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Perchlorate induced low temperature carbonate decomposition in the Mars Phoenix Thermal and Evolved Gas Analyzer (TEGA)
Author(s) -
Can K. M.,
Sutter B.,
Ming D. W.,
Boynton W. V.,
Quinn R.
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl051952
Subject(s) - calcite , perchlorate , carbonate , mars exploration program , thermal decomposition , mineralogy , chemistry , decomposition , inorganic chemistry , analytical chemistry (journal) , astrobiology , environmental chemistry , organic chemistry , ion , physics
Simulated Thermal Evolved Gas Analyzer (TEGA) analyses have shown that a CO 2 release detected between 400°C and 680°C by the Phoenix Lander's TEGA instrument may have been caused by a reaction between calcium carbonate and hydrated magnesium perchlorate. In our experiments a CO 2 release beginning at 385 ± 12°C was attributed to calcite reacting with water vapor and HCl gas from the dehydration and thermal decomposition of Mg‐perchlorate. The release of CO 2 is consistent with the TEGA detection of CO 2 released between 400 and 680°C, with the amount of CO 2 increasing linearly with added perchlorate. X‐ray diffraction (XRD) experiments confirmed CaCl 2 formation from the reaction between calcite and HCl. These results have important implications for the Mars Science Laboratory (MSL) Curiosity rover. Heating soils may cause inorganic release of CO 2 ; therefore, detection of organic fragments, not CO 2 alone, should be used as definitive evidence for organics in Martian soils.