Dark Sky

Tonight, when it’s dark and if it’s clear, go outside. Look around at your neighbors’ houses. Are their porchlights or security lights on? How bright are they? And—are they aimed up or down? Are they hooded?

Now look up at the sky. If all those lights are aimed downward and hooded, the dark sky will show you millions of heavenly bodies. If even one of those porchlights aims up, you see less.

If you can get to a beach or an open field, do that, and look up. It’s a dazzling magical scene. It’s the universe. The Milky Way, some planets, maybe a meteor, and if you look carefully, constellations and some important stars within them.

We are lucky to see all this because of where we are: a place with relatively low artificial light to block our view. And where flying creatures of the night can travel safely, able to migrate or pollinate, or just eat out of sight of their daytime predators. 

There’s a name for that: Dark Sky. It’s also a movement, a campaign, an organization, and a long list of places on the planet that have absolutely no artificial lighting at all, where you can see a sky you’ve maybe never imagined. The interfering bright lights have a name too: Light Pollution. In its own way it is as harmful as the chemical pollutants we all breathe.

DarkSky International is a United States–based nonprofit organization incorporated in 1988 by founders David Crawford, a professional astronomer, and Tim Hunter, a physician and amateur astronomer. (Their home is in my former home, Tucson, Arizona, where, believe me, the skies are dark, but not as dark as when I lived there.) The mission of DarkSky is “to preserve and protect the nighttime environment and our heritage of dark skies through quality outdoor lighting.” DarkSky’s principal approach is to “raise awareness about the value of dark, star-filled night skies and encourage their protection and restoration through education about the problems and solutions, including outdoor lighting practices that create less light pollution.” 

DarkSky International describes light pollution as the result of outdoor lighting that is not properly shielded, allowing light to shine into the eyes and the night sky. Direct light that shines into the eyes is called glare; light directed into the night sky above the horizon  causes skyglow. Lighting can also cause light trespass when it enters areas where it is unwanted, like a neighbor’s yard or windows.

Light pollution disrupts the biorhythms of nocturnal animals. Most insects navigate using moonlight, lunar phases, infrared vision, the position of the stars, and the Earth’s magnetic field. The writer of our Nature column, David LaPuma, tells us elsewhere in this magazine that the firefly is one of those creatures, endangered by the profusion of bright artificial lights that can confuse them, leading to exhaustion to the point of death, or reveal them to their natural enemies. Most species of moth are nocturnal, and daytime flyers like butterflies, bees, and other pollinating insects, serve as pollinators for many flowering plants, including species that bees do not visit. Some researchers say it is likely that many plants thought to be dependent on bees for pollination also rely on moths. Nocturnal moths fly from flower to flower to feed on nectar during the night much as their diurnal relatives do during the day.

Birds do it, too: owls, some hawks, the mockingbird and the whippoorwill, for example. And shall we not neglect the Tawny Frogmouth of Australia. Then there are land animals–consider the Aardvark, or, keeping it close to home, the beaver and the coyote. 

Just a few miles from Cape May in a field in Belleplain State Forest, the South Jersey Astronomy Club meets regularly for sky-watch events where they and the public observe important or simply interesting astronomical events. Through an arrangement with the former owner, the field is the club’s very own property.

David Rossi, a member of the board of directors, explains it all. “You can’t see the night sky if there’s light pollution. There’s a scale, called the Bordle scale, that measures light pollution, from Zero, which is out in the middle of the Pacific, to 10, in Times Square.” During our conversation, he joked that it’s probably 20 in Times Square, in Philadelphia, and in fact, any city. “You can’t see anything there except the moon.” The field in Belleplain is about 4.5 on the Bordle scale. And here’s some good news: the beaches in Cape May are also about 4.5—that is if you leave the boardwalk and go directly south to the ocean surf line, or to Sunset Beach and around Cape May Point. “You can easily see the Milky Way with the naked eye, [and] almost every constellation you can think of.”

Because he’s an actual, though amateur, astronomer, Rossi likes to find what he calls “treats”—important stars within constellations that most of us don’t know about and certainly can’t spot. But “during the summer months you can see Omega Centauri, which is this globular cluster of stars; we only get to see it a couple times per year, and one of the best places to see that is in Cape May.”

Cape May itself, in the city, is a “light dome,” as Rossi calls skyglow. So are most places in Lower Township. 

In November last year the Cape May Recreation Department, directed by David Scheffler, hosted Dark Sky Night. People came to see with the naked eye and with several powerful telescopes not only details of the moon, but of faraway objects: Jupiter, Saturn and its rings, and the track of a comet. Rossi and the South Jersey Astronomy Club were there, as was a similar group, The Astronomical Society of the Toms River Area (ASTRA). Rossi reminds us: “When we did our event at the Convention Center in November, they shut off all the lights. And we were able to give over 400 people a magnificent night.” Had the normal lights on Beach Avenue been on, “you wouldn’t have seen all that.” All the lights on Beach Avenue were off, including those on the boardwalk arches, which are properly installed under the structures, and facing down. 

Another good local spot is Two-Mile Beach. “That’s got the most perfect line of sight to the most magical skies out there.” Travel a little bit to East Point Lighthouse, beloved for many features, and for Rossi because “you can look down Delaware Bay right to the ocean and you see [constellations that are not visible anywhere else near us].”

You can travel even farther: Rossi likes Assateague, in Virginia. DarkSky International has designated 11 DarkSky Parks in the United States: drive to Cherry Springs State Park in Potter County, Pennsylvania, on Pennsylvania Route 44 in West Branch Township. A little farther, to Katahdin Woods and Waters National Monument  in northern Penobscot County, Maine. Go west to the desert, as Rossi did, “where you can reach up and touch the stars” at Rainbow Bridge in Utah. Or fly away: to Korea, Australia or Greece, or any of over 200 IDA-certified parks around the world.

Or you can also just stay home, check your own outdoor lighting, then go outside.

Cape May’s Dark Sky Ordinance

Cape May, New Jersey’s dark sky ordinance regulates outdoor lighting to reduce light pollution and protect wildlife and the night sky.