Although equinox means equal night, it doesn't mean that the day and night exactly the same. They are close. After the autumnal equinox the days are shorter though.
In 2011, the Autumnal Equinox begins on September 23rd.
September 22
The answer is autumnal equinox.
There are two answers to that. In the northern hemisphere the autumnal equinox is in September, so one answer is the letter e. In the southern hemisphere the autumnal equinox is in March, so the second answer is the letter c.
Between vernal equinox and the autumnal equinox.
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. "
Although equinox means equal night, it doesn't mean that the day and night exactly the same. They are close. After the autumnal equinox the days are shorter though.
Autumnal Equinox was 23. September in 1978
They would be the vernal equinox and the autumnal equinox.
In 2011, the Autumnal Equinox begins on September 23rd.
The North has shorter days between the Autumnal equinox and the Spring equinox, and longer days for the other half of the year. In the South, it is the other way around. Averaged over the course of a year the day lengths are the same.
September 22
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.
3 Twice. On the Autumnal equinox and on the Vernal equinox.
Equinox
The "Vernal Equinox" is the beginning of "Spring" and the end of "Winter". The Autumnal Equinox is the beginning of "Autumn" or "Fall" and the end of "Summer". In the Northern Hemisphere, the Vernal Equinox is in March and the Autumnal Equinox in September each year.