It turns out that you can’t go much of anywhere in the solar system without splashing into some water. There’s frozen water on Mars, in comets and in many asteroids, and at the surfaces of many moons. And there’s liquid water in the atmospheres of the giant planets, and beneath the icy crusts of some of their moons.
Water is especially prevalent at Jupiter, the largest planet. On Jupiter itself, it forms towering clouds that produce some of the solar system’s most powerful thunderstorms.
Liquid water is also abundant on perhaps three of Jupiter’s big moons.
There’s little doubt that a global ocean sits beneath the icy crust of Europa. It contains two or three times as much water as Earth’s oceans. And there may well be “chimneys” that belch hot, mineral-rich fluids into the bottom of the ocean, providing possible habitats for life.
There’s also evidence for an ocean on Callisto. It’s buried far deeper than the ocean on Europa. And there would be less energy in the ocean environment, making it a less likely home for life.
The third possible water world is Jupiter’s largest moon, Ganymede. Evidence includes oddities in its magnetic field that are best explained by a salty ocean, cracks in the crust like those on Europa, and minerals on the surface that likely were borne by a salty ocean. Ganymede’s ocean would be the deepest of the three, though, so there’s little chance of splashing into this water world anytime soon.
Script by Damond Benningfield, Copyright 2012