Autumnal Equinox and Chichen Itza

Today is the autumnal equinox (Latin for equal night) which marks our first day of autumn. The sun’s light is directly over the Equator, so every place on earth has an equal number of hours of light and darkness.

While the earth orbits around the sun, the position of the sun changes in relation to the Equator due to the tilt of the earth’s axis.


I am missing an amazing phenomenon back in the Yucatan now at the Maya ruins of Chichen Itza, a phenomenon that was carefully mapped by ancient architects and astronomers.

On the day of both the vernal equinox and the autumnal equinox (and several days leading up to and after the events), afternoon sunlight bathes the western balustrade of the El Castillo pyramid's main stairway causing seven isosceles triangles to form and create a shadow that imitates the body of a 120 foot long rattlesnake that creeps downwards until it joins a huge serpent's head at the bottom of the stairway. How the Maya managed to build a monument of incomprehensible scale (all done without the wheel) to highlight the time of year when the hours of daylight and darkness are equal is extraordinary! Truly, a demonstration of the Maya's extreme aptitude for astronomy.