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Scientists Change Light Bulbs At Truman State To Darken The Night Skies

A NASA satellite image of light pollution in North America in 2016.
Joshua Stevens | NASA Earth Observatory
Light pollution is expected to worsen in the coming years. Researchers like Vayujeet Gokhale, physics professor at Truman State University, are trying to slow that by persuading cities and state parks to change how they light outdoor areas.

When students and faculty at Truman State University come back for the fall semester, they might notice more stars in the sky. 

After four years of research on how artificial light brightens the night sky, scientists are planning to change lighting on campus to direct light away from the sky. That could limit light pollution, which prevents people from seeing stars and galaxies, and also can disrupt sleep patterns.

NASA satellite imagery also has shown that light pollution around the world has increased over time, and scientists predict that it could get worse in the future. There are nebulae and other objects in the sky that aren’t easy to observe anymore, said Vayujeet Gokhale, a physics professor at Truman State. 

“In really dark skies, you can see the Andromeda Galaxy with your naked eye, and I doubt in any of the cities or even small towns now you can see that at all,” Gokhale said. 

Gokhale presented his research on light pollution at the 234th annual meeting of the American Astronomical Society this month in St. Louis. He and his students have measured sky brightness with meters installed in various locations in the Kirksville area. They’ve also analyzed weather data collected at the university’s observatory to discover that cloud cover can greatly affect brightness in the sky. 

Truman State gave Gokhale a $10,000 grant to install shields on 60 outdoor light fixtures, which will direct light to the ground and away from the sky. Researchers already have installed more than 20 shields on campus. They also will replace blue- and white-colored bulbs with bulbs that emit warmer colors, like yellow and red. Scientists have purchased shields from Lens Masters, a St. Louis-based company

Many studies have shown that artificial lighting has altered behaviors for many animals, such as causing birds to sing earlier in the morning. Gokhale also expects that students could become more well-rested. There have been anecdotal reports that the lighting on campus shines into dorms and make it difficult for some students to sleep, he said. 

Eventually, Gokhale hopes to expand his efforts to reduce light pollution across Missouri. 

Gokhale is also working with the newly formed Missouri chapter of the International Dark-Sky Association to measure light pollution in St. Louis, Columbia, Kansas City and other urban areas of the state. 

Having light pollution data would help identify truly dark areas of Missouri, said Don Ficken, who runs Missouri’s International Dark-Sky Association chapter. 

“What places are really dark, and what places are not? As an astronomer, I might want to go out and look at some stars, but right now I might have to drive four hours to get stars,” Ficken said. 

Ficken is planning to create a list of state parks that are dark-sky friendly. Astro-tourism, involving people seeking out dark areas for star gazing, has also grown, and Missouri could benefit from that if the state reduced its light pollution, he said. 

Some states, like Arizona and New York, have laws that limit artificial lighting. Gokhale has done research in Flagstaff, Arizona, where there are zoning codes that restrict outdoor lighting

“Human beings have evolved and grown up with these [night skies] for millennia. And we owe it to ourselves, and we certainly owe it to future generations, that they should not be deprived of that beauty,” Gokhale said.

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Eli is the science and environment reporter at St. Louis Public Radio.