what is a comet?

Answer 1

A celestial body, observed only in that part of its orbit that is relatively close to the sun, having a head consisting of a solid nucleus surrounded by a nebulous coma up to 2.4 million kilometers (1.5 million miles) in diameter and an elongated curved vapor tail arising from the coma when sufficiently close to the sun. Comets are thought to consist chiefly of ammonia, methane, carbon dioxide, and water.

Answer 2

Comets are made up of chunks of tiny minerals held together with ice at its center. When the comet orbits near the sun the ice vaporizes.This rapid melting causes a jet force to push on the comet and alter its orbit slightly and causes lots of junk to fall off the comet forming a tail.

Answer 3

Comets are small, fragile, irregularly shaped bodies composed of a mixture of non-volatile grains and frozen gases. They usually follow highly elongated paths around the Sun. Most become visible, even in telescopes, only when they get near enough to the Sun for the Sun's radiation to start subliming the volatile gases, which in turn blow away small bits of the solid material. These materials expand into an enormous escaping atmosphere called the coma, which becomes far bigger than a planet, and they are forced back into long tails of dust and gas by radiation and charged particles flowing from the Sun. Comets are cold bodies, and we see them only because the gases in their comae and tails fluoresce in sunlight (somewhat akin to a fluorescent light) and because of sunlight reflected from the solids. Comets are regular members of the solar system family, gravitationally bound to the Sun. They are generally believed to be made of material, originally in the outer part of the solar system, that didn't get incorporated into the planets -- leftover debris, if you will. It is the very fact that they are thought to be composed of such unchanged primitive material that makes them extremely interesting to scientists who wish to learn about conditions during the earliest period of the solar system.

For more information go to: http://www.solarviews.com/eng/comet/whatis.htm

Answer 4

Comets are small, fragile, irregularly shaped bodies composed of a mixture of non-volatile grains and frozen gases. They have highly elliptical orbits that bring them very close to the Sun and swing them deeply into space, often beyond the orbit of Pluto.

Answer 5

It's typically a ball of dirty ice that orbits the sun (the orbit is usually very eccentric, but I don't think it's a defining quality). As it travels towards the sun, it starts melting - the melted residue results in a tail that gets longer as it get closer to the sun. I say 'dirty' ice, as it's not pure ice - there's plenty rock, mud and all sorts of things in it, too. When it runs out of water, though - it's just a regular rock in space: tailless

Answer 6

its a falling star