For 15 years, the search for life on Mars increased to a great extent and during this period, methane (An Organic Molecule linked with life on Earth) was observed. Since that time, attempts to study Mars’ atmospheric methane have produced varying results. In some cases, it was found in Normal concentration, in some, it was found in higher concentrations, while absent in others.
A recent study of a special team from Aarhus University stated that they have been looking for possible ways to remove methane gas from the atmosphere of Mars. Methane production on Mars varies from about 0.24 parts per billion (ppb) in winter to about 0.65 ppb during summer in the northern hemisphere.
Extended plumes were detected by Curiosity, one in December of 2014 and in June 2019. This indicates that it is released periodically from discrete regions. Different methods have been proposed for the production and disappearance of Methane over several years. In the case of production, these range from non-biological processes such as serpentinization to biological production by microbes.
As for how it is removed, that has remained a mystery as well, but even more so.
The most prominent mechanism for disappearance of methane known to us is photochemical degradation. It is the process of breaking down of Methane into carbon dioxide, formaldehyde, and methanol by UV radiation from the sun. However, this process cannot evaluate the rate of methane disappearance, which is a crucial part of the process.
In the scientific journal Icarus, the research team from Aarhus University’s laboratory proposed that wind-driven erosion (Saltation) could be responsible for the ionization of methane into compounds such as methyl (CH3), methylene (CH2), and carbyne (CH).
With the help of Mars-analog minerals such as basalt and plagioclase, the team detected that ionized methane during the erosion process reacts and bonds with the mineral surfaces. Also, in plagioclase which is a major component in Mars’ surface material, silicon atoms combine with methyl groups obtained from methane.
Based on these results, the team concluded that this mechanism is much more effective than the photochemical process and could explain how methane is removed from the Martian atmosphere and deposition within its soil in the monitored time period. These findings have the most interesting significance on the existence of life on Mars.
Further, the team proposes to carry out studies to investigate bound Methane (complex organic material) if it is originated on Mars or have been deposited by meteorites. Precisely, they want to see if the same erosion process is responsible for changing or removing of atmospheric methane.
The conclusion drawn from these investigations will guide future Mars mission like the ESA’s ExoMars 2020 rover and NASA’s Mars 2020 rover and will hopefully clear up important questions regarding the existence of life on Mars and preservation of organic materials there.