Aqueous Processes and Microbial Habitability of Gale Crater Sediments from the Blunts Point to the Glenn Torridon Clay Unit

A driving factor for sending the Mars Science Laboratory, Curiosity rover to Gale Crater was the orbital detection of clay minerals in the Glen Torridon (GT) clay unit. Clay mineral detections in GT suggested a past aqueous environment that was habitable, and could contain organic evidence of past microbiology. The mission of the Sample Analysis at Mars (SAM) instrument onboard Curiosity was to detect organic evidence of past microbiology and to detect volatile bearing mineralogy that can inform on whether past geochemical conditions would have supported microbiological activity. The objective of this work was to 1) evaluate the depositional/alteration conditions of Blunts Point (BP) to GT sediments 2) search for evidence of organics, and 3) evaluate microbial habitability in the BP, Vera Rubin Ridge (VRR), and GT sedimentary rock

The Preservation and Detection of Lipids in Mars-Relevant Sulfates and Chlorides

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Optimization of the TMAH Thermochemolysis Technique for the Detection of Trace Organic Matter on Mars by the SAM and MOMA-Pyr-GC-MS Experiment

International audienceBoththe Sample Analysis at Mars (SAM) and Mars Organic Molecule Analyzer (MOMA)instrumentsare able to identify organic material at the Martian surface and subsurface. Both experiments are equipped with pyrolysis-Gas Chromatography-Mass Spectrometry (Pyr-GC-MS)and derivatization reagents (MTBSTFA)that will allowthe analyzerefractory com-pounds,making them more volatile and protecting the labile chemical groups. In order to improve the Pyr-GC-MS analysis, TMAH (tetramethylammonium hydrox-ide) will be used on MOMA and SAM to extract refrac-tory compounds (macromolecules, kerogen, etc.) and protect polar compounds released from the pyrolysis ex-periment.We performed pyrolysis and TMAH-thermochemolysis of a Martian regolith simulant (JSC-Mars-1) to optimizeanalytical parameters, especially the thermochemolysis temperature, to ensure the success of the near future in situthermochemolysis analyses on Mars

Optimization of the TMAH Thermochemolysis Technique for the Detection of Trace Organic Matter on Mars by the SAM and MOMA-Pyr-GC-MS Experiment

International audienceBoththe Sample Analysis at Mars (SAM) and Mars Organic Molecule Analyzer (MOMA)instrumentsare able to identify organic material at the Martian surface and subsurface. Both experiments are equipped with pyrolysis-Gas Chromatography-Mass Spectrometry (Pyr-GC-MS)and derivatization reagents (MTBSTFA)that will allowthe analyzerefractory com-pounds,making them more volatile and protecting the labile chemical groups. In order to improve the Pyr-GC-MS analysis, TMAH (tetramethylammonium hydrox-ide) will be used on MOMA and SAM to extract refrac-tory compounds (macromolecules, kerogen, etc.) and protect polar compounds released from the pyrolysis ex-periment.We performed pyrolysis and TMAH-thermochemolysis of a Martian regolith simulant (JSC-Mars-1) to optimizeanalytical parameters, especially the thermochemolysis temperature, to ensure the success of the near future in situthermochemolysis analyses on Mars

Potential Sources of Artifacts and Backgrounds Generated by the Sample Preparation of SAM

International audienceSample Analysis at Mars (SAM) is one of the instruments of the MSL mission. Three analytical devices are onboard SAM: the Tunable Laser Spectrometer (TLS), the Gas Chromatography (GC) and the Mass Spectrometer (MS). To adapt the nature of a sample to the analytical devices used, a sample preparation and gas processing system implemented with (a) a pyrolysis system, (b) wet chemistry: MTBSTFA and TMAH (c) the hydrocarbon trap (silica beads, Tenax® TA and Carbosieve G) and the injection trap (Tenax® GR composed of Tenax® TA and 30% of graphite) are employed to concentrate vol-atiles released from the sample prior to GC-MS analysis [1]. This study investigates several propositions for chlo-rinated hydrocarbon formation detected in the SAM background by looking for: (a) all products coming from the interaction of Tenax® and perchlorates, (b) also between some soil sample and perchlorates and (c) sources of chlorinated hydrocarbon precursors. Here we report on the detection of chlorohydrocarbon compounds and their potential origin

Analyzing the Organic Chemistry of Hesperian Mars

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Application of TMAH thermochemolysis to the detection of nucleobases: Application to the MOMA and SAM space experiment

International audienceThermochemolysis of seven nucleobases—adenine, thymine, uracil, cytosine, guanine, xanthine, and hypoxanthine—in tetramethylammonium hydroxide (TMAH) was studied individually by pyrolysis gas chromatography mass spectrometry in the frame of the Mars surface exploration. The analyses were performed under conditions relevant to the Sample Analysis at Mars (SAM) instrument of the Mars Curiosity Rover and the Mars Organic Molecule Analyzer (MOMA) instrument of the ExoMars Rover. The thermochemolysis products of each nucleobase were identified and the reaction mechanisms studied. The thermochemolysis temperature was optimized and the limit of detection and quantification of each nucleobase were also investigated. Results indicate that 600°C is the optimal thermochemolysis temperature for all seven nucleobases. The methylated products trimethyl-adenine, 1, 3-dimethyl-thymine, 1, 3-dimethyl-uracil, trimethyl-cytosine, 1, 3, 7-trimethyl-xanthine (caffeine), and dimethyl-hypoxanthine, respectively, are the most stable forms of adenine, thymine, uracil, cytosine, guanine, and xanthine, and hypoxanthine in TMAH solutions. The limits of detection for adenine, thymine, and uracil were 0.075 nmol; the limits of detection for guanine, cytosine, and hypoxanthine were higher, at 0.40, 0.55, and 0.75 nmol, respectively. These experiments allowed to well constrain the analytical capabilities of the thermochemolysis experiments that will be performed on Mars to detect nucleobases

Preparing for the Final Thermochemolysis Experiment on the Mars Science Laboratory Mission Using the Sample Analysis at Mars Testbed

International audienceWe use the Sample Analysis at Mars Testbed to prepare for the final thermochemolysis experiment on the Mars Science Laboratory mission