Reflect Orbital space mirrors would light ground four times brighter than full moon, study finds
Anyone standing in the beam of a single Reflect Orbital space mirror would see light four times brighter than the full moon, per a new atmospheric light pollution study. The startup wants 50,000 of the 54-metre mirrors in orbit by 2035, lighting the ground at street-light brightn
A new atmospheric light pollution study has quantified what it would mean to live under one of Reflect Orbital's proposed space mirrors. A single 54-metre satellite would appear as a -16.7 magnitude object, about four times brighter than the full moon, and would light the ground below at roughly street-light brightness. The glow remains visible up to 30 kilometers from the beam, with sky brightness still exceeding a moonlit night as far as 34 kilometers away. Reflect Orbital, the startup behind the concept, has proposed launching up to 50,000 of these mirrors by 2035 to redirect sunlight to the ground after dark, marketed as sunlight on demand. Even outside the direct beam, a single satellite would appear roughly as bright as Venus. Astronomers who reviewed the plan warn a full constellation of that scale would raise overall night sky brightness three to four times above current levels. The gap between a company's commercial pitch and its physical footprint is the story here: what one satellite does to a patch of ground is very different from what tens of thousands of them would do to the sky everyone sees, whether they bought into the service or not.