Add Yahoo as a preferred source to see more of our stories on Google. On Dec. 28, 2000, NASA’s Galileo spacecraft discovered auroras on Ganymede, Jupiter’s largest moon. Galileo launched in 1989 on a ...

The ocean on Ganymede may have more water than all the water on Earth. In this artist’s concept, the moon Ganymede orbits the giant planet Jupiter. NASA’s Hubble Space Telescope observed aurorae on ...

Jupiter is the object you’ll want to be watching this evening, as Ganymede prepares to transit along with its shadow. About an hour before that event starts, Ganymede and Europa line up as the two ...