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.

The four biggest moons of Jupiter aren't just blurry smudges in Galileo's telescope anymore. The Italian astronomer Galileo Galilei discovered Ganymede, Callisto, Europa and Io back in 1610, which ...

In the 1990s, however, NASA's Galileo spacecraft captured magnetic measurements near Callisto that suggested that its ice shell surface—much like that of Europa, another moon of Jupiter—may ...