There are three possible explanations for the new find, and one involves ancient Mars microbes.
NASA's Curiosity Mars rover used two different cameras to create this selfie in front of a rock outcrop named Mont Mercou, which stands 20 feet (6 meters) tall. NASA's Curiosity rover has found some interesting organic compounds on the Red Planet that could be signs of ancient Mars life, but it will take a lot more work to test that hypothesis. Some of the powdered rock samples that Curiosity has collected over the years contain organics rich in a type of carbon that here on Earth is associated with life, researchers report in a new study. But Mars is very different from our world, and many Martian processes remain mysterious. So it's too early to know what generated the intriguing chemicals, study team members stressed. "We're finding things on Mars that are tantalizingly interesting, but we would really need more evidence to say we've identified life," Paul Mahaffy, who served as the principal investigator of Curiosity's Sample Analysis at Mars (SAM) chemistry lab until retiring from NASA's Goddard Space Flight Center in Greenbelt, Maryland, in December 2021, said in a statement . "So we're looking at what else could have caused the carbon signature we're seeing, if not life." Related: Amazing Mars photos by NASA's Curiosity rover This mosaic was made from images taken by the Mast Camera aboard NASA's Curiosity rover on the 2,729th Martian day, or sol, of the mission. It shows the landscape of the Stimson sandstone formation in Gale crater. In this general location, Curiosity drilled the Edinburgh drill hole, a sample from which was enriched in carbon 12. (Image credit: NASA/Caltech-JPL/MSSS) Nearly a decade of sample analysis Curiosity landed inside Mars' 96-mile-wide (154 kilometers) Gale Crater in August 2012 on a mission to determine if the area could ever have supported microbial life. The rover team soon determined that Gale's floor was a potentially habitable…