Here’s a comparison of large optical telescope sizes to the James Webb, Gaia, Kepler and Hubble space telescopes.

VLT is the world’s best, partly because it can operate both as single mirror and as a multi-mirror interferometer where the interferometer has a variable number of dishes (up to four main and many smaller dishes) at variable spacing. Giving 0.05 arc-sec resolution for a single dish and up to 0.002 arc-sec as an interferometer. By comparison, the James Webb’s resolution is about 0.1 arc-sec.

Keck has also done fantastic work, both in single dish and two dish interferometer mode.

Subaru, the Gemini telescopes, and Gran Canarius have done excellent work.
Large Binocular, South Africa, Hobby-Ebberly have not lived up to expectations.
Hooker and Hale were great in their day, pre-1990.

I must look into the Large Sky Area, I haven’t heard a thing about it so far.
From the graphics you can see that the OWL telescope has been cancelled.

Vera Rubin first light is expected in 2023.
The ELT began construction in 2017.
The Giant Magellan Telescope began construction in 2015.

Construction of the 30 meter telescope has been blocked by the bloody environmentalists, even though there isn’t even a single blade of grass on the site for them to complain about, and even though the court ruled that construction could go ahead.

mollwollfumble said:

Here’s a comparison of large optical telescope sizes to the James Webb, Gaia, Kepler and Hubble space telescopes.

VLT is the world’s best, partly because it can operate both as single mirror and as a multi-mirror interferometer where the interferometer has a variable number of dishes (up to four main and many smaller dishes) at variable spacing. Giving 0.05 arc-sec resolution for a single dish and up to 0.002 arc-sec as an interferometer. By comparison, the James Webb’s resolution is about 0.1 arc-sec.

Keck has also done fantastic work, both in single dish and two dish interferometer mode.

Subaru, the Gemini telescopes, and Gran Canarius have done excellent work.
Large Binocular, South Africa, Hobby-Ebberly have not lived up to expectations.
Hooker and Hale were great in their day, pre-1990.

I must look into the Large Sky Area, I haven’t heard a thing about it so far.
From the graphics you can see that the OWL telescope has been cancelled.

Vera Rubin first light is expected in 2023.
The ELT began construction in 2017.
The Giant Magellan Telescope began construction in 2015.

Construction of the 30 meter telescope has been blocked by the bloody environmentalists, even though there isn’t even a single blade of grass on the site for them to complain about, and even though the court ruled that construction could go ahead.

Smaller telescopes hitting way above their size include those at Apache Point – which gave us the Sloan Digital Sky Survey. The WISE space telescope. And the Pan-STARRS telescope with its enormous field of view.

Hmm, LAMOST = Large Area is a Schmidt telescope (very large field of view, 20 square degrees) spectrograph.
To date (data release 8) it has already released spectra of 10 million stars, 200 thousand galaxies and 65 thousand quasars. That’s as many as it was designed to find. These spectra are good enough to find element abundance.

Compare Gaia space telescope, though.
To date (data release 3) there are 220 million “BP/RP spectra” and 1 million “RVS spectra”. I don’t gave a clue as to what the difference is. RVS spectra are sufficient to identify up to 13 chemical constituents.