NASA's Perseverance rover has rewritten the expected story of Jezero Crater. Instead of finding the lake sediments that scientists had predicted for the Margin Unit, the rover encountered ancient igneous rocks. But those rocks carry a surprising record: they were chemically altered by water on at least three separate occasions.
According to the mission's findings, the alteration events involved different kinds of water. The evidence suggests groundwater, standing lakes, and even hot fluids each left their mark on the same rocks over time. This indicates that the crater experienced a dynamic and prolonged hydrological history, far more complex than a single lake filling and drying out.
The discovery challenges previous assumptions about the region's past and raises new questions about how long liquid water persisted there. It also strengthens the case for Jezero Crater as a prime location to search for signs of ancient microbial life, since multiple wet environments could have provided diverse habitats. The findings were reported by NASA and highlighted in ScienceDaily.