There Is Definitely Methane on Mars, Scientists Say. But Is It a Sign of Life?

Europe’s Mars Express orbiter captured this image of a half-lit Red Planet in December 2012. (Image: © ESA)
We may be one step closer to cracking the Mars methane mystery.

By Mike Wall |

NASA’s Curiosity rover mission recently determined that background levels of methane in Mars‘ atmosphere cycle seasonally, peaking in the northern summer. The six-wheeled robot has also detected two surges to date of the gas inside the Red Planet’s 96-mile-wide (154 kilometers) Gale Crater — once in June 2013, and then again in late 2013 through early 2014.

These finds have intrigued astrobiologists, because methane is a possible biosignature. Though the gas can be produced by a variety of geological processes, the vast majority of methane in Earth’s air is pumped out by microbes and other living creatures.

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