Gary Clark, age 11, of Las Vegas, Nev., for his question:

WHAT CAUSES A LUNAR ECLIPSE?

A lunar eclipse takes place when the moon passes through the shadow of the earth. A total eclipse occurs if the entire moon passes through the earth's shadow. A partial eclipse occurs if only part of the moon passes through the shadow.

A total lunar eclipse may last up to one hour and 40 minutes.

A lunar eclipse may be seen by most of the people on the night side of the earth. Also, there is definitely no danger in viewing a lunar eclipse.

The moon does not become completely dark during most lunar eclipses. In many cases, it becomes reddish. The earth's atmosphere bends part of the sun's light around the earth and toward the moon. This light is red because the atmosphere absorbs the other colors present in sunlight in greater amounts than it does red.

Eclipses have fascinated people for thousands of years. The ancient Chinese thought solar eclipses occured when a dragon in the sky tried to swallow the sun.