6 ms·

Bear in mind that Mauna Kea is only one of two excellent locations in the northern hemisphere... the other being Gran Canarias in the Atlantic. Chile is equally

Bear in mind that Mauna Kea is only one of two excellent locations in the northern hemisphere... the other being Gran Canarias in the Atlantic. Chile is equally as good as Hawaii with stable ocean air and dry conditions making for fantastic seeing conditions, but it covers a very different part of the night sky down south. I can’t imagine UH doing what the protectors are asking and simply plonk the TMT in a completely different ocean. TMT is the only planned 30m class telescope in the northern hemisphere at the moment. Longitudinal placement is also important for tracking transient phenomena such as FRB’s and NEO’s. this is why Hawaii is such a critical location for doing optical observations. I would not be surprised if the Chinese build a thirty meter class telescope at some stage. Not sure where though?

walrus01 7y ago
I'm no telescope expert, but wouldn't somewhere high in the mountains near Leh, India also be suitable? Or near Skardu, Pakistan? https://en.wikipedia.org/wiki/Skardu https://en.wikipedia.org/wiki/Skardu On the high Tibetan plateau somewhere not very far from this airport? https://en.wikipedia.org/wiki/Qamdo_Bamda_Airport https://en.wikipedia.org/wiki/Qamdo_Bamda_Airport
- mkl 7y ago
  China has lots of mountains and desert, so I don't think locations are a problem. There have been people-based problems though: https://www.wired.com/story/china-fast-worlds-largest-telescope-tourists/ https://www.wired.com/story/china-fast-worlds-largest-telesc...
- PopePompus 7y ago
  Mountains within large mountain ranges are not as good as a (relatively) isolated peak like Mauna Kea. An isolated peak can have something resembling laminar flow of the air over the summit, resulting in good "seeing", whilst a peak within a large range has a more turbulent air flow above it.
  - GlennS 7y ago
    Muana Kea also has a (permanent?) tropical inversion layer. This means a layer of warm air some way below the summit. What it looks like in practice is a very thick layer of dirty clouds topped by pristine, cloudless air. Additionally, Hawaii has strict rules about light pollution, and street lights designed not to disrupt the telescopes.
- brandmeyer 7y ago
  Altitude and dryness are only two factors. The other major one is the relative calmness of the atmosphere. The air is stable and calm because the "ground" is flat for many miles around at Mauna Kea, and the mountain protrudes extra high above the local "ground". Before light pollution really kicked into gear, Mt. Wilson and Mt. Palomar were also pretty good because the ground is flat upwind: The Pacific Ocean. Sites in the middle of mountain ranges aren't necessarily any good - you have to see what's upwind of the site. The high plains near Denver, CO are no good because the Rockies are upwind, for example. The technical term in astronomy circles is "seeing" if you want to learn more.

walrus01 7y ago

I'm no telescope expert, but wouldn't somewhere high in the mountains near Leh, India also be suitable? Or near Skardu, Pakistan? https://en.wikipedia.org/wiki/Skardu https://en.wikipedia.org/wiki/Skardu On the high Tibetan plateau somewhere not very far from this airport? https://en.wikipedia.org/wiki/Qamdo_Bamda_Airport https://en.wikipedia.org/wiki/Qamdo_Bamda_Airport

mkl 7y ago
China has lots of mountains and desert, so I don't think locations are a problem. There have been people-based problems though: https://www.wired.com/story/china-fast-worlds-largest-telescope-tourists/ https://www.wired.com/story/china-fast-worlds-largest-telesc...
PopePompus 7y ago
Mountains within large mountain ranges are not as good as a (relatively) isolated peak like Mauna Kea. An isolated peak can have something resembling laminar flow of the air over the summit, resulting in good "seeing", whilst a peak within a large range has a more turbulent air flow above it.
- GlennS 7y ago
  Muana Kea also has a (permanent?) tropical inversion layer. This means a layer of warm air some way below the summit. What it looks like in practice is a very thick layer of dirty clouds topped by pristine, cloudless air. Additionally, Hawaii has strict rules about light pollution, and street lights designed not to disrupt the telescopes.
brandmeyer 7y ago
Altitude and dryness are only two factors. The other major one is the relative calmness of the atmosphere. The air is stable and calm because the "ground" is flat for many miles around at Mauna Kea, and the mountain protrudes extra high above the local "ground". Before light pollution really kicked into gear, Mt. Wilson and Mt. Palomar were also pretty good because the ground is flat upwind: The Pacific Ocean. Sites in the middle of mountain ranges aren't necessarily any good - you have to see what's upwind of the site. The high plains near Denver, CO are no good because the Rockies are upwind, for example. The technical term in astronomy circles is "seeing" if you want to learn more.