As far as we know, all life requires one thing, water, and that’s why scientists are fascinated by worlds they know or suspect host giant oceans: These worlds are among the best candidates for finding life beyond Earth.
By Meghan Bartels | SPACE.com
And in a new report, a team of scientists summarizes what we know about each of these potential „water parks“ and our long-term options for furthering that knowledge with progressively more ambitious missions. The report is on behalf of the Roadmaps to Ocean Worlds group of NASA’s Outer Planets Assessment Group, designed to inform a congressionally mandated research portfolio within the agency.
The authors conclude that our best evidence for an extraterrestrial ocean that could potentially host life comes from Enceladus, an icy moon of Saturn. NASA’s Cassini mission, which ended last fall, beamed back convincing evidence for a global ocean of liquid water with an energy source that could potentially fuel life. [6 Most Likely Places for Alien Life in the Solar System]
Other promising candidates are Jupiter’s moon Europa and Saturn’s moon Titan, which each check a few boxes already. But even these worlds still pose very real puzzles to scientists, including whether their oceans would be at all habitable.
And there are some enigmatic worlds where scientists aren’t even sure yet if water is on tap. When it comes to destinations like Triton, Ceres and Pluto, scientists have only tantalizing hints that they could be wet.