A liquid ocean lying deep beneath Pluto’s frozen surface is the best explanation for features revealed by NASA’s New Horizons spacecraft, according to a new analysis. The idea that Pluto has a subsurface ocean is not new, but the study provides the most detailed investigation yet of its likely role in the evolution of key features such as the vast, low-lying plain known as Sputnik Planitia (formerly Sputnik Planum).
Scientists with NASA’s Dawn mission have identified permanently shadowed regions on the northern hemisphere of dwarf planet Ceres. Most of these areas likely have been cold enough to trap water ice for a billion years, suggesting that ice deposits could exist there now. These permanently shadowed regions could be colder than those on Mercury or the Moon.
Far in the dwarf planet’s western hemisphere, scientists on NASA’s New Horizons mission have discovered what looks like a giant “bite mark” on Pluto’s surface. They suspect that the methane ice-rich surface on Pluto may be sublimating away into the atmosphere, exposing a layer of water-ice underneath.