Water Worlds

Our planet is a water world — the wet stuff covers more than two-thirds of Earth’s surface. But that may be the proverbial drop in the bucket compared to some other worlds. Vast oceans may hide beneath the surfaces of several bodies in the solar system. And even bigger oceans may cover planets in other star systems.

Missions to the other planets in the solar system have found evidence of water on several moons, as well as two “dwarf” planets.

At least three of those water worlds are moons of Jupiter. The most intriguing is Europa. It appears to have a sub-surface ocean that could be miles deep. The ocean might hold several times as much water as all of Earth’s oceans combined. Hot, mineral-rich fountains might squirt up from far below the ocean floor — perhaps providing conditions that are comfortable for life.

Water is squirting out of a subsurface ocean on Enceladus, a moon of Saturn. And a huge ocean could lurk far below the surface of Saturn’s biggest moon, Titan.

There’s also evidence of water on Pluto, the little world that’s just beyond the realm of the major planets, and on Ceres, the largest member of the asteroid belt; more about that tomorrow.

And a recent study suggests that oceans could almost completely cover some planets in other star systems. Dry land might make up just 10 percent of the surface of such a planet. So if anyone wants a home planet with almost unlimited ocean views, there could be plenty to choose from.

Script by Damond Benningfield