Light Pollution

Adelaide's light pollution halo encroaching into the sky in this star-trail photograph taken 120km north of the city. Photo by Justin Tilbrook.

Astronomers world-wide are concerned with the disappearing stars in the night sky due to increasing skyglow from uncontrolled urban uplight.

Light pollution is stray light emitted from poorly designed and aimed lighting installations for advertising, business, security and street lighting. While some light is unavoidably reflected upward from illuminated surfaces, much of it spills outside the area that it is meant to illuminate creating glare, light-trespass and skyglow.

This stray light and the energy generated to produce it is wasted. It unnecessarily contributes to greenhouse emissions, and wastes money. Also, this wasted light does not necessarily contribute to safety nor enhance amenity. Very often it creates a nuisance. We do need outdoor lighting at night but there are better alternatives that save energy and improve the quality of nighttime lighting that also help to reduce skyglow and preserve the night sky. Light pollution is much easier and cheaper to remedy than most other kinds of pollution!

The Astronomical Society of South Australia is a member of the International Dark-Sky Association