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
Comet Shoemaker–Levy 9 Despite published predictions, astronomers had not expected to see the fireballs from the impacts and did not have any idea in advance how visible the other atmospheric effects of the impacts would be from Earth. Observers soon saw a huge dark spot after the first impact. The spot was visible even in very small telescopes, and was about (one Earth radius) across. This and subsequent dark spots were thought to have been caused by debris from the impacts, and were markedly asymmetric, forming crescent shapes in front of the direction of impact. Over the next six days, 21 distinct impacts