Craig Collins, age 10, of Florence, South Carolina, for his question:

Why do the stars seem to move around the earth?

Some 400 years ago, most of the world's wisest scholars were sure that the stars moved around the earth. All the ordinary folk in those days were quite certain that the stars, the sun and the moon circled once around our little planet every calendar day. But this is the Space Age and even the youngest student knows that this only seems to be true. The skies have many tricks to fool the eye. But this one is easy to understand with the help of a globe or a carousel. When you ride on a carousel, you get different views of the scenery as you spin around. The Ferris wheel comes into view, swings around and behind you out of sight. On the next trip around, it does the same thing. But you know that it is you moving around.and not the Ferris wheel.

Our globe shaped planet also is spinning around, though we cannot feel its motion.  It spins completely around toward the east once every calendar day. As it turns, it gives us a changing view of the star studded reaches of space that surround it. Every hour, new stars come into view above the eastern horizon. As the earth spins onward, they appear to march overhead and set in the west. They seem to be parading in a ring around the world  but really it is we who are circling around with the spinning earth.