The librational movement of the moon is caused by the gravitational interaction with the Earth.

The libration point is a stable point in the gravitational field of two large bodies.

The libration points are five points in space where the gravitational forces of two large bodies, such as Earth and the Moon, balance the centrifugal force felt by a smaller body, allowing it to maintain a stable position relative to the larger bodies.

The gymnast performed a libratory routine on the balance beam.