​Oh, like what if a satellite breaks into pieces and they hit other satellites, leading to a cascade of destruction that breaks everything in orbit and leaves the globe perpetually surrounded by flying space trash that cannot be bypassed, with no proven way to remove it? Yes, maybe. It's called the Kessler syndrome, and astronomers have been worried about it happening for decades. It's always been a theory. But now the world is in an era where companies are trying to pump thousands—even a million—satellites into orbit

“That is literally the thing that keeps me awake at night,” says John Barentine, an astronomer and founder of Dark Sky Consulting in Tucson, Arizona. “The sense that we are teetering on the edge of catastrophe, and most people don't understand that.”

Read more: https://www.wired.com/story/why-amazon-is-buying-globalstar-and-what-it-means-for-your-iphone/

John Barentine (Dark Sky Consulting), who was not involved in the Nature study, emphasizes that despite patches of dimming lights, the world is brightening on large spatial scales. That has implications for those interested in protecting dark, starry skies.

“Since artificial light at night is a pollutant that effortlessly crosses jurisdictional boundaries,” Barentine says, “village-by-village light pollution abatement plans are very limited in what they can achieve beyond hyperlocal effects.”

“[A] key take-away is that in order to be successful in reducing light pollution, we have to organize on larger spatial scales,” he adds, offering the EU Nature Restoration Regulation as a point of reference. “An increasingly top-down approach is called for.”

Read more: ​https://skyandtelescope.org/astronomy-news/light-pollution-is-increasingly-volatile-around-the-world/