Reclaiming
Our Dark Skies
"Fireflies Under the Milky Way"
That night, the fireflies looked like a reflection of the stars—I couldn't believe how many there were. Single 20-second exposure.
Radim Schreiber | www.FireflyExperience.org
On the next cloudless evening, step outside and look up at the night sky. If you are reading this on such a night, perhaps you can do it right now.
Can you see the Milky Way?
Once, people living in Iowa could look up and see it blazing across the sky. Today, light pollution has dimmed that view across much of the state, softening a sight that would once have been far more vivid.
Still, there are places in Iowa where the stars shine more clearly. At sites such as Whiterock Conservancy, Nine Eagles State Park, and the Loess Hills State Forest, observers can find something closer to the night sky our ancestors knew.
Those places remind us that the loss of darkness is more than just a missed view. It is a change to the landscape itself, and one worth noticing.
View of the Milky Way when unobstructed by light pollution.
What is Light Pollution?
If you were to look at Iowa at night from the International Space Station, you would see a network of glowing lights spread across towns, roads, and farms, something like this:
Midwest from Space Station
NASA's Earth Observatory, Public Domain
Those lights may look beautiful from above, almost like scattered jewels. But much of that light is not illuminating homes, sidewalks, and streets effectively; instead, it is spilling upward into the sky, where it does little good and causes real harm. That is light pollution: wasted or misdirected artificial light. It dims our view of the night sky and affects wildlife, human health, and entire ecosystems.
One way to understand the effects of light pollution is through the Bortle scale, a simple nine-point system that measures how bright the night sky appears and how much that brightness affects our ability to see stars and other celestial objects. On the scale, Class 1 represents the darkest skies on Earth, while Class 9 describes the brightest inner-city skies. In practical terms, the lower the number, the more stars you can see. The higher the number, the more the night sky fades from view. Because the Bortle scale evaluates how the sky appears to the human eye, you can estimate your local class by assessing what celestial objects you can naturally see on a clear, moonless night.
Two hundred years ago, Iowa would likely have ranked at the darkest end of the Bortle scale. Today, most of the state falls between Class 4 and Class 5, where light pollution dominates the sky and brightens the horizon. In Iowa’s most light-polluted urban centers, such as Des Moines, Cedar Rapids, and Davenport, much of the night sky is washed out, leaving only the moon, a few planets, and the brightest stars visible overhead.
The sky is highly light-polluted in downtown Des Moines. It has a Bortle 9 ranking.
The Bortle Scale
The Bortle scale is a nine-point system that measures how bright the night sky appears and how much light pollution affects what we can see. Developed by amateur astronomer John E. Bortle, it offers a simple way to compare sky quality from one place to another.
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Class 1: The darkest skies, with a brilliant and highly structured Milky Way.
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Class 2: Very dark skies, with only a slight glow near the horizon.
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Class 3: Rural skies, where the Milky Way is still rich in detail.
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Class 4: Transition skies, with light domes appearing in some directions.
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Class 5: Suburban skies, where the Milky Way remains visible but less distinct.
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Class 6: Bright suburban skies, where the Milky Way is faint.
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Class 7: Transition skies, with a bright sky glow and fewer visible stars.
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Class 8: City skies, where only the brightest stars and planets are easy to see.
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Class 9: Inner-city skies, with extreme light pollution and very few visible stars.
You can also check the Light Pollution Map for Bortle-scale estimates in Iowa and around the world.
Why Should We Care?
Unfortunately, the effects of light pollution reach far beyond limiting our view of the stars. Earth’s living systems evolved under predictable cycles of light and darkness, and life depends on those rhythms for health, behavior, and survival. When artificial light erases the night, the consequences ripple outward: wildlife is disrupted, human health suffers, energy is wasted, and something essential to our sense of wonder is lost.
Artificial light disrupts animal health. Virtually every species that has been studied so far is affected by light pollution. When artificial light floods the night sky, the effects ripple through pollination, rest, reproduction, feeding, and navigation patterns. On a summer night in Iowa, one of the easiest examples to see is the moth. If you step outside near a porch light or streetlight, you may notice moths circling the glow. They are not simply attracted to light; rather, artificial lighting confuses the cue they normally use to navigate—the moon. That disorientation leaves them trapped in looping flight patterns instead of moving steadily through the night. Moths are only a very small part of the story. All animals depend on darkness.
Lack of darkness also harms human health. Though there are many factors contributing to rising health challenges, research has shown that artificial light at night can increase risks related to sleep disorders, metabolic health, mood, and cardiovascular function. Like the rest of nature, our bodies depend on darkness as part of a natural circadian rhythm. If light reaches our eyes at night, it can disrupt the body’s normal production of melatonin and disturb that cycle.
Wasted light is wasted energy and money. According to DarkSky International, up to 50 percent of outdoor lighting is wasted. Rather than pointing downward only when needed, much light spills into the atmosphere. Billions of dollars each year are lost to lighting that does not do its job.
The night sky has informed and inspired humanity for countless generations. Starlight carries information from millions or even billions of light-years away. Ground-based astronomy becomes far more difficult when the stars are washed out. But more than that, much of humanity’s philosophy, spirituality, art, and science has been shaped by the night sky. As Dacher Keltner writes in Awe: The New Science of Everyday Wonder and How It Can Transform Your Life, people who experience everyday awe become more curious about art, music, poetry, science, and life’s biggest questions. Without the awe we feel when we look up and ponder the mysteries of the universe, something essential to our humanity is diminished.
A home light inventory can help determine where lights may be too bright, unshielded, or in use when not necessary
What About Safety?
Many porches, sidewalks, business lots, and yards are flooded with light at night because we assume more light means more safety. But the evidence does not support the idea that constant outdoor lighting reduces crime. In some cases, excessive lighting creates glare, deep shadows, and unnecessary visibility from a distance. Better lighting design, not simply brighter lighting, is what makes outdoor spaces safer and more functional.
Dark-sky-friendly lighting is warm-colored and only as bright as necessary.
What Can We Do Differently?
Fortunately, as DarkSky Iowa advocate James Bruton told Iowa Natives, the easiest solution is “literally just a light switch away.”
Do a home light inventory to determine where you can reduce unnecessary light on your property. Turn outdoor lights off when not needed. Close blinds and curtains to prevent interior light from spilling outdoors. These simple fixes help you save money, improve your own health and safety, and create a healthy habitat for wildlife. A good rule of thumb is to ask yourself whether each light is serving a clear purpose; if it is not, it probably does not need to be on.
Switch to dark-sky-friendly lighting that reduces glare and directs light only where and when it is needed. Outdoor lights should be no brighter than necessary, warm in color, downward-facing, and used with timers or motion sensors whenever possible. When replacing fixtures or bulbs, look for products labeled as shielded and under 3000K in color temperature, which typically cast a softer, more night-friendly glow.
Advocate for dark skies in your community. Lighting ordinances and lights-out initiatives can protect human well-being, help nature thrive, and give neighborhoods the chance to experience a truly starry night sky. Start small: talk with neighbors, attend city council meetings, and ask local leaders to consider dark-sky language in zoning and development plans.
Educate others. Share lighting resources that make better choices easier. Spread the word about the importance of dark-sky initiatives, and host sky-watching events. Youth groups, classrooms, and nature clubs are especially strong partners; a single evening under a clear sky can change how people see their own backyards.
Follow DarkSky Iowa and join DarkSky International. Your support helps protect dark skies around the world.
Visit places in Iowa that maintain dark skies. Plan trips to dark-sky-friendly parks and preserves, and let land managers know that night-sky quality is part of why you chose to visit. When communities see that darkness is valued, they have a stronger incentive to protect it.
Dark-Sky-Friendly Lighting
When replacing fixtures or bulbs, look for products labeled as shielded and under 3000K in color temperature, which typically cast a softer, more night-friendly glow. DarkSky International is a global organization dedicated to protecting the night sky. If you are shopping for new outdoor fixtures, you can also look for the DarkSky Approved seal.
Many companies offer a range of dark-sky-friendly lighting options, including:
Imagine a different night sky.
Step out into your backyard. The glow has softened. Natural darkness around you changes the whole experience. Barred owls call in the distance, fireflies flicker in the grass, and your eyes adjust to the darkness your body needs.
Look up and see the Milky Way stretching overhead. Ursa Major points to the North Star. Vega shines high above. Stars reach all the way to the horizon.
Stand there for a while, think about the mysteries of life, and then feel that deep kind of sleepiness that only natural darkness can bring.
Take a breath, exhale gratitude, and settle into the night.
Best Places in Iowa to See Dark Skies
Bortle Scale Rating 2-3
Eden Valley Refuge
Lake Darling State Park
Lake of Three Fires State Park
Lake Sugema
Lake Wapello
Loess Hills State Forest
Moore-Gosch Memorial Park
Nine Eagles State Park
Okamanpedon State Park
Palisades-Kepler State Park
Prairie Rose State Park
Preparation Canyon State Park
Rock Creek State Park
Springbrook State Park
Stephens State Forest
Whiterock Conservancy
Yellow River State Forest
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