Posted: Fri, May 13, 2011, 6:51 AM ET (1051 GMT)
Planetary scientists have determined that Io, a large, volcanically-active moon of Jupiter, has a layer of molten or partially molten magma in its interior. In a paper published Thursday by the journal Science, scientists reported the discovery by studying the interaction between Io and Jupiter's magnetic field in data collected by NASA's now-defunct Galileo spacecraft. Researchers linked unexplained signatures in the data to electrical currents flowing through a layer of magma estimated to be over 50 kilometers thick beneath the surface. That magma can explain the high degree of volcanism on Io, which has 100 times the volcanic activity as the Earth.
