Mission Objectives Overview    ===========================      The first part of Jupiter that SL9 encountered was the Jovian      magnetosphere.  Some radio and auroral activity were indeed observed      during the SL9 impacts.  The optical flashes from the bolide and      fireball phases were far more difficult to detect than predicted.      It was not immediately obvious how deep the large fragments of SL9      penetrated, or how much material was dredged up from Jupiter.  The      larger-than-expected plumes that were observed may have merely been      the blow off of material resulting from the shallow splash of an      extended cloud of debris.  The slow-moving atmospheric gravity waves      were, in fact, seen.  Finally, the dust particles from SL9 may after      several years settle into a ring around Jupiter; sensors on board      Galileo may detect such cometary dust.