Comets

Comets, Comets, Comets! What in the world are comets? Where do they come from? What do they look like? How are they created? Someone tell me! Well first off comets are a relatively small extraterrestrial body consisting of a frozen mass that travels around the sun in a highly elliptical orbit. The word comet comes from the latin word 'cometa' meaning long haired. The long term comets come from the Oort Cloud ane the short term from the Kuiper Belt. Comets generally have three main parts, Coma, Tail, and Nucleus. Other parts of the comets include dust and gas tail, and hydrogen corona. Comets usually look like a HUGE ball of ice with a LONG gaseous tail.

Comets also have orbits, a like to planets. Everytime a comet comes into the inner solar system it loses ice and dust leaving behind a trail. The oval-shaped orbits of comets can cross the near circular orbits of the planets. Because of this, comets can collide with planets and their satellites. Many of the impact craters in the solar system were caused by collisions with comets.

The kuiper belt, where short term comets come from, is located in between Uranus and Neptune. The oort cloud, where long term comets come from, is located way beyond pluto. Chinese astronomers record several observations as well. Comets throughout history have been thought to bring bad luck but these are just natural phenomena of the solar system. When the nucleus is frozen, it can be seen only by reflected sunlight, and many comets are extremely dark objects. If a comet approaches to within 5 astronomical units (750 million kilometers or 465 million miles) of the Sun, fluorescence of tail gases can become an important contributor to the brightness of the comet, together with the light reflected from the nucleus and coma.

Each time a comet swings into the inner solar system toward the Sun, it loses some of its ice component. The comet Halley is believed to lose one meter of its surface each time it approaches the Sun. Eventually, comets burn out, becoming just another rocky mass in the solar system. Some objects currently classified as asteroids are probably extinct comet nuclei. Comets are divided into two groups based on their orbital periods (the time it takes them to travel around the Sun). Short-period comets have orbital periods of less than 200 years.

So what are the differences between an asteriod, comet, meteoroid, meteor, and a meteorite? WELL, In space, a large rocky body in orbit about the Sun is referred to as an asteroid or minor planet whereas much smaller particles in orbit about the Sun are referred to as meteoroids. Once a meteoroid enters the Earth's atmosphere and vaporizes, it becomes a meteor (i. e., shooting star). If a small asteroid or large meteoroid survives its fiery passage through the Earth's atmosphere and lands upon the Earth's surface, it is then called a meteorite. Cometary debris is the source of most small meteoroid particles. Many comets generate meteoroid streams when their icy cometary nuclei pass near the Sun and release the dust particles that were once embedded in the cometary ices. Collisions between asteroids in space create smaller asteroidal fragments and these fragments are the sources of most meteorites that have struck the Earth's surface. If particular asteroids can be identified as the sources for some of the well-studied meteorites, a detailed knowledge of the meteorite's composition and structure will provide important information on the chemical mixture and conditions from which the parent asteroid formed 4. 6 billion years ago.

Now all those questions haunting you a night about comets have been answered. You've probably learned alot here and some things you may not understand. Which is okay because pictures are below. This WikiSpace has been made by Samantha Whalley and Destiny Templeton. Now go have a nice day. :).