NASA's Mars rover rock samples may contain evidence of microbial life

This mysterious rock, found in a valley that probably had a river at its heart, quickly excited scientists.

This is a major new step in the search for traces of ancient life on the Red Planet. NASA's Perseverance rover has made a significant discovery by taking a rock from Mars that could contain fossilized microbes, it was announced Thursday, July 25. NASAThe Red Planet, whose current climate is extremely arid, had abundant rivers and lakes billions of years ago, which have now evaporated.

On July 21, the rover took a sample from the surface of Mars from an arrowhead-shaped rock called Chiava Falls, which could contain fossilized microbes dating back several billion years, when the planet had water. The mysterious rock, found in the Neretva Valley, which was once home to a river, quickly puzzled scientists. And for good reason: Three suggestive signs of ancient microbial life have been observed on its surface.

NASA describes white veins of calcium sulfate running the entire length of the rock, a sign that water once passed through the rock. Between these veins is a reddish central area filled with organic compounds, according to the rover's Sherlock instrument, which is used to identify biological signatures in rocks.

Finally, small light spots surrounded by black were observed, similar to those found in a tiger. The latter resemble spots associated with the presence of fossilized microbes, according to analyses carried out by the “Pixel” device, which studies their chemical composition.On Earth, this type of feature in rocks is often associated with fossilized traces of microbes that lived underground. David Flannery, an astrobiologist and member of the Perseverance science team, explains to AFP.

To be sure they are evidence of ancient microbial life, the samples will need to be analyzed in a laboratory on Earth. NASA plans to bring them back, thanks to another mission planned for the 2030s.