. GALILEO INFRARED OBSERVATIONS OF JUPITER T. ENCRENAZ, P. DROSSART, M. ROOS AND E. LELLOUCH DESPA, Observatoire de Paris 92105 Meudon, France R. CARLSON, K, BAINES, G. ORTON AND T. MARTIN Jet Propulsion Laboratory Pasadena, CA 91109, USA AND F. TAYLOR AND P. IRWIN Department of Atmospheric, Oceanic and Planetary Physics Oxford University, UK Abstract. Galileo infrared observations of Jupiter have been performed with two instruments, the Near Infrared Mapping Spectrometer (NIMS) and the Photo-Polarimeter Radiometer (PPR). A first data set was obtained at the time of the collision of comet Shoemaker-Levy 9 with Jupiter, in July 1994. Information was retrieved about the energy budget of the event, the penetration level of the explosion, the temperature and diameter of the fie- ball and its evolution with time, the temperature of the atmosphere heated by the infalling debris, and the amount of water formed after the explosion. The second set of data was recorded in 1996 after the Galileo probe entry. Evidence was found for a very low water abundance in the hot spots; this result is in full agreement with the conclusions derived from the Galileo probe. Infrared observations of the Great Red Spot allow to derive its 3- D structure, which appears compatible with the model of an anticyclonic vortex. 1. Introduction Planetary observations in the infrared spectral range provide an information different from what is retrieved in the visible range. Indeed, the spectrum of