‘People Really Want to See the Stars’
- Julie Peterson
- Aug 21
- 7 min read
Updated: Aug 22
The Growing Campaign against Nighttime Light Pollution
Gazing up at the twinkling night sky can be awe-inspiring; its breathtaking complexity and enormity, its beauty and tranquility, are beyond compare.
Stars have shaped beliefs and cultures, guided travelers, tracked the seasons, “illustrated” myths and legends through constellations, and allowed people to relay timeless stories to their children.
But today, even as advanced telescopes and other technologies give astronomers closer and deeper views of the universe, there is increasing alarm about what is not being seen in the night sky. Many stars aren’t as visible to the naked eye as they were a few years ago.
Poorly designed outdoor lighting bathes the planet’s night sky in artificial light, and the problem is getting worse. Because of this phenomenon, there's a growing campaign to preserve dark skies so future generations can appreciate their immeasurable cultural and scientific value.
Lights Obscure Views of the Milky Way
A 2016 study estimated that more than one-third of Earth's population could not see the Milky Way from home due to light pollution.
“It’s a crime against nature and humanity that we’ve stolen that away from this generation, and it’s essential that we return it. It’s a vital piece of human heritage. It’s one of nature’s greatest gifts and we’re squandering it,” says James Lowenthal, professor of astronomy at Smith College in Northampton, Massachusetts. He is also president of DarkSky Massachusetts, an advocacy group against light pollution.
Lowenthal’s goal is to engage more people, including professional astronomers, in protecting pristine night skies from light pollution, or in returning those skies affected by it closer to their original state.
But not being able to see stars is only part of this problem—artificial lights at night are also hazards to human health and many species of wildlife, as covered in The Earth & I’s “Light Pollution: Keeping Nature Up Past Its Bedtime.” In addition, the US National Park Service’s study, “Synthesis of Studies on the Effects of Artificial Light at Night,” reviewed 457 studies on the response of humans and wildlife to light pollution. It found impacts from the psychological effects of light pollution to its destabilization effects on soil bacteria.
Globe at Night
Fortunately, Lowenthal isn’t the only one championing what some call “visual access” to a night sky unaffected by light pollution.
“Astronomers recognized light pollution as a problem in the 1970s. Even with the most powerful instruments, they could no longer view stars and other celestial objects with the same clarity,” says the National Conference on State Legislatures (NCSL).
“While at least 2,500 stars should be visible under normal nighttime conditions, only a few hundred can be seen in a typical American suburb. In most large cities, residents would be lucky to glimpse a few dozen,” says the organization, which tracks laws and policies in US states, territories, commonwealths, and the District of Columbia.
As of 2022, at least 19 states, Puerto Rico, and the District of Columbia have taken steps to curtail light pollution, according to the NCSL. These laws—which are identified online—address issues like “sky glow,” or the brightening of night sky over inhabited areas; “light trespass,” or lights that shine where they are not wanted or needed; and “glare,” where excessive brightness can cause visual discomfort, the NCSL says.
In addition, over the last 14 years, the international campaign Globe at Night has been gathering information from citizen-scientists about night sky brightness. GaN’s Sky Brightness Monitoring Network (GaN-MN) now has more than 200,000 measurements submitted by people in 180 countries.
The GaN-MN project uses a commercially available sky quality meter (SQM) for long-term monitoring of light pollution. These efforts have created a huge dataset that allows scientists to measure light pollution over time.
“Everyone over the age of 50 remembers a dramatically better sky.”
“Worldwide, we see a troublesome worsening in light pollution, as fast as 10% per year,” says Lowenthal. “It reflects what we’re seeing anecdotally. Everyone over the age of 50 remembers a dramatically better sky.”
Dark Sky Places
The positive side of this research—which is actually the dark side—is that some of Earth’s dark skies are now being protected—by responsible lighting practices at night—for future stargazing.
In 2001, Flagstaff, Arizona, was named the first International Dark Sky City. There are now over 200 certified International Dark Sky Places in 22 countries on six continents. These places might be communities, parks, or reserves that have undergone a rigorous application and approval process.
Cottonwood, Arizona, spent four years working to become accredited, but it now hosts events like star parties where volunteers bring telescopes to share. Lowenthal says events like these are fun ways to connect and can show people the sky they are missing.
The US National Park Service presents Dark Sky Events to teach about the wonders of the night sky. Such events have led to an increase in astrotourism, in which people gather to observe celestial objects. Utah, for instance, offers camping or rustic accommodations, guided tours, festivals, and storytelling.
For people interested in learning more about celestial things, it’s not necessary to travel to a Dark Sky Place. There is likely a nearby astronomy club or observatory that offers public events and viewing nights. Online resources like the NASA Night Sky Network also list upcoming activities and skywatching tips. Across the planet, there are in-person and virtual dark sky events to attend.
Conservationists to the Rescue
The dark sky movement benefits from the involvement of other conservation organizations.
“One of the lessons we learned is that the astronomers cannot fix this on our own,” says Lowenthal.
The American Astronomical Society, a trade group with 8,200 astronomers, astronomy educators, and amateur astronomers as members, is concerned about increasing and unregulated artificial lighting. Such lighting impacts the study of deep-space objects by ground-based observatories.
The dark sky movement benefits from the involvement of other conservation organizations.
Conservation organizations have a broader influence on implementing dark sky policies. For example, the Audubon Lights Out Program is a national effort to convince building owners and managers to turn off excess lighting during migrations over cities to help prevent birds from crashing into buildings. “Most birds migrate at night, making them more vulnerable to buildings and other structures lit with artificial lights they might be attracted to, often resulting in tragic collisions, entrapment, and exhaustion,” says the US Fish and Wildlife Service (FWS).
In Texas, organizations in Houston, Galveston, and other cities are doing a “lights out” campaign in which tall buildings turn off their lights from 11:00 p.m. to 6:00 a.m. during spring and fall migrations, the BBC reported in April 2024.
The Sea Turtle Conservancy aims to educate people on coastal lighting that confuses turtle hatchlings and makes it difficult for them to reach the ocean.
The American Medical Association released a report titled “Light Pollution: Adverse Health Effects of Nighttime Lighting” to inform people of the increased incidence of some diseases associated with a lack of darkness.
The FWS also urges dimming nighttime lights to benefit insects and pollinators. “Although not well-studied, we are beginning to more clearly understand the impact light pollution has on insects and pollinators. This topic is emerging in more and more conversations,” Melissa Burns, western monarch coordinator, said in a report for FWS.
Light Pollution Mapping
A good way of grasping light pollution levels is to look at a map.
Jurij Stare, of Slovenia, created Light Pollution Map, an interactive website that provides a global display of light pollution levels. It is accessible to everyone, and is often used by astronomers, stargazers, and photographers to quickly locate dark sites with clear skies.
The map allows users to check visibility using both the Bortle Dark-Sky Scale and SQM data. The Bortle Scale is a sky quality measurement scale created by American amateur astronomer John E. Bortle and ranges from 1 to 9, with a higher number indicating greater light pollution. It was developed through decades of naked-eye observations. SQM data is provided by a device the size of a cell phone. The most pristine dark sky registers on a map at Bortle 1 and SQM 22.0, whereas New York City skies, typically among the most polluted, register at Bortle 9 and SQM >18.38.
There is also the option of using the map’s color key. The most visible stars and galaxies are in areas that are darkest on the map. White areas are the most artificially lit and the stars are mostly obscured.
Public Awareness and Policy Changes
“People really want to see the stars. Nobody wants to lose the stars. That’s our silver bullet—if there is one,” says Lowenthal. “Light pollution is all due to fear of the dark, fear of strangers, and the irrational sense that more light is better. As a result, we’ve lost this immeasurable treasure.”
“People really want to see the stars. Nobody wants to lose the stars. That’s our silver bullet—if there is one.”
However, after policymakers and communities are educated about how light pollution works, people become more sensitized to the issue—they will notice harsh municipal lighting, upward facing floodlights, flashing signs, porchlights that invade neighboring homes, and office buildings that are lit from within 24/7.
The DarkSky Approved program promotes high-quality lighting and signage for outdoor environments that minimize light pollution (including sky glow), light trespass, obtrusive light, and harmful impacts on people, wildlife, and plants. For a product to be DarkSky Approved, it must have a clear purpose, be directed only to where needed, be no brighter than necessary, be used only when useful, and be a warm color.
“The reality is that most people have no idea that light pollution is an issue.”
“If we had everybody educated on this issue, if everybody understood it, then our job might be done and they would turn off their lights and wouldn’t install bad lights or overly bright lights,” Lowenthal says.
But the reality is that most people have no idea that light pollution is an issue. It will take ongoing education, collaboration, legislation, and commitment for people to save dark sky resources for themselves and for future generations—so that we don’t all lose the stars.
*Julie Peterson writes science-based articles about holistic health, environmental issues, and sustainable living from Wisconsin.
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