What is nutation in relation to earth?
The cyclic precession-nutation motion of the polar axis of the Earth
is similar to the motion of thf the spinning toy, Top.
Precession is motion along the surface of a double right circular
cone, with vertex near the center of the Earth. The period of this
revolution is called Great Year = 258 centuries, nearly. The semi-
angle of this cone is about
Tn this interactive play of mutual attractions of the triad the Earth,
the Sun and the Earth's orbiter Luna, there is lateral oscillations
(nodding) of either Pole called Nutation, on the surface of the Earth,
about its Great Year circular path.. This nutation comprises quite a
number of oscillations with different periods.
For graphic depiction see wikipedia.org/wiki/Nutation