A Mars landmark that looked like a simple ancient beach turns out to have a much stranger backstory.
NASA's Perseverance rover has spent years studying Jezero crater, a 28-mile-wide basin where a lake once existed. Scientists expected the crater's rim to hold sedimentary rock, the kind deposited by a lakeshore. Instead, a new study led by Purdue scientist Candice Bedford, published in Communications Earth and Environment, found the rock is igneous, meaning it formed from cooling magma. The rover analyzed 185 rocks across an 870-foot elevation range using its SuperCam instrument and found evidence that water altered these volcanic rocks in three distinct episodes, including one resembling a hot spring.
This matters because the rocks are loaded with carbonates, minerals that are unusually good at preserving traces of ancient microbial life on Earth. A site that got soaked repeatedly, in different ways, offers more chances for life to have formed and left something behind than a single static lakeshore would. It also means Mars's water history is more layered and dynamic than the original orbital-image theory suggested, which is a bigger deal for astrobiology than the geology reclassification alone sounds.
The catch is that Perseverance can tell researchers the order of these wet episodes but not when they happened, and the samples it already collected can't be analyzed in real labs until someone revives Mars Sample Return, which Congress defunded in January. So the most interesting rocks on Mars are, for now, just sitting there.