Comet Shoemaker-Levy 9
Comet Shoemaker-Levy 9 — Comet Shoemaker-Levy 9 is so-named because it was the ninth short-period comet discovered by Carolyn and Eugene Shoemaker and David Levy.
It was first detected in a photograph taken on the night of March 24, 1993 with the 0.4-meter Schmidt telescope at the Mount Palomar observatory in California, and subsequently observed by many other astronomers.
The comet was extremely unusual because it was in fragments, evidently due to a close encounter with the planet Jupiter in July 1992.
During the period July 16-July 22 1994, over twenty fragments of the comet collided with Jupiter’s southern hemisphere, providing the first direct observation of the collision of two solar system objects.
The impacts were observed by virtually every large ground based telescope, thousands of small and amateur telescopes, and several spacecraft including HST and Galileo.
The event was closely observed and recorded by astronomers worldwide, because of its tremendous scientific importance.
The size and mass of the original body and the individual fragments is highly uncertain. The estimates range from 2 to 10 km in diameter for the original body and from 1 to 3 km for the largest fragments.
The after-effects of the impacts were visible on Jupiter for nearly a year after the event. There are linear chains of craters on Ganymede and Callisto that are believed to have been formed by the impacts of bodies similar to SL 9.
SL 9 is no more, but its scientific legacy will be studied for decades to come.