NASA announced in September 2025 that it had found life on Mars.
NASA announced it found promising potential biosignatures on Mars. Potential biosignatures are things like chemicals and structures that could be a result of life on the planet, but more research was needed before scientists could comfortably rule out another, non-organic origin for those things.
In September 2025, people on social media shared a clip of a NASA press conference claiming the space agency had announced an incredible discovery: "NASA just revealed that they have found life on Mars!" an X post (archived) viewed over 5 million times read.
"Life on Mars!" declared an image liked 10,000 times on Instagram (archived). Another Instagram post (archived) claimed NASA said, "We found evidence of ancient life on Mars." Another X post (archived) claimed, "NASA announced microbial life discovered on Mars."
But the claim that NASA announced found life on Mars was false. NASA announced it found promising evidence of potential ancient life on the planet, but more research was needed before scientists could comfortably declare it was definitive evidence of life.
The clip shared in some social media posts was of a Sept. 10, 2025, NASA media briefing in which Sean Duffy, the Trump administration's acting NASA administrator, spoke about the discovery. "This very well could be the clearest sign of life we've ever found on Mars," Duffy said during that briefing.
"Could be" is an important part of that quote. That's because, while promising, what NASA found wasn't yet been confirmed to be definitive evidence of life. More research will be needed before scientists can feel confident enough to confirm that.
NASA's exact discovery, according to a research paper published on the same date, was Martian rock formations likely containing the minerals vivianite and greigite. These minerals are a potential biosignatures of ancient microbial life, according to a NASA news release. A potential biosignature is a substance or structure that might have been caused by the presence of life on the planet, but more research or data was needed before any definitive conclusions could be made.
How might vivianite and greigite be the result of life on Mars? Both are iron-rich minerals; vivianite is frequently found on Earth in sediments, plant-formed peat bogs and the decay of organic matter, while some microbial life on Earth can form greigite, NASA said. The formation of these minerals appeared to be caused by reactions between sediments and organic matter, reactions that microbial life could have used to produce energy for growth.
These minerals can be formed without the presence of life, according to NASA. They can be formed by sustained high temperatures, acidic conditions and binding by organic compounds. However, a major reason why the discovery of these materials was so promising was because the rock formations the minerals were discovered in didn't show evidence that they experienced high temperatures or acidic conditions. Scientists don't know whether the organic compounds present would have been capable of kickstarting the reactions necessary to form the minerals at low temperatures.
NASA scientists preached caution on claiming these minerals were definitive evidence of ancient life on Mars. "Astrobiological claims, particularly those related to the potential discovery of past extraterrestrial life, require extraordinary evidence," said Katie Morgan, the mission's project scientist at NASA's Jet Propulsion Laboratory. She added that while abiotic explanations, meaning potential sources of the minerals unrelated to life, were less likely given the researchers' findings, they could not yet be ruled out.
Although the discovery didn't quite amount to discovering life on Mars, NASA's mission page for its Mars rovers says the latest discovery "remains the mission's best candidate for containing signs of ancient microbial life processes."
Hurowitz, Joel A, et al. "Redox-Driven Mineral and Organic Associations in Jezero Crater, Mars." Nature, vol. 645, no. 8080, 10 Sept. 2025, pp. 332-340, www.nature.com/articles/s41586-025-09413-0?utm_source=join1440&utm_medium=email&utm_placement=newsletter, https://doi.org/10.1038/s41586-025-09413-0. Accessed 15 Sept. 2025.
NASA Video. "NASA to Share Details of New Perseverance Mars Rover Finding." YouTube, 10 Sept. 2025, www.youtube.com/watch?v=-StZggK4hhA. Accessed 15 Sept. 2025.
Taveau, Jessica. "NASA Says Mars Rover Discovered Potential Biosignature Last Year." NASA, 10 Sept. 2025, www.nasa.gov/news-release/nasa-says-mars-rover-discovered-potential-biosignature-last-year/. Accessed 15 Sept. 2025.
"The Mars Report: September 2025 -- Special Edition." NASA Science, 11 Sept. 2025, science.nasa.gov/mars/the-mars-report/2025-september-special-edition/. Accessed 15 Sept. 2025.