In 2015, the world got understandably excited as SpaceX mastermind Elon Musk announced the launch of a new satellite fleet that would give the world faster and cheaper internet. But as the first few satellites were launched, it made a lot of astronomers unhappy.

The constellation, which so far consists of 60 satellites but is set to be expanded to 12,000, add more clutter and significantly reduce our view of the cosmos, potentially dealing an important blow to many, many space surveys.

Screenshot taken from a video shot by Marco Langbroek with a group of SpaceX Starlink satellites passing over the Netherlands on May 24, 2019.

When the first satellites were launched, the event was tracked all around the world. Astronomer Marco Langbroek noted on his blog a calculation of where the satellites would be orbiting. He set up his camera and patiently waited, but not for long: he quickly observed a string of bright dots flying across the sky. The satellites were so bright that they were even visible to the naked eye in certain instances prompting some people to UFO sightings.

Sure enough, their brightness has diminished partly as they stabilized into orbit, but for astronomers, this was a clear message: observations are bound to get more difficult, and there’s going to be a lot more objects in the way.

To get a sense of the current situation, there are currently 2,100 active satellites orbiting our planet. If 12,000 are added by SpaceX alone, it would add an unprecedented level of visual clutter for astronomers — and SpaceX is just one of the companies who want to put internet satellites into orbit.

“People were making extrapolations that if many of the satellites in these new mega-constellations had that kind of steady brightness, then in 20 years or less, for a good part of the night anywhere in the world, the human eye would see more satellites than stars,” Bill Keel, an astronomer at the University of Alabama, told AFP.

Jonathan McDowell of the Harvard Smithsonian Center for Astrophysics also adds that at least during some parts of the year, things will get a bit more problematic for astronomers.

“So, it’ll certainly be dramatic in the night sky if you’re far away from the city and you have a nice, dark area; and it’ll definitely cause problems for some kinds of professional astronomical observation.”

SpaceX’s declared goal is a lofty one:  to provide broadband internet connectivity to underserved areas of the planet and offer cheaper, more reliable service to all the world. The cashflow received from this venture would help the company advance its Mars flight plans, helping mankind achieve its space exploration dreams. Yet at the same time, this is placing a hurdle in the way of astronomers.

If there’s anything we can learn from this story, is that things are most often complex, and even with good intentions, planetary-scale projects can have important side-effects which need to be accounted for.