Though Fort Davis is located just sixty miles from the US-Mexico border, mild mountain summers have earned it the title of the coolest town in Texas. It’s in the heart of a sky island, a desert mountain range where migrating animals — and tourists seeking reprieve from the heat — can rest awhile among juniper trees and ponderosa pines.
Fort Davis is also on the cutting edge of serious science: tucked high into the mountains, just a few miles from the sleepy main street with its antique shops and quaint country courthouse, is the McDonald Observatory, a world-class center for astronomical research.
Visitors to the observatory can tour one of the largest telescopes in the world — the Hobby Eberly Telescope, which has its sights set on the edge of the universe. “We know the universe is expanding, and expanding at an accelerated rate,” McDonald Observatory Dark Skies Initiative Coordinator Stephen Hummel explains. “But we don’t know what’s causing it.”
Scientists call whatever is causing the universe to expand “dark energy.” To study the phenomenon, scientists need the sky to be — as the name implies — very, very dark. “The dark energy experiment is the most vulnerable to light pollution,” Hummel says.
That’s because the galaxies the Hobby Eberly Telescope is tracking are so far away they emit very little light, which scientists measure in photons. Some register with only a handful of photons. In contrast, a lightbulb emits photons by the quintillions — a number with 18 zeros in it.
On a map of Texas after sunset, the region around the observatory is a dark hole in a bright spiderweb connecting the state’s major cities. That darkness is partly mandated by law: local towns have been required to adopt municipal lighting that minimizes light pollution. The other part, which Hummel is currently leading, involves convincing private citizens, school districts and businesses to get on board, too.
While the majority of his work is concentrated in nearby Presidio, Brewster and Jeff Davis Counties, he’s been trying to expand north — into the bright lights of oil and gas country.
Around an hour’s drive away from the observatory, the night sky is sometimes orange. “You look up and you can’t see anything,” says Chris Gafford, safety manager at Callon Petroleum. “When all those flares are going it’s like daylight out there.”
Gafford travels between the company’s facilities to make sure they’re safe for employees. This is no small feat in the oil and gas industry, which runs on fire and pressure and things that can explode.
Callon Petroleum’s properties aren’t staffed 24/7, but have to stay lit up all night in case something goes wrong. That’s where Hummel comes in: he and Gafford have been working together to make sure that the company’s night lights emit as little pollution as possible.
These facilities are located in the Permian Basin, an area of West Texas that produces nearly half of the country’s oil. By some accounts, the Permian Basin is the largest producer of greenhouse gases in the world.
In an act of great cosmic irony, the Permian Basin is adjacent to the Big Bend, which contains some of the most pristine wilderness anywhere in the country. In a ranking of the states by how much public land they hold, Texas scores a miserable number 45 — over 80 percent of which is located in the Big Bend region.
On top of unparalleled camping and hiking and boating, the night sky is a huge point of local pride. In 2022, after teaming up with three protected areas in Mexico, the Big Bend became the largest International Dark Sky reserve in the world.