Why should we have to go to national parks to see what the ancients saw?
by Allen Best
MONTROSE, Colo. – On a night in late June, about 100 people gathered in an amphitheater located on the south rim of the Black Canyon of the Gunnison River, but not to talk about the nearby chasm.
The canyon, the center piece of a national park, cuts through Precambrian rock in western Colorado that is nearly two billion years old. It’s 2,722 feet deep at its maximum. One rock face, Painted Wall, a magnet to climbers, is 2,250 feet high, or more than three times higher than the tallest building in downtown Denver. The narrowness of the chasm results in some portions of the canyon floor getting an average of only 33 minutes of sunshine per day.
But this crowd was drawn to look up to study the night sky. The International Dark-Sky Association says that nearly two-thirds of the world’s people can no longer see the Milky Way, the galaxy in which the Earth is located. People in cities have it worst, unable to see light years in transit because of lights close at hand, not even seconds away.
Even in more rural areas, the sparkle of a night sky has eroded as cheap outdoor lighting has too often been thoughtlessly deployed with the industrial scale of a corporate warehouse. The moderns have discarded as unimportant what enchanted the ancients.
As a few stars emerged in the evening gloom over the nearby West Elk Mountains, a tall woman in her 20s named Bettymaya Foott took the microphone. She had a PowerPoint, virtually the only light, to document the decline during the lifetimes of most baby boomers.
In the late 1950s, patches of green indicated artificial night sky brightness due to light pollution mostly confined to coastal areas and along the Great Lakes. By 1997, nearly all of the United States east of the Mississippi River was green with blotches of red and orange, indicating even higher levels of light pollution.
In a paper released in 2001, researchers from Italy and the United States projected only a few areas of dark sky remaining by 2025. Those few areas, they said, would lie mostly between the Great Plains and the two defining mountain ranges of the West coast, the Sierra Nevada and the Cascades.
As glow on the western horizon receded, Foott began describing various kinds of light pollution: sky glow, such as you would see over Denver or Los Angeles; glare such as you might experience when a neighbor has a bright light mounted on a garage that blinds you; and then light trespass, such as that neighbor’s light flooding your backyard.
Light pollution is not inevitable, she said. Rather, pollution is a matter of poor design, such as unshielded lights or lights aimed upward instead of to the ground, where the light is useful. Too, many people erect lights in the mistaken belief that more light flooding a landscape delivers greater security. Less lighting can actually be safer. Placement matters entirely. Foott showed how glare from a lighting fixture mounted on a building’s exterior made it impossible to see the man that was in plain sight once the light was shielded.
By then, the eastern sky over Crested Butte, 40 miles away (but 90 miles by car) was inky dark as Foott laid out the medical case for dark skies. Light pollution has been linked to depression, insomnia, cardiovascular disease, diabetes, obesity, and cancer, she said. A 2016 report by the American Medical Association recommended fully shielding all light fixtures and only using lighting at color temperatures of 3,000 Kelvin or less.
Lights higher on the Kelvin scale produce icy white and blue lights, unlike the warmer yellows and golds of incandescent and high-pressure sodium lights. The latter are still commonly found at street corners. New, LED lights are vastly more energy efficient, but early, high-Kelvin types produce the more intense, icy white color.
Much of that more abundant light is wasted. Foott said a third of all lighting gets wasted, because it is directed upward. That’s $3 billion of waste annually and the production of 21 million tons of carbon dioxide.
Foott is new to the lecture circuit. Her presentation was notable for its lack of polish and abundance of enthusiasm. She grew up in Moab, Utah, a desert town located about three hours by highway from Black Canyon. While earning a degree at the University of Utah in Salt Lake City, she watched a film called “The Dark City.” Seeing it, a light went on in her mind. Before then, she had never paused to puzzle through why she could see stars in Moab but not Salt Lake City.
But even the glow of Moab can be seen from the nearby state and national parks, including Arches and Canyonlands. Now, working with the University of Utah’s new Consortium of Dark Skies Studies, she is directing an effort to preserve skies in the Colorado Plateau. The plateau is located only partly in Colorado. Think instead of Zion, Bryce, and other national parks, and Lake Powell, too.
The consortium has worked with city and county officials in Moab, Kanab, and Helper, all in Utah, as well as Page, Ariz., located near the Grand Canyon, to enact ordinances to restrict the erosion of the night sky. Moab, she said, this year has integrated dark skies education into its annual arts festival. Flagstaff, Ariz., which has two observatories and one of the nation’s best lighting ordinances, has an annual dark sky-themed arts show, called NightVisions.
If the Colorado Plateau has large expanses of dark, it has glittering metropolises, too. Lights of Las Vegas can be detected up to 200 miles away.
Concluding her presentation, Foott asked her audience to use artificial light sparingly, if at all, as they made their way to the half-dozen telescopes that had been set up adjacent to the nearby campground.
As the sun sets, she explained, we go through a process called dark adaptation where the eye gradually becomes sensitive to less and less light. The entire process takes about 45 minutes. An artificial light can eliminate that adaptation.
The visitors made their way in the dark, most without lights, to a parking lot where eight large telescopes had been set up to see the rings of Saturn and the moons of Jupiter. Nobody had a smartphone out to check Facebook postings. Instead, they marveled at what the Milky Way and the other sparkling objects in the sky said to them, just as people of antiquity had.