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The Origin of the Ocean - Are There Other Ocean Worlds?

4 important questions on The Origin of the Ocean - Are There Other Ocean Worlds?

What are conditions for a large, permanent ocean of liquid water to arise?

- the planet must move in a nearly circular orbit around a stable star.
- the distance from the planet to the star must be just right to provide a temperate environment.
- the sun of such a planet must not be a double or multiple star to ensure a temperate environment.
- a solid crust must be formed by the materials of the planet.
- the planet must be large enough that its gravity will keep the atmosphere and ocean from drifting off into space.

What is so special about moon Europa?

This is a moon of Jupiter, where its crust is icy, cracked and it appears to be a slushy mix of ice and water. There was also a distinctive magnetic field discovered, which is a signature of a salty liquid-water ocean below the ice. Europa is a bit smaller than our own moon, but it has a massive ocean: amount of water is about 40x as much as on Earth. The outside crust of 8 km thick, might hold a warmer liquid form beneath that could sustain life.

What is so special about moon Enceladus?

This is a moon of Saturn, where fountains of ice crystals shooting from gashes onto the small moon's surface. The warmth of the plumes and detection of methane and CO2 molecules suggest liquid-water ocean.