Images of Jupiter show clear evidence of thunderstorm-like activity. There have been many exciting findings for the Jupiter satellites. Distant Io imaging was performed in every encounter sequence to do volcano monitoring. Large changes in volcanic activity are seen since the Voyager imaging in 1979. At least 19 hot volcanic areas have been located by Galileo.
Silicate volcanism is implied.
There is evidence of some very high lava temperatures suggesting extreme chemistry. Io's plumes may be the source of high-speed dust streams seen by both Ulysses and Galileo. Six precisely designed distant Io occultations have provided the first global picture of Io's complex ionosphere. In addition to the compelling evidence of liquid water, Galileo has found complex systems of faults and ridges covering Europa's surface. Galileo images show the first evidence for volcanic ice flows.