We’re all aware of the negative impact human activity is having on our planet’s land masses, oceans and atmosphere. But it goes beyond far that to the very night sky above us. And sadly, only sky-watchers seem aware of this increasing menace which is destroying the beauty of a star-filled sky for those living in or anywhere near large metropolitan areas.
A major factor affecting the visibility of the night sky is a man made one—that of light pollution. One of the banes of both amateur and professional astronomy today is the proliferation of outdoor lighting from city and street lights, billboards, shopping centers, car dealer lots, stadium lights, and others. This results from improper shielding, which sends light up into the sky instead of onto the ground where it’s needed. Not only does this interfere with looking at the stars, it’s also an unnecessary waste of energy and money. (And it’s been shown that it affects our health by interrupting normal nighttime sleep patterns.) There’s been a national and international effort underway for some time to curb light pollution, mainly by the International Dark-Sky Association which is open to anyone interested in preserving the right to having dark nighttime skies. As a result of its efforts, many communities have passed laws requiring any new outdoor lighting to be properly shielded. There’s also “light trespass” ordinances on the books in many places that permits annoying streetlight cutoff shields to be installed by utility companies upon request (something I’ve frequently used myself).
Many stargazers today living in brightly-lit cities or even in the suburbs find it necessary to travel to dark sites to really see the heavens at its best. A state or national park is typically an ideal location should you have one near you—and if you can obtain permission to be there after sunset when most close for the night. Also, many astronomy clubs have their own private dark-sky sites available to members. But you can still enjoy the sky wherever you happen to live. The Moon, planets, brighter stars and constellations, and even some of the more prominent deep-space wonders like star clusters can be seen under all but the brightest of skies.
Incidentally, nature offers its own form of “light pollution”—the Moon! Especially around the time of Full-Moon, our lovely satellite lights up the entire sky and makes it difficult to see any but the most prominent of celestial objects even from a country setting. But again, the brighter planets and stars are still visible, and the Moon itself is fascinating to look at when fully illuminated despite the lack of obvious craters and mountains due to the absence of shadows giving it a “flat” appearance.
In closing, a “must-read” for anyone concerned about light pollution is The End of Night by Paul Boguard. Available from Amazon, it is an eloquent and profound wake up-call about how we are losing the stars and what can be done about it.
— James Mullaney
Former assistant editor at Sky & Telescope magazine & author of nine books on stargazing. His latest, Celebrating the Universe!, is available from HayHouse.com.