Ancient life signs found in rocks by Mars rover

NASA's Perseverance rover has discovered a rock speckled with what appear to be traces of ancient life. Named Cheyaba Falls after a famous waterfall in Arizona, the rock suggests that microbial life may have existed there billions of years ago, but there's currently no certainty that life ever existed there.

The rock, about 1 meter by 0.6 meters in size, is mostly reddish with thin veins of white calcium sulfate that were likely formed when water flowed through cracks in the rock, depositing minerals in the cracks. Water is one of the elements necessary for life, but water is not the only thing researchers found as they sifted through the Perseverance data.

They found that among the white stripes were strange light-colored spots just a few millimeters in diameter, surrounded by a dark material containing iron and phosphate. “These spots were a big surprise,” they said. David Flannery NASA's Queensland University of Technology in Australia press release“On Earth, these rock features are often associated with the fossil record of microorganisms living below the Earth's surface,” because the chemical reactions that produce these leopard-print patterns in Earth's rocks can also provide useful energy for microorganisms.

In the same area where the rocks are, Perseverance also detected certain organic compounds that are considered building blocks of life. Taken together, all of this could be considered a trace of past microbial life on Mars, but it's far from conclusive proof. “We should be cautiously enthusiastic, but realistically cautious,” Perseverance said. Pole Barn “Right now, this is a sign that wet rocks are (probably) causing chemical changes,” said John Doe, a researcher at Washington University in St. Louis, Missouri, who was not involved in the study.

As it turns out, there are ways to produce all these signatures without the involvement of any living organisms, and there are some indications that the region may have once been filled with hot magma, which may have made it impossible for life to survive there.

Unfortunately, it won't be clear anytime soon whether there are signs of life at Cheyaba Falls. “We've shone lasers and X-rays on the rocks, and literally photographed them day and night, from just about every angle you can imagine,” says Dr. Ken Farley “Scientifically, Perseverance has nothing more to offer,” Caltech said in a press release.

The rover is adding samples from Cheyaba Falls to its archives, and a future mission will bring them back to Earth, where researchers will be able to study them more closely with more advanced instruments. “There's a whole different way to analyze them than you would in a lab on Earth,” Byrne says.

But NASA's Mars sample-return mission, Perseverance, has suffered a series of setbacks over the past year, and it's still not clear when or if we'll be able to get an up-close look at the intriguing rocks.