Editing Primary mirror (section)

==Superlative primary mirrors==

The largest optical telescope in the world as of 2009 to use a non-segmented single-mirror as its primary mirror is the {{convert|8.2|m|ft|abbr=on}} [[Subaru (telescope)|Subaru telescope]] of the [[National Astronomical Observatory of Japan]], located in [[Mauna Kea Observatory]] on [[Hawaii (island)|Hawaii]] since 1997;<ref>{{cite web |date=2007-05-21 |title=Hi-tech - The Subaru Telescope |url=https://web-japan.org/kidsweb/hitech/subaru/index.html |url-status=live |archive-url=https://web.archive.org/web/20230410123643/https://web-japan.org/kidsweb/hitech/subaru/index.html |archive-date=2023-04-10 |access-date=2024-01-22 |website=Kids Web Japan |language=en}}</ref>{{Better source needed|reason=The current source is insufficiently reliable ([[WP:NOTRS]]).|date=January 2024}} however, this is not the largest diameter single mirror in a telescope, the U.S./German/Italian [[Large Binocular Telescope]] has two {{convert|8.4|m|ft|abbr=on}} mirrors (which can be used together for interferometric mode).<ref name="BBC">{{cite web |date=2008-03-06 |title=Giant telescope opens both eyes |url=http://news.bbc.co.uk/2/hi/science/nature/7282385.stm |url-status=live |archive-url=https://web.archive.org/web/20230710062427/http://news.bbc.co.uk/2/hi/science/nature/7282385.stm |archive-date=2023-07-10 |access-date=2008-03-06 |work=BBC News |language=en}}</ref> Both of these are smaller than the 10 m segmented primary mirrors on the [[W. M. Keck Observatory|dual Keck telescope]]. The [[Hubble Space Telescope]] has a {{convert|2.4|m|ftin|abbr=off}} primary mirror.

Radio and submillimeter telescopes use much larger dishes or antennae, which do not have to be made as precisely as the mirrors used in optical telescopes. The [[Arecibo Telescope]] used a 305 m dish, which was the world largest single-dish radio telescope fixed to the ground.<ref>{{cite web |date=2004-12-01 |title=The 305 meter radio telescope |url=http://www.naic.edu/public/the_telescope.htm |url-status=dead |archive-url=https://web.archive.org/web/20150204114533/http://www.naic.edu/public/the_telescope.htm |archive-date=2015-02-04 |access-date=2015-01-22 |website=National Astronomy and Ionosphere Center - Arecibo Observatory}}</ref><ref name="guardian collapsed">{{cite news |date=2020-12-01 |title=Giant Arecibo radio telescope collapses in Puerto Rico |url=https://www.theguardian.com/world/2020/dec/01/arecibo-radio-telescope-collapses-puerto-rico |url-status=live |archive-url=https://web.archive.org/web/20230325192711/https://www.theguardian.com/world/2020/dec/01/arecibo-radio-telescope-collapses-puerto-rico |archive-date=2023-03-25 |access-date=2020-12-01 |work=[[The Guardian]] |language=en |agency=[[Associated Press]]}}</ref> The [[Green Bank Telescope]] has the world's largest steerable single radio dish with 100 m in diameter.<ref>{{cite web |date=2011-05-20 |title=Green Bank |url=https://science.nrao.edu/about/greenbank |url-status=live |archive-url=https://web.archive.org/web/20230813151230/https://science.nrao.edu/about/greenbank |archive-date=2023-08-13 |access-date=2015-01-22 |website=National Radio Astronomy Observatory |language=en}}</ref> There are larger radio arrays, composed of multiple dishes which have better [[image resolution]] but less [[Sensitivity (electronics)|sensitivity]].<ref>{{cite web |date=2005-02-22 |title=Radio Telescope |url=http://abyss.uoregon.edu/~js/glossary/radio_telescope.html |url-status=dead |archive-url=https://web.archive.org/web/20221006013247/http://abyss.uoregon.edu/~js/glossary/radio_telescope.html |archive-date=2022-10-06 |access-date=2015-01-22 |website=University of Oregon |language=en-US}}</ref>