by Kelly A. Mello

Created on: March 28, 2007   Last Updated: May 02, 2007

A bright object streaks across the sky, illuminating it as it passes. A "shooting star", we call it. You contemplate to yourself, "what is a shooting star, exactly?"

The process starts when a comet, asteroid or even a small planet or moon enters our solar system. Most come from the asteroid belt lying between the orbits of Mars and Jupiter, about 400 million km from the Sun. When it nears the Sun, it will heat up. small rocks, ice and similar debris detach from it. These materials are meteors and meteorites in waiting. They float around our solar system and can be seen until Earth passes through them during its revolution around the Sun. The debris then enters the atmosphere with a velocity of 20 to 60 km/s, which heat up due to the friction and become what we call a "shooting star", or the more technical term, a "meteor". If, however, the luminescent object is large enough to withstand the friction in the atmosphere and crashes into the Earth, it is known as a meteorite.

You may also witness something called a "meteor shower", which is when the Earth moves through the debris field of a comet. This often happens at certain times each year, due to the rotation of the Earth. November 3 through 15, for example, may sound familiar to you. At this time Earth crosses the group of debris called Taurids. This comes from the Encke comet, which returns every 3.3 years. Every year between June 24 and July 6 the Earth again crosses Taurids, but during this time, there is almost nothing to see.

Fun facts about meteorites:

-The biggest one found is:
Hoba, Namibia 60 tons, 3m in diameter

-There were 24,858 named meteorite falls and finds up to June 2002. 19,884 in Antartica, 1346 in the United States.

-About 350 craters are scattered throughout the world. One is the Canon Diablo ('Devil's Canyon') in Arizona, USA. It has a 1.5 km diameter and is 170 m deep. The meteorite which made this crater may have been 30,000 to 100,000 tons, and an estimated 10 m - 25 m in diameter.

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