Staring up at the night sky in northern Arizona as a child, John Barentine saw something unexpected: thousands of stars.
An amateur astronomer living in a city, Barentine was used to pointing his telescope up and seeing dozens of stars. On a family trip to Flagstaff, Barentine saw something more as he marveled at the vast Milky Way blanketing the sky. Thousands of stars. Planets. Galaxies.
“I had this revelation,” Barentine said. “It’s there every night, but there was something in the way.”
That “something” is new, at least as far as human history goes: artificial light.
Through much of human history, our ancestors looked up at a night sky filled with stars that set planting patterns and helped lead them across continents. We’ve since filled that night sky with artificial light, brightening our immediate surroundings and dimming the stars above. New York City residents can live their entire lives seeing fewer than a dozen of the brightest stars and planets. Most people living east of the Mississippi River will never see the Milky Way in all its sparkling glory
