Wayne Burr, age 9, of Indianapolis, Indiana, for his question:

Are the stars really fixed in the sky?

There are very strict traffic laws up there in the sky. For instance, the big, bright stars absolutely cannot come crashing down on the earth. The stern rules also make each star stay just so far away from the next one. A group of stars may form a pattern called a constellation. Night after night, year after year we can see the same constellation patterns in the sky. Ah, but every night they move over the sky. And every season of the year we see a different parade of constellations. Their patterns may be fixed, but certainly the constellations seem to move.

Actually they only seem to move in this way because our dizzy old earth keeps turning us around to face different parts of the sky. However, the separate stars do really move around a little, though not enough for the eye to notice changes, even in a thousand years. But the planets are great ones for roaming around. They are much closer to us. And the stars form a fixed background behind their wandering paths.