Juno spacecraft to explore Jupiter's volcanic moon Io.

NASA's Juno spacecraft will perform its closest flyby of Jupiter's volcanic moon Io on Tuesday at an altitude of around 22,060 miles. Juno has already performed more than 50 flybys of Jupiter and flown more than 510 million miles. Io is the most volcanic celestial body known in our solar system, and Juno will study its volcanoes and how they interact with Jupiter's powerful magnetosphere and auroras. The spacecraft's upcoming flybys in July and October will bring it even closer to Io, leading up to twin flyby encounters in December and February.