Seeing More Stars Near Chicago: Palos Preserves Protects Urban Night Skies

While viewing a satellite image taken from the International Space Station over the Chicago region, Adler Planetarium senior manager Ken Walczak saw a triangle of roughly 6,000 acres that was darker than all the surrounding areas. It was the Palos Preserves in Cook County. The images show “how pristine the nights are at the preserves in contrast to the city and surrounding areas,” says Walczak, a board member with DarkSky International.

The image inspired Walczak to team with the Forest Preserves of Cook County to earn an Urban Night Sky Place designation for the Palos Preserves. It’s one of only 14 such designations in the world and was achieved in August 2021. Walczak also is one of the founders of DarkSky Chicago.

“To have this designation in the middle of an urban area is an honor,” says Deborah Silic, a naturalist and assistant director at Little Red Schoolhouse located in the Palos Preserves.

“It allows me to further educate the public on light pollution and what we can do to reduce it,” she continues. “There’s so much to see out there. The night sky awakens your senses to something that’s infinite. You can’t touch it, but you know it’s something that is forever.”

DarkSky International has designated more than 160,000 square kilometers of protected land and night skies in 22 countries on six continents. Designations include International Dark Sky Sanctuaries, Reserves and Communities.

The Urban Night Sky Place designation consists of parks, open space and other similar properties near or surrounded by large, urban environments, “where an authentic nighttime experience” can be found in the middle of “significant artificial light,” according to the organization.

Light pollution—human-made alteration of outdoor light levels from what occurs naturally—disrupts wildlife, impacts human well-being, contributes to climate change and wastes energy, according to DarkSky International.

Gaining Certification as Urban Night Sky Place

Photo credit Forest Preserves of Cook County

At nighttime programs at the Palos Preserves, visitors can see constellations, craters on the moon, lunar eclipses, space station satellites and more, depending on the time of year and evening—far more than if they were in downtown Chicago. Four times as many stars are visible in the designated night sky compared with the city of Chicago, according to the Adler Planetarium, which partnered with the Forest Preserves to submit the site’s application. Satellite data show the Urban Night Sky Place emits nearly 1,000 times less light than downtown Chicago.

Forest preserves are typically darker overall at night than surrounding towns and shopping areas, but many have lit buildings within them that can add to light pollution, acknowledges Mary Busch, volunteer program specialist for the Forest Preserves of Cook County. For years, the Forest Preserves has been following a climate resiliency plan that includes reducing light pollution and improving sustainability, she says.

But when Walczak visited the Forest Preserves to talk about the unique dark sky of the Palos Preserves, that set staff on track to seek the Urban Night Sky Place designation. Adler Planetarium interns measured and documented nighttime light levels within the Palos Preserves and surrounding areas using special cameras they built. They also used satellite data and images from astronauts aboard the International Space Station.

The Adler Planetarium worked with the Forest Preserves to secure the designation by helping develop a plan to retrofit facilities to further reduce lighting levels at night.

“Though this is not a pristine wilderness like a DarkSky Reserve, it is an area where we meet all the requirements to be an Urban Night Sky Place by using recommended color spectrums, shielding lights and putting lights on motion sensors,” Busch says. The Forest Preserves is working on similar projects at other properties, she adds.

Night Sky Events

Photo by Earth Science & Remote Sensing Unit, NASA Johnson Space Center (eol.jsc.nasa.gov/esrs)

A key component of the designation includes public education, and such events had already been hosted within the preserves. Since the designation, more than 50 nighttime programs have been held annually in the Palos Preserves, says Silic, with at least 25 held at Little Red Schoolhouse. Programs include stars and stories nights, urban night sky picnics, full moon and new moon events and serenity walks. The schoolhouse is hosting a total lunar eclipse viewing on March 3.

Palos Preserves night sky programs are popular and often fill with waiting lists, even those that start at midnight, Silic says.

“We talk about constellations and tour the night sky if it is clear,” she says. “We’ll add a wildlife component, for example, beavers under a full moon or coyotes at night. We also talk about mythology while looking at the constellations. We have telescopes here for viewing. If Mother Nature cooperates, we will end programs with telescope viewing. People just love seeing the moon close up or a planet.”

Some participants have remarked that the night sky almost looks fake and exclaim how awesome it is to see something they’ve never seen before near their homes, she adds.

Light Pollution Effects on Wildlife

 Silic relays information to the public about the circadian rhythm of humans and the need for darkness. Busch says a group associated with the Adler Planetarium takes photographs, writes essays and advocates for teaching people why curbing light pollution is important.

“They’ve written about how their bedroom is next to a neon light that flashes all night and how it interrupts their sleep,” Busch says.

Light pollution affects bird migration, adds Silic. “Birds can get lost. They look at the lights, they think it’s the sun,” she says.

Frog monitors also are investigating how light pollution affects the amphibians breeding in the summer, Busch says, adding that moths at night are attracted to manmade lights at night, fly into them and then perish.

A recent study published in Biological Conservation shows that light pollution contributes to the decline of insects.

Beyond organized programs, another way to experience the night sky within the Palos Preserves is by camping, which is open year-round. “Then you have access to the night sky the whole entire night,” Silic says. Those interested in camping can visit fpdcc.com/places/locations/camp-bullfrog-lake to learn more.

Unfortunately, the Milky Way is not visible in the Chicago region, Silic notes. “You’d have to drive at least three hours outside of the Chicago area to get a glimpse of it.” She drives to Michigan’s Upper Peninsula for that experience.

“I remember seeing the Milky Way as a kid,” Silic relays. “I grew up in Brookfield. But light pollution has drowned it out, even at the Palos Preserves.”

Curbing Light Pollution

That’s why promoting Urban Night Sky Places and DarkSky International is important, she says, pointing to the real-world changes communities can make to reduce light pollution.

Some suburban Chicago communities, including Glen Ellyn, are joining the effort. The Glen Ellyn Park District now has softball fields at Ackerman Park certified in 2023 by DarkSky International as complying with requirements for controlling outdoor light pollution. Nate Troia, superintendent of planning and natural areas at the district, told Go Green Glen Ellyn that the park district intentionally installed dark-sky compliant lighting.

“This means there is light only where needed, and the lighting is completely shielded,” he says. “It’s directed down, where it needs to be. The lights are more amber and the brightness is less.”

People can help curb light pollution at home in various ways, such as avoiding blue-violet light bulbs outdoors at night, which increase glare and reach far into the sky. Instead, filtered LED lights that emit fewer blue light waves are recommended. Flashlights with warm-colored lights that appear red rather than bright white also help reduce light pollution at night.

For more tips, visit DarkSky.org/resources/guides-and-how-tos/lighting-principles.

Sheryl DeVore has written six books on science, health and nature, as well as nature, health and environment stories for national and regional publications. She is co-author of an upcoming book, Birds of the Midwest, to be published by Timber Press. Learn more at SherylDeVore.WordPress.com.