OBSERVATION OF SHOEMAKER-LEVY IMPACTS BY THE GALILEO PHOTOPOLARIMETERRADIOMETER

The Galileo Photopolarimeter Radiometer experiment made direct photome tric observations at 678 and 945 nanometers of several comet Shoemaker -Levy 9 fragments impacting with Jupiter. Initial flashes occurred at (fragment G) 18 July 1994 07:33:32, (H) 18 July 19:31:58, (L) 19 July 22:16:48, and (Q1) 20 July 20:13:52 [equivalent universal time coordin ated (UTC) observed at Earth], with relative peak 945-nanometer bright nesses of 0.87, 0.67, 1.00, and 0.42, respectively. The light curves s how a 2-second rise to maximum, a 10-second plateau, and an accelerati ng falloff. The Q1 event, observed at both wavelengths, yielded a colo r temperature of more than 10,000 kelvin at its peak.