# What direction does the earth rotate on a vernal equinox?

Apr 2, 2016

Any time and at any latitude, all points on the Earth rotate in the anticlockwise sense about polar axis, in a plane that is inclined to the orbital plane ecliptic, at ${23.4}^{o}$.

#### Explanation:

About the instants and locations for right-over-head noon-Sun, on about Mar 21 ( vernal equinox ) and September 23 ( autumnal equinox )::

Equinoxes are points of intersection of the ecliptic and the equator at the particular instant, when the Sun is right overhead at noon, in a year.

These equinoxes ( very slowly ) shift for one complete extra rotation ( besides the super-fast everyday rotation ), along the equator, in a period of about 258 centuries.

This relative motion of equinoxes is owing to precession of the tilt axis, over this great period called Great Year.

Like equinoxes going around the equator in a Great Year, the poles move around small circles of angular spacing ${46.8}^{o}$ up on the Earth, relative to the center of the Earth.