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Sort of related question: Would space telescopes use interferometry to get a clearer picture? If we had thousands of telescopes spread across the solar system

Sort of related question: Would space telescopes use interferometry to get a clearer picture? If we had thousands of telescopes spread across the solar system, what sort of images of distant stars/planets/galaxies could we gather? Would such an array be scientifically worth making in our distant future, or does it suffer from diminishing returns?

jiggawatts 2y ago
There have been plans drawn up for space telescopes flying in formation to do the same kind of interferometry thing as the Keck observatory. The problem is that even far from the Earth, there are tiny but significant forces pushing the space telescopes around. Solar wind, outgassing, gravitational influences from planets, etc... The precision required to maintain formation is... challenging. E.g.: https://arxiv.org/abs/1907.09583 https://arxiv.org/abs/1907.09583
- gus_massa 2y ago
  Why do you need to maintain formation? Can the just fly randomly and fix the problem storing the info and a software that gets the positions and calculate the delays? For radio frequency I think it's possible. For visible light, I guess you must do the interference using very accurate mirrors to aim to the central point and that move slightly forward and backward to get the correct phase shift. I think it's not impossible, but very difficult.
  - jiggawatts 2y ago
    You might be able to capture the phase information for very long IR wavelengths using something like Rapid Single Flux Quantum (RSFQ) circuitry, but I doubt it would be practical. One issue would be that the data volume would be absurd, likely petabytes per second. Practical observations where this would be useful would require long integration times of many hours.
    - gus_massa 2y ago
      In systems like https://en.wikipedia.org/wiki/Very_Large_Array https://en.wikipedia.org/wiki/Very_Large_Array , do they use the phase information to join the data from different antenas? '
      - jiggawatts 2y ago
        Yes, but at radio frequencies, where the data rate is much lower than with visible light.
Cthulhu_ 2y ago
For a comparable endeavour, they combined the data of telescopes across the world to create a planet-diameter-sized telescope and with that, the first image of a black hole; extending something like that solar-system-wide would make a solar-system-wide telescope. I'm no astronomer but I'd say it's worth it.

jiggawatts 2y ago

There have been plans drawn up for space telescopes flying in formation to do the same kind of interferometry thing as the Keck observatory. The problem is that even far from the Earth, there are tiny but significant forces pushing the space telescopes around. Solar wind, outgassing, gravitational influences from planets, etc... The precision required to maintain formation is... challenging. E.g.: https://arxiv.org/abs/1907.09583 https://arxiv.org/abs/1907.09583

gus_massa 2y ago
Why do you need to maintain formation? Can the just fly randomly and fix the problem storing the info and a software that gets the positions and calculate the delays? For radio frequency I think it's possible. For visible light, I guess you must do the interference using very accurate mirrors to aim to the central point and that move slightly forward and backward to get the correct phase shift. I think it's not impossible, but very difficult.
- jiggawatts 2y ago
  You might be able to capture the phase information for very long IR wavelengths using something like Rapid Single Flux Quantum (RSFQ) circuitry, but I doubt it would be practical. One issue would be that the data volume would be absurd, likely petabytes per second. Practical observations where this would be useful would require long integration times of many hours.
  - gus_massa 2y ago
    In systems like https://en.wikipedia.org/wiki/Very_Large_Array https://en.wikipedia.org/wiki/Very_Large_Array , do they use the phase information to join the data from different antenas? '
    - jiggawatts 2y ago
      Yes, but at radio frequencies, where the data rate is much lower than with visible light.

Cthulhu_ 2y ago

For a comparable endeavour, they combined the data of telescopes across the world to create a planet-diameter-sized telescope and with that, the first image of a black hole; extending something like that solar-system-wide would make a solar-system-wide telescope. I'm no astronomer but I'd say it's worth it.