Comet Shoemaker–Levy 9 comet was later observed as a series of fragments ranging up to in diameter. These fragments collided with Jupiter's southern hemisphere between July 16 and 22, 1994 at a speed of approximately (Jupiter's escape velocity) or . The prominent scars from the impacts were more easily visible than the Great Red Spot and persisted for many months. While conducting a program of observations designed to uncover near-Earth objects, the Shoemakers and Levy discovered Comet Shoemaker–Levy 9 on the night of March 24, 1993 in a photograph taken with the Schmidt telescope at the Palomar Observatory in California. The comet was
Comet Shoemaker–Levy 9 thus a serendipitous discovery, but one that quickly overshadowed the results from their main observing program. Comet Shoemaker–Levy 9 was the ninth periodic comet (a comet whose orbital period is 200 years or less) discovered by the Shoemakers and Levy, hence its name. It was their eleventh comet discovery overall including their discovery of two non-periodic comets, which use a different nomenclature. The discovery was announced in IAU Circular 5725 on March 27, 1993. The discovery image gave the first hint that comet Shoemaker–Levy 9 was an unusual comet, as it appeared to show multiple nuclei in an elongated region