Jupiter’s Moon Io Poster – Version A

Full disk view of Io with many volcanoes visible.
August 14, 2018
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Version A of the Io installment of our solar system poster series.

The posters are best printed on 11x17 paper. Several download options are available in the column on the right.

Back of Io Poster with Orbit Diagram and size comparison
Optional back with a brief summary and orbit diagram.

About the image: NASA's Galileo spacecraft acquired this view of Io in July 1999, and approximates what the human eye would see. Credit: NASA/JPL-Caltech/University of Arizona

On the Back

Jupiter's rocky moon Io 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 JupiterEuropa and Ganymede.

In mythology, Io is a mortal woman transformed into a cow during a dispute between the Greek god ZeusJupiter in Roman mythologyand his wife, HeraJuno to the Romans.

Explore Io in depth at https://solarsystem.nasa.gov/io