Photographs from McDonald Observatory by Stephen Hummel

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The Big Bend region is home to one of the largest protected night sky areas in the United States. In October, the McDonald Observatory will submit an application to the International Dark Sky Association. If approved, the Dark Sky Reserve in the Big Bend region of Far West Texas and Northern Mexico will encompass over 9.8 million acres and will be one of the largest reserves of its kind in the world.

Stephen Hummel is a Dark Skies Specialist at the McDonald Observatory. He promotes the use of better outdoor lighting to protect the night sky in West Texas, what he calls “an oasis of darkness”. According to the Dark Skies Initiative, light pollution can harm ecology, astronomy, and wastes money and energy. Hummel says the night sky is a “source of inspiration and motivation. It’s a shame that most Americans can’t see the sky like we can in West Texas.” In fact, over 80 percent of Americans cannot see the Milky Way from where they live. For those of us who relish walking out our back doors into a fairy land of stars and galaxies, the thought of eliminating our night sky incenses us. Thankfully, people like Hummel are working daily to preserve our view.

Hummel’s photos of sprites, electrical phenomena occurring high above thunderstorms, are illustrative of the importance of dark skies. Hummel refers to them as “the most awe-inspiring things he’s ever seen” despite having looked through a giant telescope to see “the bending of space and time itself”. Sprites are triggered by powerful lightning strikes interacting with the upper atmosphere. To the naked eye, sprites are usually white, but they can sometimes appear red due to fluorescing nitrogen. To capture these elusive events on camera, Hummel looks for thunderstorms around 75 to 400 miles away, and aims his camera above them. Then he waits. On any given night, he might see anywhere from six to fifty sprites. Sprites are only visible in dark conditions, usually on moonless nights unsullied by light pollution. West Texas is one of the few places left where sprites can be seen on a regular basis. Without the dark skies of the Big Bend area, Hummel would be unable to capture such quality photographs of these still-mysterious phenomena, which are over 30 miles in length and height.

There is a continued effort to preserve the dark skies in the Big Bend Region, often with collaboration between McDonald Observatory and the state and national parks. Stephen Hummel and Bill Wren are the main players in this initiative via McDonald Observatory, whereas Amber Harrison works on the park side. As an interpretive ranger for Big Bend Ranch State Park, Harrison’s job is to submit potential dark sky sanctuaries for a place on the International Dark Skies Association’s map, which encourages stargazers from across the world to visit the area. The process to gain this prestigious recognition can be arduous, consisting of collecting both quantitative and qualitative data regarding the light quality across the would-be preserve for several seasons, forming educational outreach programs, and showing the ability to continue such outreach in perpetuity. Each year, the IDA must be updated with fresh data and proof of outreach. Hummel and Wren are the “science guys”, who use complex tools such as all-sky photometry and fancy gadgets to determine how much natural and artificial light is in the area. Then, Harrison, Wren, and/or Hummel take the data and write the application. One of this team’s more recent accomplishments is in preserving the Black Gap Wildlife Management Area, located near Terlingua/Study Butte, which was deemed a Dark Sky Sanctuary in August 2021.

Though sanctuaries are helpful, there are other issues that have an impact on light quality. Wren has worked with oil and gas operators in the Permian Basin, one of the greatest contributors to light pollution in this region, to reduce light quality. These efforts have resulted in data showing the reduction of artificial light in the area the past two years. This effort seems to prove that outreach and education are effective on a grand scale. “It’s not about having no lights. It’s about having the right lights,” says Harrison.

So what can we, as citizens, do to preserve our dark skies? First, we can shield the outdoor lights we use from casting into the sky. We can also use amber-colored lighting instead of the bright whites or blues often found in floodlights. We can also turn off unused lights, setting timers for when we know they will not be needed. Harrison sees the data showing education efforts are effective in the community and is working with Hummel and Wren to synthesize this information for the public to show the community how their actions have directly affected the night sky and thus our ability to walk directly into our fairy lands each night.

As Harrison puts it, “Our human heritage is tied to the night sky; our cycles and growth are tied to the night sky. We are losing that.” Just as Harrison looks up and sees an entire history of humanity, so does Hummel look up and sees “billions of years of history”. What do you see in those dark skies?