Archaeoastronomy in the American Southwest

Special CP-LUHNA essay by Bryan C. Bates

Knowledge of celestial patterns and the attribution of those powers to different gods may have migrated along migratory and trade routes throughout the American Southwest. At Chaco Canyon in northwestern New Mexico, several calendar systems have been documented with numerous connections to the culture. At the Great Kiva, Casa Rinconada, the summer solstice sun rises through a window and cast light into a cubbyhole across the axis of this ceremonial chamber. There is a question as to whether the alignment was intentionally created by the ancient Chacoans as the Park Service reconstructed the window in the 1940s. Second, the Equinox sun rises over the eastern cliff and splits the Kiva into two equal halves, symbolic of the Equinox ceremony known amongst some of the Puebloan people. Elsewhere, petroglyphs show distinctive light shadow interactions as the sun migrates from south to north (winter solstice to summer solstice) or in the reverse, each time designating a time of potential survival or ceremonial significance.

Perhaps the best known of these petroglyphs is the “light-dagger” atop of Fajada Butte. Anna Sofaer, founder of The Solstice Project, noted "two very shallow grooves that cross(ed) the petroglyph." After connecting up with Rolf Sinclair and Volker Zinser, they looked further into the potential of solar or lunar markings. Their continued research supports the hypothesis that the groove descending from the center of the petroglyph intentionally aligned with the northern minimum moonrise standstill and that the groove along the southwest side of the petroglyph aligned with the northern maximum moonrise standstill. On-site observation has confirmed these two alignments indicating that the ancient Chacoans were likely observing the 18.6 lunar standstill cycle.

Fajada at summer solstice, June 21st. Photo by Bryan Bates	Fajada at equinox. Photo by Rolf Sinclair, Chevy Chase, MD	Fajada at winter solstice. Photo by Rolf Sinclair, Chevy Chase, MD
N.B. Time flows from from left (June) to right (December) and then reverses, just as the sun moves along the horizon during the season.

Because of these observations at Fajada Butte, archaeoastronomers in the US Southwest continue to examine ancient astronomical sites for evidence that the sites might be able to predict the lunar standstill cycle, and that such observations fit within the ancestral cultural pattern. Examples of such are the work by Kim Malville, Gary Fairchild, Ron Sutcliffe and others at Chimney Rock Archaeological Park near Pagosa Springs, Colorado. In addition, Greg Munson, Larry Nordby and Bryan Bates are looking at potential lunar standstill sites in the Mesa Verde region near Cortez ,CO, and Robert Preston has looked at many inscribed rock sites in the Southwest.

Similar alignments can be found at Hovenweep National Monument in Southeast Utah and Wupatki National Monument near Flagstaff, Arizona. At Wupatki's Crack’N Rock a singular wall with three small portals records the seasonal timing of sunrise. But as above, the observation of the sunrise may tell the Sunwatcher which moon to observe, as what is culturally significant is the first appearance of a new crescent moon. The South portal (February cross-quarters) marks the time for the Powamu ceremony, or “earth renewal”, a time following the winter solstice when beans are planted inside the Kiva. The middle window (May cross-quarters) marks the time at which the soil temperature will support the germination of seeds and when the likelihood of a killing frost has past. The Sunwatcher of the Water-Sand Clan indicates one may now plant their corn. And the North window marks the summer solstice, but the observation is based upon the time at which the sun changes its direction of motion. Following preparations and a 9-16 day ceremony, the Katcinas or “spirit-carriers” leave the Hopi for their home in the sacred San Francisco Peaks. The Katcinas will then return as clouds bringing water during the “monsoon cycle” of the desert SW. Thus the Katcinas return to bring life.

Summer solstice at Middle Mesa, Crack'n Rock Community, Wupatki National Monument. Photo by Bryan Bates.	View to flat horizon from Middle Mesa. Calendar wall creates reference system for seasonal movement of the sun. Photo by Bryan Bates.	Winter solstice sunrise alignment along Water-Sand Clan petroglyph. See text for explanation. Photo by Bryan Bates.
N.B. Time flows from from right (June) to left (December) and then reverses, just as the sun moves along the horizon during the season.

In nearly all cases, human observation of the biophysical world, tied to that of the celestial sphere results in the development of different calendar structures that are emanating from and tied to the culture and the environment that supports that culture. These calendar systems are often held as sacred for they are the places where the sacred reveals itself to those trained in the science and religion of the nascent culture. Among archaeoastronomers, these sites are known as “hierophanies”. Behind the evolution of these science-priest is the acquisition of knowledge as to the patterning of nature reflect on earth as in the skies. These patterns then provide vital clues as to anticipated changes in the natural world, changes that affect the available food base, the potential success of a hunt, the timing of rain or the best time to offer prayer or sacrifice to the Gods such that life maybe sustained amongst their culture.

Follow these links to:
A Primer on the Evolution of Astronomical Calendars
The Anasazi
Archaeological Treasures
Prehistoric Farmers
Population change
Paleoenvironment
The Anasazi "collapse"