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Growing Number of Satellites Will Leave Streaks on Photos from Space Telescopes

The growing number of satellites overhead may soon obscure photos taken by the Hubble Space Telescope and other orbiting observatories. New research finds that passing satellites could leave streaks on up to 96 percent of images.

Already, satellites are leaving streaks on photos taken using telescopes on Earth. Now, as SpaceX and other firms look to build out huge networks of communications satellites, the skies are set to grow far more crowded. A decade ago, there were around 1,200 active satellites orbiting the Earth. Today, there are roughly 12,000. Another 560,000 are currently planned for launch, researchers say.

To understand what the satellite surge will mean for space observatories, researchers at NASA simulated the view from four telescopes in low-Earth orbit: the NASA observatories Hubble and SPHEREx, which are now in operation; China’s Xuntian Space Telescope, which will launch next year; and the E.U. ARRAKIHS mission, which is set to launch in 2030.

With more than half a million satellites overhead, researchers found, streaks of light would taint between 40 percent and 96 percent of photos. They note that a single photo could be marked by as many as 92 streaks. The findings were published in Nature.

While it is unlikely that every planned launch will take place, scientists warn that the growing number of satellites will produce poorer imagery, fewer discoveries, and may obscure views of asteroids headed for Earth. “If your images look like they’re filled with asteroids, it’s very possible that you’ll miss a real one,” lead author Alejandro Borlaff, an astrophysicist at the NASA Ames Research Center, told Nature.

The growing number of satellites also poses other risks. As Yale Environment 360 recently reported, scientists are increasingly concerned about emissions from rocket launches and from payloads burning up as they fall back to Earth. “Both of these processes are producing pollutants that are being injected into just about every layer of the atmosphere,” Eloise Marais, an atmospheric scientist at University College London, told e360.