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
Erich Meyer Erich Meyer Erich Meyer (born August 6, 1951) is an Austrian engineer, amateur astronomer and discoverer of asteroids. Between 1996 and 1999, using the private observatory Meyer/Obermair in Davidschlag (municipality Kirchschlag bei Linz, Austria), he discovered a total of 21 asteroids. Seven of these asteroids were discovered together with his colleague Erwin Obermair and one together with Herbert Raab. Furthermore, he was involved in six other discoveries of asteroids between 1996 and 2005, which were assigned as site discoveries to the observatory Davidschlag by the International Astronomical Union. Meyer's most important observations include precisie astrometry of the comet Shoemaker–Levy 9,