Picture of galaxy

  • Thread starter johncena
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Main Question or Discussion Point

How was we able to take the pictures of galaxies?
 

Answers and Replies

  • #2
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The Hubble?
 
  • #3
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You can see galaxies with telescopes on Earth, what do you mean?
 
  • #4
You can even see adromeda with the naked eye, you should google the question you asked before putting it on this site
 
  • #5
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You can see galaxies with telescopes on Earth, what do you mean?
Kinda, I mean, with all that atmosphere and whatnot it's definitely harder. The good pictures of stuff far away probably come from satellites.
 
  • #6
turbo
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Kinda, I mean, with all that atmosphere and whatnot it's definitely harder. The good pictures of stuff far away probably come from satellites.
Wrong. There are plenty of land-based telescopes that image distant galaxies quite precisely. While it is true that space-based telescopes don't suffer from atmospheric extinction and can gather light of wavelengths that are absorbed by the atmosphere, they are necessarily MUCH smaller than the 'scopes that we can operate on Earth, and their targeting requirements, approved observation-time, etc restrict how much stuff we can image. In contrast, Earth-based telescopes can be used for dedicated survey work. Schmidt telescopes have done all-sky surveys in the Northern and Southern hemispheres for for decades.
 
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  • #7
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Can't argue with the truth.

But I guess you CAN'T get the REALLY far away stuff because it's too red-shifted :P
(Does the smallness of the telescope hurt it's ability to resolve the red-shifted wavelengths well?)

Does the same phenomenon that causes 'twinkling' stars effect land based telescopes at all?
 
  • #8
turbo
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Can't argue with the truth.

But I guess you CAN'T get the REALLY far away stuff because it's too red-shifted :P

Does the same phenomenon that causes 'twinkling' stars effect land based telescopes at all?
Well, we should be able to dig deeper with the upcoming Webb telescope. It will feature much deeper IR penetration than Hubble. Still, ground-based telescopes will do much of the heavy lifting. We can't launch something equivalent to Keck, LBT, etc, so the eyes on the ground will have the major role. Orbiting instruments have some obvious advantages, but aperture and angular resolution are the domain of ground-based instruments. Adaptive optics are helping operators of ground-based 'scopes get crisper images, and that technology is still improving.

And no, space-based telescopes don't have problems with "twinkling", because that is an effect of atmospheric refraction.
 
  • #9
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An advantage of ground based telescopes: adding, upgrading, or just fiddling with optics, filters, instruments, etc. No need for a space walk or launching another 'scope.

The far away stuff is just too dim to image without days of exposure. The Hubble Ultra Deep Fields http://en.wikipedia.org/wiki/Hubble_Ultra_Deep_Field required over eleven days of imaging.

It would be nice to have a few 1000 meter diameter telescopes in space.
 
  • #10
Chronos
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Obviously it is not our galaxy. Pictures of other galaxies are old news.
 
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