Abstract
Volume mixing and isotope ratios secured with repeated atmospheric measurements taken with the Sample Analysis at Mars instrument suite on the Curiosity rover are: carbon dioxide (CO2), 0.960(±0.007); argon-40 (40Ar), 0.0193(±0.0001); nitrogen (N2), 0.0189(±0.0003); oxygen, 1.45(±0.09) × 10−3; carbon monoxide, < 1.0 × 10−3; and 40Ar/36Ar, 1.9(±0.3) × 103. The 40Ar/N2 ratio is 1.7 times greater and the 40Ar/36Ar ratio 1.6 times lower than values reported by the Viking Lander mass spectrometer in 1976, whereas other values are generally consistent with Viking and remote sensing observations. The 40Ar/36Ar ratio is consistent with martian meteoritic values, which provides additional strong support for a martian origin of these rocks. The isotopic signature δ13C from CO2 of ~45 per mil is independently measured with two instruments. This heavy isotope enrichment in carbon supports the hypothesis of substantial atmospheric loss.
Original language | English |
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Pages (from-to) | 263-266 |
Number of pages | 4 |
Journal | Science |
Volume | 341 |
Issue number | 6143 |
DOIs | |
Publication status | Published - 19 Jul 2013 |