TY - JOUR
T1 - Depleted carbon isotope compositions observed at Gale crater, Mars
AU - House, Christopher H.
AU - Wong, Gregory M.
AU - Webster, Christopher R.
AU - Flesch, Gregory J.
AU - Franz, Heather B.
AU - Stern, Jennifer C.
AU - Pavlov, Alex
AU - Atreya, Sushil K.
AU - Eigenbrode, Jennifer L.
AU - Gilbert, Alexis
AU - Hofmann, Amy E.
AU - Millan, Maëva
AU - Steele, Andrew
AU - Glavin, Daniel P.
AU - Malespin, Charles A.
AU - Mahaffy, Paul R.
N1 - Publisher Copyright:
© 2022 National Academy of Sciences. All rights reserved.
PY - 2022/1/25
Y1 - 2022/1/25
N2 - Obtaining carbon isotopic information for organic carbon from Martian sediments has long been a goal of planetary science, as it has the potential to elucidate the origin of such carbon and aspects of Martian carbon cycling. Carbon isotopic values (δ13CVPDB) of the methane released during pyrolysis of 24 powder samples at Gale crater, Mars, show a high degree of variation (2137 ± 8 to +22 ± 10 ) when measured by the tunable laser spectrometer portion of the Sample Analysis at Mars instrument suite during evolved gas analysis. Included in these data are 10 measured δ13C values less than270 found for six different sampling locations, all potentially associated with a possible paleosurface. There aremultiple plausible explanations for the anomalously depleted 13C observed in evolved methane, but no single explanation can be acceptedwithout further research. Three possible explanations are the photolysis of biological methane released from the subsurface, photoreduction of atmospheric CO2, and deposition of cosmic dust during passage through a galactic molecular cloud. All three of these scenarios are unconventional, unlike processes common on Earth.
AB - Obtaining carbon isotopic information for organic carbon from Martian sediments has long been a goal of planetary science, as it has the potential to elucidate the origin of such carbon and aspects of Martian carbon cycling. Carbon isotopic values (δ13CVPDB) of the methane released during pyrolysis of 24 powder samples at Gale crater, Mars, show a high degree of variation (2137 ± 8 to +22 ± 10 ) when measured by the tunable laser spectrometer portion of the Sample Analysis at Mars instrument suite during evolved gas analysis. Included in these data are 10 measured δ13C values less than270 found for six different sampling locations, all potentially associated with a possible paleosurface. There aremultiple plausible explanations for the anomalously depleted 13C observed in evolved methane, but no single explanation can be acceptedwithout further research. Three possible explanations are the photolysis of biological methane released from the subsurface, photoreduction of atmospheric CO2, and deposition of cosmic dust during passage through a galactic molecular cloud. All three of these scenarios are unconventional, unlike processes common on Earth.
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U2 - 10.1073/pnas.2115651119
DO - 10.1073/pnas.2115651119
M3 - Article
C2 - 35042808
AN - SCOPUS:85123106762
SN - 0027-8424
VL - 119
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 4
M1 - e2115651119
ER -