Curiosity phones home with some interesting news on Mars that has some scientists scratching their heads: it detected methane. The substance is common in the outer solar system, but the methane detected on Mars came in “whiffs,” apparently from the ground. And while that’s not a smoking gun for life, it is consistent with the kind of microbes that might theoretically eek out a living under the cold, dry surface of the red planet in spots thought to be warmer and wetter:
The NASA scientists at AGU led by MSL project scientist Dr. John Grotzinger emphasized that they do not yet know how the methane is being generated. The process could be biological or not. There are abiotic chemical processes that could produce methane. However, the MSL SAM detections were daily spikes and represent an active real ongoing process on the red planet. This alone is a very exciting aspect of the detection.
The team presented slides to describe how methane could be generated. With the known low background levels of methane at ~ 1 part per billion, an external cosmic source, for example micro-meteoroids entering the atmosphere and releasing organics which is then reduced by sunlight to methane, could be ruled out. The methane source must be of local origin.
Back during the heady days of the Martian meteorite announcement, almost 20 years ago now, I had to endure Pat Buchanan opining on national TV that it’s unlikely Mars would have life and that there’s no possibility of intelligent life elsewhere in the Universe. His contorted reasoning was some convoluted theological malarkey that the Bible rules it out. How the hell that made it on to a news segment about planetary science, I have no idea. But there he was spouting away on Nightline, if memory serves, using up precious network time pitching utter nonsense … and that early example of the willful stupidity yet to come from his wingnut ilk always stuck with me.
Well, Pat might be right about Mars, even if his reasoning was suspect to say the least. But in better informed and less superstitious circles, speculation goes that a dozen or more meters below the surface, the overburden creates enough pressure for water to exist as a liquid. Because of the planet’s eccentric orbit and/or residual heat, it’s possible warmth flows through deep cracks in the crust created when the surface cooled dramatically billions of years ago or subsequently formed by large impacts. The latter is a near statistical certainty. Mars sits adjacent to the main asteroid belt, it’s a veritable cosmic shooting range out there.
That warm water could provide a reservoir giving rise to either abiotic or biological processes that produce methane. Bottom line: it’s not outside the realm of possibility that Mars is harboring a unique science-y gift, carefully wrapped in ancient layers of red soil and oxidized rock, just waiting for the next generation of wonder junkies to discover.