Geena Zebrasky – Features Writer
This Saturday, March 20th, marks the official beginning of spring, at least for the hemisphere we occupy. For the Southern Hemisphere, it’s officially the first day of their autumn. Match 20th is the vernal equinox–which happens every year between the 19th and 21st of March.
The word equinox comes from the Latin words aequus, meaning “equal,” and nox, meaning “night.” This implies that because the sunlight is equally distributed over both hemispheres, the length of the daylight is the same length as the night everywhere. All other times of the year, because of the Earth’s tilt on its axis, one of the hemispheres experiences less daylight than night, and vice versa.
Other than bringing longer days to us (and distracting us with nice weather), the equinox is cool for another reason: the sun is finally rising in the Arctic Circle. In both the Arctic Circle as well as the Antarctic Circle, the sun only rises and sets once each year.
In the Arctic, the sun officially goes below the horizon on the autumnal equinox in September, and the circle remains in darkness until the vernal equinox. So Santa and his elves at the North Pole spend their Christmas in total darkness, and they don’t see the sun until March. At least the sun is up for their off season!
The equinox is also important in many parts of the world as a key part of cultural practices. The equinox marks the first day of the Iranian calendars, and the Nowruz holiday is celebrated by some people in Iran, Afghanistan, and the Kurdish regions of Iraq, Turkey and Syria, and throughout Central Asia. Traditions differ between places, but it’s a New Year celebration of the spring equinox. In Japan, it’s observed as a national holiday, known as Shunbun no Hi. It’s also used by Christian churches to calculate Easter: the first full moon after the equinox is Easter, and this is when Passover usually falls as well.
Last but not least, the equinox is recognized as International Astrology Day because it marks the first day of the astrological year. The Earth spends its first full day in the astrological sign of Aries on the spring equinox.
Interestingly, even though it’ll officially be Aries season, the sun will still be shining on the Pisces constellation. If you use Co-Star to check for updates on your zodiac sign, you should know that these use the tropical zodiac, which is used for the ecliptic coordinate system that makes up the astrological year. This is different from the sidereal zodiac. The astrological signs of the ecliptic coordinate system remain fixed, so the first point of Aries will always be the March equinox. The sidereal zodiac is based upon what constellation the sun is actually shining on. The constellations of the zodiac can shift over long periods of time because of a property that causes the Earth’s axis to shift slightly, and the sidereal zodiac corrects for these shifts. So for this system, Aries season begins on April 15th.
Regardless of how you celebrate, I think all of us can probably agree we’re happier about the longer days we’ve been experiencing, and the warmth that has accompanied them.