Extraterrestrial liquid water phases of ice are thought to underlie the liquid water layer. Models of radioactive decay suggest that MOA-2007-BLG-192Lb, a small planet orbiting a small star could be as warm as the Earth and completely covered by a very deep ocean. Models of Solar System objects indicate the presence of liquid water in their internal differentiation. Some models of the dwarf planet Ceres, largest object in the asteroid belt indicate the possibility of a wet interior layer. Water vapor detected to be emitted by the dwarf planet may be an indicator, through sublimation of surface ice. A global layer of liquid
Planetary core Planetary core The planetary core consists of the innermost layer(s) of a planet; which may be composed of solid and liquid layers. Cores of specific planets may be entirely solid or entirely liquid. In the Solar System, core size can range from about 20% (Moon) to 85% of a planet's radius (Mercury). Gas giants also have cores, though the composition of these are still a matter of debate and range in possible composition from traditional stony/iron, to ice or to fluid metallic hydrogen. Gas giant cores are proportionally much smaller than those of terrestrial planets, though theirs can be considerably