The night sky is becoming increasingly congested with satellites, making it difficult for astronomers to make new discoveries. With the boom in the commercial space sector, the number of satellites orbiting the Earth has risen four times since 2019, and is estimated to be over 8,000 machines. With Elon Musk’s SpaceX preparing to launch 44,000 satellites for its Starlink internet constellation and a staggering 400,000 having been approved in total for low Earth orbit, the problem is only set to escalate.
Satellites reflect sunlight back to Earth, which is obstructing the optical field of telescopes. The bright beams of light from satellites are also interrupting sensitive radio telescopes. This has raised concerns among astronomers, with Tony Tyson, professor of physics and astronomy at the University of California, stating that by 2030 the sky would have a “macabre” look with hundreds of thousands of satellites floating around and very few stars visible.
Last week, the Royal Astronomical Society (RAS), the UK Space Agency, and the Department for Business organized a Dark and Quiet Skies conference to address these concerns and call for more regulation. As Robert Massey, deputy executive director of the RAS, noted, it will become increasingly difficult to monitor “signals from other civilizations” in a clogged sky, let alone detect the origin of life. If satellites comprise about 10 percent of night sky stars, it would be a direct attack on the natural landscape.
The Vera Rubin telescope located in the $473 million Vera C. Rubin observatory in north-central Chile is already feeling the effects of the overcrowded sky. Poised to begin a 10-year survey next year to find minor changes in the movements of 37 billion stars and galaxies, preliminary tests have found that at least 40 percent of frames are impacted during twilight hours.
Astronomers have also warned about the consequences of deorbiting satellites. Ken MacLeod, an independent expert on non-functional satellites, has found that nearly 16,000 decaying internet satellites will need to come out of orbit at any one point when all the internet constellations are in operation. This will result in fireballs from the re-entry of space debris, with an estimated 60 falling daily. The abundance of satellites is set to have severe consequences on astronomy and change the night sky forever.