Saturn's UV Aurora Imaged with HST during the Cassini Approach to Saturn

A series of HST STIS UV images of Saturn's aurora were obtained on 13 days in Jan. 2004 as the Cassini spacecraft measured the approaching solar wind properties. Clear general correlations have been found between the auroral power and a) Saturn's kilometric radiation, and b) the solar wind dynamic pressure, but not with the direction of the interplanetary magnetic field. While these general correlations are now well established, a closer examination of the data raises many interesting questions. Saturn's auroral emissions exhibit both local time and co-rotational properties, the auroral oval does not appear centered on the magnetic and rotational pole, the auroral emissions exhibit large and unexpected motions in latitude with time and/or planetary rotation, and the auroral oval does not appear continuous, but broken with longitude. This talk will present a more detailed look at Saturn's aurora from the HST images, with a comparison of auroral emission properties to those at the Earth and Jupiter.