Earth's rotation

Summary

Earth's rotation is the turning of the Earth about its axis. It is described by the rotation that carries a frame fixed to the crust onto a frame fixed relative to distant objects. Its rate is about one turn per sidereal day of about $86164$ seconds, an angular velocity of about $7.292 \cdot 10^{-5}$ rad/s. The rotation is not uniform. The axis moves in space by precession and nutation, and it moves relative to the crust by polar motion. Its rate also changes, which shows up as length of day variations.