The mystery of the presence of methane on Marsdecades tormented the minds of scientists. However, a comparison of observational data collected by the European Space Agency’s Mars Express orbital spacecraft and the Ciuriosity rover of NASA’s aerospace agency made it possible not only to confirm the presence of methane in the atmosphere of the Red Planet, but and establish its most likely source. A press release on the results of this study was published on the ESA website, and full details in the journal Nature Geoscience.
On Earth, sources of huge methane emissionsAtmosphere are all sorts of living organisms (the main one is agricultural animals), but a certain percentage of it is associated with geological processes. The trouble is that a high concentration of methane in the atmosphere enhances the processes of greenhouse effects on the plan even more than the high concentration of carbon dioxide in the air. But, fortunately, unlike the latter, methane does not linger long in the atmosphere. These two facts certainly increase the interest of detecting methane on Mars, a planet very similar to Earth, since its presence may be due to biological sources.
When the Curiosity rover just started itswork on our planetary neighbor, the rover, to the great disappointment of scientists, could not “smell” the presence of methane in the Martian air. However, in 2014, the device still confirmed the presence of high bursts of its emissions, which suggests that its concentration in the atmosphere is replenished from time to time.
One such gas emission rover found 15June 2013, when the equipment of the autonomous Martian scientific laboratory determined a surge in the level of methane in the atmosphere in the ratio of six parts per billion. Even higher concentrations of methane were confirmed by another spacecraft. Analysis of the data of the Mars Express orbital probe showed researchers the release of methane into the atmosphere at a ratio of 15 parts per billion next to one of the zones over which it flew.
“Although a few parts per billion in a general sensethey speak of an insignificant amount of methane in the atmosphere, the very fact of its presence is important here. The data obtained from the orbit, as well as our calculations say that in the Martian atmosphere, on average, there can be about 46 tons of this gas, and all this volume was recorded on a certain area of about 49,000 square kilometers, ”commented Marco Juranna, head of the new study. National Institute of Astrophysics of Rome.
The next step for scientists in the new studywas an attempt to determine the likely source of methane. By the time the Curiosity rover first determined the presence of gas in the atmosphere of the Red Planet, scientists were of the opinion that methane was formed somewhere in the northern hemisphere of our planetary neighbor, and powerful winds that are not uncommon on Mars blew it closer to the equatorial zone of the planet.
To narrow the search, scientists spent millionscomputer simulations of methane emissions into the atmosphere around the Martian crater Gale - a place that is currently being explored by the rover Curiosity. In their computer models, scientists took into account the volumes of methane in the atmosphere, which were calculated based on data obtained by the orbital probe and the rover, as well as various expected types of atmospheric circulation, together with the likely intensity and duration of methane emissions, taking into account knowledge of the same processes, but occurring on earth.
In addition, an analysis of geologicalfeatures around Gale Crater. Scientists have tested this area for probable emission sources. Interestingly, both analyzes indicated the same probable source. This is a region of volcanic origin Medusae Fossae, with a length of over 1000 km. It is located just south of the Martian equator.
"We have identified the availability in this areatectonic faults, the depth of which may be below the point at which, according to the assumptions, ice reserves may be contained, ”says study co-author Giuseppe Etiope of the National Institute of Geophysics and Volcanology of Rome.
“Since permafrost conditions are in factexcellent for sealing and holding methane under the surface, it is likely that the ice in these tectonic faults breaks from time to time, releasing the accumulated stock of methane into the atmosphere, ”adds the researcher.
The researchers are going to continue to monitor the emissions of methane on the Red Planet with the help of new rovers and orbiters, which should go there in the next decade.
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