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Jupiter Moon Io
Two sulfurous eruptions are visible on the surface of Jupiter's volcanic moon Io in this color composite image from the robotic Galileo spacecraft, which orbited Jupiter from 1995 to 2003. Io, one of Jupiter's 62 known moons, is the most volcanically active body in the solar system.
Photograph courtesy NASA/JPL

Jupiter

See a photo of Jupiter's moon, Io, taken from the robotic Galileo spacecraft, from National Geographic.