ROCKS FROM OUTER SPACE

The pieces of rocks that come from outer space have three names: meteor, meteorite, and meteoroid.

A meteoroid is a piece of matter moving in space. It moves as fast as 40 miles a second. It may be large or small. Most meteoroids are smaller than a grain of sand.

As a meteoroid comes into the air near the earth, it catches fire. Most meteoroids burn up before they hit the earth. The flash of light from the burning meteoroid is called a meteor. If a piece of meteoroid falls to the ground, it is called a meteorite.

People have studied these rocks for many years. They wanted to research ways to keep meteoroids from making holes in spacecrafts. Thick walls may help. Or perhaps spacecrafts can be covered with a metal skin that will seal itself.