1.
Kepler Data Validation I: Architecture, Diagnostic Tests, and Data Products for Vetting Transiting Planet Candidates
Document ID: 20180001990
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Author: Twicken, Joseph D.; Catanzarite, Joseph H.; Clarke, Bruce D.; Giroud, Forrest; Jenkins, Jon M.; Klaus, Todd C.; Li, Jie; McCauliff, Sean D.; Seader, Shawn E.; Tennenbaum, Peter;
Wohler, Bill; Bryson, Stephen T.; Burke, Christopher P.; Caldwell, Douglas A.; Haas, Michael R.; Henze, Christopher E.; Sanderfer, Dwight T.
Abstract: The Kepler Mission was designed to identify and characterize transiting planets in the Kepler Field
of View and to determine their occurrence rates. Emphasis was placed on identification of Earth-size planets orbiting in the Habitable Zone of their host stars. Science data were acquired for a period of four years. Long-cadence data with 29.4 min sampling were obtained for approx. 200,000 individual stellar targets in at least one observing quarter in the primary Kepler Mission. Light curves for target stars are extracted in the Kepler Science Data Processing Pipeline, and are searched for transiting planet signatures. A Threshold Crossing Event is generated in the transit search for targets where the transit detection threshold is exceeded and transit consistency checks are satisfied. These targets are subjected to further scrutiny in the Data Validation (DV) component of the Pipeline. Transiting planet candidates are characterized in DV, and light curves are searched for additional planets after transit signatures are modeled and removed. A suite of diagnostic tests is performed on all candidates to aid in discrimination between genuine transiting planets and instrumental or astrophysical false positives. Data products are generated per target and planet candidate to document and display transiting planet model fit and diagnostic test results. These products are exported to the Exoplanet Archive at the NASA Exoplanet Science Institute, and are available to the community. We describe the DV architecture and diagnostic tests, and provide a brief overview of the data products. Transiting planet modeling and the search for multiple planets on individual targets are described in a companion paper. The final revision of the Kepler Pipeline code base is available to the general public through GitHub. The Kepler Pipeline has also been modified to support the Transiting Exoplanet Survey Satellite (TESS) Mission which is expected to commence in 2018.
Publication Year: 2018
Document Type: Preprint
Report/Patent Number: ARC-E-DAA-TN53613
Date Acquired: Apr 23, 2018
2.
Fermi GBM Team Update
Document ID: 20180002194
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Author: Kocevski, Daniel
Abstract: No abstract available
Publication Year: 2018
Document Type: Oral/Visual Presentation
Report/Patent Number: MSFC-E-DAA-TN53464
Date Acquired: Apr 23, 2018
3.
Vascular Patterning for Research Discovery and Technology Development
Document ID: 20180001991
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Author: Parsons-Wingerter, Patricia A.
Abstract: No abstract available
Publication Year: 2018
Document Type: Oral/Visual Presentation
Report/Patent Number: ARC-E-DAA-TN53303
Date Acquired: Apr 23, 2018
4.
NASA Guidelines for Promoting Scientific and Research Integrity
Document ID: 20170011156
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Author: Kaminski, Amy P.; Neogi, Natasha A.
Abstract: This guidebook provides an overarching summary of existing policies, activities, and guiding
principles for scientific and research integrity with which NASA's workforce and affiliates must conform. This document addresses NASA's obligations as both a research institution and as a funder of research, NASA's use of federal advisory committees, NASA's public communication of research results, and professional development of NASA's workforce. This guidebook is intended to provide a single resource for NASA researchers, NASA research program administrators and project managers, external entities who do or might receive funding from NASA for research or technical projects, evaluators of NASA research proposals, NASA advisory committee members, NASA communications specialists, and members of the general public so that they can understand NASA's commitment to and expectations for scientific and integrity across the agency.
Publication Year: 2017
Document Type: Technical Report
Report/Patent Number: NASA/SP-2017-371, HQ-E-DAA-TN48714
Date Acquired: Apr 23, 2018
5.
Benefits and Pitfalls of GRACE Terrestrial Water Storage Data Assimilation
Document ID: 20180002203
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Author: Girotto, Manuela
Abstract: Satellite observations of terrestrial water storage (TWS) from the Gravity Recovery and Climate
Experiment (GRACE) mission have a coarse resolution in time (monthly) and space (roughly 150,000 sq km at midlatitudes) and vertically integrate all water storage components over land, including soil moisture and groundwater. Nonetheless, data assimilation can be used to horizontally downscale and vertically partition GRACE-TWS observations. This presentation illustrates some of the benefits and drawbacks of assimilating TWS observations from GRACE into a land surface model over the continental United States and India. The assimilation scheme yields improved skill metrics for groundwater compared to the no-assimilation simulations. A smaller impact is seen for surface and root-zone soil moisture. Further, GRACE observes TWS depletion associated with anthropogenic groundwater extraction. Results from the assimilation emphasize the importance of representing anthropogenic processes in land surface modeling and data assimilation systems.
Publication Year: 2018
Document Type: Oral/Visual Presentation
Report/Patent Number: GSFC-E-DAA-TN54578
Date Acquired: Apr 23, 2018
6.
Post-Formation Sodium Loss on the Moon: A Bulk Estimate
Document ID: 20180001993
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Author: Saxena, P.; Killen, R. M.; Airapetian, V.; Petro, N. E.; Mandell, A. M.
Abstract: The Moon and Earth are generally similar in terms of composition, but there exist variations in the
abundance of certain elements among the two bodies. These differences are a likely consequence of differing physical evolution of the two bodies over the solar system's history. While previous works have assumed this may be due to conditions during the Moonâ€"TM"s formation, we explore the likelihood that the observed depletion in Sodium in lunar samples may be partially due to post-formation mechanisms. Solar effects, loss from a primordial atmosphere and impacts are some of the dominant post-formation mechanisms that we examine. We describe how our past and current modeling efforts indicate that a significant fraction of the observed depletion of sodium in lunar samples relative to a bulk silicate earth composition may have been due to solar activity, atmospheric loss and impacts. Using profiles of sodium abundances from lunar crustal samples may thus serve as a powerful tool towards exploring conditions on the Moon's surface throughout solar system history. Conditions on the Moon immediately after formation may still be recorded in the lunar crust and may provide a window towards interpreting observations from some of the first rocky exoplanets that will be most amenable to characterization. Potential spatial variation of sodium in the lunar crust may be a relevant consideration for future sample return efforts. Sodium Depletion in the Lunar Crust: Lunar
Publication Year: 2018
Document Type: Conference Paper
Report/Patent Number: GSFC-E-DAA-TN53687
Date Acquired: Apr 23, 2018
7.
Effects of Surface BRDF on the OMI Cloud and NO2 Retrievals: A New Approach Based on Geometry-Dependent Lambertian Equivalent Reflectivity (GLER) Derived from MODIS
Document ID: 20180002222
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Author: Vasilkov, Alexander; Qin, Wenhan; Krotkov, Nickolay; Lamsal, Lok; Spurr, Robert; Haffner, David; Joiner, Joanna; Yang, Eun-Su; Marchenko, Sergey
Abstract: The Ozone Monitoring Instrument (OMI) cloud and NO2 algorithms use a monthly gridded surface
reflectivity climatology that does not depend upon the observation geometry. In reality, reflection of incoming direct and diffuse solar light from land or ocean surfaces is sensitive to the sun sensor geometry. This dependence is described by the bidirectional reflectance distribution function (BRDF). To account for the BRDF, we propose to use a new concept of geometry-dependent Lambertian equivalent reflectivity (GLER). Implementation within the existing OMI cloud and NO2 retrieval infrastructure requires changes only to the input surface reflectivity database. GLER is calculated using a vector radiative transfer model with high spatial resolution BRDF information from MODIS over land and the Cox Munk slope distribution over ocean with a contribution from water-leaving radiance. We compare GLER and climatological LER at 466 nm, which is used in the OMI O2-O2cloud algorithm to derive effective cloud fractions. A detailed comparison of the cloud fractions and pressures derived with climatological and GLERs is carried out. GLER and corresponding retrieved cloud products are then used as input to the OMI NO2 algorithm. We find that replacing the climatological OMI-based LERs with GLERs can increase NO2 vertical columns by up to 50 % in highly polluted areas; the differences include both BRDF effects and biases between the MODIS and OMI-based surface reflectance data sets. Only minor changes to NO2 columns (within 5 %) are found over unpolluted and overcast areas.
Publication Year: 2017
Document Type: Oral/Visual Presentation
Report/Patent Number: GSFC-E-DAA-TN54866
Date Acquired: Apr 23, 2018
8.
Extraction of Water from Martian Regolith Simulant via Open Reactor Concept
Document ID: 20180002377
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Author: Trunek, Andrew J.; Linne, Diane L.; Kleinhenz, Julie E.; Bauman, Steven W.
Abstract: To demonstrate proof of concept water extraction from simulated Martian regolith, an open reactor
design is presented along with experimental results. The open reactor concept avoids sealing surfaces and complex moving parts. In an abrasive environment like the Martian surface, those reactor elements would be difficult to maintain and present a high probability of failure. A general lunar geotechnical simulant was modified by adding borax decahydrate (Na2B4O7·10H2O) (BDH) to mimic the 3 percent water content of hydrated salts in near surface soils on Mars. A rotating bucket wheel excavated the regolith from a source bin and deposited the material onto an inclined copper tray, which was fitted with heaters and a simple vibration system. The combination of vibration, tilt angle and heat was used to separate and expose as much regolith surface area as possible to liberate the water contained in the hydrated minerals, thereby increasing the efficiency of the system. The experiment was conducted in a vacuum system capable of maintaining a Martian like atmosphere. Evolved water vapor was directed to a condensing system using the ambient atmosphere as a sweep gas. The water vapor was condensed and measured. Processed simulant was captured in a collection bin and weighed in real time. The efficiency of the system was determined by comparing pre- and post-processing soil mass along with the volume of water captured.
Publication Year: 2018
Document Type: Conference Paper
Report/Patent Number: GRC-E-DAA-TN46578
Date Acquired: Apr 23, 2018
9.
Simple Ion Channels: From Structure to Electrophysiology and Back
Document ID: 20180002151
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Author: Pohorille, Andrzej
Abstract: A reliable way to establish whether our understanding of a channel is satisfactory is to reproduce
its measured ionic conductance over a broad range of applied voltages in computer simulations. In molecular dynamics (MD), this can be done by way of applying an external electric field to the system and counting the number of ions that traverse the channel per unit time. Since this approach is computationally very expensive, we have developed a markedly more efficient alternative in which MD is combined with the electrodiffusion (ED) equation. In this approach, the assumptions of the ED equation can be rigorously tested, and the precision and consistency of the calculated conductance can be determined. We have demonstrated that the full current/voltage dependence and the underlying free energy profile for a simple channel can be reliably calculated from equilibrium or non-equilibrium MD simulations at a single voltage. To carry out MD simulations, a structural model of a channel has to be assumed, which is an important constraint, considering that high-resolution structures are available for only very few simple channels. If the comparison of calculated ionic conductance with electrophysiological data is satisfactory, it greatly increases our confidence that the structure and the function are described sufficiently accurately. We examined the validity of the ED for several channels embedded in phospholipid membranes - four naturally occurring channels: trichotoxin, alamethicin, p7 from hepatitis C virus (HCV) and Vpu from the HIV-1 virus, and a synthetic, hexameric channel, formed by a 21-residue peptide that contains only leucine and serine. All these channels mediate transport of potassium and chloride ions. It was found that the ED equation is satisfactory for these systems. In some of them experimental and calculated electrophysiological properties are in good agreement, whereas in others there are strong indications that the structural models are incorrect.
Publication Year: 2018
Document Type: Conference Paper
Report/Patent Number: ARC-E-DAA-TN53039
Date Acquired: Apr 23, 2018
10.
A D- and N-15-Rich Micrometer-Sized Aggregate of Organic Matter in a Xenolithic Clast from the Zag Ordinary Chondrite
Document ID: 20180002204
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Author: Kebukawa, Yoko; Ito, Motoo; Zolensky, Michael E.; Rahman, Zia; Suga, Hiroki; Nakato, Aiko; Chan, Queenie H. S.; Fries, Marc; Takeichi, Yasuo; Takahashi, Yoshio;
Mase, Kazuhiko; Kobayashi, Kensei
Abstract: The nature and origin of extraterrestrial organic matter are still under debate despite the
significant progress in the analyses and experimental approaches in this field over the last five decades. Xenolithic clasts are often found in a wide variety of meteorite groups, some of which contain exotic organic matter (OM). The Zag meteorite is a thermally-metamorphosed H ordinary chondrite. It contains a primitive xenolithic clast that has been proposed to have originated from Ceres, which was accreted to the Zag host asteroid after metamorphism. The cm-sized clast contains abundant large carbon-rich (mostly organic) grains or aggregates up to 20 microns. Such large OM grains are unique among astromaterials with respect to the size. Here we report organic and isotope analyses of a large (approx.10 microns) aggregate of solid OM in the Zag clast. The X-ray micro-spectroscopic technique revealed that the OM has sp2 bonded carbon with no other functional groups nor graphitic feature (1s-sigma exciton), and thus it is distinguished from most of the OM in carbonaceous meteorites. The apparent absence of functional groups in the OM suggests that it is composed of hydrocarbon networks with less heteroatoms, and therefore the OM aggregate is similar to hydrogenated amorphous carbon (HAC). The OM aggregate has high D/H and 15N/14N ratios, suggesting that it originated in a very cold environment such as the interstellar medium or outer region of the solar nebula, while the OM is embedded in carbonate-bearing matrix resulting from aqueous activities. Thus the high D/H ratio must have survived the extensive late-stage aqueous processing. It is not in the case for OM in carbonaceous chondrites of which the D/H ratio was reduced by the alteration via the D-H exchange of water. It indicates that both the OM precursors and the water had high D/H ratios, similar to the water in Enceladus. Our results support the idea that the clast originated from Ceres, or at least, a hydrovolcanically active body similar to Ceres, and further imply that Ceres originally formed in the outer Solar System and migrated to the main belt asteroid region as suggested by the "Grand tack" scenario.
Publication Year: 2018
Document Type: Preprint
Report/Patent Number: JSC-E-DAA-TN53161
Date Acquired: Apr 23, 2018