Rediscovering the Brilliance of the Stars
By GARY ANDREW POOLE
THIS is the darkest sky I have ever seen," Chad Moore said. At one o'clock in the morning, with no moon above, he was looking up from Bryce Point, a narrow Utah bluff with a thousand-foot drop-off on each side. In daylight, hundreds of the orange-colored limestone spires of Bryce Canyon National Park would have been visible below; on this night they were awash in darkness. But there was no danger that Mr. Moore might stumble off the edge of the rock in the dark. Against the deep, true black of this darkest sky glowed the brilliant light of 14,000 stars.
The Milky Way, visible on the western horizon, had thick sections and thin sections, dark veins and light veins. Jupiter, straight overhead, was so bright that it cast shadows of the nearby ponderosa and bristlecone pines. "Most people have never seen what we are witnessing," said Mr. Moore. He wishes more people could.
Mr. Moore, 32, and Dan Duriscoe, 46, working together in the 17-degree March cold, were on Bryce Point taking photographs of the sky with a research-grade digital camera. They are two-thirds of the National Park Service's night sky team, set up at Mr. Moore's initiative to help standardize methods for measuring and monitoring night skies; to count. Concerned about the growing intrusions of artificial light on even the most remote night-sky vistas, he brought the team together in the late 1990's and did much of the work to develop it in his spare time. After reading about some of Mr. Duriscoe's research on light pollution, Mr. Moore recruited him to be the technical leader.
The project fits into the National Park Service's mission to conserve "the scenery" and elements of the natural world for "the enjoyment of future generations," following policy set in the Organic Act of 1916. Each team member spends a month or two a year - a day here, a day there - on this work.
On this night they were searching for the darkest place in the United States - the farthest, that is, from the artificial light of cities, towns and even farms that obscures the stars. On Bryce Point, at an elevation of 8,300 feet, conditions were perfect: clear, dry, cold weather and a new moon.
The thousands of Americans who are dark-sky fanatics want to see stars, not light bulbs. They are drawn by the beauty and mystery of a nighttime sky once familiar and now rare, the star view that people relied on - for all the millennia before electric lights - to guide their journeys, that inspired them in art and science and caused them to ask themselves about their place in the universe. If Robert Frost were alive today, living in Massachusetts, "The Milky Way Is a Cowpath" might never be written; he might not be able to see the Milky Way.
To see a truly dark night sky - with 11,000 visible stars rather than the 500 or so visible in New York - visit remote national parks around a new moon, at a high altitude and in clear, cold weather. (Summer months are not ideal for hard-core stargazers because of moisture in the air, but for the casual observer the summer night sky is still stunning.)
Light pollution, as people who love the stars call the artificial lights that hide them, is increasing everywhere. The growth of Palm Springs has sent light into Joshua Tree National Park in California. Lights from the greater Denver area bathe Rocky Mountain National Park. Campers at Arches National Park can see the lights of Grand Junction, Colo., about 60 miles away. Las Vegas and its bedroom communities illuminate sections of Death Valley in California.
Bryce, too, has what astronomers call light trespass.
Before Mr. Moore and Mr. Duriscoe took their photographs atop Bryce Point, they ate dinner at Ruby's Inn, a motel and restaurant just outside the park entrance. In the parking lot, Mr. Duriscoe complained about the lighting system, peach-colored sodium lights pointing skyward. A Chevron station across the street was another light polluter, with bright bulbs. "Causes skyglow," said Mr. Duriscoe, who is easily frustrated by inefficient lighting because, he says, it is fixable and serves no one's interest. "It is a waste of energy and an insult to the wilderness," he said. "You'll see."
From Bryce Point, his meaning became clear. Ruby's looked like a small city, its lights reaching high into the northern sky, diminishing the human eye's ability to see the stars above it. To the east, the town of Tropic (population 518) also looked particularly loud with light. If the lights were horizontally shielded, Mr. Duriscoe said, they would not be so distracting. "I am not saying we should turn off the lights down there," he said, "but it is an insult to the scene."
Jean Seiler, Ruby's marketing director, said it had replaced many of its old lights with "night-sky-friendly lighting" and planned to continue the process. Mr. Seiler, who is also the mayor of Tropic, said he wanted to reduce light pollution in another way, too, by having an annual summer rodeo start an hour earlier to minimize its use of artificial light.
Despite Tropic and Ruby's, most of the sky over Bryce Point was at its blackest black. Mr. Moore's description of it as the darkest he had ever seen was not mere guesswork; he determines darkness through a measure called the "limiting magnitude." A magnitude of seven equals a pristine sky while four or less equals an urban sky. The method is to count the stars that are visible at the moment in a well-defined patch of sky (a corner of Gemini, for example) and compare them with a chart derived from well-established star maps. The limiting magnitude at Bryce Point that night was 7.3.
WELL into the early morning hours, Mr. Moore and Mr. Duriscoe stayed at Bryce Point, drinking coffee and hot cocoa. They lingered after they had finished taking photographs, talking about star magnitude and rocking back and forth trying to keep warm. "If the night sky is not a part of your life," Mr. Duriscoe said, shivering, "you've lost something."
Astronomy is popular nationwide, but particularly in the West, where it is almost a rite of passage for children to go camping with their families, curl into sleeping bags and fall asleep staring at the Milky Way, Orion's belt and the Big Dipper.
At Bryce, 400 people a month come to stargaze with professional astronomers and go on guided night hikes, making the night-sky program the most popular in the park, according to Kevin N. Poe, a park ranger who is working with Ruby's Inn to try to find alternatives to its bright lights. Chaco Canyon in Nageezi, N.M., has astronomy programs centered around its ancient ruins, which align with the stars.
Apart from the parks and their programs, astronomy clubs hold annual star parties where people gather to look at the night sky. The Texas Star Party draws 700 rabid amateur astronomers every year to its conference in Fort Davis, Tex., 100 miles north of Big Bend National Park.
Serving on the sky team is a part-time job. Mr. Moore, undyingly chipper at every hour, is a physical scientist at Pinnacles National Monument in California. He is married to a wildlife biologist; they have a 3-year-old daughter, Savanna, named after their favorite ecosystem. Mr. Duriscoe, who has a bushy mustache and curly gray-flecked hair, is an ecologist for Sequoia and Kings Canyon National Parks. He is the type of night owl who enjoys hiking in the dark without a flashlight. The third member of the team is Angela M. Richman, an archaeo-astronomer at Pecos National Historical Park in New Mexico who was not along for this trip.
They collect data and use spare moments to apply for grants, advise parks on lighting and work on technical issues. On moonless nights, they chase the weather, looking for clear skies at national parks.
Two days after working at Bryce Canyon, Mr. Moore and Mr. Duriscoe went to nearby Zion National Park, the red-rock Utah park often called a hanging garden of rock, but they found an overcast sky and snow. So they raced six hours to Death Valley National Park, where they had a late dinner and then drove to Dante's View. They worked there until 2:30 a.m., taking sky brightness readings - 114 digital photographs of the entire night sky. With a polar-fleece-penetrating wind, it was incredibly cold on the plateau. There was an odd sense of floating over the earth.
Because of moisture in the air and the low altitude, Dante's View was not as dark as Bryce had been a few days before, but the 11,000 or so visible stars were stunning. Racing against a brighter moon, they took one more reading the next evening on the rim of the Ubehebe Crater in Death Valley. It was a warm 50 degrees. With Mr. Duriscoe's wife, Cindy, they sat on the edge of the crater and had a picnic. They took an after-dinner night stroll. Then they took their readings. The crater is at the northern end of Death Valley, so the lights of Las Vegas, 140 miles away, were visible but not overly pronounced to the naked eye. The setting was about as isolated as it is possible to be in the lower 48 states, and the heavens were dense with stars, a window into the infinite.
Mr. Moore and Mr. Duriscoe had experienced the sky on some of the darkest nights of the year, in some of the darkest spots in the world. The following day, they drove back to their respective parks to analyze their data, and plan the next journey to darkness.
Most Americans in search of stars head for national parks, where there are stretches of wilderness far from the light pollution of cities. Based on computer models reviewed by the National Park Services Night Sky Team, these are the 10 darkest in the 48 contiguous states, starting with the darkest.
1. CAPITOL REEF, UTAH Red-rock expanses far from sizable human habitations.
2. BIG BEND, TEXAS An isolated corner of the United States that is a favorite of stargazers.
3. BRYCE CANYON, UTAH With high altitude and clear air, optimal for very dark nights.
4. DEATH VALLEY, CALIFORNIA Spectacular star vistas in the northern portion of the park, farthest from Las Vegas and Los Angeles.
5. GRAND CANYON AND GLEN CANYON, ARIZONA Good viewing in areas away from small towns and tourist facilities.
6. CANYONLANDS, UTAH Darkness diluted only by a few nearby towns threatening the night sky.
7. YELLOWSTONE, WYOMING National Park Service facility lights are being retrofitted to improve the night sky.
8. GREAT BASIN, NEVADA Distant glows of Salt Lake City and Las Vegas.
9. CAPE HATTERAS, NORTH CAROLINA Probably the darkest location on the Eastern Seaboard.
10. CRATER LAKE, OREGON Perhaps the darkest part of the Cascade Mountains.