USA Today (19 July 2018)

Artificial light is killing our view of the night sky. But we can change that.

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.

Read more: ​https://www.usatoday.com/story/news/nation/2018/07/19/artificial-light-dark-sky-park-night-sky/773451002/