Chichen Itza


*Temple of Kukulacon*	*Ball Court*	*Caracol*

Stone artifacts from the cultures of Mesoamerica (roughly from northern Mexico to Honduras) date back to about 2500 B.C. Over the centuries these cultures became quite sophisticated and were numerous, rich and varied. One of these, Mayan civilization, extended from Honduras through the Yucatan peninsula and reached its highest state in the period from 200 A.D. to 900 A.D. Chichen Itza is one of the best known Maya cities, situated right in the center of Yucatan. The Maya had a sophisticated number system (base 20) and they tracked celestial bodies with great precision. They could predict eclipses and were particularly observant of the planet Venus. To them Venus represented their feathered-serpent god, Kukulacon. The motion of Venus was correlated with the motions of the Sun and the Moon and all three motions were incorporated into a very complex calendar system. As an example of the subtleties of Mayan time keeping, you might be surprised to learn that the Maya began their year on July 26. However, this has a straightforward astronomical explanation. Since Yucatan is located in the tropics, the Sun passes directly overhead (the zenith) twice a year (see Aveni). The beginning of the Maya year was on the second of these yearly zenith passages (July 26).

These pictures of Chichen Itza were taken by me in 1969. Although the structures look basically the same today, I emphasize the time gap to illustrate a point. First consider the Temple of Kukulacon. Aveni discusses the phenomenon of how the shadow of the terraced pyramid on the temple steps seem to suggest a giant snake (symbolically, Kukulacon) writhing down the structure around the time of the equinoxes ( March 21 and September 21). This picture was taken in early October, not too many days later, so I should have been able to have seen this spectacle within a couple of hours after taking this picture. Did I wait around to see the show? No! Why? Because no one (guide books, astronomy books, guides on the spot) mentioned this phenomenon - this knowledge was not in general circulation at the time! As Aveni points out, the effect was noted by a photographer in 1940, but no one paid much attention to it until a series of papers were published in the early 1970s. Now, of course the effect is world famous and the place is packed with tourists around equinox time!

On the other hand, the Caracol has long been referred to as an observatory. Thirty years ago, some people felt that this designation arose from its resemblance to a modern observatory (you can almost see the rest of the demolished dome). Today, however, archeologists believe that it really was used as an astronomical observatory, although it was a cylindrical tower and never had a dome. It appears that its prime use was to observe Venus.