The Solar System is a soggy sort of place.

Although most of Earth’s surface is covered in liquid water, it’s a mere drop in the ocean compared to the entire volume contained in the Solar System – much of it locked away as ice in the moons of the giant planets.

The outer Solar System is icier still. Far from the warmth of the Sun, the estimated millions of icy objects that make up the Kuiper Belt beyond Neptune are thought to contain absolute scads of the stuff.