Which of the moons in the solar system have an active core?
There are Io and Ganymede. I didn’t find any others. “Galileo scientists have determined that Io has a two-layer structure. At the center is a metallic core, probably made of iron and iron sulfide, about 560 miles in radius, which is overlain by a mantle of partially molten rock and crust, according to JPL’s Dr. John Anderson, team leader of Galileo’s celestial mechanics experiment and principal author of the paper published in Science today. The core was probably formed from heating in the interior of the moon, either when it originally formed or as a result of the perpetual tidal heating driving its volcanoes. Galileo scientists also are trying to determine the cause of the hole they found in Jupiter’s magnetic field when the spacecraft was closest to Io. “Instead of increasing continuously as the spacecraft neared Jupiter, the magnetic field strength took a sudden drop of about 30 percent,” Johnson said. “The data suggest that something around Io — possibly a magnetic field generat
