Overview
- The European Southern Observatory study led by Olivier Hainaut, accepted for publication in Astronomy & Astrophysics in early July 2026, models the positions and brightness of current and proposed low‑Earth‑orbit constellations and warns that very large fleets would produce both bright streaks and a cumulative skyglow that degrade observations.
- The authors recommend limiting the total LEO satellite population to roughly 100,000 objects that remain below naked‑eye visibility (visual magnitude ≈7) to keep sky brightness and streak rates at manageable levels.
- Simulations show concrete damage to flagship facilities: SpaceX’s proposed data‑center fleet could cause dozens of trails per image on ESO’s Very Large Telescope and cut usable field of view by about 28 percent, while slightly brighter satellites could render Vera C. Rubin Observatory wide‑field images unusable for hours.
- Reflect Orbital’s proposal for up to 50,000 mirror satellites would create extremely bright objects that could appear as bright as Venus outside their beam and up to multiple times the full moon inside it, and the study says that fleet alone would multiply night‑sky brightness severalfold.
- ESO, the Royal Astronomical Society and the IAU have filed formal comments with the U.S. Federal Communications Commission about SpaceX and Reflect Orbital filings and regulators now hold pending decisions against a backdrop of rapid growth in orbit since 2019 and limited international rules on cumulative orbital carrying capacity.