it’s almost 10 years now Curiosity Gail travels to the crater. NASA rover returns after ten years astronomers data that helps them rebuild history bit by bit Mars planet, and today, researchers A disturbing signature has been found in Martian soil samples. The kind of signatures associated with our good old earth… to biological processes!

Does this mean that astronomers have finally got their hands on the Grail? that he discovered evidence of the existence of forms of extraterrestrial life , Let’s not go too soon. because even if researchers qualify their observations as“very interesting”, taking into account other plausible processes they already have to explain them. scenarios “unconventional”, sure, but who needs to be found out before being able to draw conclusions.

But what did they actually discover? rocks with isotopic compositions of carbon shocking. Remember that carbon has two stable isotopes. Carbon 12 and Carbon 13. And since the former reacts faster than the latter, analyzing their relative amounts in a sample gives researchers useful information. In sedimentary rocks When analyzed by Curiosity, they found samples that were particularly high in carbon 13 and others that were surprisingly low in carbon 13.

galactic cloud or ultraviolet

on the Earth, sediment Also low in carbon 13 are those that are exposed to biological activity. A methane consuming microbial mat (CH.)₄), for example. But researchers cannot currently confirm that a similar process took place on Mars. The presence of rocks depleted in carbon 13 may also be due to the passage of our Solar system in one Cloud Galactic Molecules – Seems to Happen Every 200 Million Years – Or For Its Breakdown carbon dioxide (C0₂) by radiation ultraviolet(UV).

Is the first scenario possible? For this, the astronomers report, it would be necessary for the galactic cloud to have previously experienced a drop in temperature on Mars. For making Glaciers, On which the dust could settle and stay when the snow melted. Leaving behind a layer of carbon-13-poor sediment. But so far, there is very limited evidence of the presence of glaciers past Gale Crater.

Is the UV track more promising? Here again, nothing really allows us to draw conclusions at the moment. Studies show that ultraviolet radiation CO. can change₂ In organic compounds of the formaldehyde type. But researchers will need more experimental results to be sure.

A biological signature?

with all necessary precautions matter Astronomers are also considering a scenario that would put extraterrestrial biological processes at the center of the story. Inspired by those who are known on earth. From bacteria Surface that would have generated a unique carbon signature by releasing methaneAtmosphere Inhabitant of Mars. UV radiation did it. would have changed molecules The larger and more complex ones that would eventually rain down on the surface and now may be preserved in Martian rocks with their distinctive carbon signatures.

“On Earth, the processes producing the carbon signal we detect are biological”Confirms Christopher House, researcher of Pennsylvania State University (United States of america). We need to understand whether the same explanation works for Mars as well.” Because the red planet is very different from us. Smaller, cooler, with weaker gravity and a different initial isotopic mixture than Earth. “On our planet, there is life everywhere we look. And it affects the carbon cycle. Preventing us from studying what it might be like in the absence of life.”

Astronomers are now waiting to find out whether Curiosity will find similar signatures at other sites. They also hope that p. be able to analyze the carbon content ofmethane painReleased by the surface as if incidentally crossed by the rover in 2019. Contains a material that may or may not be valid, hypothesis Microorganisms,