A meteor shower is when small bits of space rock produce tiny pinpoints of light that streak through the sky. These small fragments enter the Earth's atmosphere at speeds reaching 71 kilometers a second (about 158,000 miles per hour).

Meteors glow because the friction between them and air molecules makes them heat up to the point of incandescence. Most meteors are smaller than a rice grain and take about a second to burn up at altitudes of about 80 kilometers, or 50 miles in the ionosphere.

Meteors can happen sporadically or in a shower. The sporadic type come from random bits of solar system dust and are unpredictable.

Shower meteors, however, occur when Earth passes through a trail of debris released by comets as they travel in the solar system. A comet leaves a dust trail that spreads along its orbit around the sun and crosses the orbits of the planets. As the planets go around the Sun, they keep passing this trails left behind by comets.

When the Earth passes through these comet debris trails on its own orbit around the Sun every year, that's when we see the dust particles interacting with the atmosphere, hence the meteors. This is how we know when a meteor shower will occur and why they happen at the same time each year.

There are many meteor showers throughout the year and they have names that relate to certain star constellations, such as the recent Leonid meteor shower. They are named as such because when the meteors streak by they seem to come from a certain area of the sky. This area is known as the Radiant. In the case of the Leonid meteor shower the meteors appear to streak from the Leo constellation.

The location of the radiant depends on what position the Earth is when passing the comet dust trail that is producing the meteor shower.

Please check back for more informative articles on space, astronomy and science as well as for space and astronomy news as they happen.

Also check my Ft. Lauderdale Science News Examiner page, for more interesting content and news.