Ratepayers paying to illuminate the heavens

Tuscon, Arizona, is home to almost half a million people. It is famous for being one of the few cities where the Milky Way can be seen from downtown with the naked eye.

This extraordinary feat is possible because the city has some of the most stringent lighting ordinances on Earth. These ordinances were developed because professional observatories surround Tuscon.

The burghers of that city decided that the intellectual, economic and aesthetic benefits of pushing back the frontiers of human knowledge and encouraging citizens to reconnect with the night sky far outweighed humanity’s seemingly genetic obsession with increasing the amount of unshielded lights at night.

New Zealand’s South Island has roughly twice the population of Tuscon spread over an area 50 times larger. With few notable exceptions (kudos Mackenzie Country), rules relating to lighting control here are lax.

Security lighting, unshielded streetlights and petrol stations combine to create domes of light above all of our towns and cities which can be seen for hundreds of kilometres. For me, this was very much reinforced last Friday. 

The sky was beautifully clear while waiting in the Octagon for a taxi home from the Otago Chamber of Commerce Business Awards. As is my habit, I looked up at the sky and realised I could see the planets Jupiter, Mars, and Saturn, and that was about it.

Last year, while flying on Nasa’s Sofia Observatory, I obtained images of Dunedin and Invercargill from 12,500m. They illustrate the problem of light pollution quite well. Ratepayers are paying to illuminate the heavens! I’m actually hopeful things will improve.

Dunedin is replacing old energy-wasting streetlights with more efficient, fully shielded versions which illuminate the ground rather than the sky. The streets will be safer (more light at ground level thanks to lights being directed downwards means darker skies for stargazers). 

However, the problem isn’t just about streetlights.

A recent study by the International Dark Sky Association found that for Tuscon, a city where all streetlights are shielded, they are now responsible for just 20% of light pollution. We still have a long way to go.