Old data, new tricks: Fresh results from NASA's Galileo spacecraft 20 years on

Far across the solar system, from where Earth appears merely as a pale blue dot, NASA's Galileo spacecraft spent eight years orbiting Jupiter. During that time, the hearty spacecraft--slightly larger than a full-grown giraffe--sent back spates of discoveries on the gas giant's moons, including the observation of a magnetic environment around Ganymede that was distinct from Jupiter's own magnetic field. The mission ended in 2003, but newly resurrected data from Galileo's first flyby of Ganymede i...