Study: Mars could have been full of microbial life
CAPE CANAVERAL, Fla. – Ancient Mars may have had an environment capable of harboring an underground world teeming with microscopic organisms, French scientists reported Monday.
But if they existed, these simple lifeforms would have altered the atmosphere so profoundly that they triggered a Martian ice age and snuffed themselves out, the researchers concluded.
The findings provide a bleak view of the ways of the cosmos. Life – even simple life like microbes – “might actually commonly cause its own demise,” said the study’s lead author, Boris Sauterey, now a post-doctoral researcher at Sorbonne University.
The results “are a bit gloomy, but I think they are also very stimulating,” he said in an email. “They challenge us to rethink the way a biosphere and its planet interact.”
In a study in the journal Nature Astronomy, Sauterey and his team said they used climate and terrain models to evaluate the habitability of Mar’s crust some 4 billion years ago when the planet was thought to be flush with water and much more hospitable than today.
They surmised that hydrogen-gobbling, methane-producing microbes might have flourished just beneath the surface back then, with several inches of dirt, more than enough to protect them against harsh incoming radiation. Anywhere free of ice on Mars could have been swarming with these organisms, according to Sauterey, just as they did on early Earth.
Early Mars’ presumably moist, warm climate, however, would have been jeopardized by so much hydrogen sucked out of the thin, carbon dioxiderich atmosphere, Sauterey said. As temperatures plunged by nearly minus-400 degrees Fahrenheit, any organisms at or near the surface likely would have buried deeper in an attempt to survive.
The best places to look for traces of this past life? The French researchers suggest the unexplored Hellas Planita, or plain, and Jezero Crater on the northwestern edge of Isidis Planita, where NASA’s Perseverance rover currently is collecting rocks for return to Earth in a decade.