Natural methane on Mars

The reported presence of methane in the atmosphere of Mars is of interest to many geologists and astrobiologists, as methane may indicate the presence of microbial life on Mars, or a geochemical process such as volcanism or hydrothermal activity.

Since 2004, trace amounts of methane (range from 60 ppbv to under detection limit (< 0.05 ppbv)) have been reported in various missions and observational studies. The source of methane on Mars and the explanation for the enormous discrepancy in the observed methane concentrations are still unknown and are under study. Whenever methane is detected, it is rapidly removed from the atmosphere by an efficient, yet unknown process.