Australia's first astronomers

From creative spirits to celestial rivers, there's an intimate link between knowledge of the southern sky and Aboriginal culture.

Could it be that these hunter-gatherers were the first-ever astronomers?

Astronomy is deeply embedded in many of the 300-odd Aboriginal cultures across Australia, all of which share some common roots such as a belief in the Dreaming – a time beyond time when creator spirits roamed the Earth, could move easily between Earth and sky, and could change shape between animal and human. Ancient stories about the creator spirits are told in songs and dance. Often they are written in the sky, as constellations, and their sky-stories are also reflected on Earth, in rocks and lakes and cave paintings.

For example, the Milky Way is viewed by the Euahlayi people as a river. Either side of it, in Sagittarius, are two bright patches, known to astronomers as the Galactic Bulge. Euahlayi people say these are the spirits of the two sons of the creator spirit Baiame. The whole story is reflected on the Earth, where the Barwon River at Brewarrina is identified as the Milky Way, and two large rocks either side of it are identified as the bodies of the two sons.

In these ancient songs and stories can be found traces of generations of Aboriginal Australians seeking to understand the sky. For example, the Yolngu people in Northern Australia explain how the tides work: as the moon rises through the ocean, it alternately fills and empties with water, making the sea level rise and fall. This explains why the tides are synchronised with the moon, and why tides are higher at full moon and new moon than at a quarter moon, because then the moon isn’t filling up as much. If this idea seems a bit different from the modern scientific explanation involving the gravitational pull of the moon, bear in mind that, pragmatically, it works. It enables a Yolngu elder to predict the timing and height of the next tide. Contrast that with the explanation by Galileo, the father of modern science. His interpretation, involving the motion of the Earth around the sun, was not only totally wrong but also failed to explain the connection between the ocean tides and the moon. Unlike the Yolngu explanation, his theory had no predictive power.

Similarly, we find explanations of why eclipses work (it’s the sun-woman being covered by the body of the moon-man as they make love). We are told why the moon has a halo around it in cold weather (it’s a shelter to protect the moon-man from the cold winds). And we are told that the nebulae in the Milky Way galaxy are the camp fires of the spirit people camping on the banks of the great river of the Milky Way. These stories may seem quaint, but they are clear evidence that the Aboriginal people were observing the sky carefully, and sought explanations for what they saw.

Star seasons

But astronomy is not just about curiosity – it’s also about using the sky for practical purposes, such as time-keeping and navigation. Throughout Australia, Aboriginal people divide up their year into seasons, which in many cases are marked by the appearance of particular stars in the sky.

For example, many groups mark the start of winter by the appearance of the cluster of stars known as the Seven Sisters. So why did the Aboriginal people, many of whom were hunter-gatherers, need a calendar? Hunter-gatherers, such as the Yolngu people in Northern Australia, move through their land in a seasonal cycle. They must move camp at the right time, down to the beach to catch the barramundi fish, or up to the Arnhem plateau to harvest berries before the birds eat them, or down to the rivers to harvest the water chestnut roots before the magpie-geese have taken them all. And how do they navigate? One technique is to use oral maps, called songlines. For example, according to Yolngu stories, the planet Venus (Barnumbirr in Yolngu) guided the first humans to Australia in the Dreaming, by flying from the east, describing it in her song. When she reached the coast of Australia, she continued across the land, describing the land below her in great detail, including clan boundaries, waterholes, impassable swamps and pleasant camping grounds. That song, memorised by generations of Aboriginal Australians, constitutes an oral map. If you want to navigate across the Top End of Australia, Barnumbirr’s song will tell you the way, explaining the best route, the good waterholes, and the places to avoid.

Many other songlines crisscross Australia, providing a set of oral maps for traversing the continent. Because early British settlers often used Aboriginal guides to show the way, many of Australia’s great highways follow songlines. But how did people memorise all these detailed instructions? By using the stars as a mnemonic, attaching details to each star, much like the ‘method of loci’ used by ancient Greeks as a memory tool, or even the ‘memory palace’ used by BBC sleuth Sherlock Holmes, played by Benedict Cumberbatch. Modern-day Aboriginal elders can identify waypoints on their route with particular stars in the sky, and will consult the sky while travelling to remind them of the songline.

Compass points

Another navigational technique is to use the sky like a compass, to tell direction. Many Aboriginal groups use the four points of the compass just as Europeans do. How accurately did they know these directions?

A recent study of stone arrangements shows that traditional Aboriginal people knew these directions to an accuracy of a few degrees, which is no mean feat given that there is no pole star in the south. Instead, to get that sort of accuracy, you’d have to make careful measurements, such as noting the position of the sun over a year and then marking its midpoint. Do we find any evidence of this?

At a site in Victoria is Wurdi Youang, a stone ring about 50m across that’s sometimes dubbed the Aboriginal Stonehenge but could be much older than the Wiltshire circle. It has been carefully built to indicate the direction of the setting sun on midwinter day and midsummer day, and is accurately aligned on the midpoint of these two sunsets – ie, due west. There is no doubt these directions are intentional, and are not just a chance alignment, so the builders found marking these directions sufficiently important to warrant moving tonnes of rock to do it. They understood the motion of the sun sufficiently well that they were confident in this task.

How far back does this knowledge go? We don’t know. The Aboriginal people arrived in Australia at least 50,000 years ago, and were almost untouched by the outside world until the British arrived in 1788, so this expertise could reach very far back indeed. But, sadly, we haven’t yet found any way of dating the songs or stories, or the astronomical structures like Wurdi Youang. But as we learn more about this ancient heritage, at some point we may find out how old Aboriginal astronomy really is. It’s possible they really are the world’s first astronomers.

Featured image © Amit Kamble