This image is a 360-degree panorama, composed of some 104 images taken by Dan Duriscoe on the evening of November 19, 2003 from the top of Emory Peak in Big Bend National Park. Domes of light eminate from the Basin as well as from cities up to 300 miles away, intruding on the otherwise dark night sky. Still, after his visit (close to the time of the new moon), Dan Duriscoe, from the National Park Service's Night Sky Team, rates Big Bend National Park "among the top 3 [national parks] for absence of human light pollution in the 48 states."
by Marlys Hersey
“See how everything looks kind of purple?”
I don’t. I want to see the lavender of the land at twilight, but I am a novice at this. I might call this after-twilight-but-before full-on-night “dark dusk.” This is a grey area of the already grey area time of day, and as we hike up the last rocky stretch of the trail to Emory Peak, I see only shades of grey.
“I don’t know, maybe I’m crazy,” Duriscoe says. “I’ve been trying to capture this on film for years, no success. The ground looks light purple to me right after sunset.”
He should know.
After all, this is Dan Duriscoe, a physical scientist who’s part of a “Night Sky Team” of researchers instigated by the National Park Service to monitor the night skies above national parks throughout the lower 48 states. As such, Duriscoe spends a lot of his working hours outside at night. On the moonless nights. Staring at the heavens. And photographing them.
Duriscoe has spent a lot of his non-working hours walking around at night, too — for fun. Duriscoe likes this night world and its umbrella of darkness and astronomical phenomena so much that earlier this year, he resigned from his full-time, “permanent” job as Ecologist at Sequoia National Park in California to work on this project for two years.
But it’s not all just standing around staring at the stars and taking pretty photos. If “Night Sky Team” sounds like a group of superheroes, so be it. They earn it. Dan Duriscoe, Angie Richman, and Chad Moore comprise this gang of three; individually, they to far reaches of the national park system, lugging heaps of heavy, complicated, still finicky equipment out to the remotest spots they can feasibly reach, on the darkest nights of the month, and take photographs of the night sky, documenting the darkness over our national treasures — or lack thereof, due to artificial light encroaching on it (what Duriscoe calls “light trespass” in superhero speak.)
The team uses a host of specialized (and expensive) photometry equipment to collect from each place “a whole suite of visual data,” the most grandiose of which is a photograph of the entire sky — at 7 million pixels.
To take such photos requires a lot: a Celestron X-Star V telescope, a highly sensitive camera (replete with cooling system to get the camera temperature down to minus-18 degrees Celsius to ensure high-quality images), a tripod, a laptop computer — and a car or RV battery to supply enough power for this ensemble to work for a mere five hours.
Once the setup is just right, all this equipment interfaces to take 104 images in 35 minutes, each image a 15-degree slice of the viewing pie above the horizon. Duriscoe and other team members then (back at their superhero headquarters in the three other national parks where they each live) with yet more computer software, merge the images to create panoramic photos that depict the 360-degree overhead.
Duriscoe is able to visit each park for only about three nights each, so he maximizes his night work to photograph from as many points as possible. Obviously, the higher the vantage point, the better chance for a 360-degree view, so when he comes to Big Bend National Park, Duriscoe can’t resist the lure of Emory Peak, the highest point in the park at 7,825 feet (2370 meters), which is also the 3rd highest peak in Texas.
Somehow Dan Duriscoe managed to make this hiking the 4.5 miles up to the peak, sitting around in the dark while the photometry happens, then spidering back down in the dark sound appealing to me, even glamorous. And he had to, because all told, that equipment weighs 75 pounds and he needs help schlepping it. So I volunteered, as did Big Bend National Park’s Wildlife Biologist and champion of a myriad of resource management issues, Raymond Skiles.
By the time we three get to the top of Emory Peak, I am chilled from my sweat-dampened clothes, and from the wind. I nestle in some rocks, marveling at Duriscoe and Skiles’ ability to move, think, and use their un-gloved, prehensile fingers to get all of the equipmentjust right, which takes just a little under an hour. And we’re lucky: nearly everything works the way it should. Just one glitch this evening. Between the weather and the high-tech equipment, there are a lot of variables, and just one out of whack can cause delays, severe frustration, bad images, or the complete thwarting of any image-taking at all.
Meantime, despite all this fiddling with equipment, Duriscoe has developed a keen eye for the spectacular beauty and subtle changes in the heavens above. “In a place like Big Bend, the sky is pretty darn dark, so you notice these effects. Like last night,” he says, referring to his first night round of night photo-imaging in Big Bend National Park, from the K-Bar group campsite, “There was a visual glow that was too bright, especially after midnight.... That illumination was undoubtedly from solar flares. And I saw Alpha Centauri rising last night. I mean, here we’re at 29.5 [latitude] here; I haven’t seen that since I was in Australia about fifteen years ago.”
Due to severe light pollution, two-thirds of people living in the U.S. can’t even see the Milky Way, that cluster of stars that forms a distinct and prominent band of light in the night sky (evident in the photo above), the effect of looking from the inside out to the edge of our own elliptical galaxy — that is, if where you’re looking from is dark enough, like the skies of the very rural West Texas. Yet it’s not just city residents who suffer this lack darkness; a 1999 study found two-thirds of 189 national parks have marked light pollution, prompting the National Park Service to create an official investigaton of the problem.
Duriscoe contends that “the preservation of the right to view the universe from America’s wilderness national parks is a duty assigned to the National Park Service under the Wilderness Act of 1964.... The view of a dark night sky can certainly be interpreted as an integral part of that [wilderness] experience, and remote wilderness parks are among the few places left where it can be seen.”
And let’s be clear: this lack of dark is a real lack. This too-brightness caused by human propensity for over-lighting (think office buildings, shopping malls, grocery stores, schools, car dealerships, stadiums, fast food restaurants, garage floodlights, the lantern from the campers in the site next to yours) means that the majority of us earthly residents have lost, to use Duriscoe’s words,“the unfettered view of the universe on a dark, clear, moonless night.” Besides that enjoyment of the sublime just because it’s there, light pollution washes out or completely erases from view some important astronomical objects.
But there is good news: light pollution is “a simple thing to fix,” says Dursicoe. Using fewer lights, lower intensity lights, and putting shields around lights are all simple ways to “keep the light where you want it.” The International Dark Sky Association, founded in 1988 by astronomers in the Southwest, maintains that “lighting that protects night skies is efficient and cost-effective.”
In Flagstaff, Arizona, this kind of lighting is not just a good idea, it’s the law. Due to a strict ordinance passed seven years ago (and enforced) the town has significantly reduced its lighting, resulting in relatively good ratings by the Night Sky Team of two national parks just outside the city limits, Walnut Canyon and Wupatki Craters.
Especially for towns near national parks, by reducing excessive lighting, the town protects tourism, lowers electric bills, and conserves resources, slowing or preventing further environmental degradation.
Dark Skies make sense.
But of course, you know that. You live here, or at least visit here, partly because of the dark skies.
Duriscoe comes to the Science and Resource Management building at Big Bend National Park to deliver the best news of all. It’s mid-afternoon the day after he and Skiles and I hiked up Emory Peak to take photos. “Well, it seems that Emory was the way to go. These images are great.” He shows them to me, and I feel the tiredness, slight dehydration, and soreness in my legs ebbing away. The proof’s in the photos of the glorious night sky. It was worth it.
The photo confirms what I recall from the night before. Yes, the lightning in the Basin is still just a bit too much, yes there’s more light from Terlingua than I would’ve expected, and yes, it is unnerving to see light domes on the horizon which we think are from cities as far away as Chihuahua, Ojinaga/Presidio, El Paso/Juarez, and Del Rio. And there is some “extinction,” where the stars disappear close to the horizon, obscured by haze from pollution from the far reaches of Texas, Mexico, and even the Ohio Valley in the East.
Still, the image that Duriscoe has created from the 104 individual photos from our time huddled on Emory is stunning. The stars are abundant, the Milky Way and “Zodiacal Band” (the plane through the constellations in which the planets travel) are clearly visible, and the outline of the land reveals the beauty and surreal-ness of the mountains here.
“Big Bend has probably the most pristine night sky in terms of its absence of human light pollution of any park in the 48 states,” Duriscoe concludes in an email the following week. “I hope that the data we collected last week will help keep it that way.”
For more information on the Night Sky Team and some incredible images from their fieldwork, check out "The Edge of Night" by Deborah Schoch, published in the L.A. Times on October 7, 2003.
