The Maya of Central America were careful skywatchers. They built observatories for tracking the Sun, Moon, and stars. They developed accurate calendars, and could predict the motions of astronomical bodies. There’s even evidence that they could predict eclipses with a fair degree of accuracy.

One example of their astronomical prowess may be found in the ancient city of Chichen Itza, in the Yucatan Peninsula. A shadowy snake appears to descend one side of a massive pyramid there on the equinoxes. It may represent Kukulkan, the god of the underworld – a serpent with plumes of feathers.

The pyramid was built as early as a thousand years ago. It’s about 80 feet tall. It consists of multiple tiers, like a limestone layer cake. Each side has a staircase with 91 steps, which lead to a temple at the top. That creates 365 total steps – the number of days in a year.

For a couple of weeks around the equinox, the northwestern corner of the pyramid casts a shadow on the raised sides of the northern staircase. As the shadow descends, it looks like a snake slithering down the pyramid. It culminates when the shadow reaches the base of the staircase, which features a carved head that looks like a snake.

It’s not certain that the alignment was intentional. Even so, it’s one of the world’s most famous equinox markers, drawing thousands of visitors each year to mark the start of spring – which arrives tonight.

More about the equinox tomorrow.

Script by Damond Benningfield