Comet nucleus comets include 3D/Biela in 1846, Shoemaker–Levy 9 in 1992, and 73P/Schwassmann–Wachmann from 1995 to 2006. Greek historian Ephorus reported that a comet split apart as far back as the winter of 372–373 BC. Comets are suspected of splitting due to thermal stress, internal gas pressure, or impact. Comets 42P/Neujmin and 53P/Van Biesbroeck appear to be fragments of a parent comet. Numerical integrations have shown that both comets had a rather close approach to Jupiter in January 1850, and that, before 1850, the two orbits were nearly identical. Cometary nuclei are among the darkest objects known to exist in the Solar
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