Comet Shoemaker-Levy impact on Jupiter, July 1994. Artist's impression of the impact of fragments of Comet Shoemaker-Levy 9, seen from inside the upper atmosphere of Jupiter. Several vast 'mushroom' clouds are seen, caused by the disintegration of fragments of the comet in the atmosphere. Over 20 fragments of Comet Shoemaker- Levy 9, each of more than 1 km diameter, are expected to hit the planet on 18-24 July 1994. The comet was broken apart by Jupiter's gravity field during a close encounter in July 1992. The impacts will not be visible directly from Earth, but the effects on the atmosphere will be seen as the impact points rotate into view.