This company’s plans to deploy space mirrors could jeopardize the night sky for many

Reflect Orbital’s test satellite Eärendil-1 will deploy an 18 × 18 m mirror to evaluate sunlight beaming. Modeling by Miroslav Kocifaj et al. predicts a single satellite appears ~40 times brighter than the full moon within a 5 km area; a 400-satellite fleet would emit illumination equal to 10 000 full moons (2.4% of solar brightness) and remain visible as a glow up to 80 km away, potentially compromising dark-sky conditions beyond the target zone.