<\/p>\n The Margin Unit region hugs the inner edge of the crater and was identified through observations from orbit. Scientists initially expected Perseverance to encounter sedimentary rocks deposited along the shoreline of the ancient lake that once filled Jezero.<\/p>\n Instead, the rover found igneous rocks that originally formed from molten material deep underground or through volcanic activity<\/a>. That unexpected geology preserved an intricate record of water activity.<\/p>\n “Before we arrived at the Margin Unit, the main hypothesis \u2014 derived from orbital observations \u2014 was that the carbonate seen from orbit formed from interaction with the lake that existed in Jezero Crater,” Candice Bedford, lead author of the study and a research scientist at Purdue University in West Lafayette, Indiana, said in the statement. “But now we know that this location became a sort of crossroads for aqueous systems. The Margin Unit findings are important because Jezero Crater sits inside one of the largest exposures of carbonate on Mars<\/a>, so what we learn here reaches well beyond this crater.”<\/p>\n You may like<\/p>\n Using Perseverance’s SuperCam instrument, researchers analyzed more than 185 bedrock targets across the Margin Unit. They found evidence that water altered the rocks during multiple episodes.<\/p>\n During the first episode, carbon-dioxide-rich groundwater reacted with olivine, a mineral that formed as magma slowly cooled. The reaction produced carbonate minerals within fractures in the rock.<\/p>\n A later episode appears to have involved Jezero’s ancient lake<\/a>. Some of the rocks contain silica, which can form when olivine reacts with water and is particularly abundant in rocks that were once below the lake’s waterline.<\/p>\n Then came a third, hotter episode. Mineral veins containing calcium sulfate and fluorite formed in the eastern Margin Unit, suggesting that hot water once circulated through the volcanic rocks.<\/p>\n On Earth<\/a>, hydrothermal systems can create environments capable of supporting microbial life, making these ancient Martian water systems particularly interesting to scientists investigating the Red Planet’s past habitability.<\/p>\n While the researchers are able to reconstruct the sequence of these episodes, they cannot yet determine exactly when each occurred. However, the order of events suggests the Margin Unit was more than simply an ancient lakeshore. It was a place where groundwater, surface water and heated fluids interacted with Martian rocks, potentially preserving a complex record of how Mars’ environment evolved over time \u2014 one that the carbonate minerals in these rocks could help scientists use to determine when and where Mars may once have provided conditions suitable for life<\/a>.<\/p>\n “If there is one thing I have learned after 10 years working with Mars rovers, it is that Mars constantly throws surprises at you,” Bedford said in the statement. “It is very rare that things are as we expect them to be from orbital data. I hope this work helps reshape how scientists view the history of water in Jezero Crater and across Mars. Ultimately, I hope it helps planetary scientists reconstruct the changing climate and habitability of early Mars.”<\/p>\n![\"Space\"](\"https:\/\/cdn.mos.cms.futurecdn.net\/flexiimages\/dpnbewsyjn1783958986.svg\")
<\/p>\n