Jupiter's largest moon Ganymede is generating "killer" waves of electrons that astronomers say could damage spacecraft going on future missions. These electromagnetic waves can be found all around ...

A colossal asteroid, estimated to be 20 times larger than the one that led to the extinction of the dinosaurs on Earth, has left a permanent mark on Jupiter’s largest moon, Ganymede. This ...

NASA announced that it has evidence that Jupiter’s moon Ganymede, the largest moon in our solar system, has a vast ocean lurking underneath its icy crust. WSJ's Monika Auger reports.