Star sheds light on African 'Stonehenge'

By Richard Stenger - CNN Reporter

(CNN) -- Mysterious ruins in Zimbabwe, nearly brushed this week by the shadow of a total solar eclipse, once served as an astronomical observatory to track eclipses, solstices and an elusive exploding star, a South African scientist said.

The Great Enclosure in the archaeological site of Great Zimbabwe, a crumbling ring of stone walls and platforms about 250 meters in circumference, was thought to have been a palace complex for regional rulers some 800 years ago.

But Richard Wade of the Nkwe Ridge Observatory thinks that the enclosure was used in a similar capacity as the much older Stonehenge in Great Britain.

The arrangement of the walls, the complicated symbols on stone monoliths and the position of a tall tower suggest that medieval Zimbabweans used the complex to track the moon, sun, planets and stars for centuries.

"The importance of Great Zimbabwe is that it was the capital of the only known sub-Saharan African Empire that lasted almost 1,000 years. Everyone in southern Africa somehow relates to this nucleus cultural complex," Wade said.

Several of the stone monoliths, for example, line up with certain bright stars in the constellation Orion as they rise on the morning of the shortest day of the year, the winter solstice.

Boosting an ancient legend

Another contains markings that coincide with orbital patterns of Earth and Venus, which could be used to forecast eclipses, Wade said.

In his most controversial position, Wade suggests that a tower at the complex, whose purpose has baffled historians, was probably built to observe an exploding star in roughly 1300 AD.

"This large conical tower in the great enclosure stands directly in line with the rising supernova remnant when seen from the observation platform and court area of the time," Wade wrote in a paper to be submitted to the journals Science and Scientific American.

"They requested that I send the work on completion," he said. "I have been peer reviewed now for almost four years and only recently have I received a nod from the South African science community."

Modern telescope observations indicate that a supernova lit up the sky at approximately the same time. Historic records make no mention of it, an omission that does not surprise Wade since the dying star appeared over the Southern Hemisphere, which at the time had virtually no literate cultures.

But oral legends in the region lend credence to the supernova idea, Wade said. The Sena people of Zimbabwe hold that their ancestors migrated from the north by following an unusually bright star in the southern skies.