Methane can be liberated from Martian meteorites by crushing them reports a study published in Nature Communications this week. This indicates that methane exists on Mars and adds weight to the hypothesis that methane-utilising microorganisms could live there.
Life could potentially survive on Mars, either currently or in the past, by using methane to respire instead of oxygen, like some bacteria do in extreme environments on Earth. Measurements of the Martian atmosphere by the rover Curiosity suggest that methane abundance is low, but there may be more methane available in the subsurface.
Nigel Blamey and colleagues suggest that, as chemical reactions between the igneous rocks on Mars and the Martian environment causes them to break down, they might release enough methane necessary to sustain life. They test this theory by investigating six meteorites from Mars that represent the igneous rocks found there, reporting that methane and other gases were released from all six of them during crushing, likely from small pockets in the minerals and between grains. The Martian subsurface is probably more habitable than the hostile surface, and if these gases are available for microorganisms to utilise then it is possible that a deep biosphere could be supported, similar to that on Earth.