Flagstaff officials are experimenting with different types of lightbulbs in streetlights in hopes of finding one that will preserve the town's starry night skies.
KNAU reports the city's planners and engineers, as part of the "Street Lighting for Dark Skies" experiment, have teamed up with astronomers and installed five different types of light-emitting diode, or LED, lights in neighborhoods around town.
The lights are shielded so they beam down onto streets and sidewalks, not up into the sky, protecting the night sky from unwanted glare.
The results of the experiment will help planners replace Flagstaff's 3,000-plus lightbulbs. The goal is to protect dark skies for astronomers at nearby observatories, and for those who simply enjoy star-filled skies.
Flagstaff is the world's first International Dark Sky City, passing its first ordinance to combat light pollution in 1958.