In log-walled, thatch-roofed huts just west of where Fairmount Park race track lies today, villagers of a thousand years ago awoke to a glowing light low on the southern horizon, a mysterious star 16 times brighter than Venus and three times larger in diameter.
The star was visible even during the day. The date was May 1, 1006.
The bright object was a supernova, light from a collapsed star that exploded an estimated 7,200 light years away, many trillions of miles distant. Observers in more advanced civilizations at the time in Japan, China and the Arabic world made measurements that led astronomers of today to conclude that this was the brightest stellar object in recorded history.
During the 18 months it remained visible, the star undoubtedly caused a sensation in the fledgling Mississippian community that, in less than a century, would grow to one of the most populous cities in the world with a central mound that remains the largest prehistoric structure north of Mexico..
Archaeologist John Kelly of Washington University in St. Louis believes that in a society that “saw the earth as a reflection of the heavens,” the sudden arrival of a giant star would have people clamoring for their priests to reassure them. Was this a sign of impending doom? Or impending prosperity?
“It could not have been ignored,” Kelly said, “And at first priests would not have had an answer.”
But are there lasting effects of the star’s arrival that exist today?
Kelly and his long time collaborator James Brown, professor emeritus, Department of Anthropology, Northwestern University, Chicago, theorize that proof of the supernova’s effect on the villagers can be found in “sight lines.” They say these can be traced by searching for the remnants of telephone pole-sized logs that were placed upright in the ground in significant locations.
While the logs rotted away, dark circular stains marking their former location, including one 3 feet across, have been found along a south-to-north straight line that Kelly and Brown suspect was inspired by the otherworldly visitor of 1006. The line begins at Rattlesnake Mound in the south, intersects Mound 72 directly north where a priest or leader was buried with grave goods beside the headless, hand-less skeletons of four men, and then extends in a straight line north across what became known as the grand plaza to the southwestern edge of what would become Monks Mound.
At this spot on the future location of the huge mound, Kelly said researchers have found remnants of a building, probably used for religious purposes, which was rebuilt numerous times, and with each new building a large log was erected in the same hole time after time.
“Sight lines are very important,” said Brown during a telephone interview. “These people were always looking up at the sky. They set these lines with upright logs, and we have found evidence of big holes right where they should be. We are going to get ground penetrating radar to really search for them.”
Brown and Kelly said that to truly study these ancient people, much can be learned from how they laid out their city and how they developed their religion, which was based on animism, or the worship of various animals including birds of prey. This is in the same spirit as the Egyptian civilization at the time of the great pyramids when birds, lions and cats were revered.
The south-to-north straight line traverses the ground where Monk’s Mound would be constructed by villagers carrying millions of basket loads of soil. This great mound. more than 100 feet high when first built, is in the center of four large plazas that surround the mound in four directions. After centuries of weathering, it is now about 85 feet high and has concrete steps leading to a large, flat area at the top.
Another sight line extends from Woodhenge, an apparent religious site of upright poles set in a large circle to the west of Monk’s Mound. This sight line continues to the east where a housing subdivision now exists. It intersects the south-to-north line to form a “cruciform” shape, Brown said, and was inspired by a star constellation that has long been revered by ancient peoples.
Brown said this west-to-east line corresponds with the “Belt of Orion,” star formation that was important to the Mississippians and was represented on pieces of ceramic excavated by other archaeologists in the 1950s.
Of the intersecting sight lines, Brown said, “When you put these together it is super. This is it. These are sacred power lines. They were very important.”
But not all archaeologists who have worked at the Cahokia Mound site and nearby early locations agree.
Tim Pauketat, professor of anthropology at the University of Illinois, said of the appearance of the star and the south-to-north sight line, “They may be stringing things together that are going to fall apart when new evidence is discovered.”
As for the post holes, “You can find hundreds of them at Cahokia.”
Pauketat wrote a best-seller published in 2009 titled, “Cahokia: Ancient America’s Great City on the Mississippi.” He has specialized in studying satellite farm sites from the Mississippian period including locations in rural O’Fallon.
Kelly welcomed Pauketat’s comment: “He raises the level of debate,” he said.
But Kelly pointed out that the years after the supernova’s appearance were key in the development of Cahokia. At the time the bright star appeared, the early community was pretty much treeless prairie, with mounds that were only about 3 to 5 feet high topped by ritual buildings.
Within about 25-50 years, according to limited data concerning the age of Monks Mound, the city was transformed into a huge place where 10,000 to 20,000 people lived. Many others lived in nearby areas including a mound group in East St. Louis that was obliterated in the 20th century as part of flood control.
“When this star showed up they were trying to make sense of it. And then it disappeared,” Kelly said. But Native Americans from historical times after contact with Europeans may have preserved memories of the supernova in their oral traditions, he said.
Kelly said the Osage people from southern Missouri have an oral tradition about “the star that came to earth. And that was probably what they saw in that supernova.”