The reason for the slow drift of the position of the vernal equinox through the sky against the background stars over long periods of time is the
A) motion of Earth in its orbit.
B) overall movement of local stars in the sky.
C) movement of the Sun in the Milky Way Galaxy.
D) precession of the spin axis of Earth.

Question

Quizplus · Accepted Answer

The slow drift of the position of the vernal equinox through the sky against the background stars over long periods of time is due to the precession of the spin axis of Earth. This is a gradual wobble in Earth's rotation axis caused by gravitational forces exerted by the Sun and the Moon on Earth's equatorial bulge.

The Reason for the Slow Drift of the Position of the Vernal