Scientists warn orbital mirrors could obscure the night sky

Scientists from the Slovak Academy of Sciences, Comenius University, and Princeton University have modeled the atmospheric impact of orbital mirrors, revealing that such technology could significantly obscure the night sky. The research indicates that a single large mirror could create illumination levels comparable to a street lamp, making stars invisible within a radius of several dozen kilometers.

According to the study, a planned 54-meter mirror would appear 40 times brighter than a full moon. This would cause the entire volume of the atmosphere above an illuminated area to glow, potentially creating a visible light pillar visible from 34 kilometers away. The researchers noted that their current models represent an optimistic scenario based on cloudless conditions.

The technology is being pursued by the American company Reflect Orbital, which received FCC permission to launch the EARENDIL-1 pilot satellite. This satellite, featuring an 18-by-18-meter mirror, is intended to reflect sunlight to Earth from an altitude of approximately 600 kilometers. This pilot project serves as a precursor to a proposed constellation of roughly 50,000 larger mirrors.