Mars emits methane , the European Space Agency Mars Express orbiter has confirmed, but scientists cannot yet say whether the source is geological or biological.
E l methane gas periodically enters Mars atmosphere; That notion, previously considered implausible and puzzling, is now widely accepted by planetary scientists. But where does the methane come from? It is still a puzzling mystery. It can even target modern-day Martian microbes that live in rocks below the surface.
We may be one step closer to breaking the mystery of methane on Mars.
NASA’s mission with the Curiosity rover detected two methane surges within the 60-mile-wide Gale crater on the red planet, once in June 2013, and then again in late 2013 through early 2014.
These findings have puzzled astrobiologists, because methane is a possible biosignature. Although gas can be produced by a variety of geological processes, the vast majority of the methane in Earth’s air is pumped out by microbes and other living creatures.
Some answers will soon be on the horizon, as the June 2013 detection was just reaffirmed thanks to the Mars Express orbiter that also noticed the gas spike from that spacecraft’s position on Mars.
“While previous observations, including that of Curiosity, have been debated, this first independent confirmation of an increase in methane increases confidence in the detections, ” said Marco Giuranna, of the Istituto Nazionale di Astrofisica in Rome and lead author of the study that publishes the journal Nature .
The researchers used data collected by Mars Express’ Planetary Fourier Spectrometer (PFS) instrument, which also detected traces of methane from the red planet in 2004. (The spacecraft has been orbiting Mars since December 2003).
It is difficult to measure the red planet’s methane from the orbit of Mars , for a variety of reasons, including the weak absorption of the gas; So the team developed a new approach to selecting, processing, and analyzing PFS data. For the new study, they applied this approach to measurements made at Gale Crater during the first 20 months of Curiosity’s mission to Mars.
They found a hit: a peak of about 15.5 parts per trillion methane by volume on June 16, 2013. That was just one Martian day after Curiosity detected a peak of nearly 6 parts per trillion. First orbital confirmation of a methane source on Mars.
“Although parts per billion in general mean a relatively small amount, it is quite remarkable for Mars, our measurement corresponds to an average of about 46 tons of methane that was present in the area of 49,000 square kilometers observed from our orbit, ” he says Giuranna.
The researchers noted in the new study that “methane could be released sporadically along faults that cut through the permafrost due to partial melting of ice, gas pressure build-up induced by gas build-up during migration or migration. stress due to planetary adjustments or impact of local meteorites “.
There is still much left to do
The work does not address the ultimate origin of the methane, whether it was produced by Martian microbes or by reactions involving hot water and certain types of rock. And scientists don’t know if the methane detected was produced a short time or a long time ago; it could have been trapped under the ice for eons ago.
On the positive side, this new research could help scientists get to the bottom of these questions over time, as Mars Express and other spacecraft – and satellites – such as the ExoMars Trace Gas Orbiter (TGO), part of the program European-Russian ExoMars, will be shipped to Mars in the next few years.
Referencia: Independent confirmation of a methane spike on Mars and a source region east of Gale Crater. Marco Giuranna, Sébastien Viscardy, Frank Daerden, Lori Neary, Giuseppe Etiope, Dorothy Oehler, Vittorio Formisano, Alessandro Aronica, Paulina Wolkenberg, Shohei Aoki, Alejandro Cardesín-Moinelo, Julia Marín-Yaseli de la Parra, Donald Merritt & Marilena Amoroso. Nature Geoscience (2019) DOI: https://doi.org/10.1038/s41561-019-0331-9
