NASA's curiosity vehicle discovered "surprisingly high amounts of methane in Mars air" on Wednesday, which could be a sign of life on the Red Planet, the New York Times reported on Saturday.
Detection of methane would be a major discovery because, as the Times has noted, it breaks down within a few centuries because of sunlight and chemical reactions – which means that it would have to have been generated recently in historical terms. High levels of methane could be generated underground by microbes called methanogens that survive without oxygen and produce gas as a by-product of metabolism. Project scientist Ashwin R. Vasavada told the Curiosity science team in an e-mail, "Given this surprising result, we have reorganized the weekend to do a follow-up experiment," the Times wrote.
Readings on Wednesday are more than three times greater than a sudden peak in 2013, which lasted several months; After finding nothing after its landing in 2012, Curiosity detected approximately seven parts per billion methane at the end of the year. The most recent measurements are 21 parts per billion.
However, it is also possible that the Curiosity rover has detected pockets of methane leaking from inside the surface, the Times wrote, and the readings are only preliminary. When methane was detected similarly on the surface of Mars in 2004, scientists said that methane could also be generated by geothermal reactions involving water and heat, although the exact mechanism by which this could occur on Mars remained an open question. (Since then, research has suggested that Mars may not be as geologically inert as previously thought.)
The Times wrote:
Curiosity scientists developed a technique that allowed the rover to detect even smaller amounts of methane with its existing tools. The gas seems to rise and fall with the seasons of the red planet. A new analysis of the old Mars Express readings confirmed the findings of Curiosity in 2013. A day after Curiosity reported a methane peak, the orbiter, through the Curiosity location, also measured a peak.
But the Trace Gas Orbiter, a new European spacecraft launched in 2016 with more sensitive instruments, did not detect any methane in its first batch of scientific observations last year.
Scientists at Mars Express, Curiosity and Trace Gas Orbiter were discussing the findings, but there is still "a lot of data to be processed." Mars scientist Marco Giuranna, of the National Institute of Astrophysics in Italy, ".
The Curiosity rover was currently diverted from its scientific work scheduled to follow methane readings, according to the Times, with more data expected on Monday.[New York Times]