Ocean worlds are of interest to astrobiologists for their potential to develop life and sustain biological activity over … See more

Important preliminary theoretical work was carried out prior to the planetary missions launched starting in the 1970s. In particular, Lewis showed in 1971 that radioactive decay alone was likely sufficient to produce subsurface … See more

Planetary objects that form in the outer Solar System begin as a comet-like mixture of roughly half water and half rock by mass, displaying a density lower than that of rocky planets. Icy planets and moons that form near the … See more

The internal structure of an icy astronomical body is generally deduced from measurements of its bulk density, gravity moments, and shape. Determining the moment of inertia of a body can help assess wh… See more

To allow surface water to be liquid for long periods of time, a planet—or moon—must orbit within the habitable zone (HZ), possess a protective magnetic field, and have the gravitational pull needed to retain an ample amount of … See more

It is suggested that strong ocean currents exist in Enceladus, Titan, Ganymede, and Europa. In Enceladus, oceanic heat flux inferred from ice shell thickness suggests the upwelling of warm water at the poles and downwelling of … See more