Jupiter's other spots. Charged particles traveling in Jupiter's magnetic fields generate an auroral light show, just like northern (and southern) lights in Earth's polar regions. Io, a Jupiter moon, actually generates its own bright spot on Jupiter, shown with an arrow in this ultraviolet image taken by the Hubble space telescope. The light comes from charged particles originating from Io's volcanoes. Now teams of scientists from Belgium and Germany have discovered a fainter dot, also produced by Io, that had not been predicted, seen to the left of the arrowed dot.