Infrared spectrometers have discovered new signs of methane, as well as water on Mars. The methane might be the result of biological processes on Mars, but it could also be caused by geochemical processes such as volcanic or hydrothermal activity.
"Every one of these longitudes shows a very substantial enhancement in the equatorial zone," Mumma explained. "So this is a very intense source of methane on Mars in this region. It also requires a very rapid decay of methane…more rapid than photochemistry would allow," he added.
The life of photochemical methane on Mars is short, roughly 300 years. Thus any methane on Mars should have been released recently.
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