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Light pollution isn't just bad for stargazing: Why some towns are embracing darkness

There are currently 38 official Dark Sky Communities around the world. Here's why they matter.

Dark skies are good for people and the planet.

In the 17th century, the wealthy people of Scotland would escape to the small town of Moffat for its healing sulfurous springs. Today, people appreciate Moffat for another kind of healing escape…into darkness.

That's right. The healing power of the dark of night is a thing, not only for people but for the planet.

If you've ever had the bounty of sitting out under the stars far away from city lights, you know how magical it can be to gaze at the night sky, but there are benefits to natural darkness that go far beyond enjoying the aesthetic beauty of space. That's the premise behind Dark Sky Communities.

Moffat became an official Dark Sky Community in 2016 after it invested in changing the town's lighting to prevent light pollution. Now it's an ideal place for stargazing, with a community observatory housing a state-of-the-art telescope and townspeople dedicated to preserving the night sky. Moffat was one of the first Dark Sky Communities in Europe and is one of just 38 around the world as of January 2023.

What exactly is a Dark Sky Community and why does it matter?


The International Dark-Sky Association (IDA) began designating places around the world, from natural environments to cities and towns, as Dark Sky Places in 2001 as a way of recognizing "excellent stewardship of the night sky." Dark Sky Places preserve and protect the dark through responsible lighting policies and public education about the importance of reducing light pollution. A Dark Sky Community is a legally organized city or town that adopts outdoor lighting ordinances that reduce light pollution and undertakes efforts to educate residents about the importance of dark skies.

Darkness matters—a lot. Not only does light pollution make it harder to see the beauty of the night sky, but it also has a negative effect on wildlife and ecosystems. Many animals, from insects to migratory birds to nocturnal animals rely on the natural rhythm of sunlight and darkness, and artificial light can disrupt their natural behaviors, sometimes to deadly effect. Light pollution also has a detrimental impact on plants, disrupting the circadian rhythm of certain pollinators and leading to reduced plant-pollinator interactions.

Too much artificial light at night can impact human health as well, as light messes with our own circadian rhythms. It's also just a waste of energy when lights are left on unnecessarily. The IDA estimates that around 30% of outdoor lighting is wasted, just in the U.S. alone. The Artificial Light at Night (ALAN) Research Literature Database provides a wealth of scientific literature on all aspects of artificial light at night research.

But as much as science tells us about the importance of reducing light pollution, there's also what the IDA refers to as our "night sky heritage."

milky way, stars, night sky

The night sky has inspired scientists and poets alike throughout human history.

Canva


The IDA website explains:

"Until recently, for all of human history, our ancestors experienced a sky brimming with stars—a night sky that inspired science, religion, philosophy, art and literature, including some of Shakespeare’s most famous sonnets.

The natural night sky is our common and universal heritage, yet it’s rapidly becoming unknown to the newest generations.

Van Gogh painted his famous “Starry Night” in Saint Rémy, France, in 1889. Now, the Milky Way can no longer be seen from there. If he were alive today, would he still be inspired to paint “Starry Night”?

Experiencing the night sky provides perspective, inspiration, and leads us to reflect on our humanity and place in the universe. The history of scientific discovery and even human curiosity itself is indebted to the natural night sky.

Without the natural night sky we could not have:

  • Navigated the globe
  • Walked on the Moon
  • Learned of our expanding universe
  • Discovered that humans are made of stardust"

Our relationship with natural darkness is both practical and poetic, but in a world full of lights and screens, most of us probably don't it as much thought or care as we should. That's the whole purpose of naming and certifying Dark Sky Places.

The IDA shares that as of January 2023, there are 201 certified Dark Sky Places in the world, including 115 Parks, 38 Communities, 20 Reserves, 16 Sanctuaries, 6 Urban Night Sky Places, and 6 Dark Sky Friendly Developments of Distinction.

You can find the list of Dark Sky Communities here and an interactive map of all official Dark Sky Places here.

Let's all do our part to turn off lights and limit light pollution for the good of people and our planet.


How fast is a star?

Though the stars in the sky seem pretty fixed, they're actually all moving relative to each other. You just can't tell because they're so far away. Even the constellations are only temporary — in another 50,000 years, they may look very different!

No two stars are moving the exact same way, either. Some move at very different speeds, which means that while some stars are like this:


GIF from ExperimentalUTubeChannel/YouTube.

Others are like this:

GIF from "Star Wars."

Or something like that, anyway. They're not jumping to light speed, but they are pretty dang fast.

How do you track down a super-fast star?

That's what William Chick and his team of astronomers at the University of Wyoming wanted to do.

"We are using the bow shocks to find massive and/or runaway stars," said Henry Kobulnicky, another astronomer from the University of Wyoming.

Wait. Bow shock? What the heck is a bow shock?

As the stars zoom through space, material shoots out of them, creating a kind of solar wind. This wind hits any dust or gas in the star's way, causing it to pile up in front of the star. It's kind of like how a boat makes water bunch up in front of it.

Yeah, like that. Image from AlfvanBeem/Wikimedia Commons.

On a boat, it's a bow wave. On a star or a bullet or a plane, it's bow shock.

Eventually, the bow shocks' big, chaotic pileup heats up the gas and dust in front of the star and causes it to glow. Most of the light is infrared, which means it's invisible to the naked eye. But if you have an infrared telescope, you can spot the bow shocks. Some of them are a bit hard to see:

Image from NASA/JPL-Caltech/University of Wyoming.

But some of them are just ... wow.

Image from NASA/JPL-Caltech/UCLA.

That star, called Zeta Ophiuchi, is hurtling across the galaxy at 54,000 mph and is gigantic — 20 times as massive as our sun. It's the Rebel Without a Cause of stars — living fast, dying young. It'll speed across the galaxy for about another 4 million years before exploding in a gigantic supernova like some sort of cosmic firework.

What made these stars so fast in the first place?

"Some stars get the boot when their companion star explodes in a supernova," said Chick. That's what they think happened to Zeta Ophiuchi up there. Others get slingshotted out of star clusters.

Our own sun isn't moving quite as fast as Zeta Ophiuchi; it's in the slow and steady camp. As for exactly how fast, it depends on what you're measuring it against, but Stanford University puts the sun's speed at a more stately 45,000 mph. We're not sure if our sun has a bow shock.

To find these stars, Chick and his team used data from a pair of powerful telescopes located in outer space, the Spitzer Space Telescope and Wide-field Infrared Survey Explorer (WISE).Other researchers are also looking at bow shocks to try to learn how these massive, fast stars live and die. Learning more about them could help us understand more about our own solar system and how the universe works.

Want one more picture? OK, just one more.


Bow shock around LL Orionis. Image from Hubble Heritage/Flickr.

Yeah.


GIF from wolfwaffles.com