Dark Skies

StarDate: June 28, 2010

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If you live in or around just about any city or town, you're being robbed. Light pollution is stealing the night sky. And it's stealing money from your pocket, too.

Light pollution is the stray light cast into the sky by streetlamps, porch lights, neon signs, and all the other glowing objects that illuminate the night. It fills the sky with so much light that it overpowers most of the glory of the universe beyond. It obliterates the subtle glow of the Milky Way, and hides all but the brightest meteors. In fact, only a handful of bright stars and planets shine through it.

That light isn't keeping us safe from burglars or making it easier to navigate city streets, though, because it's shining up into the sky instead of down on the ground.

And wasted light equals wasted money. The International Dark Sky Association says it's costing us about 10 billion dollars a year. And to make matters worse, the electricity it requires is adding thousands of tons of carbon dioxide to the atmosphere.

But light pollution is easier to eliminate than most other types of pollution. Properly designed outdoor lights are shielded so that the light goes down, not up. These fixtures need less light to get the job done, so they can use less-powerful bulbs -- which saves money.

So a few simple changes can save money -- and give us back the glory of the night sky.

We'll talk about some things light pollution is erasing from view tomorrow.

Script by Damond Benningfield, Copyright 2010

For more skywatching tips, astronomy news, and much more, read StarDate magazine.

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