Overview
- The peer‑reviewed study led by Candice Bedford, published September 21, 2026, reports that Perseverance’s SuperCam data reveal the Margin Unit in Jezero crater is igneous and records three separate water‑alteration events.
- Perseverance analyzed about 185 bedrock targets with laser‑induced plasma spectroscopy to derive rock chemistry and identify coarse‑grained, olivine‑rich igneous rock rather than the expected lake sediments.
- At lower elevations, carbon‑dioxide‑rich groundwater reacted with olivine to form carbonate‑filled fracture ridges and left silica in places that sat below former waterlines, indicating lake or groundwater influence.
- A later hot, hydrothermal episode is recorded by roughly 25‑centimeter‑thick veins containing calcium sulfate and fluorite, showing heated fluids flowed through the rocks after earlier alteration.
- The findings raise the Margin Unit’s value for astrobiology because olivine alteration can produce hydrogen and carbonate and silica can preserve biosignatures, but absolute ages and detailed biosignature tests require returned samples and laboratory dating.