14 DAY TRIAL // NASA is now convinced that there is no methane in the Martian atmosphere, after extensive testing by the Curiosity rover was unable to detect the gas in any quantity. This is somewhat surprising and disappointing. Several previous missions gave hints of methane being available in the thin Martian atmosphere.
The presence of the gas would be a great indicator for life as well, though its absence doesn't necessarily mean there is no life on Mars, just as its presence wouldn't be proof that there is.
Curiosity has provided a final report on the matter, with scientists concluding that the gas simply isn't there. The rover sampled the atmosphere on six different occasions, from October last year to last June and found no traces of the gas.
Based on the sensitivity of the instrument used in the detection, scientists estimate that, if there is methane on Mars, it's less than 1.3 parts per billion, six times less than what some previous estimates predicted. A detailed paper on the research will be published by Science Express.
"It would have been exciting to find methane, but we have high confidence in our measurements, and the progress in expanding knowledge is what's really important," the paper's lead author, Chris Webster of NASA's JPL, said. "We measured repeatedly from Martian spring to late summer, but with no detection of methane," he added.
However, NASA is not giving up just yet. The Tunable Laser Spectrometer, which is used to detect methane and is part of the SAM (Sample Analysis on Mars) instrument, can use another method to detect methane at concentrations well below 1 parts per billion, by concentrating the gas, if there is any.
This is what NASA plans to do next so, if there is some methane on Mars, Curiosity should find it. However, finding no methane so far is an indicator that there's currently no mechanism on the planet that produces the gas in any significant amount.
The lack of methane in the atmosphere is no proof that there is no life currently on Mars, as there are plenty of organisms on Earth that don't produce methane. But it does rule out at least some types of organisms.
