You know about air pollution and water pollution. And you’ve probably heard of noise pollution. But have you even seen light pollution? If you’ve ever stepped out on a clear night to see the stars and found the sky filled with soft glow, you have. That glow isn’t the aurora borealis, which paints the sky in Arctic regions. It’s light pollution. In most of the world, it’s getting harder and harder to see the stars at night –because so many electric lights are burning around the clock.

Powerful outdoor lights are blocking out the stars, wasting electricity and having harmful effects on wildlife. But many communities are taking action to end light pollution. All kinds of outdoor lights, airport lights, security lights, shopping-mall lights, billboards lights and even the flood lights and other outdoor lights around homes –are responsible for light pollution. Many of these lights shine out and up, not just down.