21 Sep 3 Interesting Facts about the Equinox
Many people consider Labor Day or the beginning of a new school year the kickoff to the fall season. However, astronomical fall officially begins on Sept. 22, 2016, with the autumnal equinox. However, even though the autumnal equinox happens every year, there are probably a few things about it that might still surprise you.
Here are three interesting facts about the autumnal equinox.
- It happens twice a year. However, it only happens once a year in each hemisphere. The autumnal equinox in the northern hemisphere is also the spring equinox in the southern hemisphere. Likewise, the equinox in March is the spring equinox in the northern hemisphere and the fall equinox in the southern hemisphere. So depending on where you live, this equinox could signal the start of spring or the start of fall.
- The earth’s tilt is the reason for the equinox—and the seasons. The earth’s axis is tilted, and that’s responsible for the seasons. When the northern hemisphere is tilted toward the sun and gets more of its direct rays, the northern hemisphere experiences the warmer temperatures of summer. Likewise, when it’s tilted away, it experiences the cooler temperatures of winter. The equinoxes occur at the midway points between these two extremes, when the sun is directly above the equator.
- Day and night aren’t technically equal on the equinox. The term “equinox” comes from the Latin words for “equal” and “night.” Many people believe that this refers to the day on which “day” and “night” are exactly the same length, but that’s not technically true. This year, we’ll experience about eight more minutes of daylight than nighttime on the equinox. That’s because we consider day to begin the moment the sun first begins to appear over the horizon, and don’t consider the day to have ended until the last of the sun has set in the west.