For four years, NASA’s Perseverance rover has searched for possible signs of ancient life on the surface of Mars. It has found myriad interesting features in its travels, including a rock with strange spots, discovered inside Mars’ Jezero Crater. Dubbed “Cheyava Falls,” the 2024 discovery immediately caught the attention of scientists on Earth, as its spots indicated it may hold a potential biosignature—a sign of life.
The rover went to work. The bot analyzed the rock’s composition and surface chemistry, and then extracted a core nicknamed “Sapphire Canyon.”
Its hard work has seemingly paid off. On Wednesday, NASA scientists dropped the bombshell: Cheyava Falls may in fact be the clearest sign of past life ever found on Mars.
“We had almost left the crater. These were the last set of sedimentary rocks we were probably going to be looking at on the mission,” Joel Hurowitz, a planetary scientist at Stony Brook University, told Gizmodo. He is the lead author on a new study detailing the findings that was published in Nature.
“It was super surprising that this would have been the place where the potential biosignatures jumped out of the rock at us and said, ‘hey, look here!’”
Of the 30 rock and regolith samples Perseverance has collected over the last four years, none show more promise as evidence for ancient life on Mars than this one. But actually confirming a biosignature depends on getting this sample back to Earth. At stake is one of the most enduring questions of our world: Is life on Earth truly alone?
“I don’t think we’re ever going to make that determination without that sample in our hands,” Hurowitz said.
The case for a potential biosignature
The surface of Cheyava Falls bears tiny black spots that NASA scientists call “poppy seeds,” interspersed among larger “leopard” spots. These features suggested to Hurowitz and his colleagues that chemical reactions had occurred at the time these sediments were deposited.
Perseverance’s analysis found that Cheyava Falls is rich in organic carbon, sulfur, oxidized iron (rust), and phosphorus. This combination of chemical compounds could have provided a potential energy source for ancient microbes, but the researchers decided to probe the rock further.
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