The West Mountain Observatory’s once-dark skies are fading away.
“If there’s huge development as projected out west of Utah Lake ... it probably is the beginning of the end of usefulness of an observatory there in West Mountain,” said Mike Joner, the director of the West Mountain Observatory and a research professor of physics and astronomy at Brigham Young University.
The observatory opened in 1981, when Payson and Spanish Fork were still small towns.
“It was kind of the middle of nowhere,” Joner said.
The location was identified as the best spot within two hours of BYU to place an observatory. It was away from heavily-populated areas, an hour drive from the university and had a nice air flow that would lead to good observations.
“For astronomical purposes, we want nice, smooth airflow over wherever your site is because if you have turbulence on your site, the stars look like they’re twinkling,” Joner said.
Those views from the mountaintop have changed — both looking up, and down.
The county has seen tremendous growth for the last few decades, with the U.S. Census recording 368,536 people in 2000. Utah County had an estimated 622,213 people in 2019.
The population is expected to grow even more, reaching 1.6 million Utah County residents by 2065, according to a 2017 research brief from the Kem C. Gardner Policy Institute at the University of Utah.
Joner said he’s seen more interference from random light from Payson than anywhere else in the county.
“It hasn’t affected us greatly yet,” he said. “The skies are brighter than they were back then, for sure. We can see a light dome over Payson now that never was there.”
That light interference has the same impact on observations that the full moon has when researchers looking at faint objects. The brighter the nighttime background is, the harder it is to view the object. And those faint objects, Joner said, are usually the most interesting things to observe.
Researchers at the observatory have participated in the KELT survey, where they’ve been in on the discovery of about 20 newly-discovered exoplanets, including an extremely low-density planet that’s almost the consistency of styrofoam and another that’s the hottest planet that’s ever been discovered.
Having their own facility, Joner said, means BYU’s teams don’t have to apply for special time at other, farther away observatories. It also means they’re able to monitor celestial objects whenever they want and can participate in long-term observational campaigns.
The observatory’s western views are still dark. With nothing from the observatory to Reno, Joner said it makes the area a prime location for observation.
Vanishing dark skies can lead to other problems, according to Vellachi Ganesan, an associate instructor at the University of Utah in the city and metropolitan planning program, a project lighting designer and a member of a handful of boards and committees associated with dark skies.
“We are beings of day and night,” Ganesan said. “The relationship with light is just as important as the relationship with darkness.”
She said exposure to darkness is related to humans’ temperature and hormone regulation, which are sensitive to light.
Increased nighttime light can also impact bird migration. Ganesan said birds navigate by starlight, which means they can hit building facades or crash into lit parking lots that can look like the surface of a pond or lake at night.
There’s cultural impacts to diminishing darkness, as well.
“If we can no longer see the dark sky, then all of the stories and belief systems that relate to the night sky begin to disintegrate,” she said. “For example, many cultures see stars as ancestors or loved ones who have passed on.”
Ganesan, who grew up in Singapore, wasn’t in an area that was dark enough to see the Milky Way for the first time until she was 26.
“Utah has something that most parts of the developed world has lost,” she said. “It is something special and it is something to be preserved.”
In order to reduce light pollution, she suggests for people to check to assure they don’t have light that is shining onto a neighbor’s property, that lights should be directed downwards and shielded, for warm lighting to be used at night, and to reduce a light’s brightness.