Io Information Page

A bit larger than Earth's Moon, Io is the third largest of Jupiter's moons, and the fifth one in distance from the planet. It is the most volcanically active world in the solar system, with hundreds of volcanoes, some erupting lava fountains dozens of miles (or kilometers) high. Io’s remarkable activity is the result of a tug-of-war between Jupiter's powerful gravity and smaller but precisely timed pulls from two neighboring moons that orbit farther from Jupiter – Europa and Ganymede. In mythology, Io is a mortal woman transformed into a cow during a dispute between the Greek god Zeus – Jupiter in Roman mythology – and his wife, Hera – Juno to the Romans.

urn:nasa:pds:context:target:satellite.jupiter.io

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