Astronomers are always discovering new things about the sky. To share this information and collaborate for future work, the American Astronomical Society holds its large annual meeting every January. This year it was in Long Beach, Calif. However, the trip to the AAS conference is often bookended with a sight that saddens stargazers.

As I flew at night over Los Angeles and later back into Charlotte, I was greeted by the usual view of a blanket of endless lights below. The background of the streetlight grid is punctuated by extra luminous sports facilities and businesses such as car lots and gas stations.

The ironic thing is that not one of the photons of light entering my eye 1,000 feet above ground was meant for me. Nobody designed the lights to intentionally light the bottoms of airliners, clouds and birds. Actually, much of outdoor lighting is not so much designed as just installed.

We waste billions of dollars every year in powering this excess – wasted light that not only scatters off our atmosphere and pollutes the night sky but often does a poor job at its intended task.

Light pollution may also be a health risk: Researchers have discovered that blind women have a lower rate of breast cancer than sighted women. While sighted people go through a nightly melatonin production cycle, the blind person’s body always thinks it is night and produces melatonin continuously. Melatonin turns out to be a critical ingredient in preventing cancer. We all need to sleep in true darkness – the streetlight or neighbor’s so-called security light flooding your bedroom is more than a nuisance, it’s potentially harmful.

The lights of large cities have driven the amateur astronomers to drive miles to get to dark skies. The Charlotte Amateur Astronomy Club has repeatedly moved its observatory farther away, until it is now in South Carolina. Eventually there will be no darkness to be found.

We can’t continue to just run from the light – we need to develop regulations that require outdoor lighting be professionally designed so that it is both good at its task and friendly to the sky. Such ordinances, when carefully crafted with the involvement of all stakeholders, have passed without opposition all across the world. It just takes somebody to shepherd it through the process.

The disappearance of the stars is a loss for all of us, not just astronomy buffs. We lose something when we shield ourselves from the firmament that places us in the context of a much larger universe. It is time to take back the night. Who will take on that effort in your city?

 Daniel B. Caton is a physics and astronomy professor and director of observatories at Appalachian State University. Email: catondb@appstate.edu. More on this month’s column: www.upintheair.info.