New research has revealed that seismic activity on Mars could release trapped hydrogen which has the potential to support microbial life.
Microbial life on Earth is extremely versatile and can thrive in some remarkable conditions. It can also use energy sources that are very different to what humans require, such as sulphur and hydrogen.
There are microbes deep within the subsurface of the Earth which use molecular hydrogen as an energy source and it is possible that such bacteria could also exist on Mars if there was sufficient hydrogen. These types of microbes are known as “hydrogenotrophic”.
Sean McMahon from Yale University, and colleagues, studied rocks found near seismic faults on Earth and found that there is enough hydrogen trapped in these rocks which could act as a microbial energy source. Their research paper appears in the September issue of the journal Astrobiology.
“Faults change the rocks around them quite dramatically, forming new rock types,” explained McMahon. “If the friction is intense enough, the rocks on the fault can melt, flow, and rapidly cool into a glass, trapping gases within the glass.
“At lower intensities of friction, the rocks break into pieces which become cemented together forming a new type of rock full of microscopic fractures. We believe that the gas can be trapped on these tiny, sealed fracture planes.”
If a similar process occurred on Mars in order to trap hydrogen, then seismic activity on Mars – known as marsquakes – could release some of this hydrogen as the rocks grind together.
However, even if hydrogenotrophic microbial life were to exist on Mars near fault lines, the infrequent releases of hydrogen would mean that these microbes would spend most of their time dormant, unless there were other sources of hydrogen that they could use.
Earth is extremely seismically active as there is plenty of heat in the interior that powers the plate tectonics and triggers earthquakes. Mars is a much smaller planet, and has cooled to the point where it is no longer very active, however seismic activity should still occur on the Red Planet.
“Theoretically, Mars should be seismically active because of differential cooling of the lithosphere [crust and upper mantle],” McMahon told Skymania News. “What we really need is to put a seismometer on Mars. Thankfully, NASA plans to do exactly this.”
NASA’s InSight mission is due to launch in 2018 and will place a lander on Mars in order to study the deep interior. Searching for biosignatures from any microbes that exist on Mars will not be easy and will be a job for future missions.