Janet Gibson, age 10, of Santa Maria, California, for her question:

Do the stars reallv move around at night?

Certainly most of the stars seem to move during the night. When you pick a bright one and watch it for an hour or so, you may see it creep a little way toward the west. But things in the sky can fool the eye and what seems to be may not be so at all. Actually the skyful of stars does not really inch westward over the sky during the night. It seems that way because our dizzy old earth spins around like a top    and around we go with it.

We do not notice that the earth is spinning. But this does change our view of the sky above. We are turning toward the east and a new view of the sky is always appearing above the eastern horizon. The earth swings us on and on to meet the next and the next view in the eastern sky. Meantime, the stars in the west sink down out of sight. Actually the stars do not move over the sky at night. They only seem to do this because the spinning earth keeps changing our view of the sky.