A small moon of Uranus may once have had an underground ocean of liquid water.

Over the past few decades, planetary scientists have continually added to the list of satellites in our solar system that may host internal oceans, either currently or at some point in the past. For the most part, these moons (such as Europa or Enceladus) are gravitationally bound to the gas giants Jupiter or Saturn.

Recently, however, planetary scientists have turned their attention to the ice giant Uranus, the coldest planet in the solar system. Now, a new study based on images taken by the Voyager 2 spacecraft has revealed that Miranda, a small, icy moon of Uranus, may once have had a deep ocean of liquid water beneath its surface.