Billions of years ago, when it was still a young planet, Mars had the necessary conditions to host life: this is indicated by a simulation published in the journal Nature Astronomy, which tells how the red planet was habitable for bacteria that feed on hydrogen and produce methane , considered among the first forms of life also on Earth. The study, led by the Institute of Biology of the Higher Normal School of Paris (Ibens), also provides the three most likely sites on Mars to look for traces left by these ancient Martian microorganisms.
The possibility that a young red planet, more than 3.7 billion years ago, could be able to host life, has been a hotly debated issue for some time. The evidence gathered so far suggests that Mars, at least for part of its history, has had favorable conditions for the development of life forms, but the probability of this scenario has been very rarely calculated, a gap that the authors of the study, led by Boris Sauterey.
The simulations developed by the researchers indicate that the Martian crust could be a habitable place for bacteria that feed on hydrogen and produce methane, provided the surface was not completely covered by ice. According to the study, moreover, the production of methane by these microorganisms would have caused a progressive lowering of the global temperature by about 40 degrees, forcing the bacteria to move deeper and deeper into the planet’s crust.
The researchers also suggest the three best sites to look for traces of this past: Hellas Planitia, the second largest impact crater on Mars, Isidis Planitia, a plain always located in a large impact zone, and finally the Jezero crater, where in 2021, NASA’s Perseverance rover landed.