True polar wander

Internal or external processes that change the distribution of mass (internal or external loadings) disrupt the equilibrium and true polar wander will occur: the planet or moon will rotate as a rigid body (reorient in space) to realign the largest moment of inertia axis with the spin axis.

If the body is near the steady state but with the angular momentum not exactly lined up with the largest moment of inertia axis, the pole position will oscillate (Chandler wobble).

[2] Most natural loadings are small when compared to the rotational bulge and hence change the direction of the main axis of inertia only slightly.

In the context of tidally locked bodies, also the longitude of surface features can change in time[5] and the dynamics of reorientation can be more rapid.

[7][8] It has been suggested that east Asia moved south due to true polar wander by 25° between about 174 and 157 million years ago.

[11] Polar wander should not be confused with precession, which is where the axis of rotation moves, in other words the North Pole points toward a different star.

Precession is caused by the gravitational attraction of the Moon and Sun, and occurs all the time and at a much faster rate than polar wander.