Linda Sue Herbein, age 12, of Tucson, Ariz., for her question:

Are the same stars overhead everyday?

As the earth turns around on its axis, we face first one view of the starry heavens and then another. The widest turn made by our globe is at the equator, where it whizzes around at 1,000 miles an hour. The further we are from the equator the slower we turn. At the poles, the earth does not turn around at all.

The faster we turn, the faster the heavenly parade goes by. The stars above the equator seem to move fastest. They are in the sky for only 12 hours. The stars in the sky above the poles move slowest. The Big Dipper and a few others do not rise and set. They circle the heavens, though we see them only after sunset. The North Star stays put day and night. Some stars, then, are always overhead, day and night. Others show themselves first to our side of the world, then to the other.