<p>The ELT looks basically on track. It’s scheduled to start scientific observations in 2028 and is now half-completed. See <a href="https://www.eso.org/public/news/eso2310/" rel="nofollow noreferrer">https://www.eso.org/public/news/eso2310/</a></p>
<p>The TMT’s fate is less positive, though, as construction stopped in 2018 due to protests from Native Hawai’ians that it was encroaching a sacred mountain—from what I understood, it had basically been agreed with the Native Council that construction would indeed go forward, but some nonmembers of the Council see things in a different way and disagreed with the Council’s decision, and <em>they</em> are the ones who cause trouble. Wikipedia’s page says that as of June 2022, “no further construction has been announced or initiated” since the 2018 stop.</p>
<ul>
<li><a href="https://en.wikipedia.org/wiki/Thirty_Meter_Telescope" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Thirty_Meter_Telescope</a></li>
<li><a href="https://en.wikipedia.org/wiki/Opposition_to_the_Mauna_Kea_Observatories" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Opposition_to_the_Mauna_Kea_Observatories</a></li>
<li><a href="https://en.wikipedia.org/wiki/Thirty_Meter_Telescope_protests" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Thirty_Meter_Telescope_protests</a></li>
</ul>

CC BY-SA 4.0
2023-08-28T00:43:30.593Z
The Globe and Mail, July 23, 2019 [Thirty Meter Telescope dispute puts focus on Canada’s role](https://www.theglobeandmail.com/canada/article-thirty-meter-telescope-dispute-puts-focus-on-canadas-role/)
uhoh
CC BY-SA 4.0
2023-08-26T04:53:13.550Z
2023-08-28T00:39:49.120Z
2023-08-28T00:39:49.120Z
Pierre Paquette
<p>The graphic above is oft-cited in SE questions and answers. I was (a little) sad to see in it that the 100 meter telescope-engineering wunderkind <a href="https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope" rel="nofollow noreferrer">Overwhelmingly Large Telescope</a> or &quot;OWL&quot; has been canceled, leaving the Extremely Large (37 meter) and Thirty Meter (30 meter) Telescopes coming along (&quot;planned 2027&quot;) to become the (seemingly) largest two single-aperture optical telescopes for quite some time into the future.</p>
<p>Are they both coming along nicely and on-track for first light circa 2027, now only 4 years away?</p>
<hr />
<p>Wikimedia's <a href="https://commons.wikimedia.org/wiki/File:Comparison_optical_telescope_primary_mirrors.svg" rel="nofollow noreferrer">Comparison optical telescope primary mirrors</a> (click link above, or image below for full size &amp; resolution)</p>
<p><a href="https://i.sstatic.net/rbEYi.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/rbEYil.jpg" alt="Wikimedia's &quot;Comparison optical telescope primary mirrors&quot; https://commons.wikimedia.org/wiki/File:Comparison_optical_telescope_primary_mirrors.svg
" /></a></p>

CC BY-SA 4.0
2023-08-26T06:33:46.563Z
Literally the first News item on their web pages. https://elt.eso.org/media/
ProfRob
CC BY-SA 4.0
2023-08-26T23:44:27.583Z
@ProfRob literally is better than figuratively when it comes to new items for sure!
uhoh
<telescope><observatory><future>
How are the Extremely Large and Thirty Meter Telescopes coming along ("planned 2027")
uhoh
# How are the Extremely Large and Thirty Meter Telescopes coming along ("planned 2027")

(Asked by: username_0 on 2023-08-26)

The graphic above is oft-cited in SE questions and answers. I was (a little) sad to see in it that the 100 meter telescope-engineering wunderkind [Overwhelmingly Large Telescope](https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope) or "OWL" has been canceled, leaving the Extremely Large (37 meter) and Thirty Meter (30 meter) Telescopes coming along ("planned 2027") to become the (seemingly) largest two single-aperture optical telescopes for quite some time into the future.

Are they both coming along nicely and on-track for first light circa 2027, now only 4 years away?

---

Wikimedia's [Comparison optical telescope primary mirrors](https://commons.wikimedia.org/wiki/File:Comparison_optical_telescope_primary_mirrors.svg) (click link above, or image below for full size & resolution)

[![Wikimedia's "Comparison optical telescope primary mirrors" https://commons.wikimedia.org/wiki/File:Comparison_optical_telescope_primary_mirrors.svg
](https://i.sstatic.net/rbEYil.jpg)](https://i.sstatic.net/rbEYi.jpg)

**Tags:** telescope, observatory, future

> **Comments:**
> **username_1**: Literally the first News item on their web pages. https://elt.eso.org/media/  
> **username_0**: @username_1 literally is better than figuratively when it comes to new items for sure!  

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## 1 answers

### Answer by username_2 on 2023-08-26. Score: 3

The ELT looks basically on track. It’s scheduled to start scientific observations in 2028 and is now half-completed. See <https://www.eso.org/public/news/eso2310/>

The TMT’s fate is less positive, though, as construction stopped in 2018 due to protests from Native Hawai’ians that it was encroaching a sacred mountain—from what I understood, it had basically been agreed with the Native Council that construction would indeed go forward, but some nonmembers of the Council see things in a different way and disagreed with the Council’s decision, and *they* are the ones who cause trouble. Wikipedia’s page says that as of June 2022, “no further construction has been announced or initiated” since the 2018 stop.

* <https://en.wikipedia.org/wiki/Thirty_Meter_Telescope>
* <https://en.wikipedia.org/wiki/Opposition_to_the_Mauna_Kea_Observatories>
* <https://en.wikipedia.org/wiki/Thirty_Meter_Telescope_protests>

> **Comments:**
> **username_0**: The Globe and Mail, July 23, 2019 [Thirty Meter Telescope dispute puts focus on Canada’s role](https://www.theglobeandmail.com/canada/article-thirty-meter-telescope-dispute-puts-focus-on-canadas-role/)  

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