The axis of the Earth precesses with a
period of about 25,000 years. This is much like the precession of a top.
Explain how the Earths equatorial bulge gives rise to a torque exerted by the
Sun and Moon on the Earth; see Fig. 1129, which is drawn for the winter
solstice (December 21). About what axis would you expect the Earths rotation
axis to precess as a result of the torque due to the Sun? Does the torque exist
three months later? Explain.