TMT construction begins Monday 15 July

[TomK]

Here’s an article about the seven telescopes that changed how we view the cosmos.  It includes Galileo’s telescope & Isaac Newton’s telescope.  And the TMT.

Now the only limitation was how big you could make your mirror, leading to a new generation of telescopes dubbed Extremely Large Telescopes (ELTs) that will look deeper and with more precision than anything that has gone before.

There are two ELTs currently in construction.

The Thirty Meter Telescope (TMT) will have a 30m-wide mirror and is being built on Hawaii’s Mauna Kea, with an expected first light in 2027.

Elsewhere, the 39.3m-wide European Extremely Large Telescope (E-ELT) is being built in Chile, ready to start observing in 2025.
https://www.skyatnightmagazine.com/space...elescopes/

I expected a little better from the magazine when it comes to ELTs. It says two ELTs are being built - that is not true as obviously, the TMT is not currently being built. I'm not sure if it's confusion by the author or their information is old (the TMT will certainly not see first light in 2027 even if they restart construction tomorrow). The other ELT that is planned is the Giant Magellan Telescope (GMT) which, like the E-ELT, will be built in Chile with a primary mirror diameter of 24.5 meters, i.e., in the southern hemisphere, hence the need for an ELT in the northern hemisphere.