Archeologists working high in the Peruvian Andes have discovered the oldest known celestial observatory in the Americas — a 4,200-year-old structure marking the summer and winter solstices. The observatory was built on the top of a 33-foot-tall pyramid with precise alignments and sightlines that provide an astronomical calendar for agriculture, archeologist Robert Benfer of the University of Missouri said.
     The find adds strong evidence to support the recent idea that a sophisticated civilization developed in South America in the pre-ceramic era, before the development of fired pottery sometime after 1500 BCE. Benfer's discovery "pushes the envelope of civilization farther south and inland from the coast, and adds the important dimension of astronomy to these ancient folks' way of life," said archeologist Michael Moseley of the University of Florida, a noted Peru expert. The name of the people who inhabited the region is unknown because writing did not emerge in the Americas for 2,000 more years. Some archeologists call them followers of the Kotosh religious tradition. Others call them late pre-ceramic cultures of the central coast. For brevity, most simply call them Andeans.
     The Temple of the Fox, an ancient structure in the Chillon Valley that dates back to 2200 BCE, contains sculptures that can be associated with the agricultural calendar and Andean myth."The Temple of the Fox is 1,000 years older than anything of its kind found before. It's also significant because it suggests people organized their lives around Andean constellations and provides evidence of the beginning of flood-plain agriculture," Benfer said.
     In temples such as the one Benfer uncovered, the Andeans constructed offering chambers, used them for ceremonies and then built new chambers above the old. Benfer said this protected the Buena Vista site from looters, who came within one inch of the musician statuary while searching for gold and silver in the ancient temple. The well-preserved offering chamber holds ancient pieces of cotton and burned twigs, and Benfer's team used the twigs to radio-carbon-date the various components of the excavation site.
     At the entrance to the Temple of the Fox, Benfer unearthed a mural of a fox incised inside a painted llama. He said the mural depicts the significance of the fox in Andean myth and astronomy. The fox taught the ancient Andean civilizations how to cultivate and irrigate plants and, according to Andean myth, is reincarnated by drops of water. Today, the constellation of the fox also is associated with water, and farmers use the call of the fox to predict rainfall.
     While excavating the temple and sculptures, Benfer discovered several alignments at the Buena Vista site that suggest Andeans used astronomical signs and constellations to guide their agricultural activities. The lines incorporate points at the temple entrance, at the offering chamber, on sculptures, and on surrounding ridges that align with the rising and setting sun on days of astronomical significance, such as the equinox and solstices. For example, from west to east, the offering chamber aligns with a modified rock on an eastern ridge, forming a 114-degree azimuth and pointing toward the rising sun on December 21, which is the southern hemisphere's summer solstice. This date begins the season where flood waters rise, El Niño weather patterns are predicted and plants should be planted. On March 21, when flood waters recede, this same line points to the rising Andean constellation of the Fox. In addition, among the ancient statues Benfer excavated in Buena Vista is a personified disk that frowns at the sunset on June 21, the day marking the beginning of the harvest.
     Benfer and archeologist Bernardino Ojeda of Peru's National Agrarian University have been working at Buena Vista for four years. The site contains ruins dating from 10,000 years ago to well into the ceramic era in the first millennium BCE. Benfer added that other Andean temple sites he has studied contain perfect 114-degree alignments and similar astronomical features, which act as additional evidence to support his findings.

Sources: NewsWise (10 May 2006), Los Angeles Times (14 May 2006), The Sydney Morning Herald (17 May 2006)