TIME-RESOLVED OBSERVATIONS OF JUPITER FAR-ULTRAVIOLET AURORA

Simultaneous imaging and spectroscopic observations of Jupiter's far-u ltraviolet aurora covering half a jovian rotation were made on 31 May 1994, The Hubble Space Telescope Wide Field Planetary Camera 2 images revealed dramatic and rapidly changing auroral features, including dis crete longitudinal structures along the auroral ovals, with variable c ontrast; a poleward offset in a north oval sector, showing equatorward motion near dusk; emissions polewards of the ovals, apparently co-rot ating; and a bright event developing near the dawn limb. Viewing geome try effects explain the rotational intensity modulation observed by th e International Ultraviolet Explorer, without intrinsic longitudinal a symmetries.