DeCristofano is a chemical engineer, lifelong amateur astronomer, and a member of the South Shore Astronomical Society; his wife is a science educator and children’s science author. They moved to the area almost a decade earlier because of its remoteness, natural beauty, and dark sky. So when the night lights started getting brighter, they decided to do something about it.

“Zooming in on Southeastern Massachusetts, you can see a dark hole, which is Plymouth, Plympton, Middleborough, where we live,” Barry DeCristofano told people walking into the meeting. “It’s really dark, and it’s just 40 miles to Boston.”

In 2001, when Plympton residents Carolyn and Barry DeCristofano were educating their neighbors about light pollution, they set up an easel in the hallway outside the gym on Town Meeting night, displaying an image they hoped would make an impression.

It took two go-rounds, but in 2003 Plympton voters passed a lighting bylaw that requires municipal and commercial outdoor lighting to have full cut-off fixtures, shields that direct light toward the ground. It’s likely many town residents did not understand why the ordinance was needed, or how it would work, even though there were already such regulations in place in nearby Plymouth and Norwell.

Across Massachusetts, more than 40 communities have instituted dark skies bylaws since 2000, according to the New England Light Pollution Advisory Group, and others seem to be headed in that direction.


Arlington’s Town Meeting voters passed an ordinance at the annual session in April; in Cambridge, the city manager has appointed a task force to explore light pollution issues and develop an ordinance; in Chelmsford, Winstanley Enterprises, a Concord developer building a mixed-use retail center, took the town’s lighting ordinance a step further, installing LED fixtures with a soft glow and lower color temperature that are easier on the eyes, cheaper, and more efficient than the rich blue lighting typically used.

“At the community level, most development over the last 10 years — area lighting, parking lots, is fully-shielded, sending light below the horizon instead of up into the atmosphere,” said Kelly Beatty, editor of Sky and Telescope magazine and a light pollution activist who lives in Chelmsford. “When you put all that light on the ground, you’re not wasting energy. When half the light is above the horizon, a lot hits you in the eye directly,’’ he said, increasing the glow and decreasing “your ability to see well at night.”


Ryan Johnson-Rees, a Scituate 8-year-old, pondered the heavens at an event this fall held by the South Shore Astronomical Society. Debee Tlumacki for The Boston Globe

For a time during the recent recession, communities across the country shut off up to a third of their street lights to save money, and many did not go back on. LED lights, which have replaced many of the older, less efficient high-pressure sodium street lights, use less energy but produce brighter light, and have raised concerns about the effect of intense light at night on human health and the well-being of wildlife.

Beatty, who teaches astronomy at the Dexter Southfield School in Brookline, is a member of the board of directors of the International Dark-Sky Association, and chairman of the New England Light Pollution Advisory Group, said few, if any, communities with dark skies ordinances understand that it’s not just shields and LED lights that are necessary to reduce energy costs and glare. What’s also critical is something called “color temperature.”

He said bluish light, which is harsh, interrupts the human body’s production of melatonin, a hormone that promotes sleep; this light also confuses nocturnal and migratory animals, and causes vision confusion in older drivers.

By contrast, reddish light, which is softer and has a lower color temperature, allows the body to prepare for sleep, Beatty said.


Communities making decisions about replacing street lights should use care in selecting the new fixtures, focusing not only on the kind of light but also the color temperature, Beatty cautioned. LED lights typically don’t need to be replaced for 25 years — a long wait if a municipality realizes early on that it chose the wrong color temperature.

“If people care about this, they need to pay attention now,” Beatty said. “Whatever the expense and inconvenience, it’s more than offset by the energy savings and lower maintenance costs.”

Beatty has also been active in a 20-year effort to pass a state law regulating outdoor lighting. At least once, a bill came close to becoming law, he said, adding that a bill that failed in the recently ended legislative session is expected to be reintroduced this month.

Meanwhile, amateur groups such as the South Shore Astronomical Society are seeking out dark fields close to home and inviting the public to join them in viewing the night skies.

On a Friday night in October, for example, Louis Gentile and George Roberts, local amateur astronomers, set up telescopes in a field beside the Scituate Public Library. As darkness fell, the guests — young children with their parents, older children, and adults of all ages — began arriving for the weekly Star Party.

Conditions at the weekly parties, held from May through mid-November, weather permitting, are never ideal. Reflection from lights in the library’s parking lot are distracting. The new LED lights outside the nearby senior housing complex are even brighter than the ones they replaced. But the amateur astronomers are resigned to making do.


“In urban areas, the stars disappear,” said Roberts, a mechanical engineer who lives in Rockland. “Because of light pollution, we have to make a local adjustment, find a spot that’s dark, go behind a tree, let our eyes adjust. At the library, we get out of the light, into the shadows. It helps with the viewing.”

Beatty said it is the astronomers who first brought awareness of light pollution into communities. But now, sleep researchers, conservation groups such as the Audubon Society, and lighting designers are paying attention.

As a volunteer at the Boston Museum of Science in the late 1980s, Barry DeCristofano said he would break the ice with visitors by asking, “Did you see the moon last night? What did it look like?”

“Most people could tell you if it was a sunny day, but they couldn’t tell you if it was a clear night,” he said. “It’s a shame. That’s half the day.“

But without legislation, many say, the night skies, even in the most remote areas of the state, will continue to disappear — and in the process a deep human connection will be severed.

“To me, when you look up at the night sky, it connects you to a primal sense of wonder, of awe,” said Carolyn DeCristofano, the science educator from Plympton who led the charge with her husband, Barry, to get a dark skies ordinance adopted in their town.


“It opens the door to so much that every culture values. And in the Western world at least, the sky opened the world to the development of science. So much of what we value today stems from that!”

Hattie Bernstein can be reached at hbernstein1@hotmail.com.