A new study published in Science Advances has strengthened one of Perseverance’s most intriguing discoveries on Mars. Researchers have confirmed the presence of organic carbon in two rocks from the Bright Angel formation in Jezero crater – the same region where NASA previously reported a potential biosignature detected by the rover.

The paper was co-led by Ashley Murphy, a postdoctoral researcher at the Planetary Science Institute, and Kyle Uckert, Deputy Principal Investigator of Perseverance’s SHERLOC instrument. Using SHERLOC, mounted on the rover’s robotic arm, the team analyzed Martian rocks with Raman spectroscopy, a non-destructive technique that uses laser light to identify minerals and organic compounds.

The analysis detected macromolecular carbon, or MMC: large, complex networks of carbon atoms found in some terrestrial rocks and meteorites. MMC can form through biological or non-biological processes, so its presence is not evidence of life. However, it is an important marker in the search for Mars’ past habitability.

The organic carbon was found in fine-grained mudstone sediments, as well as near carbonate and sulfate minerals formed during later interactions with water. This suggests that organic material may have been introduced or preserved during more than one stage of Mars’ geological history.

One of the most striking findings is how close the MMC was to the surface – only microns below it. Mars’ surface is exposed to radiation and reactive chemicals that usually break down organic molecules, making this the shallowest known detection of MMC on the planet.

The discovery is also significant because it was made more than 2,000 miles from organic detections by Curiosity in Gale crater. This hints that organic material may once have been widespread across ancient Martian lakes and rivers.

Perseverance cannot determine whether the carbon came from life or geology. For that, scientists would need returned samples and more powerful instruments on Earth.

For more details, read the full article by Planetary Science Institute.