Exactly straight over the equator.
It's a tiny bit north of the equator just before the Autumnal Equinox, and a tiny bit
south of the equator just after it. In other words, the sun is 'moving' south.
At the Vernal Equinox, it's also precisely over the equator, but 'moving' north.
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. "
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.
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.
The "autumnal equinox" is a single point in time, not a period. In 2015, the autumnal equinox will happen at 08:20 (UT) on the 23rd September.
It's called the Equinox, which happens biannually, one called Vernal Equinox (Spring), and one called Autumnal Equinox (Fall).
Autumnal Equinox was 23. September in 1978
Equinox (autumnal or spring)