NASA’s Perseverance rover has found its most promising evidence so far that Mars may have once hosted microscopic life. Scientists announced that rock samples collected from an ancient riverbed in Jezero Crater contain chemical features that could have biological origins.
The samples, drilled last summer from clay-rich mudstones in the Neretva Vallis channel, revealed tiny mineral formations enriched with iron phosphate and iron sulfide. On Earth, such compounds are typically linked to microbial activity. However, researchers caution that non-biological processes could also explain the findings.
“This is the best candidate we’ve seen so far in the rover’s search,” said lead researcher Joel Hurowitz of Stony Brook University. “But we cannot yet say this is proof of life. It’s one possibility among others.”
Perseverance, exploring Mars since 2021, cannot directly detect life. Instead, it drills and stores rock samples for eventual return to Earth—though NASA’s mission to bring them back has been delayed, with costs ballooning to $11 billion and a return now unlikely before the 2040s.
So far, Perseverance has collected 30 samples, with six more planned. Ten backup tubes were also placed on the Martian surface as a safeguard.
Despite the uncertainty, planetary scientists call the discovery “exciting.” The chemical and structural patterns in the Bright Angel rock formation are the most compelling yet in the rover’s quest.
Even if the evidence ultimately points to geology rather than biology, Hurowitz said, “it’s still a valuable lesson in how nature can produce features that look deceptively like signs of life.”
For now, the samples remain sealed on Mars, awaiting the day they can be analyzed in Earth’s labs where the question of whether life ever existed on the Red Planet might finally be answered.