Picturing Galaxies: How We Capture Outer Space

In summary, the conversation discusses the ability to take pictures of galaxies using telescopes, both on Earth and in space. While space-based telescopes have advantages such as no atmospheric interference, ground-based telescopes can still produce high-quality images and are used for dedicated survey work. The upcoming Webb telescope is expected to have deeper infrared penetration, but ground-based telescopes will continue to play a major role due to their aperture and angular resolution capabilities. Additionally, ground-based telescopes have the advantage of being able to easily upgrade or adjust their instruments. The conversation also mentions the challenges of imaging very distant and dim objects, as well as the potential for larger space telescopes in the future.
  • #1
johncena
131
1
How was we able to take the pictures of galaxies?
 
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  • #2
The Hubble?
 
  • #3
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
Frinkz said:
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
James Leighe said:
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
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
James Leighe said:
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
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
Obviously it is not our galaxy. Pictures of other galaxies are old news.
 
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Related to Picturing Galaxies: How We Capture Outer Space

1. What is the purpose of capturing images of galaxies?

The purpose of capturing images of galaxies is to study and understand the vast and diverse universe that surrounds us. By observing these images, scientists can gather information about the formation, structure, and evolution of galaxies, as well as the processes that occur within them. This can provide insights into the origins of our own galaxy, the Milky Way, and the overall composition of the universe.

2. How do scientists capture images of galaxies?

Scientists use a variety of instruments and techniques to capture images of galaxies. Some of the most common methods include using telescopes equipped with specialized cameras, such as charge-coupled devices (CCDs) or infrared detectors, to detect the light emitted by galaxies. Scientists also use computer algorithms and image processing techniques to enhance and analyze these images, allowing them to reveal more detailed information about the galaxies.

3. Why do some galaxy images appear colorful?

The colorful appearance of galaxy images is often due to the use of filters and false-color techniques used by scientists to enhance certain features or wavelengths of light. This can help reveal specific details or structures within the galaxy that may not be visible to the human eye. The colors may also be representative of the different types of light emitted by the galaxy, such as infrared, ultraviolet, or visible light.

4. Can scientists capture images of galaxies outside of the visible light spectrum?

Yes, scientists can capture images of galaxies in a wide range of wavelengths, including radio, infrared, ultraviolet, and X-ray. Each type of light reveals different information about the galaxy, such as its temperature, composition, or activity. By combining these images, scientists can create a more complete picture of the galaxy and its properties.

5. What are some challenges scientists face when capturing images of galaxies?

One of the main challenges scientists face when capturing images of galaxies is the vast distances involved. As light travels through space, it can be distorted or absorbed by dust and gas, making it difficult to capture clear and accurate images. Scientists also have to contend with interference from Earth's atmosphere, which can affect the quality of the images. Additionally, capturing images of galaxies that are constantly moving and evolving presents its own set of challenges for scientists.

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