Many ancient cultures were interested in the changing night sky.
Basic types of ancient observatories:
Consists of several concentric circles built in three periods, beginning about 2800 BC.
The largest stones weigh 50 tons, and were transported from many miles away.
Viewed from the center, the sun rises over the heel stone at the summer solstice. (This was first noted in modern history in 1771.)
Gerald Hawkins (in the 1960's) found many other alignments which were verified by computer. He claimed that it could also be used to predict eclipses.
There were some errors, some doubts, and reinterpretations (about 4000 years ago, the sun would have risen to the left of the heel stone.)
Much is not understood, such as the Aubrey Holes - how many markers were used? How often and how far were they moved? When were they calibrated?
Click here to see information on Stonehenge from the book How the Shaman Stole the Sun.
Underground chambers (tombs) with passageways which point to the rising sun at Winter Solstice. Window allows light to enter at sunrise on the first day of winter.
Anasazi Indians of Chaco Canyon, New Mexico constructed a spiral rock carving on Fajada Butte.
At noon on the summer solstice, a dagger of sun penetrates the center of the spiral.
On the autumnal equinox, a sun dagger passes through the center of a small spiral on the left, and another passes on the edge of the large spiral. At the Winter Solstice, a big sun dagger passes on either side of the large spiral.
Discovered in 1977.
Also marks a 19-year lunar cycle. (The spiral has 19 rings.)
The mound-building Indians in the Mississippi Valley region began about 3000 years ago, and there were several cultures, and three successive groups of Indians there. There is much conjecture about their circles, but little organized study.
Built about 1050 AD. Has 28 spokes, and is about 90 ft in diameter.
About 50 similar circles exist. The oldest is in Canada (built about 2500 BC - the age of the Egyptian pyramids, for comparison).
The alignments presented by these stone circles are controversial; they could be due to chance. There is no evidence that they were astronomical in design. Why were they interested in those 3 particular stars?
See the rising sun at the equinox between two temples. (Temple of the Moon and Temple of the Sun.)
The pyramid is also aligned perfectly N-S and E-W.
The shadow of the tower was shortest at noon, and the very shortest at the summer solstice. (Markers on the ground locate shadow positions.)
This page was created by Pamela J. W. Gore
pgore@gpc.edu
DeKalb College
January 28, 1996