According to French scientists, ancient Mars may have possessed an environment capable of supporting a subterranean planet teeming with tiny creatures. The researchers determined that if these primitive life forms existed, they would have affected the environment so deeply that they would have precipitated a Martian Ice Age and suffocated themselves. According to the study's primary author, Boris Sauterey, currently a postdoctoral researcher at Sorbonne University, the findings present a dismal portrait of the cosmos' ways. Even basic life, such as bacteria, may frequently bring its own extinction.
He stated, "The results are a little bleak, but I believe they are also very stimulating." They encourage us to reconsider how a biosphere and its world interact.
Sauterey and his colleagues utilized climate and terrain models to evaluate the habitability of the Martian crust some 4 billion years ago, when the red planet was expected to be flush with water and far more habitable than it is today, according to a research published in the journal Nature Astronomy.
They hypothesized that hydrogen-consuming, methane-producing bacteria may have thrived just under the surface back then, with several inches (a few tens of centimeters) of soil protecting them from severe incoming radiation. According to Sauterey, these creatures may have swarmed wherever on Mars that was not covered by ice, much as they did on early Earth. However, the early Mars' supposedly wet, warm environment would have been imperiled by so much hydrogen drawn out of the thin, carbon dioxide-rich atmosphere, according to Sauterey. As temperatures dropped over 400 degrees Fahrenheit (200 degrees Celsius), any creatures on or near the surface would have dug deeper in an attempt to live.
According to the researchers, given the nitrogen-dominated atmosphere, bacteria on Earth may have helped preserve temperate temperatures. According to Kaveh Pahlevan of the SETI Institute, future simulations of Mars' climate must take the French study into account. Pahlevan also conducted second recent research that claimed Mars was born wet, with warm waters that lasted millions of years. Back then, the atmosphere was thick and mainly hydrogen, acting as a heat-trapping greenhouse gas that was eventually carried to higher altitudes and lost to space.
According to Pahlevan, French research looked at the climatic consequences of potential microorganisms when Mars' atmosphere was dominated by carbon dioxide and so is not applicable to previous eras. What their research shows is that "if (this) life was present on Mars" at this earlier age, it would have had a significant impact on the existing environment.
What are the greatest areas to seek for remnants of this previous life? The undiscovered Hellas Planita, or plain, and Jezero Crater on the northern side of Isidis Planita, where NASA's Perseverance rover is now gathering rocks for return to Earth in a decade, are suggested by French researchers.
Sauterey's next task is to investigate the likelihood of microbial life still existing deep inside Mars. He wondered if microorganisms descended from this primordial ecosystem may still occupy Mars today. If so, where is it?
Journal Information: Boris Sauterey, Early Mars habitability and global cooling by H2-based methanogens, Nature Astronomy (2022). DOI: 10.1038/s41550-022-01786-w. www.nature.com/articles/s41550-022-01786-w