Why does the North Star barely move?
The short answer
Polaris, the star called the North Star, lies close to the point in the northern sky where Earth’s rotation axis points. As Earth spins, the stars appear to move across the sky. Polaris is near the center of that apparent motion, so it looks almost still. It does move a little.
Why do the stars seem to move?
Earth rotates from west to east. From the ground, this makes the stars appear to move in the opposite direction. In the Northern Hemisphere, their paths seem to curve around a point in the northern sky.
Polaris is close to the center
If we extend Earth’s north rotation axis out into space, it points toward an imaginary spot called the north celestial pole. The pole is not a star. It is a point that marks the direction of Earth’s axis.
Polaris lies close to this point, so it appears to trace a small circle. Stars farther from the pole appear to trace wider circles. In a long-exposure photograph of the northern sky, the stars make arcs around the north celestial pole. Polaris is not exactly at the center, so it also makes a small arc.
A guide to north
In the Northern Hemisphere, Polaris is a useful guide to geographic north because it appears close to the north celestial pole. Its height above the horizon also gives a rough idea of latitude: how far north a place is from the equator. Polaris is not exactly at the pole, so this is an estimate; precise measurements must account for the gap.
The North Star’s role can change
Earth’s rotation axis does not always point in the same direction. Like the axis of a spinning top, it slowly changes direction and traces a circle over about 26,000 years. This motion is called precession. Gravity from the Sun and Moon acts on Earth’s slight bulge around its equator and causes this slow change.
As the north celestial pole shifts, different stars come closest to it over thousands of years. In the distant future, Vega, in the constellation Lyra, will be near the pole. The North Star is a role that different stars can take over time.