Galileo swoops by volcanic Io

“Jupiter’s strange moon Io is

literally bursting with volcanoes. Dozens of active

vents pepper the landscape, which also includes

gigantic frosty plains, towering mountains and

volcanic rings the size of California. The volcanoes

themselves are the hottest spots in the solar system

(not counting the sun) with temperatures exceeding

1800 K. The plumes, which rise 300 km into space, are so large that the Hubble

Space Telescope can see them from its low Earth orbit.”