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 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 in Gallup, New Mexico, United States. to Leonard and Hazel Arthur Spellmann. Her family moved to Chico, California, where she and her brother Richard grew up. Carolyn Spellmann earned bachelor's and master's degrees in history, political science, and English literature from Chico State University. Richard went to the California Institute of Technology (Caltech), where he earned a bachelor's degree in