Victoria's Stonehenge? Reg Abrahams at the stone arrangement outside Geelong. Photo: Jason South

Rocky ways to secrets of skies.

IT LOOKS like a simple ring of carefully laid out stones, but an egg-shaped Aboriginal stone arrangement outside Geelong is being talked about by some as Victoria's own Stonehenge.

While there are few records to explain its use, and little information about its age, it was thought to be an indigenous initiation site. But in recent years clues have emerged to suggest it could be an example of some of Australia's earliest astronomy.

After repeated observations, Victorian cultural historian John Morieson found that, viewed from three prominent stones, some smaller outlying stones seemed to indicate the position of the setting sun during equinoxes and solstices.

These observations were confirmed by CSIRO astrophysicist and Aboriginal astronomy researcher Ray Norris, who found the overall design of the circle also appeared to point towards the solstices.

Dr Norris describes the stone arrangement, Wurdi Youang, as "Aboriginal Stonehenge with a question mark". "There's enough evidence there that it looks like these people really did know about these special directions."

But he says the discovery of more rings with similar astronomical markers is needed to prove the hypothesis.

"The problem with all of this stuff is you are never 100% certain ? are we constructing something with our 21st century minds that wasn't actually intended by the people who built it?"

Some members of the Wathaurong Aboriginal Co-operative, which owns the site, are yet to be convinced by the Stonehenge theory, including cultural adviser Reg Abrahams.

"We just don't know," Mr Abrahams said.

Wurdi Youang is just one example of many sites across Australia being examined for potential evidence of indigenous astronomy.

They include a site called Ngaut Ngaut on the banks of the Murray River in South Australia, where dots and lines carved on rocks near engraved images of the sun and moon point to a possible lunar calendar. The changing skies may also be linked to seasonal patterns in animal and plant behaviour. One example is the "emu in the sky" made up of the dark clouds of the Milky Way.

This lines up with a rock engraving of an emu in the Ku-ring-gai Chase National Park in NSW at the time of the year when emus lay their eggs.

In the lead-up to 2009, the International Year of Astronomy, there is growing interest in learning more about how indigenous Australians viewed the sky.

The Melbourne Planetarium is working on a new indigenous astronomy presentation, while Dr Norris and colleagues are planning an Aboriginal astronomy conference, and hope to establish a national working group on the subject.

He hopes increased awareness about indigenous astronomy could help to bring different cultures closer together. "It's about the sky, which everybody understands."