NASA's Perseverance rover has been collecting samples from Mars since 2021, but one of its most recently collected rocks could help it achieve its goal of finding evidence of ancient life on the planet. Dubbed Cheyava Falls after the tallest waterfall in the Grand Canyon, the 3.2-foot by 2-foot sample contains “chemical signatures and structures” that could have been Formed by ancient microbial life for billions of years.
Perseverance collected the rock on July 21 from what was once a Martian river valley carved by flowing water long ago. The sample, which can be seen up close below and from afar in the center of the image above, features large white veins of calcium sulfate running its length. They indicate that water passed through the rock at some point.
More importantly, it contains millimeter-sized markings that look like “leopard spots” across its central reddish band. On our planet, such spots could form in terrestrial sedimentary rocks when chemical reactions turn hematite, one of the minerals responsible for Mars' reddish color, into white. Those reactions can release iron and phosphate, which could have served as an energy source for microbes.
The rover's Planetary Instrument for x-ray Lithochemistry (PIXL) tool has already determined that the black rings around the spots contain iron and phosphate. However, that doesn't automatically mean the rock actually served as a host for ancient microbes.
The spots could have formed through non-biological processes, and that's something scientists will have to figure out. “We can't say right now that we've discovered life on Mars,” said Katie Stack Morgan, deputy project scientist. saying“But what we are saying is that we have a potential biosignature, which is a set of characteristics that could have a biological origin but that need further study and more data.”
NASA has yet to bring back to our planet the samples that Pereverance had collected, including Cheyava Falls. The New York Times Notes: The Mars sample return mission is years behind schedule and will not be able to bring back rocks from the Red Planet until 2040 instead of the early 2030s as originally planned. NASA recently announced that it will return 100,000 Mars rocks to Earth in the 2030s. asked the aerospace companies Scientists will look for alternative solutions to get the samples to Earth much sooner and will fund their studies, which will be carried out later this year. Scientists will also have to carry out extensive tests to rule out contamination and non-biological processes, as well as other possible explanations for how the leopard spots formed, before they can proclaim that they are, indeed, evidence of ancient life on Mars.
