Was 2025 the year we found signs of past life on Mars?
Tantalising signs of past microbial life showed up on Mars this year, but to truly know whether they contain the answer to the biggest question in the universe, we will need to bring samples back to Earth
Space
Tantalising signs of past microbial life showed up on Mars this year, but to truly know whether they contain the answer to the biggest question in the universe, we will need to bring samples back to Earth
By Leah Crane
26 December 2025
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NASA’s Perseverance rover, the first mission to collect and cache Martian rock and regolith
NASA/JPL-Caltech
On Mars, it’s the little things that hint at past life. In 2025, tiny details in rocks across the Martian surface have revealed some of the most exciting clues yet that there may once have been microbial life there.
These come from analysis of samples collected by NASA’s Perseverance rover, which began to provide evidence of life last year: Perseverance came across rocks with tiny splotches, each just millimetres wide with a ring of dark material around it. These splotches, dubbed “leopard spots”, are similar to features we see on Earth associated with fossils of microbes.
This year, Joel Hurowitz at Stony Brook University in New York state and his colleagues did more detailed analyses on the leopard spots, finding forms of iron and sulphur that often come from chemical reactions involving microbes. “I find it much more promising [an indication of life] than anything I’ve seen in the last 20 years,” says at the Planetary Science Institute in Arizona.
