Dear Mr. Skilling,
Io, one of Jupiter's moons, has volcanoes but my friend Terry says I am wrong and he
won't listen to me. He says only Earth has volcanoes.
Robert Klyn, age 10
Dear Robert,
Your information is correct and we here in the WGN weather center congratulate you on
your knowledge of astrogeology.
Astronomers believe Io is the most volcanic body in the Solar System. Io revolves so
close to Jupiter (the largest planet in the Solar System) that Jupiter's powerful
gravitational field causes Io to bend and flex, heating its interior much like a paper clip
heats up when it is repeatedly flexed. That heat fuels massive volcanic eruptions on Io's
surface. NASA's Galileo spacecraft captured many high-resolution images of Io's
volcanoes in 1999 and 2000, and indicated lava at temperatures well above 2,600
degrees.
Earth's hottest lava: about 2,240 degrees.
