Callisto would be a contender. Jupiter's second-largest moon has more impact craters on its surface than any other planetary body in the solar system, and it has tons of ice on its surface as well.

The solar system is home to bizarre moons like Enceladus and Callisto, each unveiling nature’s wonders and some of science’s ...

Callisto, the second-largest moon of Jupiter, is covered in craters and appears, at first glance, geologically inactive. However, magnetic measurements taken by the Galileo probe in the 1990s suggest ...

New evidence from an old NASA mission supports the theory that Jupiter's moon Callisto is in fact an ocean world.

Ganymede, Jupiter's largest moon and the solar system's largest, is bigger than Mercury and the dwarf planet Pluto, with a diameter of 5,268 kilometers.

Its icy surface has ... Space Agency's Jupiter Icy Moon Explorer (JUICE) — which will also be exploring Europa, in addition to its larger cousins Ganymede and Callisto — performed a daring ...

But it hasn’t always been this way. Jupiter’s four largest moons – Io, Europa, Ganymede and Callisto – were the first ever discovered orbiting another planet. They were spotted by Galileo ...