Published: November 2008
Light Pollution
Star Chasing
By Tammie R. Smith

Starry nights have become rare and exotic skyscapes for many Americans. Light pollution from major cities extends some 150 miles around the population centers, creating a patchwork of bright spots across much of the country. Star visibility is improved by clean, dry air and viewing from high elevations. To find out how well your sky fares, count the stars in Orion on a clear and moonless night—a method professional astronomers recommend to estimate sky brightness. Above major cities, the constellation shows about 11 stars. But far enough away from light pollution, at least 50 should be visible. If counting becomes tedious, the International Dark-Sky Association provides a dark-sky locator to help stargazers find their way into the dark.

Darkest Nights
These spots offer excellent conditions for stargazing.
• Death Valley National Park, California and Nevada

• Natural Bridges National Monument, Utah

• Cherry Springs State Park, Pennsylvania

• Acadia National Park, Maine