Past Comets

Haley’s comet is the best known of the short period comets. These are comets having orbital periods of less than 200 years. Haley’s comet is visible from Earth every 75 to 76 years and for a short period it is clearly visible to the naked eye. It has been observed and recorded at least as far back as since 249 BC. Haley’s comet last appeared in the inner Solar System in 1986 and will next appear in mid 2061.. During it's 1986 appearance, it was closely observed and data collected by spacecraft. Haley was found to be composed of a mixture of volatile ices, such as water, carbon dioxide and ammonia and dust. The largest portion of the comet was composed of dusty, non-volatile materials, and that only a small portion of it is icy. Comets all through history have been seen as messengers from the gods, and mostly as punishments. They have been blamed from everything from the Black Plague to the eruption of Mt. Vesuvius and the destruction of Pompeii. In 1910, when it was learned that the Earth would pass though Haley’s comet tail, the doomsayers were out in force nearly causing a panic in spite of the scientific communities reassurance to the contrary. Numerous newspapers published the story that after passing through the comet's tail, the Earth's atmosphere would not be breathable due to the gasses contained in the comets tail. Some unscrupulous entrepreneurs even sold comet pill that were suppose to counter the effects of the poisonous gas. The pill sold like crazy, somewhere along the lines of duct tape being sold out in the resent past. With every comet that approaches earth, a very big faction of the public has labeled that comet, the “doomsday comet” with all kinds of predictions of mass death on earth, (people can get caught up in hysteria, remember the Y2K hysteria?) So far, few comets have been disastrous. Those I will discuss in my next article. R. Singleton  

P/Halley as taken March 8, 1986 by W. Liller from Easter Island.

Observation of Haley's Comet, recorded in Cuneiform
on a clay tablet between 22-28 September 164 BCE, Babylon, Iraq.
British Museum, London. BM 41462