The Martian surface is dry today (with a few possible seasonal exceptions), explaining the two rovers' focus on finding microfossils and other possible biosignatures from the ancient past. But there are still huge amounts of liquid water in the outer solar system, sloshing beneath the ice shell...
Exoplanets are part of the picture as well. NASA's James Webb Space Telescope, which is due to launch in 2021, will be able to sniff the atmospheres of nearby alien worlds for potential biosignatures, as will three giant ground-based observatories scheduled to come online in the middle to ...