Device that let Greeks decode solar system

A "BEAUTIFUL and extraordinary" 2,000-year-old astronomical calculator invented by the Ancient Greeks has been reconstructed for the first time, showing they were able to predict eclipses of the Sun and Moon accurately.

The broken remnants of the dials and cogs that make up the Antikythera mechanism, which dates back to the second century BC, were found by divers exploring a wrecked ship in 1901, but no-one has previously managed to explain exactly what it was used for.

Now imaging techniques have been used to see through a crust of mineral deposits coating the bronze device, enabling researchers to recreate a model of what the machine would have looked like and how it worked.

The mechanism was able to track astronomical movements precisely, following the Sun through the Zodiac, predicting eclipses and even recreating the irregular orbit of the Moon. The findings - to be reported at a conference in Athens today and in the journal Nature - suggest it might also have predicted the positions of some or all of the planets.

Professor Michael Edmunds, of Cardiff University, who led the study, said the team's research showed that Greek civilisation was far more advanced than once thought. "This device is just extraordinary, the only thing of its kind," he said.

"The design is beautiful, the astronomy is exactly right. The way the mechanics are designed just makes your jaw drop. Whoever has done this has done it extremely well.

"It does raise the question: What else were they [the Greeks] making at the time? In terms of historic and scarcity value, I have to regard this mechanism as being more valuable than the Mona Lisa."

Prof Edmunds said that the machine appeared to be based on a solar system with the Earth at its centre, but may have been designed with the idea that Mercury and Venus revolved round the Sun.