3 ms·

The only method that could be used to (in theory) see something as small as the Flag on the Moon would be to use two optical telescopes set (for example) 1000 m

by borism 16y ago

The only method that could be used to (in theory) see something as small as the Flag on the Moon would be to use two optical telescopes set (for example) 1000 miles apart. This would easily provide the required resolution, the huge problem however is combining the images from both telescopes in such a way to realize the resolution. As far as I know right now that technology is not available. Even if the technology was available, the unsteadiness of the Earth's atmosphere would likely render the method useless. I've read about this method being used a lot in radioastronomy. But how does one proceed to use it in optical astronomy? And surely if it is possible to algorithmize this it wouldn't be a problem to write a program that will take care of such "technology"?

route66 16y ago
Aperture synthesis. For instance: http://www.mrao.cam.ac.uk/telescopes/coast/handout.html http://www.mrao.cam.ac.uk/telescopes/coast/handout.html
cletus 16y ago
The method you're referring to is called optical interferometry [1] (well, interferometry in general but optical for visible light obviously). Great strides have been made in this department in recent years and I believe it's been used for exoplanet detection [2]. [1]: http://en.wikipedia.org/wiki/Optical_interferometry http://en.wikipedia.org/wiki/Optical_interferometry [2]: http://en.wikipedia.org/wiki/Astronomical_optical_interferometry http://en.wikipedia.org/wiki/Astronomical_optical_interferom...
- borism 16y ago
  mkey, but one will have to build 3.5+ mile wide optical interferometer... largest being built right now is 400m wide: http://en.wikipedia.org/wiki/Magdalena_Ridge_Observatory_Interferometer http://en.wikipedia.org/wiki/Magdalena_Ridge_Observatory_Int...
smhinsey 16y ago
I can't speak for the interferometry side, but when it comes to reducing distortion caused by the atmosphere, a lot of advances have been built into the latest generation of big terrestrial telescopes that go a long way towards solving the problem. I have no idea what sort of improvement over the status quo you might need for such a system as described, but it's not unreasonable to think that at least that part of it would be feasible one day.
mturmon 16y ago
Here's a nice pic of a wide-baseline optical interferometry setup: http://pti.jpl.nasa.gov/ http://pti.jpl.nasa.gov/ The telescopes are in the two shed-like white buildings (one in the foreground, the other in shadows in the background). The collected light is bounced through the white pipes into the large building in the middle, where it is combined and interference fringes are collected. (It has to be combined optically to preserve phase.) To work, the distances between the two collectors must be maintained very precisely. Besides the obvious optical issues, the technical challenge becomes to measure the separation of the collectors very precisely ("metrology"). For more: http://olbin.jpl.nasa.gov/ http://olbin.jpl.nasa.gov/

by borism 16y ago

route66 16y ago

Aperture synthesis. For instance: http://www.mrao.cam.ac.uk/telescopes/coast/handout.html http://www.mrao.cam.ac.uk/telescopes/coast/handout.html

cletus 16y ago

The method you're referring to is called optical interferometry [1] (well, interferometry in general but optical for visible light obviously). Great strides have been made in this department in recent years and I believe it's been used for exoplanet detection [2]. [1]: http://en.wikipedia.org/wiki/Optical_interferometry http://en.wikipedia.org/wiki/Optical_interferometry [2]: http://en.wikipedia.org/wiki/Astronomical_optical_interferometry http://en.wikipedia.org/wiki/Astronomical_optical_interferom...

borism 16y ago
mkey, but one will have to build 3.5+ mile wide optical interferometer... largest being built right now is 400m wide: http://en.wikipedia.org/wiki/Magdalena_Ridge_Observatory_Interferometer http://en.wikipedia.org/wiki/Magdalena_Ridge_Observatory_Int...

smhinsey 16y ago

I can't speak for the interferometry side, but when it comes to reducing distortion caused by the atmosphere, a lot of advances have been built into the latest generation of big terrestrial telescopes that go a long way towards solving the problem. I have no idea what sort of improvement over the status quo you might need for such a system as described, but it's not unreasonable to think that at least that part of it would be feasible one day.

mturmon 16y ago

Here's a nice pic of a wide-baseline optical interferometry setup: http://pti.jpl.nasa.gov/ http://pti.jpl.nasa.gov/ The telescopes are in the two shed-like white buildings (one in the foreground, the other in shadows in the background). The collected light is bounced through the white pipes into the large building in the middle, where it is combined and interference fringes are collected. (It has to be combined optically to preserve phase.) To work, the distances between the two collectors must be maintained very precisely. Besides the obvious optical issues, the technical challenge becomes to measure the separation of the collectors very precisely ("metrology"). For more: http://olbin.jpl.nasa.gov/ http://olbin.jpl.nasa.gov/