5 ms·

Yeah, I kinda get why astronomers are not particularly happy with satellite constellations.

by ragebol 5mo ago

HumblyTossed 5mo ago
Doesn't matter. We, as a society, have said we're willing to give up nature in exchange for money machines the go brrrrr.
adev_ 5mo ago
And this is just the visible spectrum. The situation is one order of magnitude worst in radio-astronomy. It is fair to state that satellite constellations will certainly be the main obstacle to multiple major scientific discoveries in the next decade.
- ultratalk 5mo ago
  Opinion: We need to move our astronomical observation equipment off of Earth and onto other bodies, especially radio astronomy, which, unlike telescopes that operate in other wavelengths, is still affected by Earth's emissions in LEO/near-Earth space. We should put a radio telescope on the far side of the moon [0] to benefit from the thousands of kilometers of lunar material separating Earth's emissions from telescopes. [0] https://doi.org/10.1109/AERO50100.2021.9438165 https://doi.org/10.1109/AERO50100.2021.9438165 [1] https://en.wikipedia.org/wiki/Lunar_Crater_Radio_Telescope https://en.wikipedia.org/wiki/Lunar_Crater_Radio_Telescope
  - christophilus 5mo ago
    Agreed. It’s the only solution short of a ban on constellations.
    - silon42 5mo ago
      IMO, everyone that launches/operates a constellation should pay for launch of large telescope every 5-10 years (assuming science organizations can fund/build them).
  - maxnoe 5mo ago
    Our telescopes actually need the (or at least an) atmosphere to function. There are some classes of observatories, which you cannot build in space but which are still affected by satellites to some degree.
    - ultratalk 5mo ago
      > Our telescopes actually need the (or at least an) atmosphere to function. What about Hubble, Chandra, Spitzer, JWST, etc? As of my understanding, the only reason we haven't built radio and and other long-wave telescopes in space is because of their impractical size preventing them from being deployed in orbit. > There are some classes of observatories, which you cannot build in space but which are still affected by satellites to some degree. Examples?
      - voidUpdate 5mo ago
        I believe we haven't built radio telescopes in space because we don't need to, and building them in space would be a lot more expensive. https://commons.wikimedia.org/wiki/File:Atmospheric_electromagnetic_transmittance_or_opacity.jpg https://commons.wikimedia.org/wiki/File:Atmospheric_electrom... This shows that wavelengths between ~10cm and ~10m are largely unaffected by the atmosphere, so you wouldn't gain much from putting receivers of those wavelengths in space. Spitzer and JWST (IR), and Chandra (x-ray) operate in bands that are generally blocked by the atmosphere, and Hubble gets better images than a similarly sized earth-based telescope because of the atmospheric distortion (stars don't "twinkle" when you're in space), however there are still earth-based visible light telescopes because you can more easily build a massive one on earth than in space
      - maxnoe 5mo ago
        Imaging Atmospheric Cherenkov Telescopes, we detect optical light emitted by high energy particle Cascades in the atmosphere to observe cosmic gamma radiation. The particles need the atmosphere to interact, Cherenkov light is only emitted in an optical medium and because it's optical light we measure we are affected by satellites. Not as strongly as optical telescopes though, because the air showers last for only tens of nanoseconds.
  - adrian_b 5mo ago
    Unfortunately, that seems to be the only solution. However, it has serious disadvantages. It will exclude the poorer from astronomical research, except within the limits enabled by whatever cooperation the richer will be willing to do with them. For the richer, that will make astronomical research much more expensive. When even USA, who claims to be the richest country, cuts a lot of the scientific funding, this makes likely a great reduction in the research targets that could be accomplished, even if a Lunar array of telescopes and radiotelescopes and communication relays for them were approved. While professionals might still be able to do some work, the amateurs will be able less and less to enjoy the sight of the distant Universe. There are already many years since I have become unable to see the sky that I enjoyed looking at when young, because it cannot be seen from the city where I live, due to light pollution (and high buildings). To see it again, I would have to go somewhere up in the mountains, far from a city or village, but I have not succeeded to do this recently. Even there now you can hardly look at the sky without seeing satellites, and it will only become much worse. Nowadays there are many children who have never seen even once the sky that our ancestors were seeing every night, so many passages from old texts that mention the sky are unintelligible for them.
    - inquirerGeneral 5mo ago
      [dead]
    - mgfist 5mo ago
      I get what you're saying, but poor people want cheap internet/phone connectivity. They can't afford telescopes anyways. And starlink (and the like) have more uses beyond good remote connectivity. They're a big reason why Ukraine didn't lose to Russia. They're also a potential avenue for people in oppressed nations to talk to the rest of the world (eg: Iran has a death penalty for starlink usage to counter this point).
      - adev_ 5mo ago
        > I get what you're saying, but poor people want cheap internet/phone connectivity. Nope. Starlink is not a tool for poor people. It's first and foremost a tool for middle class living in rural area with poor connectivity. As a comparison, it is estimated to that there is around 198M people in Nigeria with a Mobile phone connectivity. Compared around 67K Starlink users. Mobile being around 2-3x cheaper than Starlink there (even without considering the hardware), it remains an upper middle class privilege.
  - Aboutplants 5mo ago
    Any chance of CubeSat style of telescopes at some point?
    - SiempreViernes 5mo ago
      Sure, there have already been some launched and predictably they are only adequate to look at the bright stuff we already knew about from the big telescopes. A small telescope is just a small telescope even when you put it in space.
  - iso1631 5mo ago
    > . We should put a radio telescope on the far side of the moon [0] to benefit from the thousands of kilometers of lunar material separating Earth's emissions from telescopes. Do you really think a starlink style installation won't be put in orbit of the moon before such a telescope could be funded?
    - adev_ 5mo ago
      > Do you really think a starlink style installation won't be put in orbit of the moon before such a telescope could be funded? There are ITUs rules that forbid that and the far side of the moon is declared as radio quiet.
      - SiempreViernes 5mo ago
        Starlinks are already spewing out into supposedly protected radio bands on Earth, good look getting these rules respected on the Moon when they aren't here.
      - bluGill 5mo ago
        Those rules won't last long once (IF) there are significant numbers of people on the moon. The rules are easy to agree to today (50 years ago) because nobody could do anything otherwise anyway. Once the rules are getting in the way of a significant number of people they will change. I make no predictions how they will change, but the current rules are obviously unworkable if significant numbers of people live in space. I also make no predictions on if we will ever get significant numbers of people living in space - there are a lot of hard/expensive problems that may not be solvable.
        adev_ 5mo ago
        > Those rules won't last long once (IF) there are significant numbers of people on the moon. Maybe. If you believe we are heading to a situation with large numbers of colonies on the moon. For now we are no way there and already struggle to just get back there.
  - AntiUSAbah 5mo ago
    Its still worth while for every normal human to have access to space if the benefit of this stuff is not relevant for most people. And with 9 million customers its not.
  - NegativeLatency 5mo ago
    Or even out past the heliosphere/heliopause
chris_va 5mo ago
Not to disagree, but stacking a series of exposures with a sigma-clipped mean (or similar) should still get a nice image.
- oofbey 5mo ago
  Exactly. It’s not that hard to remove the satellites. It’s almost easier than whining about it. But whining is more fun.
  - adrian_b 5mo ago
    It is not hard to remove the satellites, but that is not free. It reduces the signal-to-noise ratio of the image, making more difficult the detection of faint objects.
    - MarkusQ 5mo ago
      It _increases_ the signal to noise ratio. It's a denoising technique, and that's what they do. Compared to the processing already done to get data from astronomical data, yeah, it's essentially free.
    - oofbey 5mo ago
      True. But that’s never the framing you hear from astronomers. It’s how the satellites are “ruining” the pictures, like this whole thread. The SNR degradation isn’t even very much. Noise goes down by 1/sqrt(N) samples. In a stack like this might have 5-40 images depending on how they did it. Typically a satellite will only show up on one of those images for a given pixel. So by excluding that image from the stack that pixel’s noise would go up by a ratio of sqrt(N/(N-1)) which for 5-40 images is between 12% more noise and 1% more noise. Only the pixels with satellite tracks. True there’s more noise if you remove the satellites. But it’s probably only a few percent noisier, and only in the places where the satellite flew. Add a few more images to the stack and accept that the world is changing.
oofbey 5mo ago
Computational photography has long been table stakes for astronomers. They just need to up their game on satellite rejection algorithms. Satellites look nothing like stars, and as such are pretty easy to remove with software. Pictures like this which leave them in are just there to make a point.
MagicMoonlight 5mo ago
So what? Astronomy doesn’t actually produce anything meaningful. Hell, astronomers were telling us the sun orbited the earth for 99% of human history. Shoot forward to the present day and they can tell us… the universe started at some point somehow. Great job guys. Really earning those billions in grants. Actually going to space has far more value.
- ragebol 5mo ago
  Have you heard of Kessler Syndrome? More satellites means higher risk on that happening and not going to space until all the debris of a collision deorbits.

Yeah, I kinda get why astronomers are not particularly happy with satellite constellations.

by ragebol 5mo ago

Yeah, I kinda get why astronomers are not particularly happy with satellite constellations.

Doesn't matter. We, as a society, have said we're willing to give up nature in exchange for money machines the go brrrrr.

adev_ 5mo ago

And this is just the visible spectrum. The situation is one order of magnitude worst in radio-astronomy. It is fair to state that satellite constellations will certainly be the main obstacle to multiple major scientific discoveries in the next decade.

ultratalk 5mo ago
Opinion: We need to move our astronomical observation equipment off of Earth and onto other bodies, especially radio astronomy, which, unlike telescopes that operate in other wavelengths, is still affected by Earth's emissions in LEO/near-Earth space. We should put a radio telescope on the far side of the moon [0] to benefit from the thousands of kilometers of lunar material separating Earth's emissions from telescopes. [0] https://doi.org/10.1109/AERO50100.2021.9438165 https://doi.org/10.1109/AERO50100.2021.9438165 [1] https://en.wikipedia.org/wiki/Lunar_Crater_Radio_Telescope https://en.wikipedia.org/wiki/Lunar_Crater_Radio_Telescope
- christophilus 5mo ago
  Agreed. It’s the only solution short of a ban on constellations.
  - silon42 5mo ago
    IMO, everyone that launches/operates a constellation should pay for launch of large telescope every 5-10 years (assuming science organizations can fund/build them).
- maxnoe 5mo ago
  Our telescopes actually need the (or at least an) atmosphere to function. There are some classes of observatories, which you cannot build in space but which are still affected by satellites to some degree.
  - ultratalk 5mo ago
    > Our telescopes actually need the (or at least an) atmosphere to function. What about Hubble, Chandra, Spitzer, JWST, etc? As of my understanding, the only reason we haven't built radio and and other long-wave telescopes in space is because of their impractical size preventing them from being deployed in orbit. > There are some classes of observatories, which you cannot build in space but which are still affected by satellites to some degree. Examples?
    - voidUpdate 5mo ago
      I believe we haven't built radio telescopes in space because we don't need to, and building them in space would be a lot more expensive. https://commons.wikimedia.org/wiki/File:Atmospheric_electromagnetic_transmittance_or_opacity.jpg https://commons.wikimedia.org/wiki/File:Atmospheric_electrom... This shows that wavelengths between ~10cm and ~10m are largely unaffected by the atmosphere, so you wouldn't gain much from putting receivers of those wavelengths in space. Spitzer and JWST (IR), and Chandra (x-ray) operate in bands that are generally blocked by the atmosphere, and Hubble gets better images than a similarly sized earth-based telescope because of the atmospheric distortion (stars don't "twinkle" when you're in space), however there are still earth-based visible light telescopes because you can more easily build a massive one on earth than in space
    - maxnoe 5mo ago
      Imaging Atmospheric Cherenkov Telescopes, we detect optical light emitted by high energy particle Cascades in the atmosphere to observe cosmic gamma radiation. The particles need the atmosphere to interact, Cherenkov light is only emitted in an optical medium and because it's optical light we measure we are affected by satellites. Not as strongly as optical telescopes though, because the air showers last for only tens of nanoseconds.
- adrian_b 5mo ago
  Unfortunately, that seems to be the only solution. However, it has serious disadvantages. It will exclude the poorer from astronomical research, except within the limits enabled by whatever cooperation the richer will be willing to do with them. For the richer, that will make astronomical research much more expensive. When even USA, who claims to be the richest country, cuts a lot of the scientific funding, this makes likely a great reduction in the research targets that could be accomplished, even if a Lunar array of telescopes and radiotelescopes and communication relays for them were approved. While professionals might still be able to do some work, the amateurs will be able less and less to enjoy the sight of the distant Universe. There are already many years since I have become unable to see the sky that I enjoyed looking at when young, because it cannot be seen from the city where I live, due to light pollution (and high buildings). To see it again, I would have to go somewhere up in the mountains, far from a city or village, but I have not succeeded to do this recently. Even there now you can hardly look at the sky without seeing satellites, and it will only become much worse. Nowadays there are many children who have never seen even once the sky that our ancestors were seeing every night, so many passages from old texts that mention the sky are unintelligible for them.
  - inquirerGeneral 5mo ago
    [dead]
  - mgfist 5mo ago
    I get what you're saying, but poor people want cheap internet/phone connectivity. They can't afford telescopes anyways. And starlink (and the like) have more uses beyond good remote connectivity. They're a big reason why Ukraine didn't lose to Russia. They're also a potential avenue for people in oppressed nations to talk to the rest of the world (eg: Iran has a death penalty for starlink usage to counter this point).
    - adev_ 5mo ago
      > I get what you're saying, but poor people want cheap internet/phone connectivity. Nope. Starlink is not a tool for poor people. It's first and foremost a tool for middle class living in rural area with poor connectivity. As a comparison, it is estimated to that there is around 198M people in Nigeria with a Mobile phone connectivity. Compared around 67K Starlink users. Mobile being around 2-3x cheaper than Starlink there (even without considering the hardware), it remains an upper middle class privilege.
- Aboutplants 5mo ago
  Any chance of CubeSat style of telescopes at some point?
  - SiempreViernes 5mo ago
    Sure, there have already been some launched and predictably they are only adequate to look at the bright stuff we already knew about from the big telescopes. A small telescope is just a small telescope even when you put it in space.
- iso1631 5mo ago
  > . We should put a radio telescope on the far side of the moon [0] to benefit from the thousands of kilometers of lunar material separating Earth's emissions from telescopes. Do you really think a starlink style installation won't be put in orbit of the moon before such a telescope could be funded?
  - adev_ 5mo ago
    > Do you really think a starlink style installation won't be put in orbit of the moon before such a telescope could be funded? There are ITUs rules that forbid that and the far side of the moon is declared as radio quiet.
    - SiempreViernes 5mo ago
      Starlinks are already spewing out into supposedly protected radio bands on Earth, good look getting these rules respected on the Moon when they aren't here.
    - bluGill 5mo ago
      Those rules won't last long once (IF) there are significant numbers of people on the moon. The rules are easy to agree to today (50 years ago) because nobody could do anything otherwise anyway. Once the rules are getting in the way of a significant number of people they will change. I make no predictions how they will change, but the current rules are obviously unworkable if significant numbers of people live in space. I also make no predictions on if we will ever get significant numbers of people living in space - there are a lot of hard/expensive problems that may not be solvable.
      - adev_ 5mo ago
        > Those rules won't last long once (IF) there are significant numbers of people on the moon. Maybe. If you believe we are heading to a situation with large numbers of colonies on the moon. For now we are no way there and already struggle to just get back there.
- AntiUSAbah 5mo ago
  Its still worth while for every normal human to have access to space if the benefit of this stuff is not relevant for most people. And with 9 million customers its not.
- NegativeLatency 5mo ago
  Or even out past the heliosphere/heliopause

chris_va 5mo ago

Not to disagree, but stacking a series of exposures with a sigma-clipped mean (or similar) should still get a nice image.

oofbey 5mo ago
Exactly. It’s not that hard to remove the satellites. It’s almost easier than whining about it. But whining is more fun.
- adrian_b 5mo ago
  It is not hard to remove the satellites, but that is not free. It reduces the signal-to-noise ratio of the image, making more difficult the detection of faint objects.
  - MarkusQ 5mo ago
    It _increases_ the signal to noise ratio. It's a denoising technique, and that's what they do. Compared to the processing already done to get data from astronomical data, yeah, it's essentially free.
  - oofbey 5mo ago
    True. But that’s never the framing you hear from astronomers. It’s how the satellites are “ruining” the pictures, like this whole thread. The SNR degradation isn’t even very much. Noise goes down by 1/sqrt(N) samples. In a stack like this might have 5-40 images depending on how they did it. Typically a satellite will only show up on one of those images for a given pixel. So by excluding that image from the stack that pixel’s noise would go up by a ratio of sqrt(N/(N-1)) which for 5-40 images is between 12% more noise and 1% more noise. Only the pixels with satellite tracks. True there’s more noise if you remove the satellites. But it’s probably only a few percent noisier, and only in the places where the satellite flew. Add a few more images to the stack and accept that the world is changing.

oofbey 5mo ago

Computational photography has long been table stakes for astronomers. They just need to up their game on satellite rejection algorithms. Satellites look nothing like stars, and as such are pretty easy to remove with software. Pictures like this which leave them in are just there to make a point.

MagicMoonlight 5mo ago

So what? Astronomy doesn’t actually produce anything meaningful. Hell, astronomers were telling us the sun orbited the earth for 99% of human history. Shoot forward to the present day and they can tell us… the universe started at some point somehow. Great job guys. Really earning those billions in grants. Actually going to space has far more value.

ragebol 5mo ago
Have you heard of Kessler Syndrome? More satellites means higher risk on that happening and not going to space until all the debris of a collision deorbits.