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Berni S, Scelta D, Fanetti S, Bini R. Complexities in the structural evolution with pressure of water-ammonia mixtures. J Chem Phys 2023; 158:2889004. [PMID: 37154278 DOI: 10.1063/5.0150639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023] Open
Abstract
The structural evolution with pressure of icy mixtures of simple molecules is a poorly explored field despite the fundamental role they play in setting the properties of the crustal icy layer of the outer planets and of their satellites. Water and ammonia are the two major components of these mixtures, and the crystal properties of the two pure systems and of their compounds have been studied at high pressures in a certain detail. On the contrary, the study of their heterogeneous crystalline mixtures whose properties, due to the strong N-H⋯O and O-H⋯N hydrogen bonds, can be substantially altered with respect to the individual species has so far been overlooked. In this work, we performed a comparative Raman study with a high spatial resolution of the lattice phonon spectrum of both pure ammonia and water-ammonia mixtures in a pressure range of great interest for modeling the properties of icy planets' interiors. Lattice phonon spectra represent the spectroscopic signature of the molecular crystals' structure. The activation of a phonon mode in plastic NH3-III attests to a progressive reduction in the orientational disorder, which corresponds to a site symmetry reduction. This spectroscopic hallmark allowed us to solve the pressure evolution of H2O-NH3-AHH (ammonia hemihydrate) solid mixtures, which present a remarkably different behavior from the pure crystals likely to be ascribed to the role of the strong H-bonds between water and ammonia molecules characterizing the crystallites' surface.
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Affiliation(s)
- Selene Berni
- LENS, European Laboratory for Non-linear Spectroscopy, Via N. Carrara 1, I-50019 Sesto Fiorentino, Firenze, Italy
| | - Demetrio Scelta
- ICCOM-CNR, Istituto di Chimica dei Composti OrganoMetallici, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Firenze, Italy
| | - Samuele Fanetti
- ICCOM-CNR, Istituto di Chimica dei Composti OrganoMetallici, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Firenze, Italy
| | - Roberto Bini
- Dipartimento di Chimica "Ugo Schiff," Università di Firenze, Via della Lastruccia 3, I-50019 Sesto Fiorentino, Firenze, Italy
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2
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Exogenic origin for the volatiles sampled by the Lunar CRater Observation and Sensing Satellite impact. Nat Commun 2022; 13:642. [PMID: 35136041 PMCID: PMC8825836 DOI: 10.1038/s41467-022-28289-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 01/11/2022] [Indexed: 11/10/2022] Open
Abstract
Returning humans to the Moon presents an unprecedented opportunity to determine the origin of volatiles stored in the permanently shaded regions (PSRs), which trace the history of lunar volcanic activity, solar wind surface chemistry, and volatile delivery to the Earth and Moon through impacts of comets, asteroids, and micrometeoroids. So far, the source of the volatiles sampled by the Lunar Crater Observation and Sensing Satellite (LCROSS) plume has remained undetermined. We show here that the source could not be volcanic outgassing and the composition is best explained by cometary impacts. Ruling out a volcanic source means that volatiles in the top 1-3 meters of the Cabeus PSR regolith may be younger than the latest volcanic outgassing event (~1 billion years ago; Gya). The water and other volatiles observed in the LCROSS impact plume contained too much nitrogen to have originated from volcanic outgassing. These volatiles, stored in the top 1-3 meters of the Cabeus permanently shaded region, were delivered by comet impacts.
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Lammer H, Sproß L, Grenfell JL, Scherf M, Fossati L, Lendl M, Cubillos PE. The Role of N 2 as a Geo-Biosignature for the Detection and Characterization of Earth-like Habitats. ASTROBIOLOGY 2019; 19:927-950. [PMID: 31314591 DOI: 10.1089/ast.2018.1914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Since the Archean, N2 has been a major atmospheric constituent in Earth's atmosphere. Nitrogen is an essential element in the building blocks of life; therefore, the geobiological nitrogen cycle is a fundamental factor in the long-term evolution of both Earth and Earth-like exoplanets. We discuss the development of Earth's N2 atmosphere since the planet's formation and its relation with the geobiological cycle. Then we suggest atmospheric evolution scenarios and their possible interaction with life-forms: first for a stagnant-lid anoxic world, second for a tectonically active anoxic world, and third for an oxidized tectonically active world. Furthermore, we discuss a possible demise of present Earth's biosphere and its effects on the atmosphere. Since life-forms are the most efficient means for recycling deposited nitrogen back into the atmosphere at present, they sustain its surface partial pressure at high levels. Also, the simultaneous presence of significant N2 and O2 is chemically incompatible in an atmosphere over geological timescales. Thus, we argue that an N2-dominated atmosphere in combination with O2 on Earth-like planets within circumstellar habitable zones can be considered as a geo-biosignature. Terrestrial planets with such atmospheres will have an operating tectonic regime connected with an aerobic biosphere, whereas other scenarios in most cases end up with a CO2-dominated atmosphere. We conclude with implications for the search for life on Earth-like exoplanets inside the habitable zones of M to K stars.
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Affiliation(s)
- Helmut Lammer
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
| | - Laurenz Sproß
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
- 2Institute of Physics, University of Graz, Graz, Austria
| | - John Lee Grenfell
- 3Department of Extrasolar Planets and Atmospheres, German Aerospace Center, Institute of Planetary Research, Berlin, Germany
| | - Manuel Scherf
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
| | - Luca Fossati
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
| | - Monika Lendl
- 1Austrian Academy of Sciences, Space Research Institute, Graz, Austria
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Contributions from Accreted Organics to Titan’s Atmosphere: New Insights from Cometary and Chondritic Data. ACTA ACUST UNITED AC 2019. [DOI: 10.3847/1538-4357/aaf561] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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5
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O'D Alexander CM, McKeegan KD, Altwegg K. Water Reservoirs in Small Planetary Bodies: Meteorites, Asteroids, and Comets. SPACE SCIENCE REVIEWS 2018; 214:36. [PMID: 30842688 PMCID: PMC6398961 DOI: 10.1007/s11214-018-0474-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 01/11/2018] [Indexed: 06/09/2023]
Abstract
Asteroids and comets are the remnants of the swarm of planetesimals from which the planets ultimately formed, and they retain records of processes that operated prior to and during planet formation. They are also likely the sources of most of the water and other volatiles accreted by Earth. In this review, we discuss the nature and probable origins of asteroids and comets based on data from remote observations, in situ measurements by spacecraft, and laboratory analyses of meteorites derived from asteroids. The asteroidal parent bodies of meteorites formed ≤4 Ma after Solar System formation while there was still a gas disk present. It seems increasingly likely that the parent bodies of meteorites spectroscopically linked with the E-, S-, M- and V-type asteroids formed sunward of Jupiter's orbit, while those associated with C- and, possibly, D-type asteroids formed further out, beyond Jupiter but probably not beyond Saturn's orbit. Comets formed further from the Sun than any of the meteorite parent bodies, and retain much higher abundances of interstellar material. CI and CM group meteorites are probably related to the most common C-type asteroids, and based on isotopic evidence they, rather than comets, are the most likely sources of the H and N accreted by the terrestrial planets. However, comets may have been major sources of the noble gases accreted by Earth and Venus. Possible constraints that these observations can place on models of giant planet formation and migration are explored.
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Affiliation(s)
- Conel M O'D Alexander
- Dept. Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015, USA. . Tel. (202) 478 8478
| | - Kevin D McKeegan
- Department of Earth, Planetary, and Space Sciences, University of California-Los Angeles, Los Angeles, CA 90095-1567, USA.
| | - Kathrin Altwegg
- Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.
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Mandt K, Luspay-Kuti A, Hamel M, Jessup KL, Hue V, Kammer J, Filwett R. Photochemistry on Pluto: part II HCN and nitrogen isotope fractionation. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 2017; 472:118-128. [PMID: 31105342 PMCID: PMC6525008 DOI: 10.1093/mnras/stx1587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We have converted our Titan one-dimensional photochemical model to simulate the photo- chemistry of Pluto's atmosphere and include condensation and aerosol trapping in the model. We find that condensation and aerosol trapping are important processes in producing the HCN altitude profile observed by the Atacama Large Millimeter Array (ALMA). The nitrogen iso- tope chemistry in Pluto's atmosphere does not appear to significantly fractionate the isotope ratio between N2 and HCN as occurs at Titan. However, our simulations only cover a brief period of time in a Pluto year, and thus only a brief portion of the solar forcing conditions that Pluto's atmosphere experiences. More work is needed to evaluate photochemical fractionation over a Pluto year. Condensation and aerosol trapping appear to have a major impact on the altitude profile of the isotope ratio in HCN. Since ALMA did not detect HC15N in Pluto's atmosphere, we conclude that condensation and aerosol trapping must be much more efficient for HC15N compared to HC14N. The large uncertainty in photochemical fractionation makes it difficult to use any potential current measurement of 14N/15N in N2 to determine the origin of Pluto's nitrogen. More work is needed to understand photochemical fractionation and to evaluate how condensation, sublimation and aerosol trapping will fractionate N2 and HCN.
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Affiliation(s)
- Kathleen Mandt
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Blvd., San Antonio, TX 78249, USA
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723, USA
| | - Adrienn Luspay-Kuti
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Mark Hamel
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Blvd., San Antonio, TX 78249, USA
| | - Kandis-Lea Jessup
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Vincent Hue
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Josh Kammer
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Rachael Filwett
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Blvd., San Antonio, TX 78249, USA
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Alexander CMO. The origin of inner Solar System water. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:20150384. [PMID: 28416723 PMCID: PMC5394251 DOI: 10.1098/rsta.2015.0384] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/05/2016] [Indexed: 05/23/2023]
Abstract
Of the potential volatile sources for the terrestrial planets, the CI and CM carbonaceous chondrites are closest to the planets' bulk H and N isotopic compositions. For the Earth, the addition of approximately 2-4 wt% of CI/CM material to a volatile-depleted proto-Earth can explain the abundances of many of the most volatile elements, although some solar-like material is also required. Two dynamical models of terrestrial planet formation predict that the carbonaceous chondrites formed either in the asteroid belt ('classical' model) or in the outer Solar System (5-15 AU in the Grand Tack model). To test these models, at present the H isotopes of water are the most promising indicators of formation location because they should have become increasingly D-rich with distance from the Sun. The estimated initial H isotopic compositions of water accreted by the CI, CM, CR and Tagish Lake carbonaceous chondrites were much more D-poor than measured outer Solar System objects. A similar pattern is seen for N isotopes. The D-poor compositions reflect incomplete re-equilibration with H2 in the inner Solar System, which is also consistent with the O isotopes of chondritic water. On balance, it seems that the carbonaceous chondrites and their water did not form very far out in the disc, almost certainly not beyond the orbit of Saturn when its moons formed (approx. 3-7 AU in the Grand Tack model) and possibly close to where they are found today.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'.
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Affiliation(s)
- Conel M O'D Alexander
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015, USA
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8
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Mandt KE, Mousis O, Luspay-Kuti A. Isotopic constraints on the source of Pluto's nitrogen and the history of atmospheric escape. PLANETARY AND SPACE SCIENCE 2016; 130:104-109. [PMID: 31068733 PMCID: PMC6501213 DOI: 10.1016/j.pss.2016.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The origin and evolution of nitrogen in solar system bodies is an important question for understanding processes that took place during the formation of the planets and solar system bodies. Pluto has an atmosphere that is 99% molecular nitrogen, but it is unclear if this nitrogen is primordial or derived from ammonia in the protosolar nebula. The nitrogen isotope ratio is an important tracer of the origin of nitrogen on solar system bodies, and can be used at Pluto to determine the origin of its nitrogen. After evaluating the potential impact of escape and photochemistry on Pluto's nitrogen isotope ratio (14N/15N), we find that if Pluto's nitrogen originated as N2 the current ratio in Pluto's atmosphere would be greater than 324 while it would be less than 157 if the source of Pluto's nitrogen were NH3. The New Horizons spacecraft successfully visited the Pluto system in July 2015 providing a potential opportunity to measure 14N/15N in N2.
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Affiliation(s)
- Kathleen E. Mandt
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78228, USA
- Depertment of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, USA
| | - Olivier Mousis
- Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
| | - Adrienn Luspay-Kuti
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78228, USA
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9
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Mandt K, Mousis O, Marty B, Cavalié T, Harris W, Hartogh P, Willacy K. Constraints from Comets on the Formation and Volatile Acquisition of the Planets and Satellites. SPACE SCIENCE REVIEWS 2015; 197:297-342. [PMID: 31105346 PMCID: PMC6525011 DOI: 10.1007/s11214-015-0161-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Comets play a dual role in understanding the formation and evolution of the solar system. First, the composition of comets provides information about the origin of the giant planets and their moons because comets formed early and their composition is not expected to have evolved significantly since formation. They, therefore serve as a record of conditions during the early stages of solar system formation. Once comets had formed, their orbits were perturbed allowing them to travel into the inner solar system and impact the planets. In this way they contributed to the volatile inventory of planetary atmospheres. We review here how knowledge of comet composition up to the time of the Rosetta mission has contributed to understanding the formation processes of the giant planets, their moons and small icy bodies in the solar system. We also discuss how comets contributed to the volatile inventories of the giant and terrestrial planets.
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Affiliation(s)
- K.E. Mandt
- Southwest Research Institute, San Antonio, TX, USA
| | - O. Mousis
- Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388, Marseille, France
| | - B. Marty
- CRPG-CNRS, Nancy-Université, Vandoeuvre-lès-Nancy, France
| | - T. Cavalié
- Max Planck Institute for Solar System Research, Göttingen, Germany
| | - W. Harris
- University of Arizona, Tucson, AZ, USA
| | - P. Hartogh
- Max Planck Institute for Solar System Research, Göttingen, Germany
| | - K. Willacy
- Jet Propulsion Laboratory, Pasadena, CA, USA
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Mandt K, Mousis O, Chassefière E. Comparative planetology of the history of nitrogen isotopes in the atmospheres of Titan and Mars. ICARUS 2015; 254:259-261. [PMID: 31118538 PMCID: PMC6527424 DOI: 10.1016/j.icarus.2015.03.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We present here a comparative planetology study of evolution of 14N/15N at Mars and Titan. Studies show that 14N/15N can evolve a great deal as a result of escape in the atmosphere of Mars, but not in Titan's atmosphere. We explain this through the existence of an upper limit to the amount of fractionation allowed to occur due to escape that is a function of the escape flux and the column density of nitrogen.
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Affiliation(s)
- Kathleen Mandt
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78228, United States
| | - Olivier Mousis
- Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
| | - Eric Chassefière
- Univ Paris-Sud, Laboratoire GEOPS, UMR 8148, Université Paris-Sud, CNRS, Orsay F-91405, France
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Sebree JA, Stern JC, Mandt KE, Domagal-Goldman SD, Trainer MG. 13C and 15N fractionation of CH 4/N 2 mixtures during photochemical aerosol formation: Relevance to Titan. ICARUS 2015; 270:421-428. [PMID: 31068732 PMCID: PMC6501594 DOI: 10.1016/j.icarus.2015.04.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The ratios of the stable isotopes that comprise each chemical species in Titan's atmosphere provide critical information towards understanding the processes taking place within its modern and ancient atmosphere. Several stable isotope pairs, including 12C/13C and 14N/15N, have been measured in situ or probed spectroscopically by Cassini-borne instruments, space telescopes, or through ground-based observations. Current attempts to model the observed isotope ratios incorporate fractionation resulting from atmospheric diffusion, hydrodynamic escape, and primary photochemical processes. However, the effect of a potentially critical pathway for isotopic fractionation - organic aerosol formation and subsequent deposition onto the surface of Titan - has not been considered due to insufficient data regarding fractionation during aerosol formation. To better understand the nature of this process, we have conducted a laboratory study to measure the isotopic fractionation associated with the formation of Titan aerosol analogs, commonly referred to as 'tholins', via far-UV irradiation of several methane (CH4) and dinitrogen (N2) mixtures. Analysis of the δ13C and δ15N isotopic signatures of the photochemical aerosol products using an isotope ratio mass spectrometer (IRMS) show that fractionation direction and magnitude are dependent on the initial bulk composition of the gas mixture. In general, the aerosols showed enrichment in 13C and 14N, and the observed fractionation trends can provide insight into the chemical mechanisms controlling photochemical aerosol formation.
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Affiliation(s)
- Joshua A. Sebree
- University of Northern Iowa, Department of Chemistry and Biochemistry, Cedar Falls, IA 50614, USA
- NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, MD 20771, USA
| | - Jennifer C. Stern
- NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, MD 20771, USA
| | - Kathleen E. Mandt
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228, USA
| | | | - Melissa G. Trainer
- NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, MD 20771, USA
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