Scientists explain why urban areas can’t enjoy all of the galaxy’s glory

By: Tiffany Esshaki, Kevin Bunch | C&G Newspapers | Published July 1, 2014

 This photo from NASA demonstrates the light pollution coming from our nation’s cities, as seen from space.

This photo from NASA demonstrates the light pollution coming from our nation’s cities, as seen from space.

One of the best things about summer is spending warm nights outside underneath the glittering stars. But, as most people in metro Detroit know, it can be hard to pick out more than a handful of stars on a given night, much less a vast sky full of them.

According to local experts, that’s because the same outdoor lights that illuminate our streets and keep us safe at night — such as business signs and street lamps — also flood our atmosphere with a bright haze that outshines the stars.

Michael Narlock, head of astronomy at the Cranbrook Institute of Science, said that the largely urban problem of light pollution dates back to the ’60s, when street lamps were installed in most of our neighborhoods.

“They were meant to light up the street, but they were poorly designed and instead what we got was lights that illuminate everything. It causes the sky to glow and makes it difficult to see distant or even bright items in the sky,” said Narlock.

Astronomers, both amateur and professional, are well aware of the problems light pollution causes. Angelo DiDonato, public outreach officer with the Warren Astronomical Society, said streetlights — and city lights in general — wash out the sky for anyone interested in seeing it for themselves.

Dimmer objects like the Milky Way, or even fainter planets, are hard to spot with light pollution, he said, which obscures the starlight stretching millions of miles to hit the Earth.

“If you go Up North and see the skies Up North compared to here, you see a dramatic distance in what you can see,” DiDonato said. “You look up, and there’s millions of stars and every constellation. Here, you only see a few. The people living down here in the city have probably never seen the Milky Way unless you drive out away from the city.”

Missing out on starry skies might not be the only problem light pollution causes, according to Narlock. He said there have been studies that suggest the bright light can cause problems for wildlife. The International Dark-Sky Association claims the light can also confuse birds, bats and moths, and reduces the visibility of fireflies while they attempt to mate. For newborn sea turtles, the light can draw animals from the water and into busy roads.

Even animals of the human variety can be affected, with disrupted sleep cycles and the unhealthy consequences that come with sleep deprivation.

It’s because of all that, DiDonato said, that “dark sky” advocates have been lobbying to reduce the amount of light pollution escaping into the world. They’ve had particular success in western states, he said, with more and more communities creating ordinances about light pollution and doing what they can to direct street lamp light downward where it’s needed — sometimes by attaching cones to the lamps.

Narlock agreed that heading to your municipal leaders is the best way to go about reducing light pollution.

“Talk to those at your municipality that are involved in the choice of what sort of street lamps to use. They could create ordinances on neon signs and (lights) of the like,” he said. “No municipality wants to get rid of the night sky. It’s usually more of a cost thing.”

Individually, Narlock said residents can do their part by making sure lights outside of their homes are directed toward the ground with little to no residual light glowing outward. When it’s time to hit the hay, all outside lights should be turned off — which Narlock noted would include the fringe benefit of saving on the electric bill.

Business owners could do the same by finding alternative security measures that don’t involve keeping their building lit at all times.

“If everyone were to reduce the amount of light they shot into the air by 10 percent, that would have an impact,” he said.

But to bring back the clear night sky our ancestors enjoyed centuries ago, it would take a group effort. DiDonato said there hasn’t been much progress in the Great Lakes state to reduce light pollution, with just one Michigan law on the books addressing the issue. The Natural Resources and Environmental Protection Act only defines what shielded light is, as well as a dark sky preserve like the one near Mackinaw City.

Narlock suggested that those eager to go stargazing this summer could head to one of those preserves, or even just make the trek to more rural areas of the state. Then there’s always the observatory at the Cranbrook Institute of Science, which has specialized filters to block light pollution so scientists and guests alike can get a detailed look at stars, planets and even the sun during the day.

“There are places around the country where light pollution is taken seriously,” said DiDonato. “It’s like sound pollution — they limit how much noise can be around because that can affect you. Unfortunately, there’s no government organization that says we can’t pollute our skies. That’s basically what it amounts to.”

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