TUCSON, July 16 — On a clear desert night, the faint glow of a satellite crossing the sky is a familiar sight to astronomers. But Dr. Richard Green sees something else: a threat. The University of Arizona astronomer and former director of the National Optical Astronomy Observatory has spent years on the front lines of a growing conflict between the space industry and the science of the stars.
Now, he is warning that a new project — a space mirror satellite — could be ten times brighter than the brightest Starlink satellites already in orbit. That, he argues, would be a significant threat to professional astronomy.
A Decade of Dimming Skies
Green is not a newcomer to this fight. He chairs the American Astronomical Society’s Committee on Light Pollution, Radio Interference, and Space Debris. In 2022, he published a study in the journal *Nature Astronomy* that quantified the increase in sky brightness caused by SpaceX’s Starlink constellation.
That paper put hard numbers on what astronomers had been observing for years: the night sky, humanity’s oldest natural resource, was getting brighter. The source of that brightness is simple physics.
Thousands of satellites in low Earth orbit reflect sunlight down to the ground, leaving long streaks across astronomical images and washing out faint celestial objects. For telescopes hunting for distant galaxies, near-Earth asteroids, or faint supernovae, every bit of extra light is a loss of data.
Testifying in Washington
Green has taken his case directly to regulators. He has testified before the Federal Communications Commission and in congressional hearings, arguing that the current voluntary approach to satellite brightness is not enough. SpaceX has adopted brightness-reducing measures for its Starlink satellites — special coatings, sunshades, and operational adjustments.
But Green says those steps, while welcome, are voluntary. He has called for mandatory brightness limits for *all* satellites in low Earth orbit.
The space mirror satellite now under consideration, he warns, would be a different class of problem. Where a typical Starlink satellite might appear as a moving point of light, the mirror satellite could be dramatically brighter — ten times brighter, by his estimate. That would make it a significant threat to professional astronomy.
What Comes Next
The fight over the space mirror satellite is far from over. Green’s testimony before the FCC and Congress has helped frame the debate, but no regulations have been finalized. The American Astronomical Society’s committee, which he leads, continues to press for binding standards.
By nightfall, astronomers will again be at their telescopes, tracking objects millions of light-years away. But the light they are watching for now is closer to home — and growing brighter by the year.
