Time-lapse artists and filmmakers Gavin Heffernan and Harun Mehmedinović have spent the last three years traveling through North America and documenting the increasing impact of light pollution on our ability to see the dark sky. Their resulting project, "SKYGLOW" is a gorgeous hard-cover book and video series named after the term for the level brightness of the night sky as a result of light pollution. (Watch the video trailer above.)

After a successful Kickstarter campaign, the duo took their cameras to incredible locations like Hawaii's Kīlauea volcano and Alberta, Canada, to see the northern lights. The result of their efforts "takes viewers on a visual journey through time, exploring our civilization’s evolving relationship with light and the night sky through the ages," according to the authors.

Star trails glimmer over a geyser at Yellowstone National Park.
Star trails glimmer over a geyser at Yellowstone National Park. (Photo: Harun Mehmedinovic)

During their 150,000-mile trip, they visited Yellowstone National Park and produced a day-to-night tour of the geothermal landscape, with time-lapse images showing the path of stars above a scene free of light-polluting streetlights, cars and buildings.

They wanted to highlight the importance of our national parks, and filmed not only at Yellowstone, but also at Shenandoah, Yosemite, Acadia, Death Valley and beyond.

Star trails over the New River Gorge.
Star trails over the New River Gorge. (Photo: Harun Mehmedinovic)

At New River Gorge in southern West Virginia, America's oldest river valley, they filmed the sky and seasons changing through the lens of the New River Gorge Bridge. Though the bridge is one of the region's most photographed landmarks, it's safe to say no one else has captured it quite like Heffernan and Mehmedinović.

Landscape from the Pinnacle time-lapse
Landscape from the 'Pinnacle' time-lapse video of the Southwest U.S. (Photo: Gavin Heffernan/Harun Mehmedinovic/BBC Earth)

In 2015, in collaboration with the BBC, they set their sights on desert landmarks the Southwest, hitting up Arizona's Monument Valley and California's Trona Pinnacles and Red Rock Canyon for unimpeded views of the night sky. Rocker Mick Jagger liked these star-scapes so much that he used them as a backdrop on a Rolling Stones tour.

A dark sky scene from timelapse artists and filmmakers Gavin Heffernan and Harun Mehmedinović as part of their new book, "Skyglow."
A dark sky scene from time-lapse artists and filmmakers Gavin Heffernan and Harun Mehmedinović as part of their new book, 'Skyglow.' (Photo: Gavin Heffernan and Harun Mehmedinović)

But the most recent piece of the "SKYGLOW" project is the 192-page photobook (edited down from the 500,000 pics they snapped), which "explores the history and mythology of celestial observation and the proliferation of electrical outdoor lighting that spurred the rise of the phenomena known as light pollution," according to a press release.

This map shows light pollution in the United States.
This map shows light pollution in the United States. (Photo: Gavin Heffernan and Harun Mehmedinović)

Eighty percent of the world lives under light-polluted skies, the filmmakers say, and that brightness has an effect on all living things. The map above shows that nearly half of the United States has an obstructed view of the night sky, and the map below shows how widespread light pollution in the U.S. is predicted to be by 2025.

This series of maps shows how light pollution has increased in the U.S. since the 1950s and how it's projected to affect the country by 2025.
(Photo: Gavin Heffernan and Harun Mehmedinović)

Light pollution affects human health and animal migratory patterns, obstructs astronomy research and leads to over $2 billion in lost energy every year in America, according to the project.

Scale of light pollution
'Artificial day' is when buildings, cars and streetlights produce so much light that the night sky doesn't even look that dark. (Photo: Gavin Heffernan and Harun Mehmedinović)

This light pollution scale shows the Bortle Scale — a nine-level numeric measure of the night sky’s brightness in a particular location. "It quantifies the astronomical visibility of celestial objects and the interference caused by light pollution. John E. Bortle created the scale and published it in the February 2001 edition of Sky & Telescope magazine to help amateur astronomers evaluate and compare the darkness of observing sites," according to the "SKYGLOW" website.

Completed in collaboration with the International Dark Sky Association (IDA), "SKYGLOW" also explores official “dark-sky” sanctuaries, like the area around the famous Mauna Kea Observatories in Hawaii, seen in the video above.

"The sky quality here at 14,000 feet was probably some of best we've ever seen. You can even see the faint glow of the Halemaʻu Crater from the active Kīlauea Volcano," Heffernan says.

'SKYGLOW' project filming the Northern Lights in Alberta, Canada.
'SKYGLOW' project filming the Northern Lights in Alberta, Canada. (Photo: Gavin Heffernan and Harun Mehmedinović)

Heffernan and Mehmedinović's work shows us what we're missing when we surround ourselves with light at night, whether from phone screens in our bedroom or the city surrounding us.

Carhenge, which is near Alliance, Nebraska, makes an appearance in 'SKYGLOW.'
Carhenge, which is near Alliance, Nebraska, makes an appearance in 'SKYGLOW.' (Photo: Gavin Heffernan and Harun Mehmedinović)

The good news is that light pollution can be reduced more easily than other kinds of pollution. "SKYGLOW" quotes this National Geographic story, which says: "Of all the pollution we face, light pollution is perhaps the most easily remedied. Simple changes in lighting design and installation yield immediate changes in the amount of light spilled into the atmosphere and, often, immediate energy savings."