Comets

Like the planets, comets orbit the sun as well. Comets, however, tend to have VERY eccentric orbits, approaching fairly close to the sun, then traveling well outside the orbit of Pluto. What makes comets such a spectacular view in the sky is their tail. This bright, cone-shaped cloud following the comet provides wonderful photographic opportunities.

Comets are made most from ice and dust particles. When a comet is outside the orbit of Jupiter it tends to simply be another object floating in space. Once it comes inside the orbit of Jupiter, however, the solar wind is strong enough to start blowing the dust from the comet. As the comet gets closer, the temperature rises, and the ice begins sublimating (going directly from a solid to a gas without passing through the liquid stage.) Many people believe that the tail of a comet is directly behind the comet like dust being left behind as the comet races through space. It is really the solar wind causes that causes a comet's tail by blowing all of the debris off of the comet. Because of this, a comet's tail always faces away from the sun and not necessarily behind the comet's path.

Some of you may be wondering what happens to all of the debris left behind from a comet. The debris results in meteor showers on our planet. When you see what is called a "falling star" it is really a piece of stellar debris that is burning up in the earth's atmosphere. When we pass through the debris left by a comet the sky is filled with these "falling stars." Since comets follow an orbit, we are always able to know when we will next be passing through the debris of a comet. Below is a list of the month (watch the news, most likely the weather, to find out when the shower is supposed to peak that year), the meteor shower associated with it, the approximate number of "falling stars" per hour, and the comet associated with the debris:

Haley's (1986): Haley first discovered the orbital period of the comet in the early 1700's. Later, searching through historical records showed the first recorded sighting of the comet to be in 240 BC. Mark Twain was born while Haley's comet was in the sky. 76 years later he died with the comet in the sky as well. In 1986, when the comet returned, it was the most celebrated return of a comet ever. The next time Haley's comet will pass by earth will be in 2061

Hale-Bopp (1997): Hale-Bopp was an incredibly bright comet, very clearly visible even to the naked eye. In fact, when it was first discovered outside the orbit of Jupiter, it was 1000 times brighter than Haley's comet was at the same distance. It is approximately 40 kilometers across which, for a comet, is rather large. Following the wave of fear from Hyakutake, Hale-Bopp was also supposed to bring the end of the world. Early tabloids claimed to spot a UFO following the comet. Although quickly shown false by scientist, 39 members of the Heaven's Gate cult killed themselves as the comet approached, claiming the UFO behind the comet was their vehicle to a better place.

"I don't care about the naming of the comet. If many people could enjoy that comet, that is the happiest thing for me."
- Yuji Hyakutake

Hyakutake (1996): On January 30, 1996, Yuji Hyakutake in Japan discovered a new comet using 25x150 binoculars. At the time of the comet's passing it was said to be the brightest comet to pass since Comet West in 1976. Tabloids claimed that this comet was on a path to impact course to earth. This, coupled with the millenium only a few years away caused many people to start fearing the end of the earth. Although the majority of fears were calmed, the spotting of Hale-Bopp in 1997 caused those fears to resurface.

Shoemaker-Levy 9 (1994): Although not a particularly bright comet, this comet's claim to fame was its bombardment of Jupiter in July of 1994. In 1992 the comet came too close to Jupiter and was ripped apart by the planets gravitational field. In 1994, over 20 pieces of the former comet smashed into the planet with more force than the entire arsenal of nuclear weapons we have on our planet right now.

As seen by the reactions to Hale-Bopp and Hyakutake, even people today fear comets. They were even more feared throughout history. Ancient peoples had identified the planets and stars and knew their orbits. Comets, to them, were unpredictable and were associated with great events happening. Below are simply some of the events associated with comets in early times.

Comet of 44 BC	Appeared shortly after the death of Julius Caesar.
Comet of 66	Thought to signify the fall of Jerusalem in 70 AD.
Comet of 79	This comet appeared somewhere around the time the Mt. Vesuvius erupted and destroyed the city of Pompeii and Herculaneum.
Comet of 1456 (Haley's)	Thought to be a heavenly sign of pleasure at the Turks successful invasion of Constantinople.
Comet of 1665	Appeared when the Black Plague struck London and killed 90 thousand people
Comet of 1811	It is also claimed that the comet of 1811 was in the sky when Napoleon made the decision to attack Russia. Napoleon took the comet as a good sign and attacked,but lost the biggest battles in his entire career.
Comet of 1861 and 1862	Blamed for starting the Civil War.

Early January	Quadrantids
Mid-Late April	Lyrids
Early May	Eta Aquarids	20-50	Halley
Late July	Southern Delta Aquarids
Mid August	Perseids
Mid Late October	Orionids	20	Halley
Mid November	Leonids		Temple-Tuttle
Mid December	Geminids