Comets have historically been regarded as omens, but whether good or bad is not always clear. Halley’s Comet appeared to observers in England in 1066 and was believed to be an omen. Harold II was defeated at the Battle of Hastings later that year, but William the Conquerer prevailed. Bad omen for Harold, good omen for William? In later centuries, Halley’s periodic appearance sometimes coincided with other historically significant events in Christendom, leading some — even prominent Church leaders at the time — to believe that the comet was a harbinger of doom.
We can forgive these people for their superstitions, given how little was known at that time about natural science. But in the 21st century, it is surprising (to me anyway), when so much is known about the natural causes of celestial events and how little physical influence they have on the Earth, that they are still regarded as omens. Take, for instance, the conspiracy theories involving the recently-discovered Comet Elenin. These “theories” mostly seem to predict cataclysmic events on Earth, yet are not based on any of the known facts about Elenin.
Motivated by the strange press surrounding the comet’s appearance, NASA’s Jet Propulsion Laboratory has compiled a list of answers to the most popular questions about Comet Elenin, and explains why it is not a threat to Earth. In short:
- It is one of many comets that are discovered each year.
- It is a smallish comet.
- It will remain far away. Its closest approach, in mid-October, will bring it 35 million km from Earth — that’s 90 times the distance from the Earth to the Moon. (Ed. note: Comet McNaught, pictured above, came even closer to Earth — 26 million km — in January, 2007.)
- Its gravitational influence on Earth, even at closest approach, will essentially be zilch.
- It will not block out any light from the Sun as it passes by.
There is no shortage of genuine disasters — both man-made and natural — that we can worry about. Strike Comet Elenin from the list.