Starlink's Growing Megaconstellation Has Astronomers Worried
With over 700 Starlink satellites in orbit, astronomers are pushing SpaceX for fixes as bright streaks threaten sky surveys.
SpaceX has now launched more than 700 Starlink satellites, and that number is just a fraction of what’s planned. The company has talked about a constellation in the thousands, eventually aiming to blanket the globe with broadband internet from low Earth orbit. It’s an impressive engineering feat if you like fast, reliable internet in places fiber will never reach. It’s also becoming a real headache if you like looking at the night sky.
The core problem is brightness. Fresh-off-the-rocket Starlink satellites are highly reflective, and in the minutes after sunset or before sunrise, when the ground is dark but satellites are still catching sunlight, they show up as bright, moving streaks. Astronomers using wide-field survey telescopes have been documenting these streaks cutting across their images for over a year now, and the complaints have only gotten louder as the constellation has grown. A single satellite is an annoyance you can work around. Thousands of them, all crossing the sky on predictable but numerous paths, start to look like a systemic problem for anyone doing large-area sky surveys.
Why this matters beyond aesthetics
This isn’t just about ruining pretty photos. Observatories doing time-domain astronomy, hunting for asteroids, supernovae, or other transient events, rely on capturing wide swaths of sky repeatedly and comparing images. A bright satellite trail can mimic or obscure a real signal, waste exposure time, or require extra processing to clean up. The International Astronomical Union has been vocal about this, pushing for the satellite industry to take the problem seriously before megaconstellations become the norm rather than the exception. Starlink isn’t the only company with big plans here, but it’s currently the one putting the most satellites up the fastest, so it’s drawn the most scrutiny.
To its credit, SpaceX hasn’t just dismissed the criticism. The company has been testing what it calls VisorSat, essentially a deployable sunshade that blocks sunlight from hitting the satellite’s most reflective surfaces. Earlier this year SpaceX also tried a darker coating on one test satellite, which apparently didn’t work as well as hoped, so the sunshade approach is the current bet. Reports from observers suggest the shaded satellites are noticeably dimmer than earlier batches, though not so dim that they’re invisible to sensitive equipment.
Where this settles is still an open question. SpaceX wants to keep launching batches every few weeks, and there’s no clear regulatory body with the authority to say “not so bright” the way one might set noise ordinances on the ground. Space has traditionally been treated as a commons without much in the way of environmental rules, and satellite brightness is a genuinely new kind of pollution to grapple with. My guess is this gets resolved through a mix of engineering fixes, like VisorSat, and negotiated operating practices with astronomers, rather than through any binding regulation. But it’s worth watching closely: the incentives for SpaceX to launch fast are strong, and the incentives for astronomers to get louder about this are only going to grow as the constellation fills out. Whether a few thousand extra satellites end up being a manageable nuisance or a lasting problem for ground-based astronomy probably depends on how seriously these mitigation efforts are followed through in the next couple of years.