Cancun, Q.R. — The annual spring equinox at Chichen Itza is always a historical experience for the thousands who make the trek.
Every year, Earth has two equinoxes, one in March and the other in September. An equinox occurs when the sun shines directly on the equator making the length of night and day almost equal. The March equinox marks the moment when the sun crosses the celestial equator from south to north.
Each year, this occurs on March 19, 20 or 21. This year in Cancún, the spring equinox happens on March 19 at 11:30 p.m. eastern standard time.
One of the most famous celebrations for those in the Yucatan is the spring equinox. The ancient Mayan ruins of Chichen Itza, or El Castillo, has four staircases that run from the top to the bottom of the pyramid’s faces. The staircases were constructed at a carefully calculated angle, and during the equinox, makes it appear as though an enormous serpent is slithering down the stairs.
The illusion of the snake is the shadow that is cast from the sunlight, which lasts about an hour. Although the serpent shadow appears for a few days during the equinox, it is most impressive on the actual day of the equinox.