Observatory worries as Texas oil rigs light up skies
West Texas is famed worldwide for its vast crudeoil reserves. But for over 75 years, a small patch of the Permian Basin has also been valued for its pitch-black night sky.
Those two prized natural resources have clashed in recent years as oil drilling has brightened the sky near McDonald Observatory. A collaboration between the petroleum industry and the observatory — home of North America’s largest telescope — appears to have made progress in slowing the creeping light pollution.
But there are no guarantees about the night sky’s future as Permian Basin production hits record levels and drilling inches closer to one of the darkest spots on the continent.
“Fortunately, we’re far enough away — at least for now — from most of the oil and gas activity,” said Bill Wren, special assistant to the observatory’s superintendent. “And we’re surrounded by mountains, so we don’t actually see it line-of-sight. We just see a glow on the horizon. … The sky overhead is still incredibly dark.”
To understand what was happening to their night sky, workers at the University of Texas-owned observatory started measuring the amount of artificial light in August 2015. The sky then was 14 percent brighter on average than if the region had no artificial light. By November 2018, it was 43 percent brighter.
While the increase is worrisome, it’s not a disaster. Almost all of that light is low in the sky. “Astronomers typically are not aiming their big research telescopes down in the dirt to look at objects close to the horizon,” Wren said.
For now, there’s been no measurable increase in brightness in the night sky high overhead, he said. But the overall increase in light has changed the way the observatory operates from its perch above the west Texas plains.
“For most of the history of the observatory, the brightest thing in our sky — apart from the sun and the moon — was El Paso and Juarez,” Wren said, pointing out that those cities are 160 miles away. “Now you can see that El Paso is largely swamped by the sky glow coming from the Permian.”
Telescopes and oil drilling were never designed to coexist.
Signs on the final stretch of road leading to McDonald Observatory warn against the use of headlights. And when staff members wander about in the dark, they use small lights that provide just enough illumination to guide their paths.
A few dozen miles away, 24-hour drilling operations are underway with light towers, each powerful enough to illuminate a half-dozen or more acres.
While those two worlds are now in conflict, there isn’t a fight over who wins.
After reaching out to the industry several years ago, Wren said he’s received large-
ly positive responses. Early offers of help came from Stacy Locke, president and CEO of Pioneer Energy Services in San Antonio.
Locke said he knew little about the observatory at the time but valued the night sky. At his wife’s family ranch near the west Texas town of Marathon, Locke said: “You see stars on every horizon you look at. The stars go right to the ground.”
But elsewhere, development had snuffed out sections of night sky. Locke and Wren both lament that generations of children are growing up without ever seeing a clear view of the Milky Way.
When Wren asked Locke if it was possible to make a drilling rig dark-skies compliant, he said: “We don’t really know, but we’re willing to try.”
Pioneer Energy Services gave observatory workers access to the company’s rigs. During his first visit, Wren said he noticed a rag stuffed in the mesh covering of one light. A worker told him the workaround was needed to reduce the distracting glare.
“That was the smoking gun,” Wren said. “I knew we could do better than a rag.”
Working with Pioneer Energy Services and Apache Corp., Wren has been able to assemble guidelines for lighting drilling rigs that are beneficial to both sides.
The overall ideas were simple. Shield the lights and point them downward to reduce glare. Also, switch from