More pocked with craters than any other object in our solar system, Jupiter's outermost and second-biggest Galilean moon, Callisto, appears geologically unremarkable. In the 1990s, however, NASA's ...

If there was a contest for the most interesting moon in our solar system, Callisto would be a contender. Jupiter's second-largest moon has more impact craters on its surface than any other ...

The latest analysis of data from the Galileo probe reveals surprising clues about Callisto, one of Jupiter's moons. These discoveries could change our understanding of this icy satellite. Callisto, ...

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.