ASTR 121 (R. W. O'CONNELL)

Ollin symbol
THE AZTEC CALENDAR STONE



THE SUN STONE

The "Aztec Calendar Stone" is the most famous of a number of similar pre-Columbian Mesoamerican carvings. It is a 12-foot diameter, 25 ton stone carved in 1479 (long after the Maya demise, ca. 950 AD, but preceding the Spanish conquest), presently in the National Museum of Anthropology, Mexico. Two reconstructions of the original appearance of the Stone are shown on this page.

The themes expressed in the stone are common to a cultural tradition that extended to more than 2000 years earlier, through the Toltec, Maya, Olmec and related societies. The stone is less a detailed representation of the well-developed Aztec calendar system than a monument to their most important deity, the Sun god Tonatiuh. It is more correctly called the "Sun Stone."

The circular shape of the stone represents the cyclic nature of time in the Aztec world view. They were closely familiar with the regular cyclic behavior of astronomical objects like the Sun, Moon, and Venus, building on observations compiled by the highly accomplished Maya astronomers who preceded them. The two concentric circular bands surrounding the complex central carving of the stone contain the 20 "day signs" of the repeating ritual calendar and 52 symbols representing the 52 year duration of the "Calendar Round," the length of a single calendrical cycle. In civic life, the Round was equivalent to our century.

The cyclic mechanism of the Mesoamerican calendar is illustrated with a Flash animation at this web site.


Aztec Sun Stone Small

Center of the Sun Stone. (Painting by R. S. Flandes)

AZTEC COSMOLOGY

Beyond reflecting the calendar, the stone describes the colorful but violent Aztec cosmology. The glaring face of the Sun god at the center of the stone (see image above) is surrounded by a six-lobed symbol for Ollin, or "movement." Also reproduced at the head of this page, the Ollin symbol is the only one of the twenty day signs to represent an abstract concept as opposed to "Reed," "Wind," or "Water," for instance. It refers to the movement of the Sun through the sky but also to earthquakes.

The four squarish panels within the Ollin symbol depict the four cosmological epochs thought to have preceded the current era of the Aztec empire. During each of these, the gods struggled to nurture mankind on Earth only to be defeated by a catastrophe. The date and nature of each cosmic holocaust is given in the panels: 4 Jaguar, 4 Wind, 4 Rain, and 4 Water---the numeral 4 being a bad omen.

Here is a description of the cosmological panels on the Sun Stone from Skywatchers of Ancient Mexico by Anthony F. Aveni (1980, p. 143):

The concept of the cyclic destruction and rebirth of the world is a common theme in Mesoamerican religion and mythology. On the famous Aztec calendar stone, surrounding the face of the Sun God, about whom all periodic phenomena in nature take place, we see four rectangular panels symbolizing the destruction of the world on each of the previous epochs through which it has passed. In the most remote epoch (upper right), giants who inhabited the earth were attacked and devoured by jaguars. At the upper left, the god of wind symbolizes the hurricanes that carried away the people of the second epoch. The third cosmogonic epoch, symbolized the god of fire-rain at the lower left, was destroyed by lava and fire in a great volcanic eruption. The few survivors were those who were able to transform themselves into birds. Storms and torrential rains epitomized by the water god ending the fourth epoch (lower right panel) caused men to be changed into fishes. In the present, or fifth, epoch destruction by earthquake is said to await us.

The fifth, and current, cosmological era began with the self-immolation of the god Nanhuatzin on behalf of mankind and his reappearance in the sky as the Sun god. Four small circles at the corners of the large Ollin symbol give the date 4 Ollin on which the transformed god, now the "Fifth Sun," began moving through the sky. But the date also predicts the earthquake catastrophe that will end the fifth cosmic epoch.

The cosmic cycles of birth and destruction were identified with periods lasting 13 "baktuns" in the remarkable Maya "Long Count" calendrical system. A baktun is 20x18x20x20 days long, or 144,000 days. A cosmic cycle of 13 baktuns is therefore slightly over 5100 years. Based on the best evidence for its starting date, the current, "fifth," epoch will end in December 2012. That is only five years from now---but it is over 1100 years since the collapse of the Maya empire.


RITUAL MURDER

To sustain him in his movement across the sky and to forestall the descent of perpetual cosmic darkness and vicious demons on the Earth, the Aztecs believed they were obligated to regularly feed the Sun god human hearts and blood. The tongue-like implement extending from the god's mouth on the stone is a sacrificial flint knife of the kind used to slash open the chests of captive warriors during the ritual murders. The god's insistence on sacrifice is symbolized by the bird-like claws that clutch human hearts on either side of his face.

The close of a Round of 52 years involved a concerted nation-wide cleansing ritual, in which all fires were extinguished, followed by the symbolic rekindling of the Sun by building a fire on the opened chest of a human sacrificial victim. The Sun Stone itself was probably intended to be mounted horizontally in order to receive the hearts and blood from this and other violent ceremonies.


PRE-SCIENTIFIC COSMOLOGIES

The Aztec Sun Stone beautifully captures the vibrant, if grim, Mesoamerican world view. This is a fascinating example of a pre-scientific cosmology. The intense, if often unconscious, desire to find human meaning in the universe and the absence of stringent standards for evidence in pre-scientific cultures are the reasons that their world views are so different from ours. The shared features of such world views include these:


SUN STONE RECONSTRUCTIONS

The images above and below are artists' reconstructions of the stone's original appearance, including its likely coloration. The image below was copied from http://copan.bioz.unibas.ch/meso/sunstone.jpg. It is an interpretation by F. Devalos from National Geographic. An interactive, interpretive map of the calendar stone used to be posted at http://www.ai.mit.edu/people/montalvo/Hotlist/aztec.html. Maybe it will reappear somewhere else soon.

Aztec Sun Stone


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Last modified June 2008 by rwo

Text, other than Aveni quote, copyright © 1999-2008 Robert W. O'Connell. All rights reserved. These notes are intended for the private, noncommercial use of students enrolled in Astronomy 121 at the University of Virginia.