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BOB HIRSHON (host):Explaining moonscapes. I’m Bob Hirshon and this is Science Update.
The moons of Jupiter are worlds unto themselves, with features ranging from roiling volcanoes to smooth ice. Harvey Leifert from Washington, DC, asked us why they’re so different from one another. According to NASA planetary geologist Rosaly Lopes, it’s a matter of position.
ROSALY LOPES (NASA Planetary Geologist):
When Jupiter formed, depending on how far away from Jupiter the various moons were, they had more water or less water.
HIRSHON:So while nearby moons dried out from Jupiter’s heat, more distant moons were able to collect ice and maybe even liquid water. Also, because Jupiter is huge and has so many moons, some of them end up in a big gravitational tug of war. That can stir up a moon’s interior, causing earthquakes, volcanoes, and other surface-altering events.
If you have a science question, calls us at 1-800-why-isit. I’m Bob Hirshon, for AAAS, the science society.