After waves of promising discoveries, NASA announced in September that they had detected no trace of methane in Mars’s atmosphere. Finding the gas would have been a strong hint familiar life was lurking that somewhere on the Red Planet. But without it, the task of finding life on Mars just got a lot harder.
Kenneth Chang, reporting for the New York Times:
The conclusion, published in the journal Science, comes from the fact that Curiosity has been looking for methane, a gas that is considered a possible calling card of microbes, and has so far found none of it. While the absence of methane does not rule out the possibility of present-day life on Mars — there are plenty of microbes, on Earth at least, that do not produce methane — it does return the idea to the realm of pure speculation without any hopeful data to back it up.
The rover Curiosity sampled the planet’s thin atmosphere for several months as it rolled across Gale Crater, providing scientists with the amount of data they needed to reach their conclusions.
Despite the disappointment, Curiosity has had a successful year. It confirmed the presence of the elements necessary for life (carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur), discovered water locked in Mars’s soil, and uncovered evidence that Gale Crater may have once held a massive freshwater lake.
There’s certain to be more discoveries in 2014 as Curiosity makes its way to the base of Mount Sharp. In the meantime, scroll through our timeline to see what the hardy rover has done so far.