PLASMA EFFECTS ON THE INTERACTION OF A COMET WITH JUPITER

I consider some plasma effects to be expected when the fragments of Co met Shoemaker-Levy 9 crash into Jupiter. Emphasis is put on pre-impact effects, and on the possibility of significant radio emission. It is shown that an ionizing shock will develop at altitudes below about 600 km, and that significant ionization will exist above that altitude. T he incoming comet and its surroundings will then represent a rapidly m oving conductor in a strong magnetic field and will induce large curre nts in Jupiter's magnetosphere, similar both qualitatively and quantit atively to a way in which lo interacts with Jupiter's magnetic field a nd with the plasma of the torus. This process is thought to be involve d in the generation of decametric radiation, so that the impact of the comet may also produce such radiation. The power involved in this int eraction is estimated to be at least 1/15th of the power due to lo, an d its duration to be for 10-20 s before the comet's impact with the su rface of Jupiter.