MARS, Laniakea Supercluster—In a moment both exhilarating and cautious, NASA announced today that its Perseverance rover has uncovered some of the most intriguing chemical traces yet suggesting the possible existence of ancient microbial life on Mars.

At a press briefing Wednesday, agency officials and researchers revealed findings from the Bright Angel formation—an ancient riverbed feeding into Jezero Crater—where samples of clay-rich mudstone display faint yet telling features. Scientists identified minerals such as vivianite and greigite embedded in colorful “leopard spots” and “poppy seed” nodules in the rock core dubbed “Sapphire Canyon.”

So, um, what's that mean?

“These rocks, very well could be the clearest sign of life that we’ve ever found on Mars, which is incredibly exciting,” said Acting NASA Administrator Sean Duffy. He called the discovery “groundbreaking,” one that “advances our understanding of Mars.”

Additional details about their findings were released in a peer-reviewed paper in Nature named Redox-driven mineral and organic associations in Jezero Crater, Mars.

After a year of scientific scrutiny, a rock sample collected by the Perseverance rover has been confirmed to contain a potential biosignature. The sample is the best candidate so far to provide evidence of ancient microbial life on Mars.

Scientists caution, however, that while the detected minerals are associated with microbial activity on Earth, non-biological explanations remain plausible. “One of the possible explanations is microbial life, but there could be other ways to make this set of features that we see,” said Joel Hurowitz, lead researcher from Stony Brook University, in an interview with CBS News.

This discovery builds on decades of Mars exploration. Previous rovers such as Curiosity had detected organic compounds and long-chain hydrocarbons on the Red Planet, particularly in the Gale Crater’s mudstones—but without chemical structures as suggestive as these new redox signatures.

The newly reported “cheetah-print” formations in the Bright Angel outcrop offer chemical characteristics that on Earth typically result from microbial redox reactions in sedimentary environments.

Despite the promise of these findings, NASA’s ability to confirm them hinges on returning the samples to Earth for detailed laboratory analysis. The agency’s Mars Sample Return mission, a partnership with ESA, aims to bring Martian rocks back in the early 2030s—but plans now face uncertainty and delay amid budget constraints.

Nicky Fox, Associate Administrator for Science at NASA, emphasized the stakes:

“Today, we are really showing you how we are kind of one step closer to answering … are we truly alone in the universe?”

If confirmed, microbial life on Mars—even in fossilized form—would profoundly reshape our understanding of life in the universe. It would suggest that life may emerge under similar conditions on multiple planets, a concept with far-reaching implications for biology, planetary science, and perhaps even philosophy.

“This finding is the closest we have ever come to discovering life on Mars,” Duffy reiterated, echoing a theme that the discovery, while far from conclusive, sets a new benchmark in the search for extraterrestrial life—and reminds us that the Red Planet still has secrets to reveal.