Preliminary results of Galileo direct imaging of S-L 9 impacts

Direct Galileo imaging data were obtained of the Jupiter impact sites for Comet Shoemaker-Levy 9 fragments K, N, and W during their early, high-energy phases. Initial ∼5s-long flashes for all 3 impacts result from radiant bolides; analogous, abrupt onsets of luminosity observed by the Galileo photopolarimeter for other impacts must also be the bolide phase. The 3 bolides were dim at 0.56 or 0.89µm (few percent of total Jupiter) and had similar amplitudes, despite huge late-stage differences observed from Earth. Subsequent, continuous luminosity lasting ∼40s for K and ∼10s for N is optical radiation as the initial bolide train erupts into a “fireball”. The K light curve may show (a) two impacts 10s apart or (b) delayed evolution of the fireball