By Gemma Tierney

 

 

 

The Mayan and Incan cultures that once had great empires in Central and South America, respectively, have also been identified to have practiced a solar-based astronomy. This means that their years were based on the changing of position of the sun at the horizon as it rises and sets. The fact that they based their years on the sun has been determined by the studying of various artifacts, such as calendars and observatory points. The earliest observatory point in the Americas, located in Chankillo, peru, was only definitively identified in recent years as an observatory, although archeologists and astronomers have hypothesized about its possible astronomical purpose for more than a century.

 

 

 

The archeological site covers about four square miles and includes more than just the thirteen towers and their observatories. It has been debated what exactly the site was created for. It has many fortification elements, making one think it was a fortress. But other aspects of it make it seem as if it was often used for ceremonial purposes. The observatory further reinforces this latter theory. It is located in the coastal region of Peru, which is very desert-like. The site is 2,300 years old, making it the oldest in the Americas and far older than those of Europe.

 

This observatory consists of thirteen towers running North to South, and two observatory points located on the Western and Eastern sides of the line of towers. The line of towers spans about 1,000 feet, while the two observatories are about 750 feet away on each side. These thirteen towers have notches in between them that create a scalloped horizon. Each of the towers can be surmounted by a set of stairs.

 

If one looks at the rising sun from the Western observatory point, one would see the sun fitting right into one of the notches. The same is true for the setting sun seen from the Eastern observatory point. As the year progresses, the sun will be seen to move from notch to notch as it rises and sets. This is due to the fact that the earth is at approximately a 23 degree tilt so that is it revolves around the sun, the sun is seen to rise and set at different locations on the horizon. Thus, the towers are lined with the solar arc of the sun throughout the year, creating a solar calendar divided into thirteen sections. This is sometimes called “landscape timekeeping”, as is mentioned by Ivan Ghezzi of Yale University. This method was something used in other places in the Incan empire. Even beyond the simple task of tracking time, the observatory- and the culture’s study of astronomy in general- was used to make political decisions. This is further reinforced by the fact that the two observation points are small, and can fit only a few people. This causes some archeologists to hypothesize that they were probably only occupied by a person of standing in the community, such as a priest who would then report back his observations and interpretations to the king.