Lost comet Comet Shoemaker–Levy 9, which collided with Jupiter in 1994. Lost comet A comet is "lost" when it has been missed at its most recent perihelion passage. This generally happens when data is insufficient to reliably calculate the comet's orbit and predict its location. The "D/" designation is used for a periodic comet that no longer exists or is deemed to have disappeared. Lost comets can be compared to lost minor planets, although calculation of comet orbits differs because of nongravitational forces, such as emission of jets of gas from the nucleus. Some astronomers have specialized in this area, such as
Carolyn S. Shoemaker Rittenhouse Medal of the Rittenhouse Astronomical Society in 1988 and the Scientist of the Year Award in 1995. The Hildian asteroid 4446 Carolyn, discovered by college Edward Bowell at Lowell Observatory in 1985, was named in her honor. Carolyn Shoemaker is credited by the Minor Planet Center with the discovery of 377 numbered minor planets made between 1980 and 1994. Carolyn S. Shoemaker Carolyn Jean Spellmann Shoemaker (born June 24, 1929) is an American astronomer and is a co-discoverer of Comet Shoemaker–Levy 9. She once held the record for most comets discovered by an individual. Carolyn Jean Spellmann was born