Scientists have discovered that there is methane on Mars, but they don’t know how it got there and why its values increase periodically: here’s the new theory.
Apparently, Mars continues to be a source of surprises for scientists: recently, the Curiosity rover discovered that methane is seeping from the Gale crater, the values of which are not constant but constantly changing. It seems to be a real mystery, capable of leaving researchers speechless. A new study, however, proposes one extremely fascinating theorylet’s find out what it is.
Methane on Mars: why it’s a mystery
During his surveys inside the Gale crater, the Curiosity rover has made a surprising discovery: methane is seeping from the Martian surface. Why is this a bizarre discovery? On Earth, most methane is produced by living creatures. And since we still have no definitive evidence of the existence – current or past – of life on Mars, it is not clear what the gas is doing in that area. However, the data does not lie: SAM (Sample Analysis at Mars), Curiosity’s chemical laboratory, detected significant traces of methane.
According to scientists, it may come from some geological mechanisms involving water and rocks deep underground. But what makes everything more complicated is another detail: methane behaves in unexpected ways, filtering at night and disappearing during the day, also seeing its levels increase (up to 40 times higher than normal) in some seasonal periods. Furthermore, it does not accumulate in the atmosphere, as revealed by ESA investigations. “It’s a story with many twists and turns,” he said Ashwin Vasavadaa researcher at NASA’s Jet Propulsion Laboratory, who is leading the Curiosity mission.
The permafrost theory
To address this mystery, a team of scientists has proposed a very interesting new theory, published in Journal of Geophysical Research: Planets. Second Alexander Pavlov, a planetary scientist at NASA’s Goddard Space Flight Center, and his researchers, it is possible that the methane is protected by a solidified layer of salt that would have formed in the Martian regolith. As the temperature rises, the gas could weaken this frozen layer and escape. Also there pressure of a rover stepping on it could cause the salt surface to break, just as happens with Curiosity.
This would explain why the methane was detected only at Gale crater – the only other rover on Mars is Perseverance, but it does not have an instrument on board to detect gases. The hypothesis arose following an experiment conducted a few years ago on the Martian permafrost, which did not produce the desired results. However, it revealed the formation of a layer of frozen salt that could crack as a result ice sublimation same. Further experiments conducted by Pavlov demonstrated that this indeed happens.
“Methane experiments require a lot of resources, so we have to be very strategic when we decide to conduct them” – he explained Charles Malespin, a researcher involved in the study. In order to find confirmation of the proposed theory, it will be necessary to wait a little longer: we will probably need to other instruments to send to Mars, so they can continuously measure methane. In fact, Curiosity can only do this for a short time, then leaving room for other studies for which it was designed.
