I'm a proud Yorta Yorta and Barapa Barapa man, an Indigenous astronomer and a trainee ecologist.
When I look at the night sky, I don't just see stars. Instead, I see an ancient knowledge system that has guided people, culture and Country for tens of thousands of years.
But that knowledge is now at risk. In many of our towns and cities, the stars are increasingly hidden behind a haze of artificial light. And that light pollution is threatening a unique way of understanding the world.
A 'living classroom'
The night sky is a living classroom, at once a calendar, map, lore book and weather forecast.
Indigenous Elders share this knowledge with younger people - often outdoors, on Country, beneath the stars.
They may start by talking about constellations, which have helped guide Indigenous Australians for millenia.
One example is the Wangel or "long-necked turtle" constellation. Various Indigenous communities looked to this constellation, based on the bright orange star Pollux , to know when it was time to travel and gather for different ceremonies. This may be because the bright orange star reflects the turtle's orange colouring.
Another is the Djurt or " red-rumped parrot " constellation. This constellation is based on the Antares star which appears bright red with a blue halo, resembling the parrot's red and blue feathers . This constellation guided communities to spots where food was abundant, such as grasslands that were full of seeds.
Constellations also hold lore, or rules, that guide sustainable practices. For example, when the Otchocut or " Murray cod " constellation appears in the night sky, we do not hunt Murray Cod. This is because it becomes visible when the rivers are warm and the fish are breeding , typically between October to November. Similarly, when the red-rumped parrot constellation appears, that means the parrot is breeding and therefore cannot be hunted.
The stars may also provide weather forecasts, but only if you have the knowledge and observation skills to understand them. For example, a star that twinkles and appears bright blue suggests a storm is coming. And if a cluster of stars twinkle quickly, it may mean the wind will become stronger.
Stars and songlines
The routes laid out by the stars are often connected to songlines . Songlines, sometimes known as dreaming tracks, are cultural pathways that connect traditional sites. Songlines also act as "drop pins" that indicate where important resources, such as waterholes and food, may be.
A well-known example is the Seven Sisters dreamtime story, which recounts the journey of seven sisters that ultimately become part of the Taurus constellation. For some Indigenous communities in central Australia, the Seven Sisters serve as a kind of celestial map. This is because the seven stars roughly mirror the location of seven waterholes.
The threat of light
As our cities grow, light pollution from streetlights, floodlights and buildings is spreading . As a result, it's increasingly rare to see dark nights and starry skies near urban areas.
For Indigenous communities, this has a direct cultural impact.
Light pollution makes it near impossible to connect with the stars, and therefore share Indigenous sky knowledge with younger generations.
Light pollution also affects culturally important species. In Barapa Barapa culture, the microbat is a men's totem and the nightjar is a women's totem. Both are nocturnal animals that rely on darkness, so artificial light makes it harder for them to survive.
Beyond culture, light pollution has widespread ecological impacts , affecting how animals grow, behave and breed. Research suggests light pollution can stop clownfish eggs from hatching, shrink the brains of spiders and disorient threatened seabirds such as petrels and shearwaters.
It can also negatively affect human health. Research shows artificial light - particularly from LED lights and electronic devices - may trigger sleep and mood disorders and certain cardiovascular problems .
So, what can we do?
The good news is, we can each help reduce light pollution by making simple lifestyle changes. Here are some ideas:
- turn off outdoor lights whenever you're not using them
- use lightbulbs with a lower brightness and warmer colouring
- choose light designs that direct light only where its needed
- close curtains and blinds at night to stop indoor light from spilling out
- during festive times such as Christmas , opt for daytime decorations instead of outdoor lights.
We can also better regulate the use of artificial light outdoors. Currently, Australia does not have any regulations around light pollution. But countries such as France have substantially reduced their light pollution levels by regulating what kind of lighting people can use and install.
Together, stronger regulation and simple lifestyle tweaks could help us tackle light pollution. And that's key to keeping Indigenous sky knowledge alive.
Kai Lane works for Ecology Restoration Australia and also co-leads the Habitat Warriors program.
Jaana Dielenberg is an Ambassador for the Australasian Dark Sky Alliance, Science Communication Director of the Biodiversity Council, Honorary Fellow at The University of Melbourne and University Fellow (Biodiversity) at Charles Darwin University. She was previously employed under a grant funded by the Australian government's National Environmental Science Program Threatened Species Recovery Hub.
Kaori Yokochi is a lecturer at Deakin University. She receives funding from various organisations for her ecological research. She is also a member of the Network for Ecological Research on Artificial Light and the Australasian Dark Sky Alliance.
