Geodetic precession

Geodetic precession, or the Einstein-De Sitter effect, was discovered by the Dutch astronomer Willem De Sitter in 1916. It was predicted by Einstein's general relativity.

An object rotating in the gravitational field of a star that is not itself rotating will be subjected to forces that modify the direction of its axis of rotation.

The effect was tested by Gravity Probe B. The phenomenon is called geodetic precession.