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
4446 Carolyn The "Collaborative Asteroid Lightcurve Link" assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 32.03 kilometers based on an absolute magnitude of 11.2. This minor planet was named by the discoverer after American astronomer Carolyn Shoemaker (born 1929), a prolific discoverer of minor planets and comets, such as Comet Shoemaker–Levy 9. Many of her discoveries were co-discoveries with her husband Gene Shoemaker. The official naming citation was prepared by David Levy and Jean Mueller, and published by the Minor Planet Center on 27 June 1991 (). 4446 Carolyn 4446 Carolyn, provisional designation , is a