Narrator: For the National Park Service, I’m Brittni Connell, and you’re listening to Voices of Science.
Narrator: In a study published in 2016, an international group of scientists said 80 percent of Americans and fully one-third of people living on Earth can no longer see the Milky Way because of light pollution. Talking with Pascal Nelson on a late-summer Hawaiian night, that statement is hard to grasp.
Pasca Nelson: I couldn't imagine living a life without being able to see the Milky Way...see the stars. It makes all the difference in the world to how I see myself as a human being. One of the things that always drove me as a person interested in astronomy is to always look up.
Narrator: Pascal has been looking up for most of his life. Hours spent gazing at the Milky Way as a kid led to study in astrophysics. Now retired, Pascal volunteers at Hawaii Volcanoes National Park where he gives talks about the night sky and shows people the stars through telescopes. He says that the clear night sky has been a critical part of the human experience for millennia. And that here in Hawaii, the night sky helped make history.
Pascal: The settlement of these islands was a great quest in human history that was by no means assured.
And yet hundreds or even thousands of years ago, the islands were settled by people who dared to reach out -- dared to put an oar in the water, and put their bodies in a canoe and launch out into that ocean and find their way across trackless expanses.
Narrator: And to do that, they needed the night.
Pascal: They had to look up in the sky. They had to look at the stars and how they moved and where they rose and where they set and where they went across the sky. They developed the ability to look at that sky with such incredible insight that it told them where they were on the ocean and how they could go across thousands of miles from one island to another which they did for many generations.
Narrator: Now, with so much simulated daylight around the world, that kind of connection with the night sky is harder to maintain. But Pascal says that out here on Hawaii Island--away from the light pollution that’s common in other places--the park is an ideal spot to look out into the ocean of space.
Pascal: The sky is just ultra transparent here. It's very dark. It's one of the darkest places on the face of the Earth.
Narrator: And that darkness is something that both Pascal and Hawaii Volcanoes National Park want to protect.
Danielle Foster: Dark skies are really important. A lot of people don't realize that they're actually a resource…
Narrator: Danielle Foster is an Environmental Protection Specialist in the park. She’s part of a team working to preserve the night sky.
Danielle: Most people think of wildlife and plants and historic structures as resources, but we also have night skies, and they're really important resources. It's something that people overlook they take for granted, but they don’t know how to put it into words I think.
Narrator: The night sky has value. Like the original Polynesian wayfinders maneuvering under the stars, Danielle says there are others who need the dark.
Danielle: We have a lot of sensitive species here in Hawaii. I mean, everybody has sensitive species. But we have our night flying seabirds, so the white lights can disorient the birds.
Narrator: The endangered Hawaiian petrels can get so confused by artificial lighting, that they collide with buildings or just fall to the ground. Once down, they’re vulnerable. They can become an easy meal or get hit by cars. And sometimes, young birds can’t figure out how to take off again and they starve.
Narrator: Sea turtles are disoriented by coastal lighting, too. Every year, countless turtle hatchlings around the world scramble inland toward brightly-lit developed areas and die instead of moving out to sea.
For billions of years, life on earth has evolved with, and depended on, the steady drumbeat of the circadian rhythm: day into night and night into day. Most species, including humans, rely on these light cues for things like sleeping, or eating, or finding protective cover. When light pollution spills into the night sky, it masks the darkness. The circadian rhythm gets disrupted. And although the consequences of that are not fully understood, scientists think that the effects on both humans and animals are significant.
Danielle: So it's important for us to just make sure that we are doing the right thing, having all our fixtures be the right type of fixtures, and the right type of bulbs to protect the dark skies.
Narrator: Because Danielle says, it’s not that all lights are bad. It’s just when there are too many lights, or the lights are too bright, or haphazardly directed that’s the problem. But for that, she says, there’s a fix.
Danielle: It's really easy. We have three golden rules to dark sky friendly lighting.
Narrator: Rule number one.
Danielle: Keep it low, meaning, keep it as low to the ground or low in height, as is necessary for the application. And also, low in lumens, you don't want to put a huge, high-wattage bulb in if you can get away with something smaller.
Narrator: Rule number two.
Danielle: Keep it shielded…
Narrator: Meaning keep the bulbs covered with a shade that directs the light downward
Danielle: …so making sure that it's keeping the light going to where you need it.
Narrator: And rule number three.
Danielle: Keep it long, keep it long wavelengths.
Narrator: Meaning the color of the bulb.
Danielle: So 560 nanometers and greater is the best, and that would be an amber-colored bulb. Although, yellow is okay, amber is better.
Narrator: So, keep it low, keep it shielded, and keep it long in the color spectrum.
Danielle: Because it makes sense not just to protect the dark skies, but there's a lot of studies that show the energy efficiency. Because you're lighting exactly what you need, you need less lumens, so your bulbs are less energy consumptive.
Narrator: And that saves money.
It’s kind of counterintuitive to think that less is more when it comes to illuminating the night. Danielle says she’s had lots of conversations like that with people.
Danielle: They still think that having their yard blaster light that comes on every time something moves is good; they don't realize the effects it could have on the night sky, and also that it's not necessarily helping them see things in the dark because your eyes dilate and then you can't see outside that bright white, so you're missing things that are in the shadows.
And now, with the corrected fixtures it lights exactly where you need the light...you can see the steps, you can see the doorknob, it's just amazing. So not only are we protecting our dark skies, we're helping the safety and the transit of people around in the dark, so it's a good thing.
Narrator: Danielle and others at Hawaii Volcanoes National Park are incorporating dark-sky friendly lighting into nearly all of the park’s infrastructure. Those changes will help the park seek designation as an official “Dark Sky Park” from the International Dark Sky Association. That means the park would be recognized for its exceptional starry nights and nocturnal habitats. Staff also work collaboratively with people living outside of the park to bring dark-sky friendly lighting into their communities.
Danielle: We need to pay attention to what we're doing, and our neighbors need to pay attention to what they're doing, so that we can maintain our world-class dark night skies into the future, for the next generations.
Narrator: The perpetual turning of the planet--now-day, now-night--sustains us all biologically...ecologically. And there’s a profound mystery to the night that we need, too. The night sky is part of our heritage. It tells us where we came from. And it inspires a curiosity that points toward the future. Protecting the night sky also protects that sense of wonder. Pascal Nelson says that being able to gaze deeply into the heavens keeps us reaching: “what’s out there?”
Pascal:...like I said, there are people who have testified that looking through that telescope changed their lives. It gave them a completely different perspective on the universe.I think the thing that I always come back to is that connectivity. We are not something apart from this. We're a product of this whole process.
Narrator: Voices of Science is produced by the National Park Service in cooperation with the Acoustic Atlas at Montana State University.
Our staff includes Jennifer Jerret, David Restivo, Sara Melena, and me, Brittni Connell.
Special thanks to Jessica Farracane, Pascale Nelson, and Danielle Foster at Hawaii Volcanoes National Park. To learn more about the park, visit their website at nps.gov/havo. Find more episodes of Voices of Science at go.nps.gov/vos.