Direct observations of the comet Shoemaker-Levy 9 fragment G impact by Galileo UVS

The Galileo Ultraviolet Spectrometer (UVS) team has detected the Shoemaker‐Levy 9 fragment G impact on Jupiter in data recently played back from the spacecraft tape recorder. A 20% brightening of the disc‐integrated signal of Jupiter was detected at 292 nm during a swath across Jupiter that lasted 1.6 sec and was centered at 1994‐July 18 (day 199)/07:33:31 UT (all times in this paper are corrected to be the time of the event as seen from Earth). The emission brightness, when combined with simultaneous Photopolarimeter Radiometer (PPR) measurements at 945 nm, is consistent with thermal radiation at a temperature of 7800 (+500, −600) K emitted over an area of 40 (+60, −25) km². No excess signal was seen during swaths 5 1/3 sec before and after the detection swath.