The brightest comet seen in recent years, even though it came no closer to Earth than 1.32 AU (197,000,000 km). Discovered independently by amateur astronomers Alan Hale (of New Mexico) and Thomas Bopp (of Arizona) on July 22, 1995, it reached perihelion on April 1, 1997, and was visible to the naked-eye for many months. Its nucleus seems to be very large – about 40 km across – and spins around once every 11.4 hours. Last seen in 1997, Hale-Bopp has an orbital period of 2,380 years and won't be seen again until AD 4377.
