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Christopher R. Webster - One of the best experts on this subject based on the ideXlab platform.
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Determination of foreign broadening coefficients for Methane Lines Targeted by the Tunable Laser Spectrometer (TLS) on the Mars Curiosity Rover
Journal of Quantitative Spectroscopy and Radiative Transfer, 2017Co-Authors: Jagadeeshwari Manne, Thinh Q. Bui, Christopher R. WebsterAbstract:Molecular line parameters of foreign- broadening by air, carbon dioxide, and helium gas have been experimentally determined for infrared ro-vibrational spectral lines of methane isotopologues (^(12)CH_4 and ^(13)CH_4) at 3057 cm^(−1) targeted by the Tunable Laser Spectrometer (TLS) in the Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) Curiosity Rover. From multi-spectrum analyses with the speed-dependent Voigt line profile with Rosenkrantz line-mixing, speed-dependence and line-mixing effects were quantified for methane spectra at total pressures up to 200 mbar. The fitted air-broadening coefficients deviated from 8–25% to those reported in the HITRAN-2012 database.
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Determination of spectral parameters for lines targeted by the Tunable Laser Spectrometer (TLS) on the Mars Curiosity Rover
Journal of Quantitative Spectroscopy and Radiative Transfer, 2016Co-Authors: Jagadeeshwari Manne, Christopher R. WebsterAbstract:Abstract Molecular line parameters of line strengths, self- and foreign-broadening by nitrogen, carbon dioxide and helium gas have been experimentally determined for infrared ro-vibrational spectral lines of water and carbon dioxide at 2.78 µm targeted by the Tunable Laser Spectrometer (TLS) in the Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) Curiosity Rover. Good agreement is found by comparison with the line parameters reported in the HITRAN-2012 database.
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Mars Atmospheric Escape Recorded by H, C and O Isotope Ratios in Carbon Dioxide and Water Measured by the Sam Tunable Laser Spectrometer on the Curiosity Rover
2013Co-Authors: Christopher R. Webster, J. C. Stern, Paul R. Mahaffy, Sushil K. Atreya, L. A. Leshin, Gregory J. Flesch, Lance E. Christensen, Ashwin R. Vasavada, T. C. Owen, Paul B. NilesAbstract:Summary: In situ measurements of the isotopic ra-tios of D/H in water, and 13 C/ 12 C, 18 O/ 16 O, 17 O/ 16 O and 13 C 18 O/ 12 C 16 O in carbon dioxide have been made in the Martian atmosphere. As part of the Sample Analysis at Mars (SAM) suite [1] on the Curiosity Rover, the tuna-ble laser spectrometer (TLS) has achieved unprece-dented precision for a planetary measurement of these isotopic ratios that record escape of lighter gases from the early Mars atmosphere and subsequent surface inte-ractions. Introduction: Stable isotope ratios in C, H, N, O and S are powerful indicators of a wide variety of pla-netary geophysical processes that can identify origin, transport, temperature history, radiation exposure, at-mospheric escape, environmental habitability and bio-logical activity [2]. For Mars, measurements to date have indicated enrichment in all the heavier isotopes consistent with atmospheric escape processes, but with uncertainty too high to tie the results with the more precise isotopic ratios achieved from SNC meteoritic analyses. We will present results to date of H, C and O iso-tope ratios in CO
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Mars Atmospheric Composition and Stable Isotope Ratios in H, C and O Measured by the SAM Instrument Suite on the Curiosity Rover
European geosciences union general assembly, 2013Co-Authors: Christopher R. Webster, J. C. Stern, Greg Flesch, Laurie A. Leshin, Michael H. Wong, Kenneth A. Farley, Heather B. Franz, Paul R. Mahaffy, Sushil K. Atreya, Javier Martin-torresAbstract:Mars Atmospheric Composition and Stable Isotope Ratios in H, C and O Measured by the SAM Instrument Suite on the Curiosity Rover
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abundance and isotopic composition of gases in the martian atmosphere first results from the mars Curiosity Rover
2013Co-Authors: Paul R. Mahaffy, Christopher R. Webster, Michael H. Wong, Heather B. Franz, Sushil K. Atreya, P G Conrad, Dan Harpold, J Jones, Leshin Laurie A, H ManningAbstract:Repeated measurements of the composition of the Mars atmosphere from Curiosity Rover yield a (40)Ar/N2 ratio 1.7 times greater and the (40)Ar/(36)Ar ratio 1.6 times smaller than the Viking Lander values in 1976. The unexpected change in (40)Ar/N2 ratio probably results from different instrument characteristics although we cannot yet rule out some unknown atmospheric process. The new (40)Ar/(36)Ar ratio is more aligned with Martian meteoritic values. Besides Ar and N2 the Sample Analysis at Mars instrument suite on the Curiosity Rover has measured the other principal components of the atmosphere and the isotopes. The resulting volume mixing ratios are: CO2 0.960(+/- 0.007); (40)Ar 0.0193(+/- 0.0001); N2 0.0189(+/- 0.0003); O2 1.45(+/- 0.09) x 10(exp -3); and CO 5.45(+/- 3.62) x 10(exp 4); and the isotopes (40)Ar/(36)Ar 1.9(+/- 0.3) x 10(exp 3), and delta (13)C and delta (18)O from CO2 that are both several tens of per mil more positive than the terrestrial averages. Heavy isotope enrichments support the hypothesis of large atmospheric loss. Moreover, the data are consistent with values measured in Martian meteorites, providing additional strong support for a Martian origin for these rocks.
A A Fraeman - One of the best experts on this subject based on the ideXlab platform.
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Iron mobility during diagenesis deduced from ChemCam observations at Gale Crater, Mars
2019Co-Authors: J. L'haridon, N. Mangold, A A Fraeman, Roger C. Wiens, Agnès Cousin, G. David, Jeffrey R. Johnson, William Rapin, Jens Frydenvang, Susanne P. SchwenzerAbstract:ChemCam onboard the Curiosity Rover analyzed dark-toned Fe-rich diagenetic features indicative of redox processes in the sedimentary rocks of Gale Crater.
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Compositional variations in sands of the Bagnold Dunes, Gale crater, Mars, from visible‐shortwave infrared spectroscopy and comparison with ground truth from the Curiosity Rover
Journal of Geophysical Research: Planets, 2017Co-Authors: Mathieu G A Lapotre, B L Ehlmann, A A Fraeman, Sarah E Minson, F Ayoub, Ryan C Ewing, Raymond E. Arvidson, Nathan T. BridgesAbstract:During its ascent up Mount Sharp, the Mars Science Laboratory Curiosity Rover traversed the Bagnold Dune Field. We model sand modal mineralogy and grain size at four locations near the Rover traverse, using orbital shortwave infrared single-scattering albedo spectra and a Markov chain Monte Carlo implementation of Hapke's radiative transfer theory to fully constrain uncertainties and permitted solutions. These predictions, evaluated against in situ measurements at one site from the Curiosity Rover, show that X-ray diffraction-measured mineralogy of the basaltic sands is within the 95% confidence interval of model predictions. However, predictions are relatively insensitive to grain size and are nonunique, especially when modeling the composition of minerals with solid solutions. We find an overall basaltic mineralogy and show subtle spatial variations in composition in and around the Bagnold Dunes, consistent with a mafic enrichment of sands with cumulative aeolian-transport distance by sorting of olivine, pyroxene, and plagioclase grains. Furthermore, the large variations in Fe and Mg abundances (~20 wt %) at the Bagnold Dunes suggest that compositional variability may be enhanced by local mixing of well-sorted sand with proximal sand sources. Our estimates demonstrate a method for orbital quantification of composition with rigorous uncertainty determination and provide key constraints for interpreting in situ measurements of compositional variability within Martian aeolian sandstones.
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Chemistry, mineralogy, and grain properties at Namib and High dunes, Bagnold dune field, Gale crater, Mars: A synthesis of Curiosity Rover observations.
Journal of geophysical research. Planets, 2017Co-Authors: B L Ehlmann, M L Litvak, K S Edgett, A A Fraeman, Brad Sutter, Cherie N Achilles, Mathieu G A Lapotre, R Sullivan, Raymond E. Arvidson, D. F. BlakeAbstract:The Mars Science Laboratory Curiosity Rover performed coordinated measurements to examine the textures and compositions of aeolian sands in the active Bagnold dune field. The Bagnold sands are rounded to subrounded, very fine to medium sized (~45–500 μm) with ≥6 distinct grain colors. In contrast to sands examined by Curiosity in a dust-covered, inactive bedform called Rocknest and soils at other landing sites, Bagnold sands are darker, less red, better sorted, have fewer silt-sized or smaller grains, and show no evidence for cohesion. Nevertheless, Bagnold mineralogy and Rocknest mineralogy are similar with plagioclase, olivine, and pyroxenes in similar proportions comprising >90% of crystalline phases, along with a substantial amorphous component (35% ± 15%). Yet Bagnold and Rocknest bulk chemistry differ. Bagnold sands are Si enriched relative to other soils at Gale crater, and H_2O, S, and Cl are lower relative to all previously measured Martian soils and most Gale crater rocks. Mg, Ni, Fe, and Mn are enriched in the coarse-sieved fraction of Bagnold sands, corroborated by visible/near-infrared spectra that suggest enrichment of olivine. Collectively, patterns in major element chemistry and volatile release data indicate two distinctive volatile reservoirs in Martian soils: (1) amorphous components in the sand-sized fraction (represented by Bagnold) that are Si-enriched, hydroxylated alteration products and/or H_2O- or OH-bearing impact or volcanic glasses and (2) amorphous components in the fine fraction (
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chemistry mineralogy and grain properties at namib and high dunes bagnold dune field gale crater mars a synthesis of Curiosity Rover observations
Journal of Geophysical Research, 2017Co-Authors: B L Ehlmann, M L Litvak, K S Edgett, A A Fraeman, Brad Sutter, Cherie N Achilles, Mathieu G A Lapotre, R Sullivan, R E Arvidson, D. F. BlakeAbstract:The Mars Science Laboratory Curiosity Rover performed coordinated measurements to examine the textures and compositions of aeolian sands in the active Bagnold dune field. The Bagnold sands are rounded to subrounded, very fine to medium sized (~45–500 μm) with ≥6 distinct grain colors. In contrast to sands examined by Curiosity in a dust-covered, inactive bedform called Rocknest and soils at other landing sites, Bagnold sands are darker, less red, better sorted, have fewer silt-sized or smaller grains, and show no evidence for cohesion. Nevertheless, Bagnold mineralogy and Rocknest mineralogy are similar with plagioclase, olivine, and pyroxenes in similar proportions comprising >90% of crystalline phases, along with a substantial amorphous component (35% ± 15%). Yet Bagnold and Rocknest bulk chemistry differ. Bagnold sands are Si enriched relative to other soils at Gale crater, and H_2O, S, and Cl are lower relative to all previously measured Martian soils and most Gale crater rocks. Mg, Ni, Fe, and Mn are enriched in the coarse-sieved fraction of Bagnold sands, corroborated by visible/near-infrared spectra that suggest enrichment of olivine. Collectively, patterns in major element chemistry and volatile release data indicate two distinctive volatile reservoirs in Martian soils: (1) amorphous components in the sand-sized fraction (represented by Bagnold) that are Si-enriched, hydroxylated alteration products and/or H_2O- or OH-bearing impact or volcanic glasses and (2) amorphous components in the fine fraction (<40 μm; represented by Rocknest and other bright soils) that are Fe, S, and Cl enriched with low Si and adsorbed and structural H_2O.
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compositional variations in sands of the bagnold dunes gale crater mars from visible shortwave infrared spectroscopy and comparison with ground truth from the Curiosity Rover
Journal of Geophysical Research, 2017Co-Authors: Mathieu G A Lapotre, B L Ehlmann, A A Fraeman, R E Arvidson, Sarah E Minson, F Ayoub, Ryan C Ewing, N. T. BridgesAbstract:During its ascent up Mount Sharp, the Mars Science Laboratory Curiosity Rover traversed the Bagnold Dune Field. We model sand modal mineralogy and grain size at four locations near the Rover traverse, using orbital shortwave infrared single-scattering albedo spectra and a Markov chain Monte Carlo implementation of Hapke's radiative transfer theory to fully constrain uncertainties and permitted solutions. These predictions, evaluated against in situ measurements at one site from the Curiosity Rover, show that X-ray diffraction-measured mineralogy of the basaltic sands is within the 95% confidence interval of model predictions. However, predictions are relatively insensitive to grain size and are nonunique, especially when modeling the composition of minerals with solid solutions. We find an overall basaltic mineralogy and show subtle spatial variations in composition in and around the Bagnold Dunes, consistent with a mafic enrichment of sands with cumulative aeolian-transport distance by sorting of olivine, pyroxene, and plagioclase grains. Furthermore, the large variations in Fe and Mg abundances (~20 wt %) at the Bagnold Dunes suggest that compositional variability may be enhanced by local mixing of well-sorted sand with proximal sand sources. Our estimates demonstrate a method for orbital quantification of composition with rigorous uncertainty determination and provide key constraints for interpreting in situ measurements of compositional variability within Martian aeolian sandstones.
Mathieu G A Lapotre - One of the best experts on this subject based on the ideXlab platform.
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Compositional variations in sands of the Bagnold Dunes, Gale crater, Mars, from visible‐shortwave infrared spectroscopy and comparison with ground truth from the Curiosity Rover
Journal of Geophysical Research: Planets, 2017Co-Authors: Mathieu G A Lapotre, B L Ehlmann, A A Fraeman, Sarah E Minson, F Ayoub, Ryan C Ewing, Raymond E. Arvidson, Nathan T. BridgesAbstract:During its ascent up Mount Sharp, the Mars Science Laboratory Curiosity Rover traversed the Bagnold Dune Field. We model sand modal mineralogy and grain size at four locations near the Rover traverse, using orbital shortwave infrared single-scattering albedo spectra and a Markov chain Monte Carlo implementation of Hapke's radiative transfer theory to fully constrain uncertainties and permitted solutions. These predictions, evaluated against in situ measurements at one site from the Curiosity Rover, show that X-ray diffraction-measured mineralogy of the basaltic sands is within the 95% confidence interval of model predictions. However, predictions are relatively insensitive to grain size and are nonunique, especially when modeling the composition of minerals with solid solutions. We find an overall basaltic mineralogy and show subtle spatial variations in composition in and around the Bagnold Dunes, consistent with a mafic enrichment of sands with cumulative aeolian-transport distance by sorting of olivine, pyroxene, and plagioclase grains. Furthermore, the large variations in Fe and Mg abundances (~20 wt %) at the Bagnold Dunes suggest that compositional variability may be enhanced by local mixing of well-sorted sand with proximal sand sources. Our estimates demonstrate a method for orbital quantification of composition with rigorous uncertainty determination and provide key constraints for interpreting in situ measurements of compositional variability within Martian aeolian sandstones.
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Chemistry, mineralogy, and grain properties at Namib and High dunes, Bagnold dune field, Gale crater, Mars: A synthesis of Curiosity Rover observations.
Journal of geophysical research. Planets, 2017Co-Authors: B L Ehlmann, M L Litvak, K S Edgett, A A Fraeman, Brad Sutter, Cherie N Achilles, Mathieu G A Lapotre, R Sullivan, Raymond E. Arvidson, D. F. BlakeAbstract:The Mars Science Laboratory Curiosity Rover performed coordinated measurements to examine the textures and compositions of aeolian sands in the active Bagnold dune field. The Bagnold sands are rounded to subrounded, very fine to medium sized (~45–500 μm) with ≥6 distinct grain colors. In contrast to sands examined by Curiosity in a dust-covered, inactive bedform called Rocknest and soils at other landing sites, Bagnold sands are darker, less red, better sorted, have fewer silt-sized or smaller grains, and show no evidence for cohesion. Nevertheless, Bagnold mineralogy and Rocknest mineralogy are similar with plagioclase, olivine, and pyroxenes in similar proportions comprising >90% of crystalline phases, along with a substantial amorphous component (35% ± 15%). Yet Bagnold and Rocknest bulk chemistry differ. Bagnold sands are Si enriched relative to other soils at Gale crater, and H_2O, S, and Cl are lower relative to all previously measured Martian soils and most Gale crater rocks. Mg, Ni, Fe, and Mn are enriched in the coarse-sieved fraction of Bagnold sands, corroborated by visible/near-infrared spectra that suggest enrichment of olivine. Collectively, patterns in major element chemistry and volatile release data indicate two distinctive volatile reservoirs in Martian soils: (1) amorphous components in the sand-sized fraction (represented by Bagnold) that are Si-enriched, hydroxylated alteration products and/or H_2O- or OH-bearing impact or volcanic glasses and (2) amorphous components in the fine fraction (
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chemistry mineralogy and grain properties at namib and high dunes bagnold dune field gale crater mars a synthesis of Curiosity Rover observations
Journal of Geophysical Research, 2017Co-Authors: B L Ehlmann, M L Litvak, K S Edgett, A A Fraeman, Brad Sutter, Cherie N Achilles, Mathieu G A Lapotre, R Sullivan, R E Arvidson, D. F. BlakeAbstract:The Mars Science Laboratory Curiosity Rover performed coordinated measurements to examine the textures and compositions of aeolian sands in the active Bagnold dune field. The Bagnold sands are rounded to subrounded, very fine to medium sized (~45–500 μm) with ≥6 distinct grain colors. In contrast to sands examined by Curiosity in a dust-covered, inactive bedform called Rocknest and soils at other landing sites, Bagnold sands are darker, less red, better sorted, have fewer silt-sized or smaller grains, and show no evidence for cohesion. Nevertheless, Bagnold mineralogy and Rocknest mineralogy are similar with plagioclase, olivine, and pyroxenes in similar proportions comprising >90% of crystalline phases, along with a substantial amorphous component (35% ± 15%). Yet Bagnold and Rocknest bulk chemistry differ. Bagnold sands are Si enriched relative to other soils at Gale crater, and H_2O, S, and Cl are lower relative to all previously measured Martian soils and most Gale crater rocks. Mg, Ni, Fe, and Mn are enriched in the coarse-sieved fraction of Bagnold sands, corroborated by visible/near-infrared spectra that suggest enrichment of olivine. Collectively, patterns in major element chemistry and volatile release data indicate two distinctive volatile reservoirs in Martian soils: (1) amorphous components in the sand-sized fraction (represented by Bagnold) that are Si-enriched, hydroxylated alteration products and/or H_2O- or OH-bearing impact or volcanic glasses and (2) amorphous components in the fine fraction (<40 μm; represented by Rocknest and other bright soils) that are Fe, S, and Cl enriched with low Si and adsorbed and structural H_2O.
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compositional variations in sands of the bagnold dunes gale crater mars from visible shortwave infrared spectroscopy and comparison with ground truth from the Curiosity Rover
Journal of Geophysical Research, 2017Co-Authors: Mathieu G A Lapotre, B L Ehlmann, A A Fraeman, R E Arvidson, Sarah E Minson, F Ayoub, Ryan C Ewing, N. T. BridgesAbstract:During its ascent up Mount Sharp, the Mars Science Laboratory Curiosity Rover traversed the Bagnold Dune Field. We model sand modal mineralogy and grain size at four locations near the Rover traverse, using orbital shortwave infrared single-scattering albedo spectra and a Markov chain Monte Carlo implementation of Hapke's radiative transfer theory to fully constrain uncertainties and permitted solutions. These predictions, evaluated against in situ measurements at one site from the Curiosity Rover, show that X-ray diffraction-measured mineralogy of the basaltic sands is within the 95% confidence interval of model predictions. However, predictions are relatively insensitive to grain size and are nonunique, especially when modeling the composition of minerals with solid solutions. We find an overall basaltic mineralogy and show subtle spatial variations in composition in and around the Bagnold Dunes, consistent with a mafic enrichment of sands with cumulative aeolian-transport distance by sorting of olivine, pyroxene, and plagioclase grains. Furthermore, the large variations in Fe and Mg abundances (~20 wt %) at the Bagnold Dunes suggest that compositional variability may be enhanced by local mixing of well-sorted sand with proximal sand sources. Our estimates demonstrate a method for orbital quantification of composition with rigorous uncertainty determination and provide key constraints for interpreting in situ measurements of compositional variability within Martian aeolian sandstones.
Caroline Freissinet - One of the best experts on this subject based on the ideXlab platform.
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Reply to Comment by F. Kenig, L. Chou, and D. J. Wardrop on “Evaluation of the Tenax Trap in the Sample Analysis at Mars Instrument Suite on the Curiosity Rover as a Potential Hydrocarbon Source for Chlorinated Organics Detected in Gale Crater” by Mi
Journal of Geophysical Research. Planets, 2019Co-Authors: Roger E Summons, Benjamin Kotrc, Caroline Freissinet, Arnaud Buch, Daniel Glavin, Jennifer Eigenbrode, Kristen Miller, Imene Belmahadi, Cyril SzopaAbstract:Kenig et al. comment on our 2015 reporting of laboratory analog experiments aimed at testing the stability of the hydrocarbon trap material used in the Sample Analysis on Mars (SAM) instrument on board the Curiosity Rover operating in Gale Crater on Mars. They propose chemical structures for some decomposition products of the Tenax TA polymer when it is exposed at high temperatures to the Cl2 and O2 gases formed by the thermal decomposition of perchlorate. Further, Kenig et al. propose that these decomposition products accumulate and then react further in cooler downstream sections of the SAM analytical pipeline to produce the chlorobenzene that was detected in the Cumberland mudstone of Gale Crater. However, numerous experiments conducted in the laboratory show that Tenax TA decomposition products only appear after repeated exposure to much higher levels of Cl2 and O2 than those seen by the flight instrument. Moreover, the sequence of chlorobenzene detections during gas chromatography‐mass spectrometry experiments conducted on Mars cannot be explained by Tenax TA decomposition, nor can the detection of chlorobenzene in Evolved Gas Analysis experiments that involve pathways devoid of Tenax TA. Kenig et al. are incorrect in their assertion that Tenax TA decomposition products can account for the chlorobenzene detected on Mars by SAM.
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reply to comment by f kenig l chou and d j wardrop on evaluation of the tenax trap in the sample analysis at mars instrument suite on the Curiosity Rover as a potential hydrocarbon source for chlorinated organics detected in gale crater by miller et
Journal of Geophysical Research, 2019Co-Authors: Roger E Summons, Kristen E Miller, Benjamin Kotrc, Daniel P. Glavin, Jennifer L. Eigenbrode, Caroline Freissinet, Arnaud Buch, Imene Belmahadi, Cyril SzopaAbstract:Kenig et al. comment on our 2015 reporting of laboratory analog experiments aimed at testing the stability of the hydrocarbon trap material used in the Sample Analysis on Mars (SAM) instrument on board the Curiosity Rover operating in Gale Crater on Mars. They propose chemical structures for some decomposition products of the Tenax TA polymer when it is exposed at high temperatures to the Cl2 and O2 gases formed by the thermal decomposition of perchlorate. Further, Kenig et al. propose that these decomposition products accumulate and then react further in cooler downstream sections of the SAM analytical pipeline to produce the chlorobenzene that was detected in the Cumberland mudstone of Gale Crater. However, numerous experiments conducted in the laboratory show that Tenax TA decomposition products only appear after repeated exposure to much higher levels of Cl2 and O2 than those seen by the flight instrument. Moreover, the sequence of chlorobenzene detections during gas chromatography‐mass spectrometry experiments conducted on Mars cannot be explained by Tenax TA decomposition, nor can the detection of chlorobenzene in Evolved Gas Analysis experiments that involve pathways devoid of Tenax TA. Kenig et al. are incorrect in their assertion that Tenax TA decomposition products can account for the chlorobenzene detected on Mars by SAM.
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Operations of the Sample Analysis at Mars instrument suite onboard the Curiosity Rover
2018Co-Authors: Jean-yves Bonnet, Caroline Freissinet, Cyril Szopa, David Coscia, Michel Cabane, Arnaud Buch, Stephen Indyk, Benito Prats, Eric Lorigny, Samuel TeinturierAbstract:The Sample Analysis at Mars instrument suite, onboard the Curiosity Rover, has been analyzing the martian environment since August 05th 2012, as one of the main tools of the Mars Science Laboratory mission. This suite is composed of three independent but interoperable instruments, namely a Quadrupole Mass Spectrometer, a Tunable Laser Spectrometer and a Gas Chromatograph, plus a sophisticated Sample Manipulation System. SAM is used to analyze soils, rocks and atmosphere. For instance, it detected in situ martian complex organics for the first time, provide us with a several years survey of the atmospheric composition and helped understand how the martian environment evolved through the planet history. At 40 kg, it represents half of the scientific payload weight of Curiosity and is one of the two analytical instruments of the mission. This instrument suite is the result of an international collaboration between the NASA Goddard Space Flight Center, the NASA Jet Propulsion Laboratory and a consortium of French laboratories supported by the Center National d’Études Spatiales (the French space agency). This contribution will present the organization of the SAM operational workflow from the ground infrastructure, to flight operations and laboratory supporting work. It will also describe how the CNES hosts and supports the SAM team during this exciting mission.
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operations of the sample analysis at mars instrument suite onboard the Curiosity Rover
2018 SpaceOps Conference 15th International Conference on Space Operations, 2018Co-Authors: Jean-yves Bonnet, Caroline Freissinet, Cyril Szopa, David Coscia, Michel Cabane, Arnaud Buch, Stephen Indyk, B D Prats, Eric LorignyAbstract:The Sample Analysis at Mars instrument suite, onboard the Curiosity Rover, has been analyzing the martian environment since August 05th 2012, as one of the main tools of the Mars Science Laboratory mission. This suite is composed of three independent but interoperable instruments, namely a Quadrupole Mass Spectrometer, a Tunable Laser Spectrometer and a Gas Chromatograph, plus a sophisticated Sample Manipulation System. SAM is used to analyze soils, rocks and atmosphere. For instance, it detected in situ martian complex organics for the first time, provide us with a several years survey of the atmospheric composition and helped understand how the martian environment evolved through the planet history. At 40 kg, it represents half of the scientific payload weight of Curiosity and is one of the two analytical instruments of the mission. This instrument suite is the result of an international collaboration between the NASA Goddard Space Flight Center, the NASA Jet Propulsion Laboratory and a consortium of French laboratories supported by the Center National d’Etudes Spatiales (the French space agency). This contribution will present the organization of the SAM operational workflow from the ground infrastructure, to flight operations and laboratory supporting work. It will also describe how the CNES hosts and supports the SAM team during this exciting mission.
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Effect of the presence of chlorates and perchlorates on the pyrolysis of organic compounds: implications for measurements done with the SAM experiment onboard the Curiosity Rover
2016Co-Authors: Maeva Millan, Daniel P. Glavin, Caroline Freissinet, Brad Sutter, Cyril Szopa, Arnaud Buch, Patrice Coll, P. Douglas Archer, Imène Belmahdi, Roger E SummonsAbstract:The Sample Analysis at Mars (SAM) experiment onboard the Curiosity Rover of the Mars Science Laboratory mission is partly devoted to the in situ molecular analysis of gases evolving from solid samples collected on Mars surface/sub-surface. SAM has a gas-chromatograph coupled to a quadrupole mass spectrometer (GC-QMS) devoted to the separation and identification of organic and inorganic material [1]. Before proceeding to the GC-QMS analysis, the solid sample collected by Curiosity is subjected to a thermal treatment thanks to the pyrolysis oven to release the volatiles into the gas processing system. As the Viking landers in 1976 [2], SAM detected chlorohydrocarbons with the pyrolysis GC-QMS experiment [3,4]. The detection of perchlorates salts in soil at the Phoenix Landing site [6] suggests that these chloro- hydrocarbons could come from the reaction of organics with oxychlorines. Oxychlorines indeed decomposed into molecular oxygen and volatile chlorine when heated and react with the organic matter in the samples by oxidation and/or chlorination processes. [3,5,7,8]. During SAM pyrolysis, samples are heated to 850◦C. SAM detected C1 to C3 chloroalkanes, entirely attributed to reaction products occurring during the pyrolysis experiment between oxychlorines and organic carbon from instrument background [3] and chlorobenzene and C2 to C4 dichloroalkanes produced by reaction between Mars endogenous organics with oxychlorines [4]. To help understanding the influence of perchlorate and chlorate salts on organic matter during SAM pyrolysis, we systemically study the reaction products formed during pyrolysis of various organic compounds mixed with various perchlorates and chlorates. We selected organics from simple molecule forms as for instance PAHs and amino acids to complex material (>30 carbon atoms) such as kerogen. The perchlorate and chlorate salts are prepared at 1 wt % concentration in silica and mixed with the organics to study the potential qualitative and/or quantitative effects. The experiments are performed on a laboratory GC-QMS with a Restek Rxi-5 column (30m x 0.25mm x 0.25μm) and an Intersciences pyrolyser. The mixture is pyrolyzed at different temperatures up to 900◦C to cover the SAM temperature range. Different experiments are done to discriminate the pyrolysis products directly coming from the organics, and those produced from the reaction with oxychlorine. These experiments are under progress and should bring key information on the potential to identify Martian organics when pyrolyzing solid samples. Depending on the organic families studied, we may find recurring molecules, which are potentially present in Mars’ surface samples. This work could thus highlight some organic precursors of the chlorinated compounds found on Mars, and support the interpretation of SAM measurements.
Jagadeeshwari Manne - One of the best experts on this subject based on the ideXlab platform.
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Determination of foreign broadening coefficients for Methane Lines Targeted by the Tunable Laser Spectrometer (TLS) on the Mars Curiosity Rover
Journal of Quantitative Spectroscopy and Radiative Transfer, 2017Co-Authors: Jagadeeshwari Manne, Thinh Q. Bui, Christopher R. WebsterAbstract:Molecular line parameters of foreign- broadening by air, carbon dioxide, and helium gas have been experimentally determined for infrared ro-vibrational spectral lines of methane isotopologues (^(12)CH_4 and ^(13)CH_4) at 3057 cm^(−1) targeted by the Tunable Laser Spectrometer (TLS) in the Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) Curiosity Rover. From multi-spectrum analyses with the speed-dependent Voigt line profile with Rosenkrantz line-mixing, speed-dependence and line-mixing effects were quantified for methane spectra at total pressures up to 200 mbar. The fitted air-broadening coefficients deviated from 8–25% to those reported in the HITRAN-2012 database.
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Determination of spectral parameters for lines targeted by the Tunable Laser Spectrometer (TLS) on the Mars Curiosity Rover
Journal of Quantitative Spectroscopy and Radiative Transfer, 2016Co-Authors: Jagadeeshwari Manne, Christopher R. WebsterAbstract:Abstract Molecular line parameters of line strengths, self- and foreign-broadening by nitrogen, carbon dioxide and helium gas have been experimentally determined for infrared ro-vibrational spectral lines of water and carbon dioxide at 2.78 µm targeted by the Tunable Laser Spectrometer (TLS) in the Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) Curiosity Rover. Good agreement is found by comparison with the line parameters reported in the HITRAN-2012 database.
