Paul VoosenNASA’s newest Mars rover, Perseverance, is going back in time to the bottom of a vanished lake. If all goes well, in February 2021 it will land in Jezero crater and pop the dust covers off its camera lenses.
Towering in front of it, in all likelihood, will be a 60-meter cliff of mudstone: the edge of a fossilized river delta. These lithified martian sediments could hold answers to urgent questions about the earliest days of Earth’s chilly, parched neighbor: How did this pintsize planet, so distant from a faint young Sun, support liquid water on its surface?
How much water was there, and how long did it persist? And did Mars ever spawn life?The 45-kilometer-wide crater is an intriguing target.