February 9th

On this day - February 9th 1986 - Halley's Comet last apperance

Halley's comet is the only short-period comet which can be clearly visible to the naked eye from Earth. It is also the only short-period comet that might appear twice in a human lifetime and the first to be recognized as a periodic comet. The comets periodicity was determined by Edmond Halley, a friend of Newton, in 1705 and the comet is therfore named after him. The last appearance was in 1986 and the next is estimated to be July 28th in 2061. The comet has been recorded by astronomers, possible as far back as 240 BC. There are also records by Chinese, Babylonian and medieval Europeans, but it was not established that they observed the same object at the time. In 1066 was the comet recorded in England as an omen about the future. Halley's 1986 apperance was the least favorable on record, because the comet and the Earth were on opposite sides of the Sun which created the worst viewing circumstances for observing the comet. The viewing possibilities for 2061 is expected to be a lot better.  The comet is mostly created from hydrogen, carbon and oxygen. 

NSSDC's Photo Gallery (NASA)

    

Kuiper Airborne Observatory, C141 aircraft April 8/9, 1986, New Zealand Expedition