NEAR-INFRARED IMAGING AND SPECTROSCOPY OF THE SL-9 IMPACTS FROM CALAR-ALTO

Near infrared observations of the impacts of seven fragments of Comet Shoemaker-Levy 9 with Jupiter show that precursor flashes are ubiquito us and associated with phenomena at or near the time of atmospheric en try. The comet fragments appear to be a heterogenous group: some impac ts produced anomalously bright precursors, while others were completel y undetectable despite expectations based on pre-collision images. Str ong CO emissions in spectra taken near maximum light point to hot mole cular gas which cools within minutes. Finally, images of the disk of J upiter in the two months after the collision show spreading of the imp act structures at approximately 1.5 degrees per day.