Amid a number of discoveries announced at the American Geophysical Union's fall meeting, researchers have revealed that the Martian Jezero crater s was formed from molten volcanic magma. Organic molecules have also been isolated by the Perseverance rover in certain rocks on Mars.
First of all, who says "organic molecules" doesn't necessarily mean "proof of life". These compounds simply offer carbon-hydrogen bonds and canalso form through non-biological processes . Moreover, such molecules have been identified several times on Mars, more recently by the Curiosity rover.
That being said, this new discovery made in the heart of Jezero Crater (once filled with water) is significant. Indeed, it proves that the rocks analyzed by the Perseverance rover can protect these compounds. By extension, we could therefore imagine that biological organic matter, if present, could also be preserved .
The detection was carried out using Scanning Habitable Environments with Raman &Luminescence for Organics &Chemicals (or SHERLOC for short). It is one of the main instruments of the rover. Molecules of this type have been identified in the rocks cored by the rover in order to collect samples, but also in the surrounding dust. Upcoming analyzes will be carried out to try to determine how these organic materials could have been produced .
The Planetary Instrument for X-ray Lithochemistry (or PIXL), another instrument from Perseverance, also allowed researchers to learn more about Jezero Crater's bedrock. After taking a core from an area dubbed "Brac", PIXL data indeed clearly showed the presence of olivine crystals embedded in pyroxene crystals.
On Earth, such a mineral configuration is of igneous origin. In other words, the bottom of the Jezero crater would therefore have formed from hot magma .
"A good geology student will tell you that such a texture indicates that the rock was formed when the crystals grew and were deposited in a magma that cools slowly, for example a thick lava flow, lava lake or magma chamber “, details Ken Farley, of the California Institute of Technology.
This rock would then have been weathered by water several times. Its analysis will therefore allow scientists to better understand the history of this crater.
