What are the upper physical resolution limits on telescopes?

In summary: The angular resolution of a telescope is directly related to the size of the telescope and inversely related to the distance to the target. If you double the size of the telescope you quadruple the resolution. So a 200 meter telescope would have a resolution of 1 meter at one parsec.
  • #1
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So if we become a Kardashev type II civilization, able to harvest all the energy and matter in the solar system what could we see through the massive telescopes that would be possible to construct? (say with a lens the size of Saturn). Could you get surface detail on extrasolar planets, for example?
 
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  • #2
Theoretically, yes. The theoretical angular resolving power of a telescope is given by θ = 1.2 λ / D, where λ is the wavelength of light and D is the diameter of the telescope. The angle subtended by an object of size S at a distance d is just S/d. So with a telescope of size D, you could resolve an object of size S = 1.2 λ / D * d at a distance d. If you plug in the numbers, in visible light with a telescope the size of Saturn, on a planet 10 parsecs away you could resolve an object about 1.5 km across, so you could see surface detail nicely. Of course the technical challenge of building a telescope the size of Saturn are pretty huge.
 
  • #3
Size would not be the only consideration. The reason we launch sensitive telescopes into space is because the atmosphere distorts images. Software can help with that, but it's not as good as being above the atmosphere. Space isn't empty, gas, dust, warped space... all would limit the theoretical resolution of a telescope.
 
  • #4
Cool, thanks. I do wonder if a few hundred years from now this kind of telescope is less of a challenge than interstellar travel. In theory, you could have the same kind of knowledge of our local area of the Milky Way as we do today of our solar system

So playing with this a more realistic 100 meter diameter lens in a space telescope could resolve a Jupiter-sized object at 1 parsec and a 1KM lens could see an Earth sized object at that distance
 
  • #5
Size actually is not limited that way. With interferometry, it would likely be feasible with existing or near-term technology to use Earth's orbit as the baseline.
 
  • #7
The only thing you lose with aperture synthesis is light gathering power. You give that up using small telescopes placed far from one another where you gain the resolution of a mirror roughly the size of the distance between them. The light gathering power is then just the sum of the area's of the telescopes used. So you could theoretically make a telescope aperture the size of the solar system if you had one say at the distance of Pluto and another on the opposite side, then you would have a telescope with the resolving power of a scope about 10 billion kilometers across but with the light gathering power of just the scopes. That would give a resolution of one MICRON at one parsec:)
 
  • #8
Resolution is strongly related to angular diameter of the target vs aperature diameter. For extraterrestrial bodies it is hopelessly tiny. Even our best telescopes cannot resolve anything smaller than a few hundred meters on the moon.
 

1. What is the maximum resolution of a telescope?

The maximum resolution of a telescope is determined by its aperture, or the diameter of its primary lens or mirror. The theoretical limit for a telescope's resolution is known as the diffraction limit, and it is calculated using the formula λ/D, where λ is the wavelength of light and D is the diameter of the telescope's aperture. In practice, factors such as atmospheric turbulence can further limit a telescope's resolution.

2. How does the size of a telescope affect its resolution?

The size of a telescope's aperture directly impacts its resolution. A larger aperture allows for more light to enter the telescope and be focused, resulting in a higher resolution image. This is why larger telescopes are generally able to produce clearer and more detailed images than smaller ones.

3. Can technology improve the resolution of telescopes beyond the diffraction limit?

While the diffraction limit sets a theoretical maximum for a telescope's resolution, advancements in technology have allowed for techniques such as adaptive optics and interferometry to improve the resolution beyond this limit. These methods use advanced equipment and algorithms to correct for atmospheric disturbances and combine the light from multiple telescopes, resulting in sharper and more detailed images.

4. What is the role of atmospheric conditions in telescope resolution?

The Earth's atmosphere can greatly impact the resolution of a telescope. Turbulence in the atmosphere can cause the light from stars to appear distorted or blurry, limiting the telescope's ability to produce clear images. This is why many telescopes are built in remote locations with stable atmospheric conditions, or use adaptive optics to compensate for atmospheric disturbances.

5. Are there any limits to how much resolution can be improved on telescopes?

While technology and advancements in techniques have greatly improved the resolution of telescopes, there are still limits to how much it can be improved. The diffraction limit is a fundamental limitation based on the properties of light, and it cannot be completely overcome. Additionally, there are practical limitations such as cost and the size of equipment that can also restrict the resolution of telescopes.

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