An ocean in Uranus?

Abstract

We live on a planet where water dominates many aspects of our environment and lives. Liquid water forms our oceans, controls much of our climate and is the main constituent of living matter. Among the planets closest to the Sun - the terrestrial planets Mercury, Venus, Earth and Mars - only Earth has a water ocean today Venus once had much more water than it has now (perhaps even in liquid form), and Mars has large amounts still, locked up in permafrost and ice caps, but the conditions required for water oceans seem rather restrictive.