Why the stars move

Watch the sky for an hour and the stars drift together, rising in the east and setting in the west, as the Sun does by day. They are not moving across the sky. We are turning.

The Earth spins once a day, so the whole sky seems to wheel around us. In the northern hemisphere one star, Polaris, sits almost exactly above the North Pole, so it barely moves while the rest circle it.

The stars keep the same patterns relative to each other over a lifetime — which is why the constellations people named thousands of years ago still look the same.