The Sun doesn't do anything at such. The Autumnal equinox is more down to the position of the Earth on its orbit of the Sun. The sun is directly over the equator and the amount of daylight and darkness is about equal around the world.
The autumnal equinox is also known as the fall equinox and the September equinox. An example of a sentence using "autumnal equinox" is "This year's autumnal equinox falls on a full moon. "
Autumnal Equinox
12 hours
An equinox is when the sun crosses the celestial equator, resulting in day and night being nearly equal lengths all over the world. There are two equinoxes each year: the vernal equinox in March and the autumnal equinox in September.
In 2011, the Autumnal Equinox begins on September 23rd.
September 22
Approximately 12 hours of Sun-over-the-horizon. (Same as the vernal equinox)
In the Northern hemisphere, daylight hours decrease after the autumnal equinox.
Southern.
The event when the sun crosses the celestial equator is known as the equinox. There are two equinoxes in a year: the vernal (spring) equinox and the autumnal equinox. During these times, day and night are approximately equal in length all over the world. The vernal equinox marks the beginning of spring in the Northern Hemisphere and fall in the Southern Hemisphere, while the autumnal equinox marks the beginning of fall in the Northern Hemisphere and spring in the Southern Hemisphere.
For a vernal equinox, it occurs is March 20th. For an autumnal equinox, it occurs September 22nd.
The time of year, which puts us on opposite sides of the sun.