NASA’s Perseverance rover has discovered possible hints of ancient life on Mars, according to planetary scientists. The rover found dark-rimmed “leopard spots” in a rock studied last year, which could be the remains of Martian microbial activity. However, researchers caution that the spots may have formed without living organisms.
The discovery is considered a low-confidence claim for extraterrestrial life, with only a 1 on a scale of 1 to 7, representing a detection of an intriguing signal. To confirm the findings, scientists need to bring the rock back to Earth for further analysis. A sample is currently stored in the rover’s belly.
The finding is significant and marks a crucial step in searching for extraterrestrial life. It also tests researchers’ ability to evaluate potential biosignatures on other planets. The discovery was first teased by NASA in July, but details were scarce until now.
Chemical analysis of the rock revealed that the dark spots contain high levels of iron and phosphorus, while the centers are rich in sulfur. These findings suggest that the spots formed through reactions involving carbon-containing compounds, minerals, and microorganisms on Earth.
While the discovery is intriguing, it’s essential to note that past false positives have led NASA to exercise caution. To move from a 1 to a higher confidence level, more measurements are needed, which could involve bringing the rock back to Earth for further analysis.
Source: https://www.nature.com/articles/d41586-025-00772-2