Perseverance finds a layered water history in Jezero crater
Perseverance observations indicate that rocks in Jezero crater's Margin Unit were altered by water during at least three distinct episodes.
Perseverance observations indicate that rocks in Jezero crater's Margin Unit were altered by water during at least three distinct episodes. The sequence began with neutral-to-alkaline carbon-dioxide-rich fluids that formed carbonate-rich ridges, continued with lake water or changed groundwater that moved carbonate and deposited silica, and ended with heated groundwater that formed calcium-sulfate and fluorite-bearing veins. The research used Perseverance's SuperCam measurements from more than 185 bedrock targets in the Margin Unit. The findings preserve evidence of changing habitable environments, but they do not establish when the alteration episodes occurred or provide evidence that life existed there.