Perseverance Reveals How Complex Water Systems Shaped the Jezero Crater on Early Mars

What happened

When the Perseverance rover reached there in September 2023, mission scientists expected to find sedimentary rocks that formed from sand deposits, which are good at preserving past microbial life. A new study reveals that Jezero Crater’s enigmatic ‘Margin Unit’ was shaped by a complex sequence of ancient lakes, groundwater systems, and hydrothermal fluids.

Instead, they were surprised to find olivine-rich igneous rock, which typically forms from underground magma or by volcanic activity on the surface. These rock deposits are also excellent record-keepers, preserving details about their precise moment of formation through their mineral crystals.

The minerals Perseverance detected with its SuperCam , which determines the mineralogy of geologic features based on reflected light, preserved a very complex record of water activity in the region when Mars was young. Specifically, they revealed how the rocks interacted with water on three separate occasions, each altering their chemistry and appearance. The results were reported in the journal Communications Earth & Environment .