Ancient astronomer's work found on Roman statue


SAN DIEGO (Reuters) - A Roman statue of Atlas -- the mythical titan who carried the heavens on his shoulders -- holds clues to the long-lost
work of the ancient astronomer Hipparchus, an astronomical historian says.

The statue in question is known as the Farnese Atlas, a 2.1 metre tall marble work which resides in the Farnese Collection in the National
Archeological Museum in Naples, Italy.

What makes it important to scientists is not the titan's muscular form but the globe he supports: carved constellations adorn its surface in
exactly the locations Hipparchus would have seen in his day, suggesting that the sculptor based the globe on the ancient astronomer's star
catalogue, which no modern eyes have seen.

"There are really very few instances where lost ancient secrets or wisdom are ever actually found," said Bradley Schaefer of Louisiana
State University. "Here is a real case where rather well-known lost ancient wisdom has been discovered."

Hipparchus, who flourished around 140-125 BC, is believed to have been one of the world's first path-breaking astronomers. Among other
innovations, he put together the first comprehensive list of the hundreds of stars he observed, known as a star catalogue.

This catalogue no longer exists, and previously the only evidence for it came from references made to it by astronomers who followed
Hipparchus, Schaefer said.

Another Hipparchus invention -- the idea of precession, which is the slow movement of the stars and constellations across the sky in relation
to the celestial equator -- led Schaefer to believe that Atlas's globe referred to Hipparchus's star catalogue.

An analysis of the positions of the constellation figures on Atlas's globe allowed Schaefer to date the work to 125 BC, plus or minus 55
years. This would have been within the range when Hipparchus would have been working.

Other theories about who wrote the star catalogue include observers who were either too early -- including a poet writing around 275 BC
and an Assyrian observer around 1130 BC -- or too late. This includes the astronomer Ptolemy, writing in 128 AD.