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 ...

NASA's Galileo spacecraft took this image of the Moon on December 7, 1992, showing the bright Tycho crater at the bottom. This image, captured by Lunar Orbiter 2, shows Copernicus crater on the Moon ...

Europa's frozen, fissured surface, seen here in a colorized mosaic image from the Galileo spacecraft, hides a liquid ocean that may hold all the ingredients needed for life. Three key ingredients ...