Isotopic fractionation of methane in the martian atmosphere
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چکیده
The existence of methane in the martian atmosphere may be an indicator of subsurface life. Biological processes are known to fractionate the common isotopologues of methane, and hence measuring these isotopic ratios may yield constraints on the nature of the methane source. Any measurement of the isotopic ratios of atmospheric methane must consider the additional fractionation due to photochemistry in order to quantify the isotopic ratios of the source. We find that photochemical processing of the methane family in the atmosphere has a small (4.5h) contribution to δC(CH4) but has a large (90h) contribution to δD(CH4). Subject headings: Exobiology; Mars, atmosphere; Photochemistry
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تاریخ انتشار 2005