NASA's Perseverance rover has made an important discovery on Mars, identifying organic carbon molecules in rocks formed in a riverbed that carried water billions of years ago.
The measurements were carried out by the SHERLOC instrument, which detected organic carbon in shale rocks as the rover was exploring the Neretva Valley, an ancient river that once flowed into the Jezero crater.
Scientists explain that the form of carbon discovered, known as macromolecular carbon (MMC), may have a biological origin, but could also have been created by natural geological processes. For this reason, the discovery does not yet constitute proof that life existed on Mars.
Dr. Ashley Murphy from the Planetary Science Institute in Arizona explained that this type of carbon can come from fossilized organic materials, but also be created by chemical reactions between rocks and water or transported by meteorites hitting the planet.
In the study published in the journal Science Advances, the researchers describe how they used the SHERLOC instrument's ultraviolet laser to analyze rocks and identify complex carbon compounds.
One of the most interesting samples was taken from the Cheyava Falls rock, where macromolecular carbon was found on the surface. According to the researchers, this could mean that the material was recently exposed to the Martian surface or that it has resisted the radiation and oxidative processes that usually destroy organic substances on Mars.
This discovery is particularly important because it confirms the presence of organic matter in shale rocks in two different areas of the planet. Previously, the Curiosity rover, exploring Gale Crater, had also discovered similar compounds.
According to the study authors, this suggests that favorable conditions for habitability and the presence of organic matter may have been widespread in many parts of Mars billions of years ago.
However, NASA's current rovers do not have the necessary equipment to determine whether these molecules were created by ancient microorganisms or by geological processes. This requires laboratory analysis on Earth.
NASA had planned to return samples collected by Perseverance to Earth, but the project was canceled in January. The agency is working on a new mission, aiming to return samples in the 2030s. Meanwhile, China has announced that it aims to bring its own samples from Mars in 2031.
