Starlink Satellites Threaten to Blind Radio Telescopes, Study Finds

Radio telescopes may face severe operational challenges due to unintended radio emissions from SpaceX’s Starlink satellites, according to new research using the Netherlands-based Low Frequency Array (LOFAR). The findings, published in Astronomy & Astrophysics, reveal that second-generation Starlink satellites emit up to 32 times more stray radio waves than earlier versions.

Unintended Emissions Disrupt Observations

The emissions, though unintentional, are 10 million times brighter than the faint celestial sources LOFAR and similar telescopes study. Lead author Cees Bassa from the Netherlands Institute for Radio Astronomy compared the interference to trying to see a faint star beside a full Moon.

With over 6000 Starlink satellites already in orbit and plans for tens of thousands more, LOFAR researchers warn of continuous interference. “It’s a bit depressing how much worse it’s gotten so quickly,” Bassa said.

Previous Efforts and Growing Concerns

The interference issue isn’t new. Optical astronomers raised concerns five years ago about the brightness of low-orbiting satellites reflecting sunlight. SpaceX made adjustments but hasn’t yet achieved the International Astronomical Union’s recommended dimming levels.

In 2020, radio astronomers also raised alarms when emissions in Starlink’s communication bands began affecting reserved astronomy frequencies, prompting SpaceX to make some improvements.

Phil Diamond, director of the Square Kilometre Array Observatory, expressed disappointment with the second-generation satellites: “It’s extremely disappointing to see that in this latest generation the emission is there and it’s brighter.”

Potential Military Satellites and Regulatory Needs

LOFAR researchers suspect some of the brighter emissions may come from unlisted military Starlink satellites deployed under the U.S. Department of Defense’s Starshield project, potentially worsening the interference problem.

Astronomer Aaron Boley from the University of British Columbia called for stricter regulations:
“This is a really big threat to radio astronomy.”