The exploding, electrified moon This time we spend time with IO—the most volcanically active body in the solar system; and how it interacts with Jupiter’s magnetic field. Here’s a video on how a gravity assist works. What's a gravity assist? Here’s a site about gravity assists. Gravity assist Here’s a site on the Galileo mission. Lessons from NASA's Galileo Probe Here’s a site about Io. This is our best look yet at Io, the solar system's most volcanic object Here’s a nifty video about Io. The Bizarre Characteristics of Io And a site for kids about the tidal forces acting on Io. High Tide on IO!