Australia and Russia have large land areas. However, I am only aware of one 3.9m telescope in Australia. As far as I know, there are lots of mountains in Australia and Russia.

So why are there not many large optical telescopes?

The reasons for each country may differ because of their latitudes.

  • $\begingroup$ Why are you insisting that the largest optical telescope in Australia is 2.3m? It isn't. Re-edit your question to reflect the facts. $\endgroup$
    – ProfRob
    Commented Jun 2, 2015 at 22:04
  • $\begingroup$ @RobJeffries I had rolled the edit back. The information that had been edited in was suitable for an answer, as it would change the intent of the question (and effectively nullify it). $\endgroup$ Commented Jun 3, 2015 at 9:12
  • $\begingroup$ @MitchGoshorn The question needs to be edited because it is factually inaccurate. An answer that merely points out this factual inaccuracy is just a comment, not an answer. I am sure that the intent of the question is to ask why neither Russia or Australia are considered good sites to place the world's largest telescopes. $\endgroup$
    – ProfRob
    Commented Jun 3, 2015 at 12:58
  • $\begingroup$ @RobJeffries OP never claimed there weren't others, they stated what they knew of - changing this would make it factually inaccurate, as it states that the OP was aware of a telescope that they were apparently not aware of. The wording of the original question would have been answerable with contradicting examples of existing optical telescopes, but based on the OPs comment to Vivian's question, their intent is more in line with why there aren't more/larger optical telescopes. $\endgroup$ Commented Jun 3, 2015 at 13:31
  • $\begingroup$ 3.9 is quite a big telescope... aat.anu.edu.au/files/AAT_cross-section.jpg $\endgroup$ Commented Apr 20, 2021 at 10:48

2 Answers 2


Optical telescope sites ideally need to be somewhat remote (to avoid light pollution) yet still accessible for construction, engineering, and observing; high in altitude; dry; with exceptional "seeing" (stable atmospheric conditions); and clear weather. Neither Australia nor Russia really have any sites meeting all those criteria: their mountains tend to have some combination of too low altitude, poor seeing, and/or bad weather. (This is also why there aren't any really big, modern telescopes in Europe.)

This site has some discussion of the different criteria that go into choosing the best sites for new, large telescopes.


Russia has BTA-6 which is a 6m optical reflector telescope (which is good enough for their research). Additionally, Australia is a member of many telescope projects throughout the world, and one of them (3.89m telescope) is in Australia itself. Have a look at the link here.

  • $\begingroup$ I don't know if this is exactly an answer, but for earth based telescopes, it helps to build them high. Australia's highest point is a bit over 7,000 feet. It's not known for it's mountains. and, according to this map, they have their fare share: astro.uni-bonn.de/~rcbruens/links/worldmap.jpg $\endgroup$
    – userLTK
    Commented Jun 2, 2015 at 22:21
  • $\begingroup$ @userLTK In yout jpg, all of the three are radio telescopes $\endgroup$ Commented Jun 3, 2015 at 1:23
  • $\begingroup$ Oops. My mistake. $\endgroup$
    – userLTK
    Commented Jun 3, 2015 at 9:38
  • $\begingroup$ This is a comment on the question. Not an answer. $\endgroup$
    – ProfRob
    Commented Jun 3, 2015 at 12:57
  • $\begingroup$ you mean aat, right? Both of the two countries have poor optical telescope resources. Australia has famous radio telescopes. Why do they just have a 3.89m optical telescope? $\endgroup$ Commented Jun 3, 2015 at 13:00

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