The leopard-spot-like features in the center of the image may be a sign of ancient life.
NASA/JPL-Caltech/MSSS
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.
Among the white streaks, the researchers saw strange light-colored spots just a few millimeters in diameter, surrounded by a dark material containing iron and phosphate. “These spots are a big surprise,” David Flannery of Queensland University of Technology in Australia said in a NASA press release. “On Earth, these kinds of features in rocks are often associated with the fossil record of microorganisms living below the surface.” That’s because the chemical reactions that create these leopard spots in Earth’s rocks could also provide useful energy for microorganisms.
In the same area where the rocks are found, Perseverance also detected certain organic compounds that are considered building blocks for life. Taken together, all of this could be taken as evidence of microbial life that once lived on Mars, but it’s far from conclusive. “We should be cautiously excited, but also realistic,” says Paul Byrne of Washington University in St. Louis, Missouri, who was not involved in the study. “For now, this is a sign that wet rocks are (probably) causing chemical changes.”
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, we won’t know for sure anytime soon whether there are signs of life at Cheyaba Falls. “We’ve shone lasers and X-rays on the rocks, taking images from just about every angle imaginable, literally day and night,” Ken Farley of the California Institute of Technology said in a press release. “Scientifically, there’s nothing more that Perseverance has to offer.”
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.
topic:
(TagToTranslate)Mars
