Orbital Mirror Project Could Create Night Sky Beams 10,000 Times Brighter Than Full Moon
Astronomers warn that Reflect Orbital's plan for thousands of solar-reflecting satellites could permanently erase stars for millions of people.
A proposed network of orbital mirrors designed to provide nighttime solar power could create artificial beams of light so intense they would effectively erase the stars for anyone beneath them. A study led by Princeton University astrophysicist Gaspar Bakos warns that these mirrors would introduce a level of light pollution far exceeding that of the world's largest cities.
The startup Reflect Orbital plans to eventually deploy up to 40,000 large mirrors to reflect sunlight to Earth for disaster zone illumination and nighttime solar energy production. According to the research, a single operational mirror measuring 174 by 174 feet would appear 40 times brighter than a full moon to observers within its 3.4-mile-wide beam. To make solar panels efficient enough for commercial power, at least 400 mirrors would need to reflect light simultaneously, creating a concentrated beam 10,000 times brighter than the full moon.
Regulatory Gaps and Early Launches
Despite significant objections from environmentalists and the scientific community, the Federal Communications Commission (FCC) has already licensed a demonstration satellite known as EARENDIL-1. This initial craft features a 60-by-60-foot mirror and will orbit at an altitude of 373 miles (600 km). When questioned about the potential impact on the night sky, the FCC stated that impacts on optical astronomy fall outside its review and authorization scope.
This regulatory vacuum is compounded by a decades-old legal loophole. Satellite projects in the United States are currently exempt from the National Environmental Policy Act (NEPA), a rule established in the 1980s. This exemption allows companies to proceed with orbital deployments without the rigorous environmental impact assessments required for terrestrial projects.
The Cost of Artificial Light
For the astronomical community, the stakes are catastrophic. Professor Gaspar Bakos noted that the intensity of the light would be "worse than big cities like London," asserting that observers within the beam would be unable to see any stars. The deployment of thousands of these mirrors could create permanent "twilight zones" on Earth, fundamentally altering the natural night sky for millions of people.
This conflict highlights a growing tension between commercial utility goals—such as extending the reach of renewable energy—and the preservation of the celestial environment. While Reflect Orbital claims the majority of people will not see the light because service locations will be remote, astronomers argue the scale of the proposed constellation makes widespread disruption inevitable.
What to Watch
As EARENDIL-1 moves toward operation, the scientific community is monitoring whether the demonstration will trigger a re-evaluation of NEPA exemptions for space-based infrastructure. The primary remaining question is whether the U.S. government will establish a framework to protect optical astronomy before the project scales from a single demonstration satellite to a fleet of 40,000 mirrors.