Mars Needs Beano

More methane on Mars:

“Methane is quickly destroyed in the Martian atmosphere in a variety of ways, so our discovery of substantial plumes of methane in the northern hemisphere of Mars in 2003 indicates some ongoing process is releasing the gas,” said Michael Mumma of NASA’s Goddard Space Flight Center in Greenbelt, Md. “At northern mid-summer, methane is released at a rate comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, Calif.” Mumma is lead author of a paper describing this research that will appear in Science Express on Thursday.

Methane, four atoms of hydrogen bound to a carbon atom, is the main component of natural gas on Earth. Astrobiologists are interested in these data because organisms release much of Earth’s methane as they digest nutrients. However, other purely geological processes, like oxidation of iron, also release methane.

“Right now, we do not have enough information to tell whether biology or geology — or both — is producing the methane on Mars,” Mumma said. “But it does tell us the planet is still alive, at least in a geologic sense. It is as if Mars is challenging us, saying, ‘hey, find out what this means.’ “

Previous posts on Mars methane here and here.

As I’ve said before, extant life on Mars (or just the possibility of it) is a mixed blessing.

On the positive side, a solid indication of life would focus more scientific attention on Mars, and could provide justification for sending humans to explore the planet in person. The benefits from this would be the development of new space technologies and operations experience, and the possibility that humans could, having finally gotten there, maintain a permanent presence as settlers. (And yes, there are no doubt better means of accomplishing the same goal than another wasteful and politics-conflicted government program – or worse, a program based on international kumbayaaism.  Just thinking overly-optimistically here of the potential for such a program to disrupt the chicken-egg problem and provide us with the minimal technology set required to establish a beachhead.)  Plus, it would be interesting as a scientific curiosity, regardless of the origin to which the methane is ultimately attributed – though obviously more interesting if it turned out to be biogenic, since that attribution would merely answer one question while opening up thousands more – and for its potential to completely derail antiscientific nonsense like intelligent design and creationism.

On the negative side, a solid indication of life could prompt arguments to prevent further direct exploration of Mars by landers or (especially) humans, and take settlement of the planet completely off the table.  Such arguments against direct exploration and settlement would center on the risk of biological cross-contamination – concern over some Martian microbe hitchhiking back to Earth and improbably devastating the “defenseless” life on this planet, or that by taking terrestrial biology with us (via microbes on nearly-but-not-perfectly sterilized landers or quite literally by sending human explorers to the surface) we would destroy any scientific value the discovery of life on an untampered-with Mars might yield.¹

Further in this vein, there is the possibility that a Mars inhabited by even primitive life would trigger a trekkish “Prime Directive” response, whereby concerned citizens would seek a prohibition on exploration and settlement of the planet based on the ‘self-determination rights’ of microbes to evolve on their own, without outside interference. 

It’s impossible to predict exactly what the response would be, of course, since it will depend on the circumstances and the prevailing attitudes at the time of discovery.  One hopes rationality will prevail, but one never knows.

¹ For an example of keeping an uninhabited place pristine for scientific purity, examine the case of Surtsey: “The scientists have strict rules against not carrying any seeds to Surtsey – the idea behind no human interference is to witness colonization and secession as naturally as possible.” While the quarantine of Surtsey is a nearly-unique and highly valuable scientific experiment on Earth with negligible effects on anyone else, closing off an entire planet to human activity based on the presence of the most primitive forms of life would be excessive.