“Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

Join the discussion

• Hacker News
• Should it be possible to coordinate orbits to create permanent clear spots on the sky where observatories are? A LEO no flight zone of sorts.
  by manoDev
• It’s not just about where the observatories are. It’s where they want to point to. Good luck figuring out which part of the night sky isn’t important for astronomy.
  by stouset
• I remember Bucky Fuller writing how seeing an airplane fly overhead used to be rare.

  In my own childhood, seeing a satellite fly overhead used to be rare.

  Now I see one every 2 minutes.

  by tmach32
• For the first time in human history, the generations living now have been systematically robbed of their ancestral right to witness the night sky and its jaw-droppingly awe-inspiring magnificence.
  by zoilism
• Cry me a river
  by sajithdilshan
• you can still go outside at night and look up. get a grip.
  by qntmfred
• Did you know that if you stay up a bit later* than twilight, the satellites disappear?

  *The later you stay up the more disappear, until the middle of the night. But they're most obvious shortly after dark.

  by BenjiWiebe
• These kinds of caps have for years been a dampener on human flourishing. My observation has been that those in stagnation or decline tend to attach themselves to these desires to hold the status quo. Anti-energy, anti-housing, anti-industry and so on because they've reached a local maxima in their ability to live and have chosen to spend their life in leisure.

  But there is the rest of the world, and if I'm told that the Africans should not have access to high-speed satellite Internet[0] so that the Europeans can use one specific method of looking at the stars, I don't find that convincing. In time, as we expand, space-based observation will become fairly feasible for everyone. And the satellites we have will decay to the Earth should we fail to keep them up there.

  We will build Earth orbital structures and swarms, and we will build Sun orbital structures and swarms, and we will go to the stars, and it will be better for humanity as a whole.

  0: https://www.economist.com/middle-east-and-africa/2026/07/02/...

  by arjie
• > These kinds of caps have for years been a dampener on human flourishing. My observation has been that those in stagnation or decline tend to attach themselves to these desires to hold the status quo. Anti-energy, anti-housing, anti-industry and so on because they've reached a local maxima in their ability to live and have chosen to spend their life in leisure.

  This kind of attitude has for millenia been a dampener on human flourishing. My observation has been that those without empathy or foresight tend to attach themselves to these initiatives to obliterate our shared human heritage to satisfy their own ridiculous misconception of progress. Anti-intellectual, anti-curious, anti-social and so on because they've reached a local maxima in their ability to give a damn about what it means to live a good life and have chosen to spend their life in self-satisfied ignorance.

  by kibwen
• Well, if you build too many satellites in the swarms, at some point you will lose the ability to see or go to the stars.
  by isatty
• Rubbish. Its 99% of the time people trying to make money and that's it.

  As though Africans aren't interested in the stars, or climate change, or that they can't figure out fibre optics is borderline racist.

  Europe - and soon the rest of us - are facing massive heat waves that are likely driven by climate change, it's a real problem.

  That's 'actual science'.

  By all means, build what you like, but you don't get to dump your externalizations on everyone else. There is no 'We' in your projects, you don't speak for us.

  by bluegatty
• In related news, earlier this year Chile cancelled plans for a gigawatt-scale solar/wind powered hydrogen production plant nearby the ESO facility in the Atacama desert after light pollution complaints from European scientists.
  by gordonhart
• I didn't understand what these satellites were really like until I visited Zion National Park two weeks ago. Zion is an International Dark Sky park, and so I was really looking forward to seeing the stars. Instead we sat outside and watched dozens and dozens of fast-moving stars zip around on all sorts of trajectories. I'm not saying it ruined the experience (I'm not an astronomer, and it was kind of fun.) But it really brought home how fundamentally we've changed the sky. I also hope we're able to lay enough fiber in developing countries that this many satellites don't need to stay up there forever.
  by matthewdgreen
• As a literal leftist by any reasonable metric, the recent trend towards “I wish it was 1995” and “AI is the worst” and “tech sucks now” from people I agree with on many other points frustrates me to no end.

  “You guys know we could basically live in a Star Trek style utopia if we get this right, right?”

  “The DATA cenTERS are STEALING the water and breaking Taleckshual ProPerty LERRS!”

  Like, I thought we were for piracy, and against capital colonizing the space of creative ideas? But I guess what a lot of people were fond of was feeling important.

  by piloto_ciego
• > These kinds of caps have for years been a dampener on human flourishing.

  I don't think blocking the view of the night sky is necessary for "human flourishing", actually. Your attitude reminds me of the Victorians, who saw their coal-smoke filled skies as a sign of virtuous progress.

  More reasonable minds prevailed, in the end, and now most people have a more balanced view - with the understanding that progress and industry must be balanced with the ecosystem we live in and depend upon for life.

  by solid_fuel
• I think that "Africans should not have access to high-speed satellite Internet" is something you've just made up; the article you link talks about African people turning to Starlink because of local infrastructure issues, and the original article notes that the current satellite count is currently around 14k satellites. 100k is more than enough satellites to provide high-speed satellite internet globally.

  The article makes mention of specific endeavours, like the night-time mirror satellites, which are particularly disruptive to astronomy, and the general risks of high numbers of satellites.

  The ability to do Earth based astronomy is something that is of value to all the peoples of Earth, and is mainly funded by the western nations because of their current position as the people with more money.

  by Normal_gaussian
• If we can launch 1M satellites, how many telescopes can we launch?
  by 0-_-0
• Who is we? Certainly not amateur astronomers who made important discoveries with their telescopes
  by croes
• Agreed, I think the entire issue can be resolved with more telescopes in orbit.

  I can understand European Southern Observatory (ESO) being concerned about becoming obsolete, but is the astronomy community as a whole concerned about the issue?

  I understand there's currently around 722 observatories (some defunct, some are in orbit) based on this source: https://en.wikipedia.org/wiki/List_of_astronomical_observato...

  But perhaps there are others I am unaware of.

  Quoted: Hainaut explains that "satellites, illuminated by the Sun, are much brighter than distant galaxies. When a satellite crosses what we observe, it makes a bright streak on our image, zapping whatever is behind it."

  It sounds like this only affects visible light telescopes.

  by SapporoChris
• Ugh the part about Munich is depressing. Finding a dark clear sky spot is one of the worlds greatest joys and most awesome experiences.
  by tapland
• Worrying for sure. But I doubt the current USA, along with Israel and Russia are going to be bothered about this. Everyone is launching satellites and other gear into orbit for war.
  by michelb
• Or defense.
  by SubiculumCode
• They're already itching to throw space-lasers into orbit. [0]

  I wish I was joking.

  [0] https://www.jpost.com/defense-and-tech/article-900854

  by johnnyApplePRNG
• Interesting that your list omits China considering they have firm plans to launch ~41k satellites for government/commercial constellations plus ITU filings for >200k proposed satellites.
  by gordonhart
• >SpaceX plans to send one million more satellites into orbit, for space-based data centres, ...

  I think we should wait to see how the first satellite data centre works out. It seems fairly unlikely that it could be practical. It seems kind of nuts...

  >Reflect Orbital, a US start-up, aims to launch a constellation of very large mirror-like satellites to provide sunlight at night, with reflected beams that span at least five kilometres on Earth's surface.

  Straight up nuts with no practical value, even if it did work out.

  by upofadown
• I can think of several practical uses. It would be very useful immediately after a disaster. Lighting up the night would make search & rescue much more effective. It would also allow for more solar power generation in an area, reducing pollution. Extra light at high latitudes in the winter would reduce seasonal depression.

  Are they worth the cost/tradeoffs? I don’t know. But there is practical value to lighting up the night.

  by ggreer
• There are many feasibility and safety issues associated with the Reflect Orbital plan. It doesn’t make as much sense as you might think. For instance, the satellites can only illuminate areas a relatively short time after local sunset. The Sun reflection could potentially damage an amateur astronomer’s eye if one of the satellites crosses their telescope’s field of view: https://bigthink.com/starts-with-a-bang/true-cost-solar-powe...
  by nyankosensei
• > I think we should wait to see how the first satellite data centre works out. It seems fairly unlikely that it could be practical. It seems kind of nuts...

  I strongly suspect that what'll happen is SpaceX does launch satellites with onboard GPUs, so the SpaceX hypemen can go "the skeptics said it couldn't be done!" and take off before the actual, more crucial question of "does it make _financial_ sense?" is answered in the extreme negative

  by strangecasts
• I'm not sure how exactly they are making these calculations but I just don't see it. Both Reflect and SpaceX are targeting SSO orbits where they are only reflecting for an hour or two at sunset. That isn't true of Starlink, but that constellation is already up there and if its fine right now, I don't see it getting much worse as the materials on it get refined to be less problematic.

  More regulations would just have the result of cementing a monopoly for Spacex.

  by nablaxcroissant
• All satellites in LEO only show up at close to sunset (and sunrise): When they're away from the terminator, they're either on the sun-side, and hence you can't see them for all the blue sky around them, or the night-side, in which case you can't see them because they're not lit by the sun because the Earth is in the way.

  I'm still checking the maths on how bright a million satellites in a terminator-following SSO would be. I'm getting very big numbers. But then, the (vague and aspirational) suggestions I'm seeing right now for SpaceX are in the 120 kW range, which is huge, and lining up a million of those is enough for a contiguous ring just under 10 meters wide (how much under is "just under" depends both on how efficient the PV is and how high in LEO you go).

  Regardless of if they're all in one orbit or spread over in multiple orbits at different shells that are all terminator-following SSO, from the ground you're getting a train of things with somewhat higher brightness than the ISS, with a fairly small apparent separation that (I tentatively think) becomes less than your eyes can resolve at at least one point in the sky (if there's say 50 shells, where those 50 get close to crossing).

  by ben_w