When was the last time you looked up at the night sky and could really see the stars? Probably not recently: 80 percent of the world’s population lives under light-polluted skies. That pollution has altered most people’s relationship to the night sky in such a fundamental way that when the Northridge quake in 1994 knocked out power to significant chunks of Los Angeles, citizens called 911, concerned about a huge gray cloud they saw in the sky. It was the Milky Way.
“Because humanity evolved over years and years, there’s an ingrained personality attached to the night sky—people wish upon stars and count the stars. When we lose that connection to the sky, we lose part of our connection to nature,” says Mike Weasner, amateur astronomer and chair of the International Dark-Sky Association Dark Sky Places committee. Being in touch with natural darkness, and the stars it brings, has also been shown to positively affect our health.
Perhaps that’s part of the reason that “astrotourism,” or vacations to dark-sky sanctuaries free of light pollution, has been on the rise for the last few years. “Dark skies” were even named one of the top travel trends of 2019 by Lonely Planet. “People want to come out and see the night sky—it’s a relaxing, therapeutic thing,” says Weasner.
The link between light pollution and our wellbeing
It’s more than just a sad inconvenience that most of us can’t look out of our windows and contemplate the stars—overexposure to artificial light can lead to actual health concerns. Continued exposure to artificial light at nighttime can decrease sleep quality and can contribute to mental health concerns, such as depression and anxiety.
Artificial lights blazing into the night sky are disruptive and harmful to wildlife, too. Artificial light negatively affects sea turtles, causing hatchlings to become disoriented and struggle to find the ocean. Seeing bright lights at night disrupts the navigational abilities of night-flying birds, and more.
In contrast, there’s research to support that exposure to the night sky lowers stress, increases positive mood, and leads to great experiences of awe—all things we could use more of.
Spending just two hours per week out in nature is associated with increased health benefits, according to recent research. “That holds true of being out in nature after dark,” Weasner says—and research about the benefits of stargazing back him up.
Finding the night sky
Seeking out the night sky the way it was meant to be seen, pre-ambient glow of streetlights, isn’t as simple as driving to a rural area. When outside lights are directed upward, the light is dispersed by clouds and fog, creating a secondary reflection that can affect a larger area. In cities with more light, 10 percent of light pollution is typically a result of that secondary reflection. In rural areas with less light pollution, even one outdoor light source can increase that number to 50 percent, according to the International Astronomical Union.
To get a real view of the stars, astrotourism seekers may need to visit sites designed to limit light pollution. Currently, the IDA has designated more than 115 sites worldwide as dark-sky places. Among those, dark-sky parks, reserves, and sanctuaries offer the best chances to view the stars unencumbered.
The biggest clusters of dark-sky parks and reserves are designated in North America and Europe, but there are options in Asia (home to Hong Kong, the world’s worst city for light pollution), South America, Australia, and Africa. Dark-sky parks or reserves have very little light pollution, allowing visitors to see many of the night’s stars without the use of a telescope.
Even harder to obtain than the title “dark-sky park or reserve” is a dark-sky sanctuary, of which there are currently only five worldwide (three of those are located in the United States). Dark-sky sanctuaries differ from dark-sky parks or reserves in that sanctuaries are considered the most fragile dark-sky ecosystems because they’re isolated locations that still experience the night sky as it was viewed before artificial light became a problem—and those areas are becoming increasingly rare. Sanctuaries may offer the greatest amount of visible stargazing.
The newest dark-sky sanctuary in the U.S., Devils River State Natural Area in Texas, was officially designated in 2019, following the Cosmic Campground Dark Sky Sanctuary in New Mexico, Rainbow Bridge National Monument in Utah, and Massacre Rim Wilderness Study Area in Nevada. Globally, the other sanctuaries include Great Barrier Island/Aotea in New Zealand, Ae Hai Kalahari Heritage Park in South Africa, Pitcairn Islands in the South Pacific, Stewart Island/Rakiura National Park in New Zealand, the Jump-Up in Australia, and the Gabriela Mistral Dark Sky Sanctuary in Chile.
If visiting a designated park or sanctuary isn’t possible, plenty of places have been noted for their stargazing, such as the W.M. Keck Observatory at Mauna Kea, Hawaii, and Cedar Breaks National Monument in Utah. Although these sites don’t offer the full darkness and visibility of designated dark places, the stars shine brighter than they do in places like Las Vegas, where lights are visible 40 miles into the air.
Make the most of your trip by coming prepared. For the very darkest spots (sanctuaries and parks or reserves), Weasner says that a great deal of stars are going to be visible simply to the naked eye. For those who want a more in-depth look at the cosmos, there’s always the option of bringing binoculars or a telescope. Respect other visitors by using a red-light setting on your headlamp to avoid bringing light pollution in, and plan on driving to your final night viewing location before the sun sets, so you can avoid using your headlights when possible. If you’re camping in the area, use dim lighting only when necessary. If you have any astrophotographers in the area, ask their permission before using any amount of light, as it may compromise photographs.
Fighting light pollution
While some of the large aspects of light pollution—such as streetlights—might be out of your hands, that doesn’t mean you can’t take steps to improve the light pollution in your area through simple measures such as changing the color of your bulbs to an amber light or using shielded lights that direct their beams downward.
From 2012 to 2016, outdoor artificial lighting increased 2.2 percent globally. Weasner says that much of our drive to light outdoor spaces comes from a perception that lighting at night deters crime and increases safety and security. Experts disagree on the effectiveness of lighting in crime prevention, though. While crime prevention through environmental design, such as using lighting to make spaces appear to be safe or guarded is a recognized technique that may result in lowered crime rates, some experts say you’re more likely to attract burglars by leaving your lights on 24/7. If you were home, the lights would be shut off in the middle of the night, the reasoning goes. In the meantime, you’re wasting money and energy and polluting the night sky with your lights.
If you want to leave lights on at night for safety, do it wisely. Weasner suggests that property and businessowners walk across the street from their property. “If you can see your lightbulbs from there, that’s a problem,” Weasner says, adding that the effect is called light trespassing, and you may be affecting your neighbors. An easy switch is to do something to shield those lights—such as using blinds or shades or finding ways to direct the light fixture so that light is more specifically pointed and not wasted. You can also switch out lightbulbs to a lower wattage or amber lights to prevent contributing to light pollution.
And while LED lights are a great solution in terms of longevity, Weasner says that people occasionally take the energy efficiency of LED lights to mean they should use more of them, undoing both the energy savings of LED lights and contributing to pollution. A good rule of thumb for all lighting is that light sources should always point downward and optimize visibility for exactly what you want lit—not for every corner of your property.
It may seem like small steps, but cutting down on our own light pollution will help keep the skies darker and the stars brighter—protecting the areas around our own homes and dark-sky parks and ensuring astrotourism can continue long into the future.