Models of the Solar System: SS-T1: Chankillo, Peru

Background

Chankillo or Chanquillo is a ruin located around 250 miles north of the Peruvian capital city of Lima. It is thought to be around 2,300 years old and its purpose has remained a mystery. Since the nineteenth century many have wondered what the function of the site was, and many theories have been produced: some suggesting it was some form of ceremonial ground, or possibly a fort, but the fact that there were many gates and no water supply quickly discounted these theories. Then in March of 2007 researchers Ivan Ghezzi and Clive Ruggles came up with the idea that it was a solar observatory; one of the earliest of its kind in the Americas.

The People of the Time: The Moche

Around the time Chankillo was constructed, thought to be around 300 B.C., there was a predominant civilisation in the north of

Peru

, known as The Moche. The Moche are thought to have existed from around 250 B.C. until around 750 A.D. The name given to these people was taken from an archaeological dig around the Moche river valley, which was thought to have been their capital city. The Moche people have been found to be rather industrious and successful; the large amount of beautiful pottery and sculptures that have been discovered shows that even the early potters were very skilled in their art.

A Moche Monkey Effigy Pot

However, there was a dark side to the Moche people. At the site of their capital city, two large pyramids still stand today: Huaca de la Luna and the Huaca del Sol, also known as the Pyramids of the Moon and Sun. Archaeologists working on the site have found numerous wall paintings showing scenes of war and ritual decapitation. They have also found pots and other ceremonial vessels showing warrior-priests dressed in ornate clothing slitting captives' throats, drinking their blood, and hanging their skinless bones from ropes. At first it was thought that these were just exaggerated pictures of actual events, but archaeologist Steve Bourget and his colleague John Verano discovered the remains of at least 70 people at one of the pyramids, and these are thought to be the remains of victims used in sacrifices.

A wall painting from the pyramids showing the Moche God Ai Apec, also known as The Decapitator.

The site of Chankillo:

The site of Chankillo, are found in the in the Casma-Sechín River Basin of the

coastal Peruvian desert, assumed to be a ceremonial base, seems to have been built in order to assist in the observations made on the sunrises and sunsets during the period of a year.

The site consists of Thirteen Tower structures and plazas, covering an area, of rock outcrops and sand ramps, of approximately 4km^2. The best known feature of this site is mainly the 300m structure on a remote hilltop, which is fortified by massive walls, gates restricting free entry and low walls (‘parapets’) along the edge.

The Thirteen Towers are in fact a row of 13 cuboidal structures that run along the ridge of a small hill, said to resemble the spines on the back of a dragon. These towers run from North to South, albeit that three of the towers face south west (Towers 11 to 13).

The Towers can be seen from other structures and plazas below, on either side of the hill. This gives a view of a “toothed horizon”, with the gaps between the cuboids at regular intervals.

These rectangular structures were all flat-topped and of the same shape, but their sizes varied (from 75 to 125m2 and from 2 to 6m in height), with the gaps being between 4.7 and 5.1 m. Each Tower has a pair of built-in staircases, on the north and south sides, leading to the top. No relics have been found on the towers themselves, but through observation of the staircases, they appear to have been an area popularly used.

200m west of the towers there is a collection of enclosures. The southernmost building has a set of two courtyards (one of which measuring 53.6m long by 36.5m wide). Along the exterior southern side, there runs a 40m long corridor. The odd note about the corridor is that it never led into the building itself. This produced the theory that instead it was used to connect to a doorway on the northeast side, with an opening on the southeast side which directly faced the Thirteen Towers. Artefacts found in the corridor itself, rather than anywhere else, prove that this was a place probably involved with rituals and religious practices, involving passing through the corridor to the Towers.

This is considered the “western observing point”.

A large area on the east of the Towers, covering approximately 1.4km^2, contains a vast network of patios, rooms, storage areas and plazas interconnecting to form an impressive layout. Relics found in this area, suggest that the area was used for ritualistic feasts. The Thirteen Towers are a dominant feature in the landscape view from this area.

Also there is one isolated building in the middle of a large, open space, whose position is an exact mirror of the “western observing point”, making this structure particularly interesting to researchers, as it lies exactly on the east-west line. It also contains an outline of what appeared to be a similar corridor as that on the west side.

How does Chankillo function as a solar calendar?

A solar calendar, in basic terms, is a calendar that is based around the sun and its cycles. It is supposed to show where the planet Earth is on its orbit around the sun, so works in the same way the western calendar works; the Earth takes 365 days to revolve around the sun and this is classed as a year.

It has been determined that from the east and west observing points, in relation to the corners of the towers on the “false horizon”, allowed the cultures of the time to make direct observations of the sunrises.

The declinations of the towers and observing points, allowed the observers to centre the sun, relative to the towers, indicating t he solstices and the sunrises and sunsets of other specific dates. It was also noted that from the two observing points, the layout of the towers matches the range of movement of the position of the sun, during sunrises and sunsets, over the year.

When viewing the Towers from the sides closest to the twelfth and first Towers, the December and June solstice sun can be seen in exact positions over the southernmost and northernmost towers respectively. Therefore, once the sun has begun to move from either of its extreme positions, using the tower, the observers were able to track, with help of the gaps, the progress of the sun, along the horizon.

The regularity of the gaps, thus suggests that the year was divided into regular intervals (it is assumed, due to the positioning of the sunrises relative to the tower gaps that there could have been a 10-day interval).

Equinoctial sunrise is assumed to be seen between towers 6 and 7.

References

http://earthobservatory.nasa.gov/IOTD/view.php?id=7606

http://www.archaeology.org/0801/topten/solar_observatory.html

http://www.worldlingo.com/ma/enwiki/en/Pre-Columbian

http://www.sciencemag.org/content/315/5816/1239.full.pdf

http://onlinelibrary.wiley.com/doi/10.1525/aa.2002.104.3.881/abstract

http://anthropologistintheattic.blogspot.com/2010/12/2300-year-old-maya-ruins-destroyed-for.html

http://realhistoryww.com/world_history/ancient/South_America.htm

http://www.escapedtoperu.com/english/peru-moche-culture.htm

http://www.archaeology.org/0203/abstracts/moche.html

http://www.beloit.edu/logan_online/collections/catalogue/south_america/peru/early/moche/moche.php