Methane is one of the markers of the presence of life, and therefore astronomers pay special attention to its search. Scientists recently discovered that there were no traces of methane left in the atmosphere of Mars - although they were a couple of years ago!
Methane on Mars has gone missing - and now scientists are perplexed. For the first time traces of gas (on Earth this is one of the "markers" indicating the presence of life) were seen in the atmosphere of the Red Planet about two decades ago. However, researchers today reported that the satellite never detected any signs of methane in the atmosphere. If these data are confirmed, then the dream of scientists about bacteria that spew gas somewhere in the bowels of the planet may even die.
The Mars Express orbiter first detected hints of methane in the Martian atmosphere in 2004. However, then some experts stated that the equipment of the orbital device is not sensitive enough to obtain a reliable result. 10 years later, the Curiosity rover also found traces of methane (almost 7 ppb) while exploring Gale Crater. A few years later, astronomers, using the same rover, deduced a small seasonal cycle, where the peak methane levels were already at the level of 0.7 billion shares - that is, 10 times less!
To unravel this mystery, ESA launched the TGO probe to Mars in 2016. It is equipped with two sensitive spectrographs - the Belgian NOMAD system and the Russian ACS - which can detect even very low methane concentrations. Both instruments analyze horizontal slices of the Martian atmosphere and, scientists say, they still perform excellently. Now the researchers are in complete confusion: even though there are now a lot of "noise" in the data that has yet to be filtered out, it is already quite obvious that there is no methane in the atmosphere of Mars!
The Curiosity team suspected that the cyclical nature of methane emissions was provided by sources from the interior of the planet (perhaps not only geological, but also organic). Now this hypothesis has received even more arguments - scientists know for sure that methane does not come from outside. There is another mysterious circumstance: astronomers suspect that every year hundreds of tons of organic substances enter the Martian atmosphere along with cosmic dust, which, when burned, should also form methane. The question is - where did all this huge mass of matter disappear?
So far, astronomers have no answer. TGO will continue to operate until 2022, so while humanity still has a small chance to unravel the mystery of Mars. It remains to be seen what other secrets the Red Planet will present to us in the future.
Vasily Makarov