Io: The Most Volcanic Moon in the Solar System

  1. Io is Jupiter’s third-largest moon, slightly larger than Earth’s Moon.
  2. It has over 400 active volcanoes, making it the most volcanic body in the solar system.
  3. Some eruptions shoot lava fountains up to 250 miles high.
  4. Io’s intense volcanism is powered by tidal heating from Jupiter’s immense gravity.
  5. Its surface is a patchwork of sulfur and lava flows, giving it vivid yellow, red, and black colors.
  6. The moon’s thin atmosphere is mostly sulfur dioxide gas.
  7. Io’s volcanoes constantly reshape its surface, leaving no impact craters visible.
  8. Its volcanic activity was first discovered in 1979 by NASA’s Voyager 1 spacecraft.
  9. Plumes from Io’s volcanoes extend hundreds of miles into space.
  10. Studying Io helps scientists understand tidal forces and planetary geology across the solar system.