Carolyn Wentworth, age 11, of Monroe, La., for her question:

DO MANY METEORS FALL TO EARTH?

Meteors result when chunks of metallic or stony matter called meteoroids enter the earth's atmosphere from space. Friction with the air makes the meteoroid so hot it glows and creates a trail of hot glowing gases. Meteoroids that reach the earth's surface before burning up are called "meteorites."

Scientists estimate that as many as 200 million visible meteors occur in the earth's atmosphere every day. These and invisible meteorites are estimated to add more than 1,000 tons daily to the earth's weight.

Meteors are often called shooting stars or falling stars because they look like stars falling from the sky. They rarely blaze for more than a few seconds.

Most of the meteors we see were originally no larger than a pinhead or a grain of sand.

We first see most of the meteors when they are about 65 miles above the earth. Air friction heats them and the air around them to about 4,000 degrees Fahrenheit and they burn out at altitudes of 30 to 50 miles.