Astronomers Alarmed by Plans for Space-Based Mirrors to Illuminate Earth at Night
Reflect Orbital's proposal to deploy thousands of satellites with mirrors to reflect sunlight onto Earth at night has raised significant concerns among astronomers about potential disruptions to scientific observations and the natural night sky.
Reflect Orbital, a California-based startup, has proposed launching a constellation of satellites equipped with large mirrors designed to reflect sunlight onto specific areas of Earth during nighttime. The company asserts that this technology could extend daylight hours for solar farms and provide emergency lighting after natural disasters.
The Royal Astronomical Society (RAS) has expressed strong opposition to the plan, stating that it poses a significant threat to astronomical observations and the natural darkness of the night sky. Astronomers warn that the artificial beams could be up to four times brighter than the full moon, with scattered light affecting regions beyond the intended targets.
Reflect Orbital envisions deploying approximately 50,000 such mirrors in orbit. Estimates suggest that a constellation of this scale could make the night sky three to four times brighter overall, severely impacting ground-based telescopic observations.
In a related development, SpaceX has applied to launch up to one million satellites intended to function as space-based data centers to power artificial intelligence systems. The RAS has also raised concerns about this proposal, noting that the brightness of these satellites could outnumber visible stars, significantly affecting astronomical research.
Both Reflect Orbital and SpaceX have submitted their proposals to the U.S. Federal Communications Commission (FCC) for approval. In response, the RAS and the European Southern Observatory have submitted comments opposing the plans, warning that such projects could severely damage ground-based astronomy and permanently alter the appearance of the night sky.
Robert Massey, the deputy executive director of the RAS, stated:
"These proposals would not only have a disastrous impact on the science of astronomy, they would also hinder the right of everybody on Earth to enjoy the night sky. That is unacceptable."
He emphasized the cultural and scientific value of the stars, expressing hope that the FCC would reject the plans to prevent permanent scarring of the natural landscape.