Spring Equinox

The Spring Equinox occurs March 20, and with it marks the beginning of Spring! So what exactly does this mean? Every place on earth will experience a 12 hour day AND a 12 hour night.

Occurring only twice a year, around March 20 or 21 and September 22 or 23, the sun will shine directly on the equator causing the length of day and night to be nearly equal in all parts of the world.

These two days are known as the March (vernal or spring in the northern hemisphere) equinox and the September equinox.

The Spring Equinox

Diagram showing the sun’s rays during the equinox. (Image courtesy of Blueshade)

Vernal (Spring) Equinox vs. Autumnal Equinox

Derived from the Latin words meaning “equal night”, equinox refers to the time when the sun crosses the equator. During this period, day and night everywhere will be nearly equal in length (12 hours).

The March equinox marks the beginning of Spring in the northern hemisphere while it is the start of autumn in the southern hemisphere.

After the Spring Equinox, the Sun continues to follow a higher and higher path through the sky, with the days growing longer and longer, until it reaches its highest point in the sky on the Summer Solstice.

Historical Fact

Hipparchus (ca. 190-ca.120 BCE), a Greek astronomer and mathematician was attributed by various sources to have discovered the precession of the equinoxes, the slow movement among the stars of the two opposite places where the sun crosses the celestial equator. Hipparchus made observations of the equinox and solstice. However, the difference between the sidereal and tropical years (the precession equivalent) was known to Aristarchus of Samos (around 280 BCE) prior to this.

Astronomers use the spring equinoctial point to define their frame of reference, and the movement of this point implies that the measured position of a star varies with the date of measurement. Hipparchus also compiled a star catalogue, but this has been lost.

Spring Equinox Celebrates Rebirth

The Spring equinox has a long history as being a time of rebirth. Holidays and festivals around the world are celebrated by many cultures and religions, such as Easter.

The spring equinox is sacred to dawn, youth, the morning star (Venus) and the east. The Saxon goddess, Eostre (from whose name we get the direction East and the holiday Easter) is a dawn goddess, like Aurora and Eos. Just as the dawn is the time of new light, so the vernal equinox is the time of new life.

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