Comet Shoemaker–Levy 9 brought the impact sites into view for terrestrial observers a few minutes after the collisions. Two other space probes made observations at the time of the impact: the "Ulysses" spacecraft, primarily designed for solar observations, was pointed towards Jupiter from its location away, and the distant "Voyager 2" probe, some from Jupiter and on its way out of the Solar System following its encounter with Neptune in 1989, was programmed to look for radio emission in the 1–390 kHz range and make observations with its ultraviolet spectrometer. The first impact occurred at 20:13 UTC on July 16, 1994, when fragment
Eugene Merle Shoemaker Institute in 1965. Coming to Caltech in 1969, he started a systematic search for Earth orbit-crossing asteroids, which resulted in the discovery of several families of such asteroids, including the Apollo asteroids. Shoemaker advanced the idea that sudden geologic changes can arise from asteroid strikes and that asteroid strikes are common over geologic time periods. Previously, astroblemes were thought to be remnants of extinct volcanoes — even on the Moon. In 1993, he co-discovered Comet Shoemaker–Levy 9 using the 18-inch Schmidt camera at Palomar Observatory. This comet was unique in that it provided the first opportunity to observe the planetary