Figure 2: Groundbased images of the Io plasma torus in [S II] 6731Å. Jovian north is up; east (approaching) ansa is visible. UT (at start of integration) is given in the lower left corner of each image; System III CML (at mid-integration) is given in the lower right. Intensity range is zero (black) to three (white) kilorayleighs. Scattered light has not been removed. The increase in scattered light and defocussing of Jupiter in later images are a result of deteriorating sky conditions.