Perseverance will search for signs of life in an ancient mud layer.

NASA’s Perseverance rover has spent the last eight months in the dry, forlorn landscape of Jezero Crater. But analysis of some of the rover’s first images have confirmed that roughly 3.7 billion years ago, the crater was home to an ancient lake fed by a river - one that occasionally experienced flash floods, washing boulders into the lake from up to tens of miles away.