A NASA-led study published in Nature warns that reflections from the rapidly growing number of satellites could spoil more than 95% of images captured by some upcoming space telescopes over the next decade. Sunlight glinting off satellites produces bright streaks—so-called satellite trails—that have already appeared in Hubble Space Telescope photos and are projected to become much more common as low-Earth orbit fills up.
The researchers say several missions face severe contamination risks, including NASA’s recently launched SPHEREx, the European Space Agency’s ARRAKIHS, and China’s planned Xuntian Space Telescope. Lead author Alejandro S. Borlaff, a NASA scientist, emphasized that transient astronomical events—such as a distant supernova—could be irretrievably lost if a satellite crosses the telescope’s field of view during a critical observation.
Satellite launches have accelerated in recent years. Astrophysicist Jonathan McDowell reported more than 10,000 active satellites in orbit as of Dec. 1, with SpaceX operating over 7,800 Starlink craft. The International Telecommunication Union (ITU) says thousands more satellites are planned. When satellite numbers were lower, a 2023 Nature Astronomy study found roughly 4% of Hubble images showed satellite streaks (data from 2018–2021). The new analysis suggests that at least one in three Hubble images could now include a streak, while certain missions could see roughly 96% of their exposures affected.
The astronomical community has repeatedly raised alarms about the growing constellations. The American Astronomical Society (AAS) has highlighted risks including increased collision probability, glare, and streaks that degrade scientific observations; it says it will coordinate with federal agencies and the satellite industry to mitigate impacts.
Satellite operators and regulators are pursuing countermeasures. SpaceX reports testing darker coatings, deployable visors to block sunlight, and orbital adjustments to reduce reflectivity. The ITU is calling for stronger international regulation of satellite numbers and improved management of orbital traffic to protect long-term sustainability, reduce collision and debris risks, and preserve orbital resources for future scientific use.