Origin of Chlorobenzene Detected by the Curiosity Rover in Yellowknife Bay: Evidence for Martian Organics in the Sheepbed Mudstone?

• Main Authors: Glavin, Daniel, Freissinet, Caroline, Eigenbrode, J., Miller, K., Martin, M., Summons, R., Steele, A., Franz, H., Archer, D., Brinckerhoff, W., Brunner, A., Buch, A., Cabane, Michel, Coll, Patrice, Conrad, P., Coscia, David, Dworkin, J., Grotzinger, J., Kashyap, S., Mahaffy, P., Mckay, C., Ming, D., Navarro-González, R., Sutter, B., Szopa, Cyril, Teinturier, Samuel
• Other Authors: NASA Goddard Space Flight Center (GSFC), Massachusetts Institute of Technology (MIT), Catholic University of America, Carnegie Institution for Science, NASA Johnson Space Center (JSC), NASA, Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), CentraleSupélec, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH), NASA Ames Research Center (ARC), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2014
• Subjects: [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology; [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]; Yellowknife; Yellowknife Bay
• Online Access: https://hal.archives-ouvertes.fr/hal-01815497; https://hal.archives-ouvertes.fr/hal-01815497/document; https://hal.archives-ouvertes.fr/hal-01815497/file/1157.pdf

International audience The Sample Analysis at Mars (SAM) instrument on the Curiosity rover is designed to determine the inventory of organic and inorganic vola-tiles thermally evolved from solid samples using a combination of evolved gas analysis (EGA), gas chromatography mass spectrometry (GCMS), and tunable laser spectroscopy [1]. The first solid samples analyzed by SAM, a scoop of windblown dust and sand at Rocknest (RN), revealed chlorinated hydrocarbons derived primarily from reactions between a martian oxychlorine phase (e.g. perchlorate) and terrestrial carbon from N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA) vapor present in the SAM instrument background [2]. Chlorobenzene (CBZ) was also identified by SAM GCMS at RN at trace levels (~0.007 nmol) and was attributed to the reaction of chlorine with the Tenax polymers used in the hydrocarbon traps [2]. After the RN analyses, Curiosity traveled to Yellowknife Bay and drilled two separate holes designated John Klein (JK) and Cum-berland (CB). Analyses of JK and CB by both SAM and the CheMin x-ray diffraction instrument revealed a mudstone consisting of ~20 wt% smectite clays [3,4], which on Earth are known to aid the concentration and preservation of organic matter. In addition, higher abundances and a more diverse suite of chlorinated hydrocarbons in CB compared to RN suggests that martian or meteoritic organic sources may be preserved in the mudstone [3]. Here we discuss the SAM EGA and GCMS measurements of volatiles released from the Sheepbed mud-stone. We focus primarily on the elevated CBZ detections at CB and laboratory analog experiments conducted to help determine if CBZ is derived from primarily terrestrial, martian, or a combination of sources.