So Is There Life On Mars? – Or What?
And Just What Did They Say, Again?
On occasion we get inundated with reports that NASA is about to announce the discovery of life on Mars. Happened last week, again, starting with 16 pt. type on Drudge, with a link to a breathless UK Sun article, declaring that “NASA has (already)/Is about to reveal life on Mars.” Uh-huh.
No one takes that at face value any more, but it’s fun to contemplate.
What did NASA say, incidentally? Seems you have to dig a little deeper to find that. What they found, after years of searching, was Methane. From the New Scientist:
Methane gas in the Martian atmosphere is concentrated in three specific regions, according to the most sensitive measurements yet made. The discovery will likely stoke further debate on the source of the gas, which could be created through geological processes but might be tantalising evidence of life below the Martian surface.
Might be. From Space.com:
Plumes of methane gas detected over certain locations on Mars in 2003 could point to active geological processes on the red planet, or perhaps even to methane-burping microbes deep below the Martian surface, a new study reports.
There is no firm evidence for life on the red planet, however, despite news reports early today suggesting as much. Rather, scientists are puzzled by the new findings.
And from The Universe Today:
Methane has been measured in large quantities in Mars atmosphere over several seasons, meaning Mars is active, either geologically or biologically. “We found methane,” said Dr. Geronimo Villanueva from the NASA Goddard Space Flight Center, one member of a team of scientists reporting on their research at a press conference today at NASA Headquarters. “We can measure not only the methane, and but where it is coming from and when it is being released.” This is the first definitive detection of methane on Mars that includes maps identifying areas of active release. “Mars is active,” said Michael Meyers, lead NASA scientist for the Mars Program, “but we don’t know if it’s because of biology or geology or both.”
Just in case you think I’m poo-pooing entirely the idea that we might find some sort of methane-producing, microbial life on the Red Planet, I’m here to assure you that’s not the case. And here’s the reason. If methane is produced either by biology or by geology, we must ask about evidence of active geological processes on Mars that might give this result. Are there any?
“If there is an “A” line of evidence that makes me think we need to seriously consider biology, it’s the processes in the subsurface that would allow for methane generation that seems slightly more plausible for biology than geochemistry,” she said. “Serpentinization is a simple water/rock reaction and is a process we see only in a few special places on Earth, usually associated with major fracturing and faulting that allows mantle like materials to be exposed to sea water and groundwater. That’s a process that ‘plugs up the plumbing’ and isolates the reactive site, and we don’t see a lot of evidence for major active, deep faulting and uplift that would bring these reactive materials into contact with water.”
In other words, those processes exist, but they are not seen on Mars (and they’re rare on Earth). Of course, it would be very hard to deduce (indirectly) the existences of these processes from a hundred million miles away when you’ve sent no instruments to detect them directly…
Today the existence of microbial life on Mars is far more likely than it was just last week.