The free screensaver, The Northern Lights of Jupiter, was created by RateMyScreensaver.com and contains 10 high resolution images. Both Jupiter and Saturn have magnetic fields much stronger than Earth's (Uranus, Neptune and Mercury are also magnetic), and both have large radiation belts. Aurora has been observed on both, most clearly with the Hubble Space Telescope. These auroras seem, like Earth's, to be powered by the solar wind.
