Dark sky at night

A dark-sky map

We have what I call night visitors in our neighborhood—people who try car doors looking for anything to steal. Sometimes they take porch furniture or plants. Because of this constant threat, we have motion sensitive lights in the driveway, Ring on the front door, floodlights in the back yard outside my door and illuminating the deck. We’ve accepted it as part of urban living. But now I’m rethinking our lighting because I read an article about Pittsburgh.   

That is the first major U.S. city to pass ordinances designed to deal with light pollution, a concept I’d never thought of. Pittsburg officials announced that new, dark-sky policies were enacted to cut down on energy costs, restore as much as possible the day/night cycle for animals, bird, and plants—and I would add humans, reduce glare and restore better night vision. The city will replace all streetlights with lower wattage lights and enact other measures to reduce light pollution. Whe I read this I realized I’d never thought about light pollution. I’ve just always known and accepted that it’s quieter and darker in the country, like at my brother’s ranch where the stars really do seem closer. When I was a kid you could go outside, look up at the sky, and on a clear night and pick out the Big Dipper. Not now in my backyard. Not now in our cities.

Light pollution is so widely recognized that there is an International Dark-Sky Association (International Dark Sky Association - International Dark-Sky Association). They recommend five criteria for judging when lights are needed:

1.     Is it useful? How will it impact the area? Could reflective or luminous paint be used on curbs, signs, steps etc., to reduce the need for permanent outdoor lighting?

2.     Is it targeted? Is the source of the light shielded so that it focuses where needed and doesn’t spill not adjacent areas?

3.     Is the light the lowest possible level to do what is needed? Some surfaces may reflect more light into the sky than others, and that reflection should be taken into account.

4.     Is it controlled? Dimmers, automatic timers, and motion sensors can be installed to turn lights on only when needed.

5.     Are you using warm lights? Warm colors are recommended opposed to shorter wave-length ultra-blue violet lights which are brighter.

Jordan and Christian turn their outdoor lights off in the morning, but my patio light switch is in a place where I cannot easily get to it with my walker, so I’ve been letting those lights burn 24/7. I’m re-thinking that.

There’s the matter of safety. I feel safer with a well-lit yard and a low lamp light in the cottage at night. Studies in Great Britain have shown that lighting does not deter crime. I find that hard to believe, but I am convinced about the importance of cutting down light pollution. We will be buying warmer, low-wattage light bulbs, and I’ll find a way to turn off my patio lights.

Want to visit some dark-sky areas? The international association maintains a list of communities, parks, reserves, sanctuaries, and even urban dark sky sites. Texas maintains its own list of dark-sky sites in the state (Stargazing — Texas Parks & Wildlife Department). No surprise that Big Bend leads thelist.