Archaeologists are studying a group of stones that line up with the Sun at the solstices and equinoxes, and think it may represent the world's oldest astronomical observatory. The Australian site is particularly notable because it is only recently that archaeologists recognized that the Indigenous people of the area built permanent dwellings and practiced agriculture, rather than being nomadic hunter-gatherers, as previously assumed.
Although Stonehenge in the UK is the most dramatic and famous, many sites were built by ancient peoples to track the movement of the Sun and Moon, providing them with an indication of when the seasons were turning and often used as sites for spiritual ceremonies. Some, such as Stenness in Orkney, an island off the coast of Scotland, were extraordinarily sophisticated, aligned to reveal events that happen only once every 19 years.
However, the quest to find the oldest such site may have been looking in the wrong place, focusing on locations in Europe and the Middle East, the oldest of which dates back 7,000 years. The hundred basalt stones that form the Wurdi Youang stone arrangement, west of Melbourne, have yet to be dated accurately. However, Monash University's Dr Duane Hamacher, an expert on Australian indigenous astronomy, told IFLScience nearby structures have been dated as 11,000 to 14,000 years old, and the observatory may well be of a similar age.
The arrangement combines what Hamacher calls an “egg-shaped” curve of stones with two straight lines. Collectively, these align with the setting Sun at the solstices and equinoxes.
The placement of the stones at Wurdi Youang and the positions where the Sun sets at the solstices and equinoxes. Norris et al/Rock Art Research