“Beyond the limit”: Satellites and mirrors in space pose threat to the night sky
Points and comments are a snapshot, not live.
A new ESO study warns 1.7 million proposed satellites would devastate ground-based astronomy.
The study, led by ESO astronomer Olivier Hainaut, finds proposed mega-constellations-including SpaceX's 1 million satellites and Reflect Orbital's 50,000 mirror satellites-would brighten the night sky by 3-4 times, causing unacceptable losses for telescopes like the VLT and Rubin Observatory. Reflect Orbital's satellites could appear four times brighter than the full Moon. Hainaut recommends limiting total orbiting satellites to 100,000 faint ones (below magnitude 7) to preserve astronomical observations. ESO, the Royal Astronomical Society, and the IAU have filed responses with the FCC on these proposals.
Companies like SpaceX have taken mitigation measures, but Hainaut says current proposals go "beyond the limit."
What commenters are saying
Commenters split between concern for astronomy and a pro-progress stance. Some dismiss the threat as overblown, arguing satellites can be ignored or noting orbital decay will clear them. Others highlight risks to asteroid detection and light pollution's broader ecological/health effects.
#1 comment notes the U.S., Israel, and Russia won't be bothered, while #2 omits China's firm plans for 41,000+ satellites. Skeptics question the rarity of asteroid impacts or suggest space-based detectors. A pro-space commenter argues "progress is more important" and LEO satellites will deorbit naturally.