But not, alas, any kind of ocean planets that could be the planet I conjured up for Marseguro (if that ends up being its title), my new SF novel I’m still anxiously awaiting editorial reaction to.
Still, this is a pretty cool concept and would make a great setting for some kind of SF story:
The water content of the Earth is only about one part in 4400, yet water covers over two-thirds of its surface. Not only would water cover the entire surface of an ocean planet, but its average depth would on the order of 100 kilometers! All the rocky matter would sink to the center of the planet, forming a dense core not unlike the Earth’s. Where the Earth has a thick mantle of magma, however, ocean planets would have a mantle of exotic ice. The pressure at the bottom of the ocean would be10 million atmospheres or more; under such a crushing weight, water has no choice but to solidify.