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For many reasons, ground-based telescopes will continue to play a major role in astronomy. Space telescopes offer advantages for particular types of observatio
by DiogenesKynikos 6y ago
For many reasons, ground-based telescopes will continue to play a major role in astronomy.
Space telescopes offer advantages for particular types of observations, but there are many types of observations for which ground-based telescopes are superior. The basic advantages that ground-based telescopes have are:
* Larger collecting area, which means more photons collected, which means you can see fainter objects.
* With adaptive optics, ground-based telescopes can actually achieve better resolution than space telescopes over small fields of view.
* Ground-based telescopes are far easier to maintain and upgrade.
* Much looser weight, size, radiation-hardening requirements mean that you can do things on the ground that would just be unthinkable in space. You can attach things like massive spectrometers to ground-based telescopes, without having to worry nearly as much about form factor and weight, or whether radiation will damage your electronics.
The advantages that space telescopes have are:
* No weather to deal with.
* You can observe UV and IR wavelengths which the Earth's atmosphere absorbs or emits in - which is extremely difficult/impossible from the ground.
* You can get high resolution over large fields of view. However, you can't reach the same resolution on small fields of view, because ground-based telescopes with a large aperture + adaptive optics will beat you there.
Basically, at any fixed budget, you will be able to build a much larger, more complex instrument on the ground. You only go to space when there's a compelling technical reason to do so (e.g., you need to observe UV light).
- dr_dshiv 6y agoGreat run down, thanks for sharing that. I wanted to make sure you saw this article, I wonder how it changes things when we have a "fast, cheap and out of control" approach to science with many cheap satellites. The article is about ground-based telescopes, but seems extendable to space-based telescopes. Optical aperture synthesis with electronically connected telescopes https://www.nature.com/articles/ncomms7852 https://www.nature.com/articles/ncomms7852