A company called Reflect Orbital plans to beam sunlight from space to Earth on demand using satellites equipped with large mirrors. However, according to a new study, this could unintentionally brighten the night sky for many more people than intended. The launch of Eärendil-1, an 18-by-18-meter mirror satellite, has been approved by the Federal Communications Commission but met with disbelief from astronomers and environmental groups who argue that it is incompatible with astronomy.

Miroslav Kocifaj, an astronomer at the Slovak Academy of Sciences, and his colleagues have calculated the broader effect on the night sky. They found that within the beam’s target area, intended to be a circular patch five kilometers across, a single Reflect Orbital satellite would appear about 40 times brighter than the full moon in the sky. Even up to 80 kilometers away, this combined beam of light from 400 satellites would still be visible as “a glow above the horizon,” altering the night sky for many more people than those within the area Reflect Orbital intends to illuminate. The company has stated that their safeguards and exclusion zones take account of scattering, but Kocifaj argues that Reflect Orbital has not provided data or descriptions of models to back up these claims.

This is a summary. Read the original at technologyreview.com.