Mars methane gas discovery may hint at some form of present-day life on the planet

Newly-released data from NASA’s Mars Curiosity rover may re-ignite the debate of the possibility of life on the Red Planet.

New rover findings suggests that low levels of methane skyrocketed ten fold over a two-month period. The same gas in Earth’s atmosphere is mostly the result of daily biological activity.

These exciting results now suggests that methane is being produced or vented, and quickly dispersed around the Gale Crater landing site.

“Strictly speaking, our observations are evidence for methane production on Mars, and in themselves cannot directly provide evidence of microbial life,” said Chris Webster, lead author form NASA’s Jet Propulsion Laboratory in Pasadena, California. “However, from our positive detection of methane on Mars, we cannot rule out the possibility that both the low background level and the high methane values originate in part from microbial activity (methanogenesis).

“Our peak observed values correspond to about 5,000 tonnes of methane in the whole martian atmosphere, compared to 500 million tonnes in Earth’s atmosphere – most of which on Earth is biologically produced.”

Recent observations indicate that either the source has shut off or the wind field at the source location has changed and is directing away from the rover.

“So at this time, we have no idea what we will see in the future, or if we will ever see high values again,” Webster said.

One of the most intriguing mysteries brewing the past decade about Mars has centred on claims of methane gas hotspots in its atmosphere.

So not surprisingly, when Earth-based telescopes and Mars orbiters showed tentative hints of this trace gas on Mars, a debate began on whether it could be a result of present-day biological activity or signify other non-biological processes.

NASA, of course, immediately had Curiosity on the case when it landed in August 2012, ordering the rover to sniff the Martian air.

Interestingly, the one-ton, roving geo-chemisity lab had initially detected very little methane within its landing site, Gale Crater. In fact, scientists were reporting some 600 times less methane than the amount we see in Earth’s atmosphere.

So researchers interpreted this as as meaning that the conditions on ancient Mars may have been conducive to life at one point, but today’s environment may just be too harsh for life to exist. So these new findings, reported in the journal Science this week, has left scientists dumbfounded.

“We thought that we had laid the matter to rest, but then were surprised to see the high levels emerge last Thanksgiving,” Webster said.

“We believe that time is what changed, not rover location, and that clearly Mars is active over a timescale shorter than the expected lifetime of methane [which is 300 years].”

NASA believes that the source is north of Curiosity – and close – however it is nearly impossible to define its precise location. And it may remain a mystery for the time being, since the mission has its sights on its prime goal of investigating the sedimentary layered rocks at the base of the crater’s central mountain.

“With the emphasis on studying Mt. Sharp, it would not be possible to send the rover on a wild goose chase to search for a source we cannot accurately locate,” Webster said.

So the hope now is that other Mars assets from other space agencies may add their own pieces to the methane puzzle.

Over the next few months, India’s Mars orbiter, Mangalyaan, will also try to sniff out potential sources of methane gas. And in 2018, the European ExoMars mission may also help contribute to solving this mystery.

Webster and his NASA team believe that this is indeed an important discovery that may very well tell us about how the building blocks of life may be delivered not only to Mars but also to other planets in the solar system.

“Meanwhile, this episodic release tells us that we do not fully understand the behaviour of the Martian atmosphere at a time when human exploration is being considered,” he added.