Mosaic image of Jezero crater, Mars. NASA's Perseverance rover will travel across the crater and investigate several ancient environments for signs of life. Over three billion years ago, Jezero crater was home to a lake. The wet conditions of the lake and surrounding river delta could have made it habitable for ancient microbial life. Mosaic image composed of multiple precisely aligned images obtained by the Context Camera on NASA's Mars Reconnaissance Orbiter (MRO) spacecraft.