TY - JOUR
T1 - A review of sample analysis at mars-evolved gas analysis laboratory analog work supporting the presence of perchlorates and chlorates in gale crater, mars
AU - Clark, Joanna
AU - Sutter, Brad
AU - Archer, P. Douglas
AU - Ming, Douglas
AU - Rampe, Elizabeth
AU - McAdam, Amy
AU - Navarro-González, Rafael
AU - Eigenbrode, Jennifer
AU - Glavin, Daniel
AU - Zorzano, Maria Paz
AU - Martin-Torres, Javier
AU - Morris, Richard
AU - Tu, Valerie
AU - Ralston, S. J.
AU - Mahaffy, Paul
N1 - Funding Information:
The research reviewed in this paper was funded by the Mars Science Laboratory (MSL) project office. M.-P.Z. acknowledges funding from the Ministerio de Ciencia e Innovaci?n (ref. PID2019-104205GB-C21). The authors are grateful to the engineers and scientists of the MSL Curiosity team, who have made the mission possible and the reported data available. The authors would also like to thank the two anonymous reviewers who provided careful reviews that increased the quality of this manuscript. The authors would like to remember and recognize the contributions of Rafael Navarro-Gonz?lez, a dedicated SAM and HABIT team member who passed away on 28 January 2021. Navarro-Gonz?lez, who was a distinguished researcher, conducted laboratory experiments that demonstrated that chloromethanes could form through a reaction between perchlorates and organics during sample heating, which greatly advanced our understanding of perchlorates and organic detection on Mars.
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/5
Y1 - 2021/5
N2 - The Sample Analysis at Mars (SAM) instrument on the Curiosity rover has detected evidence of oxychlorine compounds (i.e., perchlorates and chlorates) in Gale crater, which has implications for past habitability, diagenesis, aqueous processes, interpretation of in situ organic analyses, understanding the martian chlorine cycle, and hazards and resources for future human exploration. Pure oxychlorines and mixtures of oxychlorines with Mars-analog phases have been analyzed for their oxygen (O2 ) and hydrogen chloride (HCl) releases on SAM laboratory analog instruments in order to constrain which phases are present in Gale crater. These studies demonstrated that oxychlorines evolve O2 releases with peaks between ~200 and 600◦ C, although the thermal decomposition temperatures and the amount of evolved O2 decrease when iron phases are present in the sample. Mg and Fe oxychlorines decompose into oxides and release HCl between ~200 and 542◦ C. Ca, Na, and K oxychlorines thermally decompose into chlorides and do not evolve HCl by themselves. However, the chlorides (original or from oxychlorine decomposition) can react with water-evolving phases (e.g., phyllosilicates) in the sample and evolve HCl within the temperature range of SAM (<~870◦ C). These laboratory analog studies support that the SAM detection of oxychlorine phases is consistent with the presence of Mg, Ca, Na, and K perchlorate and/or chlorate along with possible contributions from adsorbed oxychlorines in Gale crater samples.
AB - The Sample Analysis at Mars (SAM) instrument on the Curiosity rover has detected evidence of oxychlorine compounds (i.e., perchlorates and chlorates) in Gale crater, which has implications for past habitability, diagenesis, aqueous processes, interpretation of in situ organic analyses, understanding the martian chlorine cycle, and hazards and resources for future human exploration. Pure oxychlorines and mixtures of oxychlorines with Mars-analog phases have been analyzed for their oxygen (O2 ) and hydrogen chloride (HCl) releases on SAM laboratory analog instruments in order to constrain which phases are present in Gale crater. These studies demonstrated that oxychlorines evolve O2 releases with peaks between ~200 and 600◦ C, although the thermal decomposition temperatures and the amount of evolved O2 decrease when iron phases are present in the sample. Mg and Fe oxychlorines decompose into oxides and release HCl between ~200 and 542◦ C. Ca, Na, and K oxychlorines thermally decompose into chlorides and do not evolve HCl by themselves. However, the chlorides (original or from oxychlorine decomposition) can react with water-evolving phases (e.g., phyllosilicates) in the sample and evolve HCl within the temperature range of SAM (<~870◦ C). These laboratory analog studies support that the SAM detection of oxychlorine phases is consistent with the presence of Mg, Ca, Na, and K perchlorate and/or chlorate along with possible contributions from adsorbed oxychlorines in Gale crater samples.
KW - Chlorates
KW - Chlorides
KW - Curiosity Gale crater
KW - Evolved gas analysis
KW - MSL
KW - Oxychlorines
KW - Perchlorates
KW - Sample Analysis at Mars
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U2 - 10.3390/min11050475
DO - 10.3390/min11050475
M3 - Review article
AN - SCOPUS:85104980749
SN - 2075-163X
VL - 11
JO - Minerals
JF - Minerals
IS - 5
M1 - 475
ER -