Satellites are changing the night sky as we know it

Expect the night sky to start changing fast. One day soon, the stars we can see from Earth could be outnumbered by a vast swarm of satellites.

While many people today live under the murk of light pollution, we can at least still travel to a glittering night sky in the mountains, the desert, or at sea. But if communications technology follows its current trajectory, anyone who wants to escape the byproducts of human activity might have to go to the moon.

Some professional astronomers raised alarms last spring, and again in November, after Spacex launched batches of 60 Starlink satellites. These don’t present a big problem yet, but when thousands more shine down on us, they could interfere with our ability to detect the farthest, faintest objects in the universe — the ones that give us a portal into the distant past. The wider effect will be on amateur sky watchers, campers, sailors, dreamers, poets, children, visionaries and anyone else who has ever been moved by the sparkle of the Milky Way set against the dark mystery of space.

We’re entering a second space age now, 70 years after the start of the first one, says space historian and astrophysicist Jonathan Macdowell of the Harvard-smithsonian Center for Astrophysics. The cost of launching things into space is finally cheap, so the number of things in space is going to explode.

Spacex has plans to launch 30,000 more satellites, in addition to the 12,000 already approved by the FCC and FAA. Macdowell predicts that other companies are likely to launch “mega constellations” of their own satellites. The result could be cheap or free high speed Internet access for everyone on the planet, at the price of our view of timeless constellations.

Some communication can be done with much higher, less obtrusive satellites in geostationary orbit, he explains, but those can’t get enough bandwidth to offer everyone video streaming. For that we need the satellites in low earth orbit, where they will parade across our view. The sky will become even more cluttered if Jeff Bezos carries out his plan to move heavy industry into space — an endeavor that would require hundreds of thousands of much larger, brighter satellites, says Macdowell.

“Our concern is about our connection to the universe,” says Ruskin Hartley, the president of the International Dark-sky Association. His group, which has been active in trying to decrease earthbound light pollution, has also taken a stand on the spacebased kind. While there are billions and billions of stars out there, our eyes can pick up just 10,000 or so from a relatively dark place, he says, so soon our view could be “twinkling with satellites.”

Macdowell says his calculations suggest that even a modest 30,000 satellites would profoundly change the view from Earth. Astronomers say that number will start to complicate their work as well, especially an ambitious project known as the Large Synoptic Survey Telescope, which will take wide-field images of the sky from Chile in an attempt to penetrate the mysteries of dark matter, dark energy, and the origin of galaxies. Will public enthusiasm for such ventures deflate when the rest of us no longer look at the stars and wonder where it all came from and where it’s all going?

Is it selfish to want to keep our night sky, knowing some people still don’t have Internet access? Maybe. But many of the disconnected surely feel a connection to the night sky, too.

Macdowell says one good compromise solution would be an international agreement, similar to a space junk pact negotiated through the Interagency Space Debris Coordination Committee. Through that agreement, companies with plans to launch satellites now design them so they fall to Earth after 25 years. A similar agreement might encourage people to design satellites with minimal impact on our view.