Ever since humans first looked up at the stars with an awareness that those far off lights were physical bodies, bobbing like islands in the vast sea of space, we’ve wondered if we were not alone. Today, we have more tools at our disposal to enable us to explore the heavens than ever before, but life outside our delicate blue pebble remains elusive. Evidence still crops up from time to time, however.
The most recent evidence to suggest life may exist in our own celestial backyard has found its way to scientific discussion, and despite the lofty language one can ascribe to this endeavor, the science behind it is really pretty simple: it’s farts. Okay, so it’s the gas that you can usually find in farts – methane.
Methane has been detected on Mars a number of times in the past, but most detection remained the subject of debate. Now, the European Space Agency’s (ESA) Mars Express Orbiter has corroborated those findings, settling the debate once and for all, and spurring a whole series of new ones.
Within astrobiologist circles, methane is considered to be a “possible biosignature.” What that means is, the presence of methane in an alien environment could be indicative of life as we know it. While there are geological processes that can produce methane, the vast majority of naturally occurring methane found on Earth is produced by living creatures.
“While previous observations, including that of Curiosity, have been debated, this first independent confirmation of a methane spike increases confidence in the detections,” said the ESA study’s lead author Marco Giuranna of Rome’s Istituto Nazionale di Astrofisica.
The methane that’s been detected could certainly have been created on Mars without any life present whatsoever. A geological process known as serpentinization is also capable of producing methane in areas where both heat and liquid water are present. However, on Earth, the vast majority of methane created actually comes from microbial life that releases methane as a waste product. What makes this confirmation an important potential indicator for life is that those microbes (called methanogens) thrive in oxygen-deprived environments, as well as inside the digestive tracts of animals.
Put simply, places where methane is detected on Mars could (at worst) lead scientists to pools of liquid water beneath the planet’s surface. At best, they could lead scientists to thriving colonies of Martian microbes.
“I think the game is afoot,” said Michael J. Mumma, a scientist at NASA’s Goddard Space Flight Center. “The story is continuing to evolve, and evolving rapidly now.”