what are commets in science?

Question

it's a project for science!

Answer 1

A comet is a small body of the solar system, usually made of mixed rocks, dust and ice.

When it approaches the sun, the light and heat causes the ice to vaporize, creating a halo of dust and gas around the body.

Sunlight pushes the dust and gas "back" from the halo. This formes the tail or tails (as there can be two, one of gas, the other of dust).

The body is called the nucleus (central part), the halo is called the coma (from a latin word for hair) and the tails are simply called tails.

The word comet comes from aster cometes (hairy star).

Answer 2

A comet is a small body in the solar system that orbits the Sun and (at least occasionally) exhibits a coma (or atmosphere) and/or a tail — both primarily from the effects of solar radiation upon the comet's nucleus, which itself is a minor body composed of rock, dust, and ice. Comets' orbits are constantly changing: their origins are in the outer solar system, and they have a propensity to be highly affected (or perturbed) by relatively close approaches to the major planets. Some are moved into sungrazing orbits that destroy the comets when they near the Sun, while others are thrown out of the solar system forever.

Comets are usually discovered visually or photographically using a wide-field telescope or other optical means of magnification, such as binoculars. However, even without access to optical equipment, it's still possible to discover a sungrazing comet online with a computer and an Internet connection.

Most comets are believed to originate in a cloud (the Oort cloud) at large distances from the Sun consisting of debris left over from the condensation of the solar nebula; the outer edges of such nebulae are cool enough that water exists in a solid (rather than gaseous) state. Asteroids originate via a different process, but very old comets which have lost all their volatile materials may come to resemble asteroids.

The word comet came to the English language through Latin cometes. From the Greek word komē, meaning "hair of the head," Aristotle first used the derivation komētēs to depict comets as "stars with hair." The astronomical symbol for comets accordingly consists of a disc with a tail of hair.

http://groups.google.co.in/group/neat-astronomy?hl=en

Answer 3

A comet (that's what you wanted, right?) is like a big snowball, a chunk of dirty ice floating in space. Since they are made of ice, they evaporate when they approach the sun. The solar wind blows the vapour out into a huge tail.

But since comets evaporate, they disappear a bit more each time they pass the sun. So why aren't they all gone?

There is a gigantic cloud of comets and other debris from the formation of the Solar System called the Oort Cloud. That's where future comets are floating, far away in deep-freeze. Occasionally the sun passes close enough to another star to disrupt part of the Oort Cloud; that causes some comets to drift off into space forever and causes some to fall into the warm inner Solar System -- where they become comets.

Answer 4

a comet is a cosmic object made of ice(mainly frozen gases) and dust. comets come from the Oort Cloud, a spherical cloud of of matter that surrounds the solar system.

Answer 5

its a huge hunk of hot rock