Experts warn that reflective satellites could pose eye-injury risk and disrupt astronomy

The Federal Communications Commission has approved an experimental satellite from Reflect Orbital that is designed to reflect sunlight onto the Earth at night to support solar farms and emergency lighting. Astronomers and health experts warn that the bright reflector, known as Eärendil-1, could cause permanent eye injury, even when viewed through a 12-inch telescope commonly used by amateurs.

"The risk to human health makes the FCC's approval extraordinary," said Robert Massey, deputy executive director of the Royal Astronomical Society.

The concern mirrors earlier research on a Russian mirror-satellite project, which was found to produce illumination comparable to looking directly at the Sun during a total eclipse. Critics note that the FCC did not consider the potential for eye damage a significant factor in its decision.

Reflect Orbital spokesperson Christopher Buscombe said the company is consulting scientists, astronomers, and environmental researchers and will test safety measures on its demonstration satellite. He added that the reflected light will be limited to levels that humans and animals already tolerate, though experts point out uncertainties such as atmospheric scattering and cloud interactions.

The Air Line Pilots Association and several chronobiology societies have also expressed concerns about possible impacts on aviation safety, sleep patterns, and migratory species.

"The proposed scale of orbital deployment would represent a significant alteration of the natural night-time light environment at a planetary scale," said the presidents of several international chronobiology associations.

With the number of low-Earth-orbit satellites increasing rapidly, scientists caution that a large fleet of highly reflective satellites could impair deep-space observations and alter the night sky that many consider a cultural and scientific heritage.