Say goodbye to summer as the autumnal equinox—the beginning of fall—begins Saturday.
The equinox occurs when the sun travels directly over the Earth's equator, making day and night equal in length. Equinox means "equal light" in Latin.
Space.com points out that this observation is not quite correct, however, as daylight is still a little longer, given that "night" is measured by the moment the sun dips below the horizon. In fact, even before it seems to have gone down, it is simply an optical illusion that keeps it hovering and twilight carrying on.
The autumnal equinox is the first day of autumn in the northern hemisphere only. In the southern half of the world, spring has sprung once again. The autumnal equinox doesn't always fall on the same day. It sometimes falls on the 23rd or 24th due to Earth's irregular orbit.
LiveScience reports that humans can react very oddly to seasonal changes.This includes high sexual drive during the early summer and seasonal affective disorder during winter.