What is a comet?
Composition: A comet is like a large “dirty snowball”. They are composed of ice, clay and organic matter, including hydrocarbons in the form of an oil-like tar.8 Size: Comets can range in sizes up to several hundreds of miles in diameter. Several comets start out as great behemoths, which break up into smaller comets and eventually particles of dust and vapors over time. The comet Chiron is 120 miles across and so is the comet Pholus. Comet 1993 HA2 is 50 miles across.22 The comet “Shoemaker-Levy 9” that struck Jupiter on 1994 was composed of 21 discernible fragments, several ranging in size from around 0.5 mile to around 2 miles in diameter.7 It is estimated that this comet before it broke up was approximately 12 miles in diameter.1 The comet “Hale-Bopp” is 25 miles in diameter and weighs 10 trillion tons.3, 6 Speed: Comets travel at incredible speeds, around 100,000 miles per hour as they approach Earth. Mass: It is theorized that the density of comets range from that of a fluffy sno
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,
A comet is a small astral body, similar in construction to a planet. A comet may have an unusual orbit, which may at times bring the comet close to the sun and make it visible to the naked eye, or through relatively low strength telescopes. When such a comet can be viewed it is usually noted as having a tail, made of gasses, which early astronomers often mistook for a shooting star. Most observable comets in our solar system derive from the Oort Cloud, a hypothesized cloud made up of leavings from the sun. These materials form comets, which orbit the sun because are then affected by the gravitational pull of the sun and other planets. While passing by individual planets, the comet may be affected by the gravitational forces of the planets, thus causing an elliptical or oval-type orbit. Usually, people on earth see a comet when the comet passes in between earth and the sun. It is thought that the comet and its tail, sometimes called the coma and tail, reflect the light of the sun, enhan
A comet is one of the many kinds of bodies that make up our solar system. Comets are different from planets, asteroids, and meteors because they are largely made up of ice, with some rocks and dust mixed in. A comet is a lot like a dirty snowball — except that it's as big as a mountain! While most comets can be a mile or two across, Comet Hale-Bopp seems especially huge. Scientists think it may be five miles or more across. Comets spend most of their time out in the farthest parts of the solar system, where it's cold and dark. When a comet is that far from the Sun, we can't see it. A comet's orbit is usually a very long oval, known as an “ellipse,” looping around the Sun. It takes the comet thousands of years to travel along this path. But when it comes into our part of the solar system, closer to the Sun, the sunlight heats the ice and causes it to “sublimate” (go directly from ice to gas). This makes a huge cloud of gas, called the “coma,” which gives the comet its fuzzy
The English word comet derives from kome, the Greek word for hair of the head, first used by the Greek philosopher Aristotle (384-322 B.C.) to characterize a comets hairlike tail. The word koman and kometes are Greek for wearing long hair and comet. Kometes morphed to cometes in the Latin language, to cometa in Late Latin, cometa in Old English, and comet in modern English.
