Comet Shoemaker Levy 9 | Universe Today

Written by Jerry Coffey

Comet Shoemaker Levy 9, also known as SL9 and D/1993 F2, that broke apart and collided with Jupiter in June of 1994. This was the first direct observation of an extraterrestrial collision of solar system objects. This generated a large amount of coverage in main stream media, and SL9 was closely observed by astronomers worldwide. The collision provided new information about Jupiter and highlighted its role in reducing space debris in the inner solar system.

Comet Shoemaker Levy 9 was discovered by astronomers Carolyn and Eugene Shoemaker and David Levy. Shoemaker Levy 9 was located on the night of March 24, 1993, in a photograph taken with the 40 centimeters Schmidt telescope at the Palomar Observatory. It was the first comet observed to be orbiting a planet. In July 1992 the orbit of Shoemaker-Levy 9 passed within Jupiter's Roche limit, and Jupiter's tidal forces acted to pull the comet apart. SL9 was later observed as a series of fragments ranging up to 2 km in diameter. These fragments collided with Jupiter's southern hemisphere between July 16 and July 22, 1994, at a speed of approximately 60 km per second. The prominent scars from the impacts were more easily visible than the Great Red Spot and persisted for many months.

Orbital studies of Comet Shoemaker Levy 9 soon revealed that it was orbiting Jupiter rather than the Sun. This was unlike all other comets known at the time. Its orbit around Jupiter was very loosely bound, with a period of about 2 years and an apojove (furthest distance from Jupiter) of 0.33 AU. Its orbit around the planet was highly eccentric.
Tracing back the comet's orbital motion revealed that it had been orbiting Jupiter for some time. It seems most likely that it was captured from a solar orbit in the early 1970s, although the capture may have occurred a decade earlier. Before the comet was captured by Jupiter, it was probably a short-period comet with an aphelion just inside Jupiter's orbit, and a perihelion interior to the asteroid belt.

There is a nice article that is more in depth about Comet Shoemaker Levy 9 here. Here on Universe Today we have a great article about the one that got away. A comet the escaped the gravity pull of Jupiter Astronomy Cast has a great episode about comets in general. .

Filed under: Astronomy

Tags: Comet Shoemaker Levy 9, D/1993 F2, SL9