Where Dark Skies Draw Star-Gazers, Wildfire Smoke Spoils the View

• Aug. 13, 2021Updated 1:50 p.m. ET

GREAT SAND DUNES NATIONAL PARK — The high, lonesome dunes that run up against the Rocky Mountains at 7,500 feet above sea level in southern Colorado are a long, long drive from the closest streetlight, and after dusk, the almost untainted darkness and thin, dry air reveals just how bright the night sky can actually be.

Stars burn fierce enough to cast shadows on the sand. The core of the Milky Way is a blazing arch, soaring over the Continental Divide. Like other remote parts of the West, the dunes are usually an ideal spot to catch the annual summer light show put on by the Perseid meteor shower, which peaks this week.

But not so much this year. The West is on fire, the sky is full of smoke, and on many nights, even in the darkest corners of the West, the meteors that once slashed across the heavens with fiery intensity only pulse faintly through the murk — if they can be seen at all.

“It’s been horrible — I’ve never seen it so smoky as this year,” Bob Bohley, a volunteer astronomy ranger who has been giving evening star presentations at Great Sand Dunes National Park for nine years, said just before starting his nightly ranger talk on Thursday. “Some nights it’s been so thick that even the brightest stars were hard to make out. I would just point in the direction of a constellation and hope folks would see something.”

Great Sand Dunes is one of 27 national parks and monuments, nearly all in the intermountain West, that are designated as dark-sky parks, where light pollution from cities is scant. But in recent years, the fire season — as summer is now often called — has meant that the chance for stargazing depends not just on the phase of the moon, but also on how many square miles are burning upwind.

Climate change has made wildfires more common and more intense. More than 105 large fires in the West this year have already torched a total area the size of Connecticut, sending millions of tons of fine ash into the sky. That ash can stay airborne for months, spreading a smoke screen that acts like a cataract on the night sky over thousands of miles.

Star watchers have noticed a distinct dimming as far East as Martha’s Vineyard in Massachusetts in recent weeks. With vast blazes like the Dixie Fire in California still far from contained, and a forecast of scorching weather for much of the West over the next week, the celestial view isn’t expected to improve any time soon.

To be sure, the clarity of the heavens ranks low on the list of impacts from the fires ravaging the West. Hundreds of people have lost their homes, and smoke blanketing the region has sent increasing numbers of people to the hospital.

“A natural starry sky is the embodiment of awe,” said Bettymaya Foott, a photographer of the night sky and director of engagement for the International Dark-Sky Association. “When you are faced with the infinite, it’s an incredibly humbling experience.”

Ms. Foott said she would probably miss the peak of the meteor shower this week because of persistent smoke over her home in southwestern Colorado.

Though the association has focused on preventing light pollution, she said, it is starting to realize that climate change also poses a threat to clear dark skies.

“It’s all connected,” she said. “Just as light pollution and smoke don’t respect boundaries, the consequences of how we handle climate change travel far.”

If the stars lost their luster, much of the country might not notice. NASA estimates that only about 17 percent of Americans live in dark rural places where they can see the Milky Way.

Colorado’s high terrain and arid climate have long given it a special connection to the night sky. One of the state’s official songs, “Rocky Mountain High” by John Denver, was inspired by an August night at a high mountain lake, when the singer was awakened by the dazzling starlight and had a transcendent experience watching the “raining fire” of the Perseid meteors shooting by overhead.

On Friday, a cold front is likely to push some of the smoke out of the Rockies, providing a window of clear viewing. But with major fires still burning on the West Coast, forecasters say the clarity may not last long.

For many visitors to the West’s dark-sky parks, the promise of diamond-glittered skies are a key attraction. On Thursday night, as Mr. Bohley, the ranger, prepared for the evening astronomy talk, a man from Philadelphia stopped by to say that he had timed his vacation especially to be in a dark-sky park at the peak of the Perseid shower, and asked the ranger if it was OK to stay out all night on the dunes, watching.

“Oh, yeah, we should see plenty tonight,” Mr. Bohley replied. “It looks like we’re finally catching a break.”

A stiff East wind swept down over the mountains just after sunset, driving the drifting smoke back to the West. The sky over the park grew clear — or at least clearer.

As darkness settled in, a small crowd of visitors gathered around and Mr. Bohley lifted his eyes upward, guiding them to planets and galaxies, white dwarfs and red giants.

The night sky, he told them, is not just a spectacle, but a critical piece of cultural heritage. Peering up at the stars and wondering is as ancient and universal as dance or song or music. It is a part of the essential human experience, he said

Right on cue, a meteor coursed across the sky, leaving a long, silent, silvery tail. In unison, the entire crowd sighed, “Oooooooh.”