Reading the Stars: Weather, Seasons and Country

Long before printed calendars or weather forecasts, Aboriginal and Torres Strait Islander Peoples read the night sky to know what time of year it was and what was about to happen on Country. This is one of the oldest continuing knowledge systems in the world, built up over tens of thousands of years. It is also genuine science: it comes from careful, repeated observation that became reliable, predictive knowledge.

The key idea is that the sky changes through the year in a regular, repeating pattern. As the Earth travels around the Sun, different stars and constellations rise at different times of year. A particular star might appear low on the horizon just before dawn in one season, then be missing at another. Because this pattern repeats every year, the position of a star becomes a dependable signal, like a page turning on a calendar.

Different Nations across the continent watched their own local skies and developed their own detailed Cultural Knowledges. These were not the same everywhere, and they were tied closely to the plants, animals and Country of each place. That is why it is wrong to talk about one single "belief". There are many Nations, each with its own knowledge, language and Lore.

Two of the best known and most widely documented examples of sky knowledge are the Seven Sisters and the Emu in the Sky.

• The Seven Sisters (the Pleiades): the Pleiades is a small, sparkling cluster of stars. It is known as the Seven Sisters across many Aboriginal Nations, and it also features in the knowledge of cultures all over the world. The time of year when this cluster appears in the sky is used by many Nations to mark a change of season, often signalling the coming of cooler weather and showing which foods will soon be available.
• The Emu in the Sky: this is not made of bright stars. It is a shape made by the dark, dusty clouds inside the Milky Way. The head is near the Southern Cross and the body and legs stretch along the dark lanes of the Milky Way. The Wiradjuri people of central New South Wales know this Emu as Gugurmin, and it is recognised by many other Nations too. As the year turns, the Emu appears to change its position and orientation in the sky. When the Emu looks as though it is running, and later when it appears to be sitting, these changes signal when wild emus are nesting and when it is the right time to collect their eggs.

Notice the pattern in both examples: a feature of the sky changes in a regular way through the year, and that change is matched to a real event on Country. This matching only works because people observed it carefully again and again, across many generations, until they were sure it was reliable.

The syllabus tells us that Aboriginal and Torres Strait Islander Peoples use stars to identify specific weather phenomena. One well-documented example is reading the way stars twinkle. When you look at a star, its light has to travel down through layers of moving air before it reaches your eye. If the air is very unsettled, the star seems to shimmer, flicker and even change colour strongly. If the air is calm, the star shines more steadily.

By watching how much the stars twinkle, and where they sit in the sky, careful observers can read signs of changing winds and coming weather. Scientists today call this shimmering effect scintillation, and they agree it is caused by turbulent air high in the atmosphere. So the traditional reading of twinkling stars matches what modern science understands about the sky.

The position of certain stars is also used to mark wetter and drier times of the year. When a particular star appears at a particular time, it can signal that the wet season is near, or that a dry spell is coming. Again, this is reliable because the pattern repeats each year and has been checked by observation over a very long time.

The syllabus dot point says that Aboriginal and Torres Strait Islander Peoples use the stars and the phases of the Moon to predict animal behaviour, plant cycles and tidal changes. The idea is that events in the sky and events on the land and sea happen in step with each other through the year, so one can be used to predict the other.

• Animal behaviour: as we saw, the changing position of the Emu in the Sky signals when wild emus are nesting and laying eggs. Knowing this means people know when, and when not, to collect eggs, which also helps protect the emus for the future.
• Plant cycles: the appearance of a certain star can line up with the time when a certain plant flowers or fruits. When the star is seen, people know that food is becoming ready. This links the calendar in the sky to the food calendar on the ground.
• Tidal changes: the phases of the Moon are tied closely to the tides. A full Moon or a new Moon brings the largest tides, which is useful to know for fishing and for gathering shellfish safely along the coast.

In the Torres Strait, the great constellation Tagai is central to Torres Strait Islander seasonal and navigational knowledge. Tagai is pictured as a figure standing in a canoe, made from stars that many other cultures group into different constellations. The position of Tagai through the year guides Torres Strait Islander Peoples in knowing the seasons, when to plant gardens, and when to fish.

Earlier in this unit you learned that science builds knowledge through careful observation, and that reliable knowledge comes from observing something again and again until you are sure of the pattern. Reading the stars to predict the seasons, the weather and events on Country is exactly that kind of work.

To know that the Emu in the Sky reliably signals emu nesting, or that a certain star marks the start of the wet season, people had to observe the sky and Country closely, record what they saw in story, song and Lore, and test the link year after year. A pattern that holds true over thousands of years is a very strong, well-tested piece of knowledge. This is sophisticated observational science, developed and refined over a longer period than almost any other science on Earth.

It is also a powerful reminder that science is done by many different peoples in many different ways. Aboriginal and Torres Strait Islander astronomical Knowledges deserve to be respected both as Cultural Knowledges and as careful, predictive science.