Since the dawn of time, humans have spent half their time under skies like these.

But today, 80% of people in North America can't see the Milky Way.

The culprit: nighttime lights that have proliferated since the advent of the lightbulb.

In many urban areas, only the brightest dozen stars can be seen, where thousands were once visible.

How bright is your neighborhood?

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Ninety-nine percent of the continent lives under skies that experience some level of light pollution.

Streetlights, car headlights and indoor lights reflect skyward, causing a “sky glow” effect.

Unshielded fixtures emit light upwards as waste.
Other lights reflect off nearby surfaces.
LEDs are often several times
brighter, sending more light skyward.

And it's getting brighter all the time.

The growth of LED lights over the past decade has been a boon for energy efficiency. However, they emit a blue-white color temperature that has increased light pollution considerably.

Other trends have also illuminated previously dark places. A boom in natural gas drilling lit swaths of the Bakken region of North Dakota, as well as other rural areas in Texas and Pennsylvania.

Population growth and automobile dependence often lead to urban sprawl, expanding urban light into former green space. The Houston metro area grew by over 15% between 2010 and 2020.

This constant light is wreaking havoc on human and wildlife physiology.

We rely on the release of melatonin to regulate the sleep-wake cycle, also known as the circadian rhythm.

Many animals rely on natural light sources for navigation. Baby sea turtles use moonlight to navigate to the ocean after hatching.

However, blue-white light blocks the release of melatonin, disrupting the circadian rhythm and increasing our chance of developing heart disease, depression and breast cancer. Urban light lures sea turtles away from the sea, killing tens of thousands each year.

As the number of places that experience dark skies dwindles, public awareness of the value of darkness is growing.

The International Dark-Sky Association (IDA) works to protect these islands of darkness through their Dark Sky Places program. Since its founding in 2001, the program has recognized over 130 places in North America for their efforts to preserve night skies. The number of Dark Sky Places has increased rapidly over the past decade.

The program has spurred policies that reduce light pollution from small parks like the nearly 2-square-mile Geauga Observatory Park on the outskirts of Cleveland to a 1,400-square-mile reserve in central Idaho.

Stanley Lake in the Central Idaho Dark Sky Reserve

Flagstaff, Arizona became the IDA’s first Dark Sky City in 2001. It enforces outdoor lighting regulations and fines property owners for careless light pollution. A city ordinance states:
"Dark starry nights, like natural landscapes, forests, clean water, wildlife, and clear unpolluted air, are valued in many ways by the residents of this community."

Humphreys Peak looms over the city of Flagstaff, AZ

Dark Sky parks, sanctuaries and reserves tend to be in remote locales far from most of the country's inhabitants. In 2019, the IDA began recognizing Urban Night Sky Places—spots in urban areas that are managed to maintain night skies in the midst of significant artificial light.

Valle de Oro National Wildlife Refuge on the outskirts of Albequerque, NM

Select a point to learn more about the Dark Sky Place.