investigate changes in personality during the hospital-to-home transition period and examine associations between personality and mood. Forty participants with stroke (52.5% male, M age=65.55 years) were recruited at time of hospital discharge and completed the NEO-FFI, Centre for Epidemiologic Studies - Depression and Geriatric Anxiety Inventory. Significant others completed an informant version of the NEO-FFI. Stroke participants were re-assessed on the NEO-FFI at 1-month and 4-months post-discharge. Forty matched controls also completed the NEO-FFI. Internal consistency was adequate for the NEO-FFI (α=0.57-0.86), although low for agreeableness. There was fair to excellent concordance between self-rated and informant versions of the NEO-FFI (ICC=0.58-0.78). Significant positive associations were found between neuroticism and mood (r=0.50-0.68), and significant negative associations were found between extraversion and mood (r=-0.33-0.36) and agreeableness and anxiety (r=-0.43). Self-ratings of stroke participants on the NEO-FFI at discharge did not significantly differ from matched controls. Extraversion levels significantly decreased, and agreeableness levels significantly increased between discharge and 1- and 4-months post-discharge. Overall, the results support the reliability of the NEO-FFI for assessing personality characteristics in the context of stroke.

Near-Earth-object survey progress and population of small near-Earth asteroids

NASA Astrophysics Data System (ADS)

Harris, A.

2014-07-01

Estimating the total population vs. size of NEAs and the completion of surveys is the same thing since the total population is just the number discovered divided by the estimated completion. I review the method of completion estimation based on ratio of re-detected objects to total detections (known plus new discoveries). The method is quite general and can be used for population estimations of all sorts, from wildlife to various classes of solar system bodies. Since 2001, I have been making estimates of population and survey progress approximately every two years. Plotted below, left, is my latest estimate, including NEA discoveries up to August, 2012. I plan to present an update at the meeting. All asteroids of a given size are not equally easy to detect because of specific orbital geometries. Thus a model of the orbital distribution is necessary, and computer simulations using those orbits need to establish the relation between the raw re-detection ratio and the actual completion fraction. This can be done for any sub-group population, allowing to estimate the population of a subgroup and the expected current completion. Once a reliable survey computer model has been developed and ''calibrated'' with respect to actual survey re-detections versus size, it can be extrapolated to smaller sizes to estimate completion even at very small size where re-detections are rare or even zero. I have recently investigated the subgroup of extremely low encounter velocity NEAs, the class of interest for the Asteroid Redirect Mission (ARM), recently proposed by NASA. I found that asteroids of diameter ˜ 10 m with encounter velocity with the Earth lower than 2.5 km/sec are detected by current surveys nearly 1,000 times more efficiently than the general background of NEAs of that size. Thus the current completion of these slow relative velocity objects may be around 1%, compared to 10^{-6} for that size objects of the general velocity distribution. Current surveys are nowhere near

Neo-Liberalism in British Columbia Education and Teachers' Union Resistance

ERIC Educational Resources Information Center

Poole, Wendy

2007-01-01

Since the election of the Campbell government in 2001, teachers have experienced heightened conflict with the provincial government. An analysis of the discourse and power relations between the BC Teachers' Federation (BCTF) and government reveals a neo-liberal agenda on the part of government and anti-neo-liberalism on the part of the BCTF.…

The Mastodon in the room: how Darwinian is neo-Darwinism?

PubMed

Brooks, Daniel R

2011-03-01

Failing to acknowledge substantial differences between Darwinism and neo-Darwinism impedes evolutionary biology. Darwin described evolution as the outcome of interactions between the nature of the organism and the nature of the conditions, each relatively autonomous but both historically and spatially intertwined. Furthermore, he postulated that the nature of the organism was more important than the nature of the conditions, leading to natural selection as an inevitable emergent product of biological systems. The neo-Darwinian tradition assumed a creative rather than selective view of natural selection, with the nature of the organism determined by the nature of the conditions, rendering the nature of the organism and temporal contingency unnecessary. Contemporary advances in biology, specifically the phylogenetics revolution and evo-devo, underscore the significance of history and the nature of the organism in biology. Darwinism explains more biology better, and better resolves apparent anomalies between living systems and more general natural laws, than does neo-Darwinism. The "extended" or "expanded" synthesis currently called for by neo-Darwinians is Darwinism. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

Harris, Alan W.; Drube, Line, E-mail: alan.harris@dlr.de

The metal content of asteroids is of great interest, not only for theories of their origins and the evolution of the solar system but, in the case of near-Earth objects (NEOs), also for impact mitigation planning and endeavors in the field of planetary resources. However, since the reflection spectra of metallic asteroids are largely featureless, it is difficult to identify them and relatively few are known. We show how data from the Wide-field Infrared Survey Explorer (WISE)/NEOWISE thermal-infrared survey and similar surveys, fitted with a simple thermal model, can reveal objects likely to be metal rich. We provide a listmore » of candidate metal-rich NEOs. Our results imply that future infrared surveys with the appropriate instrumentation could discover many more metal-rich asteroids, providing valuable data for assessment of the impact hazard and the potential of NEOs as reservoirs of vital materials for future interplanetary space activities and, eventually perhaps, for use on Earth.« less

Increasing Space Situational Awareness for NEOs

NASA Astrophysics Data System (ADS)

Hestroffer, Daniel J. G. J.; Eggl, Siegfried; Thuillot, William

2015-05-01

Over the past years, Europe has strengthened its commitment to foster space situational awareness. Apart from the current efforts in tracking space weather, artificial satellites and space debris, Near Earth Asteroid threat assessment is a key task. NEOshield has been part of this European effort. We will give an overview over national projects and European programs with French participation such as PoDET, ESTERS, FRIPON, NEOShield, Gaia-FUN-SSO and Stardust. Future plans regarding Near Earth Object threat assessment and mitigation are described. The role of the IMCCE in this framework is discussed using the example of the post mitigation impact risk analyis of Gravity Tractor and Kinetic Impactor based asteroid deflection demonstration mission designs.

Creationism, Neo-Darwinism and Panspermia

NASA Astrophysics Data System (ADS)

Klyce, Brig; Wickramasinghe, N. Chandra

2011-10-01

Creationists and neo-Darwinists have spent the past several decades engaged in a sullen trench warfare, occasionally firing at each other with little effect. We argue in this article that an acceptance of panspermia as a "third way" might lead to a long over-due reconciliation between the contending groups.

Rapid neo-sex chromosome evolution and incipient speciation in a major forest pest.

PubMed

Bracewell, Ryan R; Bentz, Barbara J; Sullivan, Brian T; Good, Jeffrey M

2017-11-17

Genome evolution is predicted to be rapid following the establishment of new (neo) sex chromosomes, but it is not known if neo-sex chromosome evolution plays an important role in speciation. Here we combine extensive crossing experiments with population and functional genomic data to examine neo-XY chromosome evolution and incipient speciation in the mountain pine beetle. We find a broad continuum of intrinsic incompatibilities in hybrid males that increase in strength with geographic distance between reproductively isolated populations. This striking progression of reproductive isolation is coupled with extensive gene specialization, natural selection, and elevated genetic differentiation on both sex chromosomes. Closely related populations isolated by hybrid male sterility also show fixation of alternative neo-Y haplotypes that differ in structure and male-specific gene content. Our results suggest that neo-sex chromosome evolution can drive rapid functional divergence between closely related populations irrespective of ecological drivers of divergence.

Population Policies and Education: Exploring the Contradictions of Neo-Liberal Globalisation

ERIC Educational Resources Information Center

Bovill, Catherine; Leppard, Margaret

2006-01-01

The world is increasingly characterised by profound income, health and social inequalities (Appadurai, 2000). In recent decades development initiatives aimed at reducing these inequalities have been situated in a context of increasing globalisation with a dominant neo-liberal economic orthodoxy. This paper argues that neo-liberal globalisation…

Neo-sex chromosome inheritance across species in Silene hybrids.

PubMed

Weingartner, L A; Delph, L F

2014-07-01

Neo-sex chromosomes, which form through the major restructuring of ancestral sex chromosome systems, have evolved in various taxa. Such restructuring often consists of the fusion of an autosome to an existing sex chromosome, resulting in novel sex chromosome formations (e.g. X1X2Y or XY1Y2.). Comparative studies are often made between restructured sex chromosome systems of closely related species, and here we evaluate the consequences of variable sex chromosome systems to hybrids. If neo-sex chromosomes are improperly inherited across species, this could lead to aberrant development and reproductive isolation. In this study, we examine the fate of neo-sex chromosomes in hybrids of the flowering plants Silene diclinis and Silene latifolia. Silene diclinis has a neo-sex chromosome system (XY1Y2) that is thought to have evolved from an ancestral XY system that is still present in S. latifolia. These species do not hybridize naturally, and improper sex chromosome inheritance could contribute to reproductive isolation. We investigated whether this major restructuring of sex chromosomes prevents their proper inheritance in a variety of hybrid crosses, including some F2 - and later-generation hybrids, with sex chromosome-linked, species-specific, polymorphic markers and chromosome squashes. We discovered that despite the differences in sex chromosomes that exist between these two species, proper segregation had occurred in hybrids that made it to flowering, including later-generation hybrids, indicating that neo-sex chromosome formation alone does not result in complete reproductive isolation between these two species. Additionally, hybrids with aberrant sex expression (e.g. neuter, hermaphrodite) also inherited the restructured sex chromosomes properly, highlighting that issues with sexual development in hybrids can be caused by intrinsic genetic incompatibility rather than improper sex chromosome inheritance. © 2014 The Authors. Journal of Evolutionary Biology © 2014

Environmental Epigenetics and a Unified Theory of the Molecular Aspects of Evolution: A Neo-Lamarckian Concept that Facilitates Neo-Darwinian Evolution.

PubMed

Skinner, Michael K

2015-04-26

Environment has a critical role in the natural selection process for Darwinian evolution. The primary molecular component currently considered for neo-Darwinian evolution involves genetic alterations and random mutations that generate the phenotypic variation required for natural selection to act. The vast majority of environmental factors cannot directly alter DNA sequence. Epigenetic mechanisms directly regulate genetic processes and can be dramatically altered by environmental factors. Therefore, environmental epigenetics provides a molecular mechanism to directly alter phenotypic variation generationally. Lamarck proposed in 1802 the concept that environment can directly alter phenotype in a heritable manner. Environmental epigenetics and epigenetic transgenerational inheritance provide molecular mechanisms for this process. Therefore, environment can on a molecular level influence the phenotypic variation directly. The ability of environmental epigenetics to alter phenotypic and genotypic variation directly can significantly impact natural selection. Neo-Lamarckian concept can facilitate neo-Darwinian evolution. A unified theory of evolution is presented to describe the integration of environmental epigenetic and genetic aspects of evolution. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Histidine-decarboxylase knockout mice show deficient nonreinforced episodic object memory, improved negatively reinforced water-maze performance, and increased neo- and ventro-striatal dopamine turnover.

PubMed

Dere, Ekrem; De Souza-Silva, Maria A; Topic, Bianca; Spieler, Richard E; Haas, Helmut L; Huston, Joseph P

2003-01-01

The brain's histaminergic system has been implicated in hippocampal synaptic plasticity, learning, and memory, as well as brain reward and reinforcement. Our past pharmacological and lesion studies indicated that the brain's histamine system exerts inhibitory effects on the brain's reinforcement respective reward system reciprocal to mesolimbic dopamine systems, thereby modulating learning and memory performance. Given the close functional relationship between brain reinforcement and memory processes, the total disruption of brain histamine synthesis via genetic disruption of its synthesizing enzyme, histidine decarboxylase (HDC), in the mouse might have differential effects on learning dependent on the task-inherent reinforcement contingencies. Here, we investigated the effects of an HDC gene disruption in the mouse in a nonreinforced object exploration task and a negatively reinforced water-maze task as well as on neo- and ventro-striatal dopamine systems known to be involved in brain reward and reinforcement. Histidine decarboxylase knockout (HDC-KO) mice had higher dihydrophenylacetic acid concentrations and a higher dihydrophenylacetic acid/dopamine ratio in the neostriatum. In the ventral striatum, dihydrophenylacetic acid/dopamine and 3-methoxytyramine/dopamine ratios were higher in HDC-KO mice. Furthermore, the HDC-KO mice showed improved water-maze performance during both hidden and cued platform tasks, but deficient object discrimination based on temporal relationships. Our data imply that disruption of brain histamine synthesis can have both memory promoting and suppressive effects via distinct and independent mechanisms and further indicate that these opposed effects are related to the task-inherent reinforcement contingencies.

Characterizing Resident Space Object Earthshine Signature Variability

NASA Astrophysics Data System (ADS)

Van Cor, Jared D.

There are three major sources of illumination on objects in the near Earth space environment: Sunshine, Moonshine, and Earthshine. For objects in this environment (satellites, orbital debris, etc.) known as Resident Space Objects (RSOs), the sun and the moon have consistently small illuminating solid angles and can be treated as point sources; this makes their incident illumination easily modeled. The Earth on the other hand has a large illuminating solid angle, is heterogeneous, and is in a constant state of change. The objective of this thesis was to characterize the impact and variability of observed RSO Earthshine on apparent magnitude signatures in the visible optical spectral region. A key component of this research was creating Earth object models incorporating the reflectance properties of the Earth. Two Earth objects were created: a homogeneous diffuse Earth object and a time sensitive heterogeneous Earth object. The homogeneous diffuse Earth object has a reflectance equal to the average global albedo, a standard model used when modeling Earthshine. The time sensitive heterogeneous Earth object was created with two material maps representative of the dynamic reflectance of the surface of the earth, and a shell representative of the atmosphere. NASA's Moderate-resolution Imaging Spectroradiometer (MODIS) Earth observing satellite product libraries, MCD43C1 global surface BRDF map and MOD06 global fractional cloud map, were utilized to create the material maps, and a hybridized version of the Empirical Line Method (ELM) was used to create the atmosphere. This dynamic Earth object was validated by comparing simulated color imagery of the Earth to that taken by: NASAs Earth Polychromatic Imaging Camera (EPIC) located on the Deep Space Climate Observatory (DSCOVR), and by MODIS located on the Terra satellite. The time sensitive heterogeneous Earth object deviated from MODIS imagery by a spectral radiance root mean square error (RMSE) of +/-14.86 [watts/m. 2sr

Pedagogy of the Consumer: The Politics of Neo-Liberal Welfare Reform

ERIC Educational Resources Information Center

Wilkins, Andrew

2012-01-01

Situated against the backdrop of a widespread and growing interest in the linkages between neo-liberalism and welfare, this paper introduces the lens of neo-liberalism as a conceptual strategy for thinking about contemporary issues in education policy. Through charting the historic rise of unfettered market institutions and practices in the…

Education Policy as Proto-Fascism: The Aesthetics of Racial Neo-Liberalism

ERIC Educational Resources Information Center

Webb, P. Taylor; Gulson, Kalervo N.

2011-01-01

We argue that neo-liberal educational policy has emerged as a proto-fascist governmentality. This contemporary technology relies on State racisms and racial orderings manifested from earlier liberal and neo-liberal practices of biopower. As a proto-fascist technology, education policy, and school choice policies in particular, operate within a…

Neo-Racism and Neo-Nationalism within East Asia: The Experiences of International Students in South Korea

ERIC Educational Resources Information Center

Lee, Jenny; Jon, Jae-Eun; Byun, Kiyong

2017-01-01

This research, based in South Korea, compares the experiences of international students from within and outside the Asian region and then examines Chinese international students' perceptions of discrimination. Utilizing the concept of neo-nationalism, survey findings revealed that Asian students reported greater difficulties and unfair treatment…

Germline stem cells and neo-oogenesis in the adult human ovary.

PubMed

Liu, Yifei; Wu, Chao; Lyu, Qifeng; Yang, Dongzi; Albertini, David F; Keefe, David L; Liu, Lin

2007-06-01

It remains unclear whether neo-oogenesis occurs in postnatal ovaries of mammals, based on studies in mice. We thought to test whether adult human ovaries contain germline stem cells (GSCs) and undergo neo-oogenesis. Rather than using genetic manipulation which is unethical in humans, we took the approach of analyzing the expression of meiotic marker genes and genes for germ cell proliferation, which are required for neo-oogenesis, in adult human ovaries covering an age range from 28 to 53 years old, compared to testis and fetal ovaries served as positive controls. We show that active meiosis, neo-oogenesis and GSCs are unlikely to exist in normal, adult, human ovaries. No early meiotic-specific or oogenesis-associated mRNAs for SPO11, PRDM9, SCP1, TERT and NOBOX were detectable in adult human ovaries using RT-PCR, compared to fetal ovary and adult testis controls. These findings are further corroborated by the absence of early meiocytes and proliferating germ cells in adult human ovarian cortex probed with markers for meiosis (SCP3), oogonium (OCT3/4, c-KIT), and cell cycle progression (Ki-67, PCNA), in contrast to fetal ovary controls. If postnatal oogenesis is confirmed in mice, then this species would represent an exception to the rule that neo-oogenesis does not occur in adults.

Transformation of Neomycin Resistance Gene (neo(R)) into Silkworm (Bombyx mori.L.).

PubMed

Chen, Xiu; Zhao, Yun; Zhang, Feng; Peng, Wei-Ping; Feng, Xiao-Li; Huang, Jun-Ting; Lu, Chang-De

1999-01-01

Neomycin resistance gene (neo(R)) flanked by 5' and 3' regions of fibroin H-chain gene of silkworm (Bombyx mori.L.) was transferred into eggs of silkworm by gene gun in the early period of fertilization. The larvae were fed with an artificial diet containing neomycin in early 24 hours post transfettion, and some of them survived. The neo(R) encoding sequence in G(2) generation derived from the survivals was detected by Southern blotting. The results indicated that neo(R) could be used as a selective marker for studies on transgenic silkworm.

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

Mainzer, A.; Masiero, J.; Bauer, J.

Enhancements to the science data processing pipeline of NASA's Wide-field Infrared Survey Explorer (WISE) mission, collectively known as NEOWISE, resulted in the detection of >158,000 minor planets in four infrared wavelengths during the fully cryogenic portion of the mission. Following the depletion of its cryogen, NASA's Planetary Science Directorate funded a four-month extension to complete the survey of the inner edge of the Main Asteroid Belt and to detect and discover near-Earth objects (NEOs). This extended survey phase, known as the NEOWISE Post-Cryogenic Survey, resulted in the detection of {approx}6500 large Main Belt asteroids and 86 NEOs in its 3.4more » and 4.6 {mu}m channels. During the Post-Cryogenic Survey, NEOWISE discovered and detected a number of asteroids co-orbital with the Earth and Mars, including the first known Earth Trojan. We present preliminary thermal fits for these and other NEOs detected during the 3-Band Cryogenic and Post-Cryogenic Surveys.« less

The Impact Hazard

NASA Technical Reports Server (NTRS)

Morrison, David

1994-01-01

The Earth has been subject to hypervelocity impacts from comets and asteroids since its formation, and such impacts have played an important role in the evolution of life on our planet. We now recognize not only the historical role of impacts, but the contemporary hazard posed by such events. In the absence of a complete census of potentially threatening Earth-crossing asteroids or comets (called collectively Near Earth Objects, or NEOs), or even of a comprehensive cur-rent search program to identify NEOs, we can consider the hazard only from a probabilistic perspective. We know the steep power-law relationship between NEO numbers and size, with many more small bodies than large ones. We also know that few objects less than about 50 m in diameter (with kinetic energy near 10 megatons) penetrate the atmosphere and are capable of doing surface damage. But there is a spectrum of possible impact hazards associated with objects from this 10-megaton threshold all the way up to NEOs 5 km or larger in diameter, which are capable of inflicting severe damage on the environment, leading to mass extinction's of species. Detailed analysis has shown that, in general, the larger the object the greater the hazard, even when allowance is made for the infrequency of large impacts. Most of the danger to human life is associated with impacts by objects roughly 2 km or larger (energy greater than 1 million megatons), which can inject sufficient submicrometer dust into the atmosphere to produce a severe short-term global cooling with subsequent loss of crops, leading to starvation. Hazard estimates suggest that the chance of such an event occurring during a human lifetime is about 1:5000, and the global probability of death from such impacts is of the order of 1:20000, values that can be compared with risks associated with other natural hazards such as earthquakes, volcanic eruptions, and severe storms. However, the impact hazard differs from the others in that it can be largely

The Lifeworld Earth and a Modelled Earth

ERIC Educational Resources Information Center

Juuti, Kalle

2014-01-01

The goal of this paper is to study the question of whether a phenomenological view of the Earth could be empirically endorsed. The phenomenological way of thinking considers the Earth as a material entity, but not as an object as viewed in science. In the learning science tradition, tracking the process of the conceptual change of the shape of the…

Neo-Liberal Discourse in the Academy: The Forestalling of (Collective) Resistance

ERIC Educational Resources Information Center

Davies, Bronwyn; Petersen, Eva Bendix

2005-01-01

In this article we analyse the ways in which neo-liberalism is taken up in the discourses and practices of university life. In the "knowledge economy" it might be thought that intellectual work would flourish. Yet the neo-liberal technologies through which universities and individual academics are made into entrepreneurs and made "productive" are…

Conditions for double layers in the earth's magnetosphere and perhaps in other astrophysical objects

NASA Technical Reports Server (NTRS)

Lyons, L. R.

1987-01-01

It is suggested that the features which govern the formation of the double layers are: (1) the divergence of the magnetospheric electric field, (2) the ionospheric conductivity, and (3) the current-voltage characteristics of auroral magnetic field lines. Also considered are conditions in other astrophysical objects that could lead to the formation of DLs in a manner analogous to what occurs in the earth's auroral zones. It is noted that two processes can drive divergent Pedersen currents within a collisional conducting layer: (1) sheared plasma flow applied anywhere along the magnetic field lines connected to the conducting layer and (2) a neutral flow with shear within the conducting layer.

Neo-clerodane diterpenoids and phenylethanoid glycosides from Teucrium chamaedrys L.

PubMed

Bedir, Erdal; Manyam, Rangavalli; Khan, Ikhlas A

2003-08-01

A neo-clerodane type diterpenoid, 12(S)-15,16-epoxy-19-hydroxy-neo-cleroda-13(16),14-dien-18,6alpha:20,12-diolide, and two phenylethanoid glycosides, teucrioside-3(IIII)-O-methylether and teucrioside-3(IIII),4(IIII)-O-dimethylether were isolated from the aerial parts of Teucrium chamaedrys. Their structures were identified on the basis of extensive NMR spectra, LC-ESIMS analysis, and molecular modeling studies.

Near-Earth Asteroid Tracking with the Maui Space Surveillance System (NEAT/MSSS)

NASA Technical Reports Server (NTRS)

Helin, Eleanor F.; Pravdo, Steven H.; Lawrence, Kenneth J.; Hicks, Michael D.

2001-01-01

Over the last year the Jet Propulsion Laboratory's (JPL) Near-Earth Asteroid Tracking (NEAT) program has made significant progress and now consists of two simultaneously-operating, autonomous search systems on the 1.2-m (48") telescopes: on the Maui Space Surveillance System (NEAT/MSSS) and NEAT/Palomar on the Palomar Observatory's Oschin telescope. This paper will focus exclusively on the NEAT/MSSS system. NEAT/MSSS is operated as a partnership between NASA/JPL and the United States Air Force Research Laboratory (AFRL), utilizing the AFRL 1.2-m telescope on the 3000-m summit of Haleakala, Maui, The USAF Space Command (SPCMD) contributed financial support to build and install the 'NEAT focal reducer' on the MSSS 1.2-m telescope giving it a large field of view (2.5 square degrees), suitable for the near-earth object (NEO),both asteroids and comets, survey. This work was completed in February 2000. AFRL has made a commitment to NEAT/MSSS that allows NEAT to operate full time with the understanding that AFRL participate as partners in NEAT/MSSS and have use of the NEAT camera system for high priority satellite observations during bright time (parts of 12 nights each month). Currently, NEAT has discovered 42 NEAs including 12 larger than 1-km, 5 Potentially Hazardous Asteroids (PHAs), 6 comets, and nearly 25,000 asteroid detections since March 2000.

Higher Degree Research by Numbers: Beyond the Critiques of Neo-Liberalism

ERIC Educational Resources Information Center

Grealy, Liam; Laurie, Timothy

2017-01-01

This article argues that strong theories of neo-liberalism do not provide an adequate frame for understanding the ways that measurement practices come to be embedded in the life-worlds of those working in higher education. We argue that neo-liberal metrics need to be understood from the viewpoint of their social usage, alongside other practices of…

Low Openness on the Revised NEO Personality Inventory as a Risk Factor for Treatment-Resistant Depression

PubMed Central

Takahashi, Michio; Shirayama, Yukihiko; Muneoka, Katsumasa; Suzuki, Masatoshi; Sato, Koichi; Hashimoto, Kenji

2013-01-01

Background Recently, we reported that low reward dependence, and to a lesser extent, low cooperativeness in the Temperature and Character Inventory (TCI) may be risk factors for treatment-resistant depression. Here, we analyzed additional psychological traits in these patients. Methods We administered Costa and McCrae's five-factor model personality inventory, NEO Personality Inventory-Revised (NEO-PI-R), to antidepressant-treatment resistant depressed patients (n = 35), remitted depressed patients (n = 27), and healthy controls (n = 66). We also evaluated the relationships between scores on NEO and TCI, using the same cohort of patients with treatment-resistant depression, as our previous study. Results Patients with treatment-resistant depression showed high scores for neuroticism, low scores for extraversion, openness and conscientiousness, without changes in agreeableness, on the NEO. However, patients in remitted depression showed no significant scores on NEO. Patients with treatment-resistant depression and low openness on NEO showed positive relationships with reward dependence and cooperativeness on the TCI. Conclusions Many studies have reported that depressed patients show high neuroticism, low extraversion and low conscientiousness on the NEO. Our study highlights low openness on the NEO, as a risk mediator in treatment-resistant depression. This newly identified trait should be included as a risk factor in treatment-resistant depression. PMID:24019864

Low openness on the revised NEO personality inventory as a risk factor for treatment-resistant depression.

PubMed

Takahashi, Michio; Shirayama, Yukihiko; Muneoka, Katsumasa; Suzuki, Masatoshi; Sato, Koichi; Hashimoto, Kenji

2013-01-01

Recently, we reported that low reward dependence, and to a lesser extent, low cooperativeness in the Temperature and Character Inventory (TCI) may be risk factors for treatment-resistant depression. Here, we analyzed additional psychological traits in these patients. We administered Costa and McCrae's five-factor model personality inventory, NEO Personality Inventory-Revised (NEO-PI-R), to antidepressant-treatment resistant depressed patients (n=35), remitted depressed patients (n=27), and healthy controls (n=66). We also evaluated the relationships between scores on NEO and TCI, using the same cohort of patients with treatment-resistant depression, as our previous study. Patients with treatment-resistant depression showed high scores for neuroticism, low scores for extraversion, openness and conscientiousness, without changes in agreeableness, on the NEO. However, patients in remitted depression showed no significant scores on NEO. Patients with treatment-resistant depression and low openness on NEO showed positive relationships with reward dependence and cooperativeness on the TCI. Many studies have reported that depressed patients show high neuroticism, low extraversion and low conscientiousness on the NEO. Our study highlights low openness on the NEO, as a risk mediator in treatment-resistant depression. This newly identified trait should be included as a risk factor in treatment-resistant depression.

Assessing the Five Factors of Personality in Adolescents: The Junior Version of the Spanish NEO-PI-R

ERIC Educational Resources Information Center

Ortet, Generos; Ibanez, Manuel I.; Moya, Jorge; Villa, Helena; Viruela, Ana; Mezquita, Laura

2012-01-01

This article presents the development of a junior version of the Spanish (Castilian) NEO Personality Inventory-Revised (JS NEO) suitable for adolescents aged 12 to 18 years. The psychometric properties of the new JS NEO were investigated using two samples of 2,733 and 983 adolescents in Spain. The results showed that the adult NEO-PI-R factor…

A state of limbo: the politics of waiting in neo-liberal Latvia.

PubMed

Ozoliņa-Fitzgerald, Liene

2016-09-01

This article presents an ethnographic study of politics of waiting in a post-Soviet context. While activation has been explored in sociological and anthropological literature as a neo-liberal governmental technology and its application in post-socialist context has also been compellingly documented, waiting as a political artefact has only recently been receiving increased scholarly attention. Drawing on ethnographic fieldwork at a state-run unemployment office in Riga, this article shows how, alongside activation, state welfare policies also produce passivity and waiting. Engaging with the small but developing field of sociological literature on the politics of waiting, I argue that, rather than interpreting it as a clash between 'neo-liberal' and 'Soviet' regimes, we should understand the double-move of activation and imposition of waiting as a key mechanism of neo-liberal biopolitics. This article thus extends the existing theorizations of the temporal politics of neo-liberalism. © London School of Economics and Political Science 2016.

[The relationship between acupuncture-moxibustion theory of DOU Hanqing and Neo- Confucianism].

PubMed

Li, Baojin; Huang, Longxiang

2018-02-12

For the construction factors of acupuncture-moxibustion theory of DOU Hanqing , a doctor in Jin-Yuan Dynasty, we studied his life, acupuncture-moxibustion theory and culture background in the History of Medicine and Philosophy of Science & Technology. It was found that the major source of DOU Hanqing ' s Confucianism was the CHENG - ZHU Neo-Confucianism. The data show that Neo-Confucianism played an important role in the enrichment of his human nature, spirit, moral cultivation and political talent, making him a scholar in the Jin - Yuan dynasty, also shaping his medical ethics, medical skill and acupuncture-moxibustion theory. The inheritance, development and application of CHENG - ZHU Neo-Confucianism provided the most fundamental thinking, research methods and patterns for DOU Hanqing to interpret the acupuncture classics, summarize his teachers' experience and develop his theoretical system. DOU Hanqing ' s acupuncture-moxibustion practice and theory reached a new level, because he took acupuncture-moxibustion as one of the knowledge investigation and attainment of CHENG - ZHU Neo-Confucianism.

Soul man meets the blind watchmaker: C.G. Jung and neo-Darwinism.

PubMed

Pietikainen, Petteri

2003-01-01

C.G. Jung's name has recently been connected with neo-Darwinian theories. One major reason for this connection is that Jungian psychology is based on the suggestion that there exists a universal structure of the mind that has its own evolutionary history. On this crucial point, Jungians and neo-Darwinian evolutionary psychologists agree. However, it will be argued in this paper that, although Jungian psychology opposes the "tabula rasa" doctrine (mind as a blank state), Jung cannot be regarded as the founding father of evolutionary psychology. From the scientific perspective, Jung's biological assumptions are simply untenable and have been for many decades. In his attempt to fuse biology, spirit, and the unconscious, Jung ended in speculative flights of imagination that bear no resemblance to modern neo-Darwinian theories. The premise of the paper is that, when Jungian psychology is presented to us as a scientific psychology that has implications for the development of neo-Darwinian psychology, we should be on guard and examine the evidence.

Space Object Query Tool

NASA Technical Reports Server (NTRS)

Phillips, Veronica J.

2017-01-01

STI is for a fact sheet on the Space Object Query Tool being created by the MDC. When planning launches, NASA must first factor in the tens of thousands of objects already in orbit around the Earth. The number of human-made objects, including nonfunctional spacecraft, abandoned launch vehicle stages, mission-related debris and fragmentation debris orbiting Earth has grown steadily since Sputnik 1 was launched in 1957. Currently, the U.S. Department of Defenses Joint Space Operations Center, or JSpOC, tracks over 15,000 distinct objects and provides data for more than 40,000 objects via its Space-Track program, found at space-track.org.

Spacewatch discovery of near-Earth asteroids

NASA Technical Reports Server (NTRS)

Gehrels, Tom

1992-01-01

Our overall scientific goal is to survey the solar system to completion - that is, to find the various populations and to study their statistics, interrelations, and origins. The practical benefit to SERC is that we are finding Earth-approaching asteroids that are accessible for mining. Our system can detect Earth-approachers in the 1-km size range even when they are far away, and can detect smaller objects when they are moving rapidly past Earth. Until Spacewatch, the size range of 6-300 meters in diameter for the near-Earth asteroids was unexplored. This important region represents the transition between the meteorites and the larger observed near-Earth asteroids. One of our Spacewatch discoveries, 1991 VG, may be representative of a new orbital class of object. If it is really a natural object, and not man-made, its orbital parameters are closer to those of the Earth than we have seen before; its delta V is the lowest of all objects known thus far. We may expect new discoveries as we continue our surveying, with fine-tuning of the techniques.

Neo-liberal economic practices and population health: a cross-national analysis, 1980-2004.

PubMed

Tracy, Melissa; Kruk, Margaret E; Harper, Christine; Galea, Sandro

2010-04-01

Although there has been substantial debate and research concerning the economic impact of neo-liberal practices, there is a paucity of research about the potential relation between neo-liberal economic practices and population health. We assessed the extent to which neo-liberal policies and practices are associated with population health at the national level. We collected data on 119 countries between 1980 and 2004. We measured neo-liberalism using the Fraser Institute's Economic Freedom of the World (EFW) Index, which gives an overall score as well as a score for each of five different aspects of neo-liberal economic practices: (1) size of government, (2) legal structure and security of property rights, (3) access to sound money, (4) freedom to exchange with foreigners and (5) regulation of credit, labor and business. Our measure of population health was under-five mortality. We controlled for potential mediators (income distribution, social capital and openness of political institutions) and confounders (female literacy, total population, rural population, fertility, gross domestic product per capita and time period). In longitudinal multivariable analyses, we found that the EFW index did not have an effect on child mortality but that two of its components: improved security of property rights and access to sound money were associated with lower under-five mortality (p = 0.017 and p = 0.024, respectively). When stratifying the countries by level of income, less regulation of credit, labor and business was associated with lower under-five mortality in high-income countries (p = 0.001). None of the EFW components were significantly associated with under-five mortality in low-income countries. This analysis suggests that the concept of 'neo-liberalism' is not a monolithic entity in its relation to health and that some 'neo-liberal' policies are consistent with improved population health. Further work is needed to corroborate or refute these findings.

NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos

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

Masiero, Joseph R.; Mainzer, A. K.; Kramer, E.

The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) reactivation mission has completed its third year of surveying the sky in the thermal infrared for near-Earth asteroids and comets. NEOWISE collects simultaneous observations at 3.4 and 4.6  μ m of solar system objects passing through its field of regard. These data allow for the determination of total thermal emission from bodies in the inner solar system, and thus the sizes of these objects. In this paper, we present thermal model fits of asteroid diameters for 170 NEOs and 6110 Main Belt asteroids (MBAs) detected during the third year of the survey,more » as well as the associated optical geometric albedos. We compare our results with previous thermal model results from NEOWISE for overlapping sample sets, as well as diameters determined through other independent methods, and find that our diameter measurements for NEOs agree to within 26% (1 σ ) of previously measured values. Diameters for the MBAs are within 17% (1 σ ). This brings the total number of unique near-Earth objects characterized by the NEOWISE survey to 541, surpassing the number observed during the fully cryogenic mission in 2010.« less

Preoperative neo-adjuvant therapy for curable rectal cancer--reaching a consensus 2008.

PubMed

Scott, N A; Susnerwala, S; Gollins, S; Myint, A Sun; Levine, E

2009-03-01

Our aim was to determine the range of neo-adjuvant therapy the multidisciplinary team (MDT) currently offers patients with curable (M(0)) rectal cancer. A senior oncologist from each of the four oncology centres in north Wales and the north-west of England (approximate target population 8 million - Glan Clwyd, Clatterbridge, Christie and Preston) reviewed his/her understanding of the current evidence of neo-adjuvant therapy in rectal cancer. Then a representative from each centre was asked to identify which of three neo-adjuvant options (no neo-adjuvant therapy, short-course radiotherapy 25 Gy over five fractions and long-course chemoradiotherapy) he/she would use for a rectal cancer in the upper, middle or lower third of the rectum staged by magnetic resonance imaging as being T(2)-T(4) and/or N(0)-N(2). In all cases of locally advanced rectal cancer (T(3a) N(1)-T(4)), oncologists from the four oncology centres recommended long-course chemoradiotherapy before rectal resection. This consensus was maintained for cases of lower third T(3a) N(0) cancers. Thereafter, the majority of patients with rectal cancer are offered adjuvant short-course radiotherapy. Neo-adjuvant therapy is less likely to be offered if the tumour is early (T(2), N(0)) and/or situated in the upper third of the rectum.

Transnational pharmaceutical corporations and neo-liberal business ethics in India.

PubMed

D'Mello, Bernard

2002-03-01

The author critiques the expedient application of market valuation principles by the transnational corporations and other large firms in the Indian pharmaceutical industry on a number of issues like patents, pricing, irrational drugs, clinical trials, etc. He contends that ethics in business is chiseled and etched within the confines of particular social structures of accumulation. An ascendant neo-liberal social structure of accumulation has basically shaped these firms' sharp opposition to the Indian Patents Act, 1970, government administered pricing, etc. The author contents that the practice of neo-liberal economics is strongly associated with a "one-dimensional" ethics that privileges market valuation principles over all others. This seems to inevitably generate a social counter-movement that struggles for social protections. He critiques neo-liberal business practices from a perspective that derives from the work of the economic anthropologist Karl Polanyi. Before the present phase of liberalization in India, markets were "managed", but without a "welfare state" in place. Moving toward deregulation of the markets without a welfare state in place is unethical. Keeping the debilities of the institutional framework of public policy in mind, the author adopts a Polanyian perspective that places its trust and hope in the growing social legitimacy of the counter-movement in opposition to both neo-liberal business practices and the degenerate behavior of state agencies.

Aesthetic neo-glans reconstruction after penis-sparing surgery for benign, premalignant or malignant penile lesions

PubMed Central

Palminteri, Enzo; Fusco, Fernando; Berdondini, Elisa; Salonia, Andrea

2011-01-01

Purpose To describe the technique and results of penis-sparing surgery combined with a cosmetic neo-glans reconstruction for benign, pre-malignant or malignant penile lesions. Patients and methods Twenty-one patients (mean age 61 years) with penile lesions with a broad spectrum of histopathology underwent organ-sparing surgery with neo-glans reconstruction, using a free split-thickness skin graft harvested from the thigh. Three patients were treated by glans-skinning and glans-resurfacing, 10 by glansectomy and neo-glans reconstruction, four by partial penectomy and a neo-glans reconstruction, and four by neo-glans reconstruction after a traditional partial penectomy. Results The mean follow-up was 45 months; all patients were free of primary local disease. All patients were satisfied with the appearance of the penis after surgery, and recovered their sexual ability, although sensitivity was reduced as a consequence of glans/penile amputation. Conclusion In benign, premalignant or malignant penile lesions, penis-sparing surgery combined with a cosmetic neo-glans reconstruction can be used to assure a normally appearing and functional penis, while fully eradicating the primary local disease. PMID:26579279

Neo-Industrial and Sustainable Development of Russia as Mineral Resources Exploiting Country

NASA Astrophysics Data System (ADS)

Prokudina, Marina; Zhironkina, Olga; Kalinina, Oksana; Gasanov, Magerram; Agafonov, Felix

2017-11-01

In the Russian economy, the world leadership in the extraction of different mineral resources is combined with the potential for their processing and a significant scientific sector. Innovative development of raw materials extraction is impossible without the parallel technological modernization of the high-tech sector. In general, the complex of these processes is a neo-industrialization of the economy. Neo-industrially oriented transformation of the economy reflects complex changes in its structure, the transformation of established stable relationships between various elements of the system of social production that determine macroeconomic proportions. Neo-industrial transformations come along with the modification of economic relations associated with investments, innovations, labor and income distribution, with the process of locating productive forces and regulating the economy by the government. Neo-industrialization of economy is not only significant changes in its technological and reproductive structure (the development of high-tech industries, the integration of science and industry), but, above all, the implementation of a system structural policy of innovative development of raw material industry and the recovery of manufacturing industries on a new technological basis.

Automatic detection of asteroids by 16" and 41" telescopes at the SFA Observatory

NASA Astrophysics Data System (ADS)

Fuls, David Carson

2015-05-01

Major upgrades were carried out to the hardware and software of the 16-inch and 41-inch telescopes at the Stephen F. Austin State University Observatory. These upgrades allow remote operation of both telescopes and are specifically designed to enhance the amount of time the telescopes are looking for Near Earth Objects (NEO's). This ability was tested by obtaining images and astrometry data remotely from both telescopes of target NEO's which required follow-up observation.

Migration and hypertension: a cross-sectional study among neo-migrants and settled-migrants in Delhi, India.

PubMed

Kusuma, Yadlapalli; Gupta, Sanjeev; Pandav, Chandrakant

2009-10-01

Understanding the blood pressure (BP) distribution within populations is fundamental to an understanding of the etiology of cardiovascular diseases and to develop effective preventive strategies. This study focuses on whether the BP levels and hypertension prevalence differ between neo-migrants and settled-migrants in the city of Delhi. Data on BP, anthropometry, social variables, and demographic variables were collected from a cross-sectional sample of 226 settled-migrants and 227 neo-migrants. Men possessed significantly higher BP levels than women. Settled-migrants possessed higher BP levels, except diastolic BP in males. The prevalence of hypertension ranges from 15% (neo-migrant women) to 25% (settled-migrant men), with no significant gender differences. Group differences were significant for men. Hypertension was more prevalent in older settled-migrants and younger neo-migrants. Recent migration was found to be a significant contributor to hypertension prevalence. Age contributed significantly to BP variation in both groups except in neo-migrant men. Pulse rate also contributed to systolic BP among neo-migrant women and settled-migrant men. Thus, urban residence and migration to urban areas can be a leading cause of increased prevalence of hypertension. Neo-migrants were subjected to more lifestyle insults and the stress generated during the adjustment process may be contributing to rise of BP even at younger ages.

Radar investigations of near-Earth asteroids at Arecibo and Goldstone

NASA Astrophysics Data System (ADS)

Brozovic, M.; Nolan, M.; Benner, L.; Busch, M.; Howell, E.; Taylor, P.; Springmann, A.; Giorgini, J.; Margot, J.; Magri, C.; Sheppard, M.; Naidu, S.

2014-07-01

Radar observations are a powerful technique to study near-Earth asteroids (NEAs). The Arecibo and Goldstone planetary radars can provide delay-Doppler images that can directly resolve surface features such as concavities, hills, ridges, and boulders. Goldstone's 3.75-m resolution capability is invaluable when attempting to image NEAs with diameters smaller than 50 m. To date, over 430 near-Earth asteroids and 136 main-belt asteroids have been observed with radar. 80 % of the radar-detected NEAs have been observed within the last 10 years. The radar detection rate in the last three years has tripled relative to the average in the previous decade due to an increase in funding and greater scheduling flexibility. Currently, ˜400 observing hours per year at Goldstone and ˜600 observing hours per year at Arecibo are devoted to observing asteroids. We strive to observe all strong and moderately strong imaging targets, Yarkovsky drift candidates, NEOWISE targets, asteroids with very low perihelia that can be used to measure solar oblateness, and as many other detectable asteroids as resources allow. We also regularly attempt to observe any asteroid that is flagged by the Near-Earth Object Human Spaceflight Accessible Targets Study (NHATS) list (http://neo.jpl.nasa.gov/nhats/). To date, we have observed more than 60 NHATS objects at Arecibo and Goldstone. In the past three years, ˜1/3 of the detected asteroids were targets of opportunity (TOOs), some of which we observed within 24 h from when the discoveries were announced. Many TOOs are small, rapidly moving objects that are detectable by radar only within few lunar distances. Radar astrometry is particularly important for these asteroids because they are too faint to be followed for long with optical telescopes. A radar-range measurement often secures their orbit for decades or centuries, where otherwise the object would be lost and require rediscovery. In one of the extreme cases, two delay and two Doppler

Large Bodies Associated with Meteoroid Streams

NASA Technical Reports Server (NTRS)

Badadzhanov, P. B.; William, I. P.; Kokhirova, G. I.

2011-01-01

It is now accepted that some near-Earth objects (NEOs) may be dormant or dead comets. One strong indicator of cometary nature is the existence of an associated meteoroid stream with its consequently observed meteor showers. The complexes of NEOs which have very similar orbits and a likely common progenitor have been identified. The theoretical parameters for any meteor shower that may be associated with these complexes were calculated. As a result of a search of existing catalogues of meteor showers, activity has been observed corresponding to each of the theoretically predicted showers was found. We conclude that these asteroid-meteoroid complexes of four NEOs moving within the Piscids stream, three NEOs moving within the Iota Aquariids stream, and six new NEOs added to the Taurid complex are the result of a cometary break-up.

Comprehensive primary health care under neo-liberalism in Australia.

PubMed

Baum, Fran; Freeman, Toby; Sanders, David; Labonté, Ronald; Lawless, Angela; Javanparast, Sara

2016-11-01

This paper applies a critical analysis of the impact of neo-liberal driven management reform to examine changes in Australian primary health care (PHC) services over five years. The implementation of comprehensive approaches to primary health care (PHC) in seven services: five state-managed and two non-government organisations (NGOs) was tracked from 2009 to 2014. Two questions are addressed: 1) How did the ability of Australian PHC services to implement comprehensive PHC change over the period 2009-2014? 2) To what extent is the ability of the PHC services to implement comprehensive PHC shaped by neo-liberal health sector reform processes? The study reports on detailed tracking and observations of the changes and in-depth interviews with 63 health service managers and practitioners, and regional and central health executives. The documented changes were: in the state-managed services (although not the NGOs) less comprehensive service coverage and more focus on clinical services and integration with hospitals and much less development activity including community development, advocacy, intersectoral collaboration and attention to the social determinants. These changes were found to be associated with practices typical of neo-liberal health sector reform: considerable uncertainty, more directive managerial control, budget reductions and competitive tendering and an emphasis on outputs rather than health outcomes. We conclude that a focus on clinical service provision, while highly compatible with neo-liberal reforms, will not on its own produce the shifts in population disease patterns that would be required to reduce demand for health services and promote health. Comprehensive PHC is much better suited to that task. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Neo-sex Chromosomes in the Monarch Butterfly, Danaus plexippus

PubMed Central

Mongue, Andrew J.; Nguyen, Petr; Voleníková, Anna; Walters, James R.

2017-01-01

We report the discovery of a neo-sex chromosome in the monarch butterfly, Danaus plexippus, and several of its close relatives. Z-linked scaffolds in the D. plexippus genome assembly were identified via sex-specific differences in Illumina sequencing coverage. Additionally, a majority of the D. plexippus genome assembly was assigned to chromosomes based on counts of one-to-one orthologs relative to the butterfly Melitaea cinxia (with replication using two other lepidopteran species), in which genome scaffolds have been mapped to linkage groups. Sequencing coverage-based assessments of Z linkage combined with homology-based chromosomal assignments provided strong evidence for a Z-autosome fusion in the Danaus lineage, involving the autosome homologous to chromosome 21 in M. cinxia. Coverage analysis also identified three notable assembly errors resulting in chimeric Z-autosome scaffolds. Cytogenetic analysis further revealed a large W chromosome that is partially euchromatic, consistent with being a neo-W chromosome. The discovery of a neo-Z and the provisional assignment of chromosome linkage for >90% of D. plexippus genes lays the foundation for novel insights concerning sex chromosome evolution in this female-heterogametic model species for functional and evolutionary genomics. PMID:28839116

The future of planetary defense

NASA Astrophysics Data System (ADS)

Mainzer, A.

2017-04-01

Asteroids and comets have impacted Earth in the past and will do so in the future. While the frequency of impacts is reasonably well understood on geologic timescales, it is difficult to predict the next sizeable impact on human timescales by extrapolation from population statistics alone. Fortunately, by identifying and tracking individual objects, we can make precise predictions of any potential close encounters with Earth. As more advance notice is provided, the range of possible mitigation options expands. While the chance of an impact is very small, the potential consequences can be severe, meaning that sensible risk reduction measures should be undertaken. By implementing surveys, the risk of an unforeseen impact can be greatly reduced: the first step is finding the objects. Fortunately, the worldwide community of professional and amateur astronomers has made significant progress in discovering large near-Earth objects (NEOs). More than 95% of NEOs capable of causing global devastation (objects larger than 1 km in diameter) have been discovered, and none of these pose an impact hazard in the near future. Infrastructure is in place to link observations and compute close approaches in real time. Interagency and international collaborations have been undertaken to strengthen cooperative efforts to plan potential mitigation and civil defense campaigns. Yet much remains to be done. Approximately 70% of NEOs larger than 140 m (large enough to cause severe regional damage) remain undiscovered. With the existing surveys, it will take decades to identify the rest. Progress can be accelerated by undertaking new surveys with improved sensitivity.