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<span>Planning</span> </div> </a> <ul id="toc-Planning-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Design" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Design"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Design</span> </div> </a> <button aria-controls="toc-Design-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Design subsection</span> </button> <ul id="toc-Design-sublist" class="vector-toc-list"> <li id="toc-ELT_mirror_and_sensors_contracts" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#ELT_mirror_and_sensors_contracts"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>ELT mirror and sensors contracts</span> </div> </a> <ul id="toc-ELT_mirror_and_sensors_contracts-sublist" class="vector-toc-list"> <li id="toc-Primary_mirror" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Primary_mirror"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1.1</span> <span>Primary mirror</span> </div> </a> <ul id="toc-Primary_mirror-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Secondary_mirror" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Secondary_mirror"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1.2</span> <span>Secondary mirror</span> </div> </a> <ul id="toc-Secondary_mirror-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Tertiary_mirror" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Tertiary_mirror"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1.3</span> <span>Tertiary mirror</span> </div> </a> <ul id="toc-Tertiary_mirror-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Quaternary_mirror" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Quaternary_mirror"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1.4</span> <span>Quaternary mirror</span> </div> </a> <ul id="toc-Quaternary_mirror-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Quinary_mirror" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Quinary_mirror"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1.5</span> <span>Quinary mirror</span> </div> </a> <ul id="toc-Quinary_mirror-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-ELT_dome_and_structure" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#ELT_dome_and_structure"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>ELT dome and structure</span> </div> </a> <ul id="toc-ELT_dome_and_structure-sublist" class="vector-toc-list"> <li id="toc-Dome_construction" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Dome_construction"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2.1</span> <span>Dome construction</span> </div> </a> <ul id="toc-Dome_construction-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Astronomical_performance" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Astronomical_performance"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2.2</span> <span>Astronomical performance</span> </div> </a> <ul id="toc-Astronomical_performance-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Windscreen" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Windscreen"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2.3</span> <span>Windscreen</span> </div> </a> <ul id="toc-Windscreen-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Ventilation_and_air-conditioning" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Ventilation_and_air-conditioning"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2.4</span> <span>Ventilation and air-conditioning</span> </div> </a> <ul id="toc-Ventilation_and_air-conditioning-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> </ul> </li> <li id="toc-Science_goals" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Science_goals"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Science goals</span> </div> </a> <ul id="toc-Science_goals-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Instrumentation" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Instrumentation"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Instrumentation</span> </div> </a> <ul id="toc-Instrumentation-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Comparison" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Comparison"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Comparison</span> </div> </a> <ul id="toc-Comparison-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" title="Table of Contents" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Extremely Large Telescope</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 40 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-40" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">40 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%A7%D9%84%D9%85%D9%82%D8%B1%D8%A7%D8%A8_%D9%81%D8%A7%D8%A6%D9%82_%D8%A7%D9%84%D9%83%D8%A8%D8%B1_%D8%A7%D9%84%D8%A3%D9%88%D8%B1%D9%88%D8%A8%D9%8A" title="المقراب فائق الكبر الأوروبي – Arabic" lang="ar" hreflang="ar" data-title="المقراب فائق الكبر الأوروبي" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%A6%E0%A6%BF_%E0%A6%8F%E0%A6%95%E0%A7%8D%E0%A6%B8%E0%A6%9F%E0%A7%8D%E0%A6%B0%E0%A6%BF%E0%A6%AE%E0%A6%B2%E0%A6%BF_%E0%A6%B2%E0%A6%BE%E0%A6%B0%E0%A7%8D%E0%A6%9C_%E0%A6%9F%E0%A7%87%E0%A6%B2%E0%A6%BF%E0%A6%B8%E0%A7%8D%E0%A6%95%E0%A7%8B%E0%A6%AA" title="দি এক্সট্রিমলি লার্জ টেলিস্কোপ – Bangla" lang="bn" hreflang="bn" data-title="দি এক্সট্রিমলি লার্জ টেলিস্কোপ" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-bh mw-list-item"><a href="https://bh.wikipedia.org/wiki/%E0%A4%AF%E0%A5%82%E0%A4%B0%E0%A5%8B%E0%A4%AA%E0%A4%BF%E0%A4%AF%E0%A4%A8_%E0%A4%8F%E0%A4%95%E0%A5%8D%E0%A4%B8%E0%A4%9F%E0%A5%8D%E0%A4%B0%E0%A5%80%E0%A4%AE%E0%A4%B2%E0%A5%80_%E0%A4%B2%E0%A4%BE%E0%A4%B0%E0%A5%8D%E0%A4%9C_%E0%A4%9F%E0%A5%87%E0%A4%B2%E0%A4%BF%E0%A4%B8%E0%A5%8D%E0%A4%95%E0%A5%8B%E0%A4%AA" title="यूरोपियन एक्सट्रीमली लार्ज टेलिस्कोप – Bhojpuri" lang="bh" hreflang="bh" data-title="यूरोपियन एक्सट्रीमली लार्ज टेलिस्कोप" data-language-autonym="भोजपुरी" data-language-local-name="Bhojpuri" class="interlanguage-link-target"><span>भोजपुरी</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Ekstremno_veliki_teleskop" title="Ekstremno veliki teleskop – Bosnian" lang="bs" hreflang="bs" data-title="Ekstremno veliki teleskop" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/European_Extremely_Large_Telescope" title="European Extremely Large Telescope – Catalan" lang="ca" hreflang="ca" data-title="European Extremely Large Telescope" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Extr%C3%A9mn%C4%9B_velk%C3%BD_dalekohled" title="Extrémně velký dalekohled – Czech" lang="cs" hreflang="cs" data-title="Extrémně velký dalekohled" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/European_Extremely_Large_Telescope" title="European Extremely Large Telescope – Danish" lang="da" hreflang="da" data-title="European Extremely Large Telescope" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Extremely_Large_Telescope" title="Extremely Large Telescope – German" lang="de" hreflang="de" data-title="Extremely Large Telescope" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Eriti_Suur_Teleskoop" title="Eriti Suur Teleskoop – Estonian" lang="et" hreflang="et" data-title="Eriti Suur Teleskoop" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Telescopio_Extremadamente_Grande" title="Telescopio Extremadamente Grande – Spanish" lang="es" hreflang="es" data-title="Telescopio Extremadamente Grande" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Ege_Granda_Teleskopo" title="Ege Granda Teleskopo – Esperanto" lang="eo" hreflang="eo" data-title="Ege Granda Teleskopo" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%AA%D9%84%D8%B3%DA%A9%D9%88%D9%BE_%D8%A8%D8%B3%E2%80%8C%D8%A8%D8%B2%D8%B1%DA%AF_%D8%A7%D8%B1%D9%88%D9%BE%D8%A7%DB%8C%DB%8C" title="تلسکوپ بس‌بزرگ اروپایی – Persian" lang="fa" hreflang="fa" data-title="تلسکوپ بس‌بزرگ اروپایی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/T%C3%A9lescope_g%C3%A9ant_europ%C3%A9en" title="Télescope géant européen – French" lang="fr" hreflang="fr" data-title="Télescope géant européen" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Telescopio_Europeo_Extremadamente_Grande" title="Telescopio Europeo Extremadamente Grande – Galician" lang="gl" hreflang="gl" data-title="Telescopio Europeo Extremadamente Grande" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%9C%A0%EB%9F%BD_%EC%B4%88%EB%8C%80%ED%98%95_%EB%A7%9D%EC%9B%90%EA%B2%BD" title="유럽 초대형 망원경 – Korean" lang="ko" hreflang="ko" data-title="유럽 초대형 망원경" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D5%89%D5%A1%D6%83%D5%A1%D5%A6%D5%A1%D5%B6%D6%81_%D5%B4%D5%A5%D5%AE_%D5%A1%D5%BD%D5%BF%D5%B2%D5%A1%D5%A4%D5%AB%D5%BF%D5%A1%D5%AF" title="Չափազանց մեծ աստղադիտակ – Armenian" lang="hy" hreflang="hy" data-title="Չափազանց մեծ աստղադիտակ" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-ig mw-list-item"><a href="https://ig.wikipedia.org/wiki/Telescope_buru_oke_ibu" title="Telescope buru oke ibu – Igbo" lang="ig" hreflang="ig" data-title="Telescope buru oke ibu" data-language-autonym="Igbo" data-language-local-name="Igbo" class="interlanguage-link-target"><span>Igbo</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Extremely_Large_Telescope" title="Extremely Large Telescope – Indonesian" lang="id" hreflang="id" data-title="Extremely Large Telescope" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Extremely_Large_Telescope" title="Extremely Large Telescope – Italian" lang="it" hreflang="it" data-title="Extremely Large Telescope" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%94%D7%98%D7%9C%D7%A1%D7%A7%D7%95%D7%A4_%D7%94%D7%92%D7%93%D7%95%D7%9C_%D7%91%D7%9E%D7%99%D7%95%D7%97%D7%93" title="הטלסקופ הגדול במיוחד – Hebrew" lang="he" hreflang="he" data-title="הטלסקופ הגדול במיוחד" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-lb mw-list-item"><a href="https://lb.wikipedia.org/wiki/European_Extremely_Large_Telescope" title="European Extremely Large Telescope – Luxembourgish" lang="lb" hreflang="lb" data-title="European Extremely Large Telescope" data-language-autonym="Lëtzebuergesch" data-language-local-name="Luxembourgish" class="interlanguage-link-target"><span>Lëtzebuergesch</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Europos_Didysis_teleskopas" title="Europos Didysis teleskopas – Lithuanian" lang="lt" hreflang="lt" data-title="Europos Didysis teleskopas" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Rendk%C3%ADv%C3%BCl_Nagy_Eur%C3%B3pai_T%C3%A1vcs%C5%91" title="Rendkívül Nagy Európai Távcső – Hungarian" lang="hu" hreflang="hu" data-title="Rendkívül Nagy Európai Távcső" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%AF%E0%B5%82%E0%B4%B1%E0%B5%8B%E0%B4%AA%E0%B5%8D%E0%B4%AF%E0%B5%BB_%E0%B4%8E%E0%B4%95%E0%B5%8D%E0%B4%B8%E0%B5%8D%E0%B4%9F%E0%B5%8D%E0%B4%B0%E0%B5%80%E0%B4%AE%E0%B5%8D%E2%80%8C%E0%B4%B2%E0%B4%BF_%E0%B4%B2%E0%B4%BE%E0%B5%BC%E0%B4%9C%E0%B5%8D_%E0%B4%9F%E0%B5%86%E0%B4%B2%E0%B4%BF%E0%B4%B8%E0%B5%8D%E0%B4%95%E0%B5%8B%E0%B4%AA%E0%B5%8D" title="യൂറോപ്യൻ എക്സ്ട്രീമ്‌ലി ലാർജ് ടെലിസ്കോപ് – Malayalam" lang="ml" hreflang="ml" data-title="യൂറോപ്യൻ എക്സ്ട്രീമ്‌ലി ലാർജ് ടെലിസ്കോപ്" data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Extremely_Large_Telescope" title="Extremely Large Telescope – Malay" lang="ms" hreflang="ms" data-title="Extremely Large Telescope" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Extremely_Large_Telescope" title="Extremely Large Telescope – Dutch" lang="nl" hreflang="nl" data-title="Extremely Large Telescope" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E6%AC%A7%E5%B7%9E%E8%B6%85%E5%A4%A7%E5%9E%8B%E6%9C%9B%E9%81%A0%E9%8F%A1" title="欧州超大型望遠鏡 – Japanese" lang="ja" hreflang="ja" data-title="欧州超大型望遠鏡" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Extremely_Large_Telescope" title="Extremely Large Telescope – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Extremely Large Telescope" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/European_Extremely_Large_Telescope" title="European Extremely Large Telescope – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="European Extremely Large Telescope" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Ekstremalnie_Wielki_Teleskop" title="Ekstremalnie Wielki Teleskop – Polish" lang="pl" hreflang="pl" data-title="Ekstremalnie Wielki Teleskop" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/European_Extremely_Large_Telescope" title="European Extremely Large Telescope – Portuguese" lang="pt" hreflang="pt" data-title="European Extremely Large Telescope" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/European_Extremely_Large_Telescope" title="European Extremely Large Telescope – Romanian" lang="ro" hreflang="ro" data-title="European Extremely Large Telescope" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%A7%D1%80%D0%B5%D0%B7%D0%B2%D1%8B%D1%87%D0%B0%D0%B9%D0%BD%D0%BE_%D0%B1%D0%BE%D0%BB%D1%8C%D1%88%D0%BE%D0%B9_%D1%82%D0%B5%D0%BB%D0%B5%D1%81%D0%BA%D0%BE%D0%BF" title="Чрезвычайно большой телескоп – Russian" lang="ru" hreflang="ru" data-title="Чрезвычайно большой телескоп" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-ckb 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/ srpski</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Extremely_Large_Telescope" title="Extremely Large Telescope – Finnish" lang="fi" hreflang="fi" data-title="Extremely Large Telescope" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/European_Extremely_Large_Telescope" title="European Extremely Large Telescope – Swedish" lang="sv" hreflang="sv" data-title="European Extremely Large Telescope" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a 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href="https://geohack.toolforge.org/geohack.php?pagename=Extremely_Large_Telescope&params=24.5893_S_70.1916_W_"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">24°35′21″S</span> <span class="longitude">70°11′30″W</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">24.5893°S 70.1916°W</span><span style="display:none"> / <span class="geo">-24.5893; -70.1916</span></span></span></a></span></span></div></div> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Major astronomical facility in Chile</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">For the general type of observatory, see <a href="/wiki/Extremely_large_telescope" title="Extremely large telescope">extremely large telescope</a>.</div> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox vcard"><caption class="infobox-title fn org">Extremely Large Telescope</caption><tbody><tr><td colspan="2" class="infobox-image"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:The_E-ELT.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e2/The_E-ELT.jpg/290px-The_E-ELT.jpg" decoding="async" width="290" height="163" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e2/The_E-ELT.jpg/435px-The_E-ELT.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e2/The_E-ELT.jpg/580px-The_E-ELT.jpg 2x" data-file-width="5000" data-file-height="2808" /></a></span><div class="infobox-caption">Artist's impression of the ELT</div></td></tr><tr><th scope="row" class="infobox-label">Alternative names</th><td class="infobox-data">ELT <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Part of</th><td class="infobox-data"><a href="/wiki/European_Southern_Observatory" title="European Southern Observatory">European Southern Observatory</a> <span class="penicon autoconfirmed-show"><span class="mw-valign-text-top" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105?uselang=en#P361" title="Edit this on Wikidata"><img alt="Edit this on Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></span></td></tr><tr><th scope="row" class="infobox-label">Location(s)</th><td class="infobox-data label"><a href="/wiki/Cerro_Armazones" title="Cerro Armazones">Cerro Armazones</a>, <a href="/wiki/Antofagasta_Province" title="Antofagasta Province">Antofagasta Province</a>, <a href="/wiki/Antofagasta_Region" title="Antofagasta Region">Antofagasta Region</a>, Chile</td></tr><tr><th scope="row" class="infobox-label">Coordinates</th><td class="infobox-data"><span class="geo-inline"><style data-mw-deduplicate="TemplateStyles:r1156832818">.mw-parser-output .geo-default,.mw-parser-output .geo-dms,.mw-parser-output .geo-dec{display:inline}.mw-parser-output .geo-nondefault,.mw-parser-output .geo-multi-punct,.mw-parser-output .geo-inline-hidden{display:none}.mw-parser-output .longitude,.mw-parser-output .latitude{white-space:nowrap}</style><span class="plainlinks nourlexpansion"><a class="external text" href="https://geohack.toolforge.org/geohack.php?pagename=Extremely_Large_Telescope&params=24.5893_S_70.1916_W_"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">24°35′21″S</span> <span class="longitude">70°11′30″W</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">24.5893°S 70.1916°W</span><span style="display:none"> / <span class="geo">-24.5893; -70.1916</span></span></span></a></span></span> <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105#P625" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Organization</th><td class="infobox-data"><a href="/wiki/European_Southern_Observatory" title="European Southern Observatory">European Southern Observatory</a> <span class="penicon autoconfirmed-show"><span class="mw-valign-text-top" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105?uselang=en#P137" title="Edit this on Wikidata"><img alt="Edit this on Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></span></td></tr><tr><th scope="row" class="infobox-label">Altitude</th><td class="infobox-data">3,046 m (9,993 ft) <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105#P2044" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Built</th><td class="infobox-data"><strong class="error">not a number value</strong> <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105#P793" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Telescope style</th><td class="infobox-data category"><a href="/wiki/Extremely_large_telescope" title="Extremely large telescope">extremely large telescope</a><br /><a href="/wiki/Infrared_telescope" title="Infrared telescope">infrared telescope</a><br /><a href="/wiki/Nasmyth_telescope" title="Nasmyth telescope">Nasmyth telescope</a> <span class="penicon autoconfirmed-show"><span class="mw-valign-text-top" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105?uselang=en#P31" title="Edit this on Wikidata"><img alt="Edit this on Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></span></td></tr><tr class="note"><th scope="row" class="infobox-label">Diameter</th><td class="infobox-data">39.3 m (128 ft 11 in) <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105#P2386" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr class="note"><th scope="row" class="infobox-label">Secondary diameter</th><td class="infobox-data">4.09 m (13 ft 5 in) <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105#P2386" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr class="note"><th scope="row" class="infobox-label">Tertiary diameter</th><td class="infobox-data">3.75 m (12 ft 4 in) <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105#P2386" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/Angular_resolution" title="Angular resolution">Angular resolution</a></th><td class="infobox-data">0.005 arcsecond <span class="penicon autoconfirmed-show"><span class="mw-valign-text-top" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105?uselang=en#P3439" title="Edit this on Wikidata"><img alt="Edit this on Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></span></td></tr><tr><th scope="row" class="infobox-label">Collecting area</th><td class="infobox-data">978 m<sup>2</sup> (10,530 sq ft) <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105#P2046" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/Focal_length" title="Focal length">Focal length</a></th><td class="infobox-data">743.4 m (2,439 ft 0 in) <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105#P2151" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Enclosure</th><td class="infobox-data"><a href="/wiki/Dome" title="Dome">dome</a> <span class="penicon autoconfirmed-show"><span class="mw-valign-text-top" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105?uselang=en#P3158" title="Edit this on Wikidata"><img alt="Edit this on Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></span></td></tr><tr><th scope="row" class="infobox-label">Website</th><td class="infobox-data"><span class="url"><a rel="nofollow" class="external text" href="https://elt.eso.org/">elt<wbr />.eso<wbr />.org</a></span> <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q635105#P856" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><td colspan="2" class="infobox-full-data"><style data-mw-deduplicate="TemplateStyles:r1238443738">.mw-parser-output .locmap .od{position:absolute}.mw-parser-output .locmap .id{position:absolute;line-height:0}.mw-parser-output .locmap .l0{font-size:0;position:absolute}.mw-parser-output .locmap .pv{line-height:110%;position:absolute;text-align:center}.mw-parser-output .locmap .pl{line-height:110%;position:absolute;top:-0.75em;text-align:right}.mw-parser-output .locmap .pr{line-height:110%;position:absolute;top:-0.75em;text-align:left}.mw-parser-output .locmap .pv>div{display:inline;padding:1px}.mw-parser-output .locmap .pl>div{display:inline;padding:1px;float:right}.mw-parser-output .locmap .pr>div{display:inline;padding:1px;float:left}@media screen{html.skin-theme-clientpref-night .mw-parser-output .od,html.skin-theme-clientpref-night .mw-parser-output .od .pv>div,html.skin-theme-clientpref-night .mw-parser-output .od .pl>div,html.skin-theme-clientpref-night .mw-parser-output .od .pr>div{background:#fff!important;color:#000!important}html.skin-theme-clientpref-night .mw-parser-output .locmap{filter:grayscale(0.6)}html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data .locmap div{background:transparent!important}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .locmap{filter:grayscale(0.6)}html.skin-theme-clientpref-os .mw-parser-output .od,html.skin-theme-clientpref-os .mw-parser-output .od .pv>div,html.skin-theme-clientpref-os .mw-parser-output .od .pl>div,html.skin-theme-clientpref-os .mw-parser-output .od .pr>div{background:white!important;color:#000!important}html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data .locmap div{background:transparent!important}}</style><div class="center"><div class="locmap" style="width:108px;float:none;clear:both;margin-left:auto;margin-right:auto"><div style="width:108px;padding:0"><div style="position:relative;width:108px"><span class="notpageimage" typeof="mw:File"><a href="/wiki/File:Relief_Map_of_Chile.jpg" class="mw-file-description" title="Extremely Large Telescope is located in Chile"><img alt="Extremely Large Telescope is located in Chile" src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Relief_Map_of_Chile.jpg/108px-Relief_Map_of_Chile.jpg" decoding="async" width="108" height="243" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Relief_Map_of_Chile.jpg/162px-Relief_Map_of_Chile.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Relief_Map_of_Chile.jpg/216px-Relief_Map_of_Chile.jpg 2x" data-file-width="668" data-file-height="1500" /></a></span><div class="od notheme" style="top:18.387%;left:56.542%;font-size:91%"><div class="id" style="left:-4px;top:-4px"><span class="notpageimage" typeof="mw:File"><span title="Extremely Large Telescope"><img alt="Extremely Large Telescope" src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Red_pog.svg/8px-Red_pog.svg.png" decoding="async" width="8" height="8" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Red_pog.svg/12px-Red_pog.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Red_pog.svg/16px-Red_pog.svg.png 2x" data-file-width="64" data-file-height="64" /></span></span></div></div></div><div style="padding-top:0.2em"><div style="line-height:1.2em;">Location of Extremely Large Telescope</div></div></div></div></div></td></tr><tr><td colspan="2" class="infobox-full-data"> <span class="noviewer" typeof="mw:File"><a href="/wiki/File:Commons-logo.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></a></span> <a href="https://commons.wikimedia.org/wiki/Category:Extremely_Large_Telescope" class="extiw" title="commons:Category:Extremely Large Telescope">Related media on Commons</a></td></tr><tr><td colspan="2" class="infobox-below"><div class="metadata" style="text-align: right;">[<a href="https://www.wikidata.org/wiki/Q635105" class="extiw" title="d:Q635105">edit on Wikidata</a>]</div></td></tr></tbody></table> <p>The <b>Extremely Large Telescope</b> (<b>ELT</b>) is an <a href="/wiki/Observatory#Astronomical_observatories" title="Observatory">astronomical observatory</a> under construction.<sup id="cite_ref-NYT-20240308_1-0" class="reference"><a href="#cite_note-NYT-20240308-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> When completed, it will be the world's largest <a href="/wiki/Optical_telescope" title="Optical telescope">optical</a> and <a href="/wiki/Infrared#Regions_within_the_infrared" title="Infrared">near-infrared</a> <a href="/wiki/Extremely_large_telescope" title="Extremely large telescope">extremely large telescope</a>. Part of the <a href="/wiki/European_Southern_Observatory" title="European Southern Observatory">European Southern Observatory</a> (ESO) agency, it is located on top of <a href="/wiki/Cerro_Armazones" title="Cerro Armazones">Cerro Armazones</a> in the <a href="/wiki/Atacama_Desert" title="Atacama Desert">Atacama Desert</a> of northern <a href="/wiki/Chile" title="Chile">Chile</a>. </p><p>The design consists of a reflecting telescope with a 39.3-metre-diameter (130-foot) <a href="/wiki/Segmented_mirror" title="Segmented mirror">segmented</a> <a href="/wiki/Primary_mirror" title="Primary mirror">primary mirror</a> and a 4.2 m (14 ft) diameter secondary mirror. The telescope is equipped with <a href="/wiki/Adaptive_optics" title="Adaptive optics">adaptive optics</a>, six <a href="/wiki/Laser_guide_star" title="Laser guide star">laser guide star</a> units, and various large-scale scientific instruments.<sup id="cite_ref-govert_2-0" class="reference"><a href="#cite_note-govert-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-50percent_3-0" class="reference"><a href="#cite_note-50percent-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> The observatory's design will gather 100 million times more light than the human eye, equivalent to about 10 times more light than the largest <a href="/wiki/List_of_largest_optical_reflecting_telescopes" title="List of largest optical reflecting telescopes">optical telescopes</a> in existence as of 2023, with the ability to correct for atmospheric distortion. It has around 250 times the light-gathering area of the <a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubble Space Telescope</a> and, according to the ELT's specifications, will provide images 16 times sharper than those from Hubble.<sup id="cite_ref-E-ELT_4-0" class="reference"><a href="#cite_note-E-ELT-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p><p>The project was originally called the <b>European Extremely Large Telescope</b> (<b>E-ELT</b>), but the name was shortened in 2017.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> The ELT is intended to advance astrophysical knowledge by enabling detailed studies of planets around other stars, the first galaxies in the Universe, supermassive black holes, the nature of the Universe's dark sector, and to detect water and organic molecules in <a href="/wiki/Protoplanetary_disk" title="Protoplanetary disk">protoplanetary disks</a> around other stars.<sup id="cite_ref-E-ELT_Alone_6-0" class="reference"><a href="#cite_note-E-ELT_Alone-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> As planned in 2011, the facility was expected to take 11 years to construct, from 2014 to 2025.<sup id="cite_ref-eso_executive_summary_7-0" class="reference"><a href="#cite_note-eso_executive_summary-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>On 11 June 2012, the ESO Council approved the ELT programme's plans to begin civil works at the telescope site, with the construction of the telescope itself pending final agreement with governments of some member states.<sup id="cite_ref-Approval_8-0" class="reference"><a href="#cite_note-Approval-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> Construction work on the ELT site started in June 2014.<sup id="cite_ref-beginning_9-0" class="reference"><a href="#cite_note-beginning-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> By December 2014, ESO had secured over 90% of the total funding and authorized construction of the telescope to start, estimated to cost around one billion <a href="/wiki/Euro" title="Euro">euros</a> for the first construction phase.<sup id="cite_ref-spaceref2014_10-0" class="reference"><a href="#cite_note-spaceref2014-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> The first stone of the telescope was ceremonially laid on 26 May 2017, initiating the construction of the dome's main structure and telescope.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-eso1419-groundbreaking_12-0" class="reference"><a href="#cite_note-eso1419-groundbreaking-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> The telescope passed the halfway point in its development and construction in July 2023, with the expected completion and <a href="/wiki/First_light_(astronomy)" title="First light (astronomy)">first light</a> set for 2028.<sup id="cite_ref-start2027_13-0" class="reference"><a href="#cite_note-start2027-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-50percent_3-1" class="reference"><a href="#cite_note-50percent-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=1" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:The_ESO_Council_during_their_meeting_in_Garching_on_11%E2%80%9312_June_2012.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/95/The_ESO_Council_during_their_meeting_in_Garching_on_11%E2%80%9312_June_2012.jpg/260px-The_ESO_Council_during_their_meeting_in_Garching_on_11%E2%80%9312_June_2012.jpg" decoding="async" width="260" height="173" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/95/The_ESO_Council_during_their_meeting_in_Garching_on_11%E2%80%9312_June_2012.jpg/390px-The_ESO_Council_during_their_meeting_in_Garching_on_11%E2%80%9312_June_2012.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/95/The_ESO_Council_during_their_meeting_in_Garching_on_11%E2%80%9312_June_2012.jpg/520px-The_ESO_Council_during_their_meeting_in_Garching_on_11%E2%80%9312_June_2012.jpg 2x" data-file-width="5187" data-file-height="3458" /></a><figcaption>ESO Council meets at ESO headquarters in <a href="/wiki/Garching" title="Garching">Garching</a> bei München, Germany, 2012.<sup id="cite_ref-eso1225_14-0" class="reference"><a href="#cite_note-eso1225-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup></figcaption></figure> <p>On 26 April 2010, the <a href="/wiki/European_Southern_Observatory" title="European Southern Observatory">European Southern Observatory</a> (ESO) Council selected <a href="/wiki/Cerro_Armazones" title="Cerro Armazones">Cerro Armazones</a>, <a href="/wiki/Chile" title="Chile">Chile</a>, as the baseline site for the planned ELT.<sup id="cite_ref-eso1018_15-0" class="reference"><a href="#cite_note-eso1018-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> Other sites that were under discussion included Cerro Macon, Salta, in Argentina; <a href="/wiki/Roque_de_los_Muchachos_Observatory" title="Roque de los Muchachos Observatory">Roque de los Muchachos Observatory</a>, on the Canary Islands; and sites in North Africa, Morocco, and Antarctica.<sup id="cite_ref-Finding-a-home_16-0" class="reference"><a href="#cite_note-Finding-a-home-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Vernin2011_17-0" class="reference"><a href="#cite_note-Vernin2011-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> </p><p>Early designs included a segmented primary mirror with a diameter of 42 metres (140 feet) and an area of about 1,300 m<sup>2</sup> (14,000 sq ft), with a secondary mirror with a diameter of 5.9 m (19 ft). However, in 2011 a proposal was put forward to reduce overall size by 13% to 978 m<sup>2</sup>, with a 39.3 m (130 ft) diameter primary mirror and a 4.2 m (14 ft) diameter secondary mirror.<sup id="cite_ref-govert_2-1" class="reference"><a href="#cite_note-govert-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> This reduced projected costs from 1.275 billion to 1.055 billion euros and should allow the telescope to be finished sooner. The smaller secondary is a particularly important change; 4.2 m (14 ft) places it within the capabilities of multiple manufacturers, and the lighter mirror unit avoids the need for high-strength materials in the secondary mirror support spider.<sup id="cite_ref-constrproposal_18-0" class="reference"><a href="#cite_note-constrproposal-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page: 15">: 15 </span></sup> </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Drone_image_of_the_ELT_dome_construction_(dji-0680-gui).jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/be/Drone_image_of_the_ELT_dome_construction_%28dji-0680-gui%29.jpg/260px-Drone_image_of_the_ELT_dome_construction_%28dji-0680-gui%29.jpg" decoding="async" width="260" height="146" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/be/Drone_image_of_the_ELT_dome_construction_%28dji-0680-gui%29.jpg/390px-Drone_image_of_the_ELT_dome_construction_%28dji-0680-gui%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/be/Drone_image_of_the_ELT_dome_construction_%28dji-0680-gui%29.jpg/520px-Drone_image_of_the_ELT_dome_construction_%28dji-0680-gui%29.jpg 2x" data-file-width="5472" data-file-height="3078" /></a><figcaption>ELT construction status in June 2024</figcaption></figure> <p>ESO's Director General commented in a 2011 press release that "With the new E-ELT design we can still satisfy the bold science goals and also ensure that the construction can be completed in only 10–11 years."<sup id="cite_ref-esoann11034_19-0" class="reference"><a href="#cite_note-esoann11034-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> The ESO Council endorsed the revised baseline design in June 2011 and expected a construction proposal for approval in December 2011.<sup id="cite_ref-esoann11034_19-1" class="reference"><a href="#cite_note-esoann11034-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> Funding was subsequently included in the 2012 budget for initial work to begin in early 2012.<sup id="cite_ref-eso1150_20-0" class="reference"><a href="#cite_note-eso1150-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> The project received preliminary approval in June 2012.<sup id="cite_ref-Approval_8-1" class="reference"><a href="#cite_note-Approval-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> ESO approved the start of construction in December 2014, with over 90% funding of the nominal budget secured.<sup id="cite_ref-spaceref2014_10-1" class="reference"><a href="#cite_note-spaceref2014-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> </p><p>The design phase of the 5-mirror <a href="/wiki/Anastigmat" title="Anastigmat">anastigmat</a> was fully funded within the ESO budget. With the 2011 changes in the baseline design (such as a reduction in the size of the primary mirror from 42 m to 39.3 m), in 2017 the construction cost was estimated to be €1.15 billion (including first generation instruments).<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-E-ELT_Revolution_22-0" class="reference"><a href="#cite_note-E-ELT_Revolution-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> In 2014, the start of operations was planned for 2024.<sup id="cite_ref-eso1419-groundbreaking_12-1" class="reference"><a href="#cite_note-eso1419-groundbreaking-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> Actual construction officially began in early 2017,<sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> and a technical <a href="/wiki/First_light_(astronomy)" title="First light (astronomy)">first light</a> is planned for 2028.<sup id="cite_ref-start2027_13-1" class="reference"><a href="#cite_note-start2027-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Planning">Planning</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=2" title="Edit section: Planning"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Cerro_Armazones_night-time_panorama.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/3f/Cerro_Armazones_night-time_panorama.jpg/350px-Cerro_Armazones_night-time_panorama.jpg" decoding="async" width="350" height="160" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/3f/Cerro_Armazones_night-time_panorama.jpg/525px-Cerro_Armazones_night-time_panorama.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/3f/Cerro_Armazones_night-time_panorama.jpg/700px-Cerro_Armazones_night-time_panorama.jpg 2x" data-file-width="8268" data-file-height="3780" /></a><figcaption>Cerro Armazones at night (2010)</figcaption></figure> <p>ESO focused on the current design after a feasibility study concluded the proposed 100 m (328 ft) diameter, <a href="/wiki/Overwhelmingly_Large_Telescope" title="Overwhelmingly Large Telescope">Overwhelmingly Large Telescope</a>, would cost €1.5 billion (£1 billion), and be too complex. Both current fabrication technology and road transportation constraints limit single mirrors to being roughly 8 m (26 ft) per piece. The next-largest telescopes currently in use are the <a href="/wiki/Keck_Telescopes" class="mw-redirect" title="Keck Telescopes">Keck Telescopes</a>, the <a href="/wiki/Gran_Telescopio_Canarias" title="Gran Telescopio Canarias">Gran Telescopio Canarias</a> and the <a href="/wiki/Southern_African_Large_Telescope" title="Southern African Large Telescope">Southern African Large Telescope</a>, which each use small hexagonal mirrors fitted together to make a composite mirror slightly over 10 m (33 ft) across. The ELT uses a similar design, as well as techniques to work around atmospheric distortion of incoming light, known as <a href="/wiki/Adaptive_optics" title="Adaptive optics">adaptive optics</a>.<sup id="cite_ref-messenger_24-0" class="reference"><a href="#cite_note-messenger-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> </p><p>A 40-metre-class mirror will allow the study of the atmospheres of <a href="/wiki/Extrasolar_planet" class="mw-redirect" title="Extrasolar planet">extrasolar planets</a>.<sup id="cite_ref-esoscience_25-0" class="reference"><a href="#cite_note-esoscience-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> The ELT is the highest priority in the European planning activities for research infrastructures, such as the <a href="/wiki/Astronet" title="Astronet">Astronet</a> Science Vision and Infrastructure Roadmap and the ESFRI Roadmap.<sup id="cite_ref-E-ELT_Europe_26-0" class="reference"><a href="#cite_note-E-ELT_Europe-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> The telescope underwent a Phase B study in 2014 that included "contracts with industry to design and manufacture prototypes of key elements like the primary mirror segments, the adaptive fourth mirror or the mechanical structure (...) [and] concept studies for eight instruments".<sup id="cite_ref-astronet-eu.org_27-0" class="reference"><a href="#cite_note-astronet-eu.org-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Design">Design</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=3" title="Edit section: Design"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:The_European_Extremely_Large_Telescope.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/bf/The_European_Extremely_Large_Telescope.jpg/260px-The_European_Extremely_Large_Telescope.jpg" decoding="async" width="260" height="252" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/bf/The_European_Extremely_Large_Telescope.jpg/390px-The_European_Extremely_Large_Telescope.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/bf/The_European_Extremely_Large_Telescope.jpg/520px-The_European_Extremely_Large_Telescope.jpg 2x" data-file-width="3478" data-file-height="3366" /></a><figcaption>Schematic view of the ELT</figcaption></figure> <p>The ELT will use a novel design with a total of five mirrors.<sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> The first three mirrors are curved (non-spherical) and form a <a href="/wiki/Three-mirror_anastigmat" title="Three-mirror anastigmat">three-mirror anastigmat</a> design for excellent image quality over the 10-arcminute field of view (one-third of the width of the full Moon). The fourth and fifth mirrors are (almost) flat, and respectively provide <a href="/wiki/Adaptive_optics" title="Adaptive optics">adaptive optics</a> correction for atmospheric distortions (mirror 4) and tip-tilt correction for image stabilization (mirror 5). The fourth and fifth mirrors also send the light sideways to one of two <a href="/wiki/Nasmyth_telescope" title="Nasmyth telescope">Nasmyth</a> focal stations at either side of the telescope structure, allowing multiple large instruments to be mounted simultaneously. </p> <div class="mw-heading mw-heading3"><h3 id="ELT_mirror_and_sensors_contracts">ELT mirror and sensors contracts</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=4" title="Edit section: ELT mirror and sensors contracts"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading4"><h4 id="Primary_mirror">Primary mirror</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=5" title="Edit section: Primary mirror"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:The_optical_system_of_the_ELT_showing_the_location_of_the_mirrors.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/2c/The_optical_system_of_the_ELT_showing_the_location_of_the_mirrors.jpg/440px-The_optical_system_of_the_ELT_showing_the_location_of_the_mirrors.jpg" decoding="async" width="440" height="247" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/2c/The_optical_system_of_the_ELT_showing_the_location_of_the_mirrors.jpg/660px-The_optical_system_of_the_ELT_showing_the_location_of_the_mirrors.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/2c/The_optical_system_of_the_ELT_showing_the_location_of_the_mirrors.jpg/880px-The_optical_system_of_the_ELT_showing_the_location_of_the_mirrors.jpg 2x" data-file-width="20834" data-file-height="11717" /></a><figcaption>The optical system of the ELT showing the location of the mirrors<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup></figcaption></figure> <p>The 39-metre (128 ft) primary mirror will be composed of 798 hexagonal segments, each approximately 1.4 metres (4.6 ft) across and with a thickness of 50 mm (2.0 in).<sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> Two segments will be re-coated and replaced each working day, to keep the mirror always clean and highly reflective. </p><p>Edge sensors constantly measure the positions of the primary mirror segments relative to their immediate neighbours. 2394 position <a href="/wiki/Actuators" class="mw-redirect" title="Actuators">actuators</a> (3 for each segment) use this information to adjust the system, keeping the overall surface shape unchanged against deformations caused by external factors such as wind, gravity, temperature changes and vibrations.<sup id="cite_ref-31" class="reference"><a href="#cite_note-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> </p><p>In January 2017,<sup id="cite_ref-contracts-eso_32-0" class="reference"><a href="#cite_note-contracts-eso-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> ESO awarded the contract for the fabrication of the 4608 edge sensors to the FAMES consortium, which is composed of French company Fogale<sup id="cite_ref-33" class="reference"><a href="#cite_note-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> and German company Micro-Epsilon.<sup id="cite_ref-34" class="reference"><a href="#cite_note-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> These sensors can measure relative positions to an accuracy of a few nanometres, the most accurate ever used in a telescope. </p> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:First_ELT_Main_Mirror_Segments_Successfully_Cast.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/First_ELT_Main_Mirror_Segments_Successfully_Cast.jpg/260px-First_ELT_Main_Mirror_Segments_Successfully_Cast.jpg" decoding="async" width="260" height="143" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/First_ELT_Main_Mirror_Segments_Successfully_Cast.jpg/390px-First_ELT_Main_Mirror_Segments_Successfully_Cast.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/00/First_ELT_Main_Mirror_Segments_Successfully_Cast.jpg/520px-First_ELT_Main_Mirror_Segments_Successfully_Cast.jpg 2x" data-file-width="5332" data-file-height="2928" /></a><figcaption>Cast of the first ELT main mirror segments<sup id="cite_ref-35" class="reference"><a href="#cite_note-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup></figcaption></figure> <p>In May 2017, ESO awarded two additional contracts. One was awarded to the German company <a href="/wiki/Schott_AG" title="Schott AG">Schott AG</a> who manufactures the blanks of the 798 segments, as well as a maintenance set of 133 additional segments. This maintenance set allows segments to be removed, replaced, and recoated on a rotating basis once the ELT is in operation. The mirror is being cast from the same low-expansion ceramic <a href="/wiki/Zerodur" title="Zerodur">Zerodur</a> as the existing <a href="/wiki/Very_Large_Telescope" title="Very Large Telescope">Very Large Telescope</a> mirrors in Chile. </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:E-ELT_mirror_segments_under_test.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/88/E-ELT_mirror_segments_under_test.jpg/260px-E-ELT_mirror_segments_under_test.jpg" decoding="async" width="260" height="173" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/88/E-ELT_mirror_segments_under_test.jpg/390px-E-ELT_mirror_segments_under_test.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/88/E-ELT_mirror_segments_under_test.jpg/520px-E-ELT_mirror_segments_under_test.jpg 2x" data-file-width="4000" data-file-height="2667" /></a><figcaption>Several segments of the primary mirror</figcaption></figure> <p>The other contract was awarded to the French company, Safran Reosc,<sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> a subsidiary of <a href="/wiki/Safran_Electronics_%26_Defense" title="Safran Electronics & Defense">Safran Electronics & Defense</a>. They receive the mirror blanks from Schott, and polish one mirror segment per day to meet the 7-year deadline. During this process, each segment is polished until it has no surface irregularity greater than 7.5 nm <a href="/wiki/Root_mean_square" title="Root mean square">root mean square</a>. Afterward, Safran Reosc mounts, tests, and completes all optical testing before delivery. This is the second-largest contract for ELT construction and the third-largest contract ESO has ever signed. </p><p>The segment support system units for the primary mirror were designed and are produced by CESA (Spain)<sup id="cite_ref-37" class="reference"><a href="#cite_note-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> and <a href="/wiki/VDL_Groep" title="VDL Groep">VDL</a> (the Netherlands). The contracts signed with ESO also include the delivery of detailed and complete instructions and engineering drawings for their production. Additionally, they include the development of the procedures required to integrate the supports with the ELT glass segments; to handle and transport the segment assemblies; and to operate and maintain them.<sup id="cite_ref-38" class="reference"><a href="#cite_note-38"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup> </p><p>As of July 2023, over 70% of the mirror segment blanks and their supporting structures had been manufactured,<sup id="cite_ref-50percent_3-2" class="reference"><a href="#cite_note-50percent-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> and by early 2024 tens of segments had been polished.<sup id="cite_ref-SPIE2024_39-0" class="reference"><a href="#cite_note-SPIE2024-39"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading4"><h4 id="Secondary_mirror">Secondary mirror</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=6" title="Edit section: Secondary mirror"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Blank_Canvas_the_ELT%E2%80%99s_M2_Mirror_Blank.tif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/53/Blank_Canvas_the_ELT%E2%80%99s_M2_Mirror_Blank.tif/lossy-page1-260px-Blank_Canvas_the_ELT%E2%80%99s_M2_Mirror_Blank.tif.jpg" decoding="async" width="260" height="195" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/53/Blank_Canvas_the_ELT%E2%80%99s_M2_Mirror_Blank.tif/lossy-page1-390px-Blank_Canvas_the_ELT%E2%80%99s_M2_Mirror_Blank.tif.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/53/Blank_Canvas_the_ELT%E2%80%99s_M2_Mirror_Blank.tif/lossy-page1-520px-Blank_Canvas_the_ELT%E2%80%99s_M2_Mirror_Blank.tif.jpg 2x" data-file-width="2362" data-file-height="1772" /></a><figcaption>ELT's M2 mirror blank<sup id="cite_ref-40" class="reference"><a href="#cite_note-40"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup></figcaption></figure> <p>Making the secondary mirror is a major challenge as it is highly convex, and aspheric. It is also very large; at 4.2 metres (14 ft) in diameter and weighing 3.5 tonnes (7,700 lb), it will be the largest secondary mirror ever employed on an optical telescope and the largest convex mirror ever produced. </p><p>In January 2017,<sup id="cite_ref-contracts-eso_32-1" class="reference"><a href="#cite_note-contracts-eso-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> ESO awarded a contract for the mirror blank to <a href="/wiki/Schott_AG" title="Schott AG">Schott AG</a>, who cast it later the same year from <a href="/wiki/Zerodur" title="Zerodur">Zerodur</a>. In May 2017,<sup id="cite_ref-41" class="reference"><a href="#cite_note-41"><span class="cite-bracket">[</span>41<span class="cite-bracket">]</span></a></sup> Schott AG was also awarded the contract for the much larger primary segment of the mirror. </p><p>Complex support cells are also necessary to ensure the flexible secondary and tertiary mirrors retain their correct shape and position; these support cells will be provided by <a href="/wiki/SENER" title="SENER">SENER</a>.<sup id="cite_ref-42" class="reference"><a href="#cite_note-42"><span class="cite-bracket">[</span>42<span class="cite-bracket">]</span></a></sup> Like the tertiary mirror, the secondary mirror will be mounted on 32 points, with 14 along its edges and 18 on the back. The entire assembly will be mounted on a hexapod, allowing its position to be aligned every few minutes to sub-micrometer precision. Deformations on the secondary mirror have a much smaller effect on the final image compared to errors on the tertiary, quaternary, or quinary mirrors.<sup id="cite_ref-M2M3_43-0" class="reference"><a href="#cite_note-M2M3-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup> </p><p>The pre-formed glass-ceramic blank of the secondary mirror is being polished and tested by Safran Reosc.<sup id="cite_ref-44" class="reference"><a href="#cite_note-44"><span class="cite-bracket">[</span>44<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-45" class="reference"><a href="#cite_note-45"><span class="cite-bracket">[</span>45<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-50percent_3-3" class="reference"><a href="#cite_note-50percent-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> The mirror will be shaped and polished to a precision of 15 nanometres (15 millionths of a millimetre) over the optical surface. </p><p>By early 2024 this mirror was reported to be close to final accuracy.<sup id="cite_ref-SPIE2024_39-1" class="reference"><a href="#cite_note-SPIE2024-39"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading4"><h4 id="Tertiary_mirror">Tertiary mirror</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=7" title="Edit section: Tertiary mirror"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The 3.8-metre (12 ft) concave tertiary mirror, also cast from Zerodur, will be an unusual feature of the telescope. Most current large telescopes, including the VLT and the NASA/ESA Hubble Space Telescope, use two curved mirrors to form an image. In these cases, a small, flat tertiary mirror is sometimes introduced to divert the light to a convenient focus. However, in the ELT the tertiary mirror also has a curved surface, as the use of three mirrors delivers a better final image quality over a larger field of view than would be possible with a two-mirror design.<sup id="cite_ref-contracts-eso_32-2" class="reference"><a href="#cite_note-contracts-eso-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> </p><p>Much like the secondary mirror (with which it shares many design characteristics), the tertiary mirror will be slightly deformable to regularly allow deviations to be corrected. Both mirrors will be mounted on 32 points, with 18 on their backside and 14 along their edges.<sup id="cite_ref-M2M3_43-1" class="reference"><a href="#cite_note-M2M3-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup> </p><p>As of July 2023, the tertiary mirror has been cast and is in polishing.<sup id="cite_ref-50percent_3-4" class="reference"><a href="#cite_note-50percent-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading4"><h4 id="Quaternary_mirror">Quaternary mirror</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=8" title="Edit section: Quaternary mirror"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The 2.4-metre (7.9 ft) quaternary mirror is a flat, 2 mm (0.08 in) thick adaptive mirror. With up to 8,000 actuators, the surface can be readjusted one thousand times per second.<sup id="cite_ref-46" class="reference"><a href="#cite_note-46"><span class="cite-bracket">[</span>46<span class="cite-bracket">]</span></a></sup> The deformable mirror will be the largest adaptive mirror ever made,<sup id="cite_ref-contract-ann_47-0" class="reference"><a href="#cite_note-contract-ann-47"><span class="cite-bracket">[</span>47<span class="cite-bracket">]</span></a></sup> and consists of six component petals, control systems, and voice-coil actuators. The image distortion caused by the turbulence of the Earth's atmosphere can be corrected in real-time, as well as deformations caused by the wind upon the main telescope. The ELT's adaptive optics system will provide an improvement of about a factor of 500 in the resolution compared to the best seeing conditions achieved so far without adaptive optics.<sup id="cite_ref-contract-ann_47-1" class="reference"><a href="#cite_note-contract-ann-47"><span class="cite-bracket">[</span>47<span class="cite-bracket">]</span></a></sup> </p><p>The AdOptica consortium,<sup id="cite_ref-48" class="reference"><a href="#cite_note-48"><span class="cite-bracket">[</span>48<span class="cite-bracket">]</span></a></sup> partnered with <a href="/wiki/INAF" class="mw-redirect" title="INAF">INAF</a> (Istituto Nazionale di Astrofisica) as subcontractors, are responsible for the design and manufacture of the quaternary mirror.<sup id="cite_ref-49" class="reference"><a href="#cite_note-49"><span class="cite-bracket">[</span>49<span class="cite-bracket">]</span></a></sup> The 6 petals were cast by Schott in Germany and polished by Safran Reosc.<sup id="cite_ref-50" class="reference"><a href="#cite_note-50"><span class="cite-bracket">[</span>50<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-51" class="reference"><a href="#cite_note-51"><span class="cite-bracket">[</span>51<span class="cite-bracket">]</span></a></sup> </p><p>As of July 2023, all six petals are completed and in the process of being integrated into their support structure.<sup id="cite_ref-50percent_3-5" class="reference"><a href="#cite_note-50percent-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> The six laser sources for the adaptive optics system, which will work hand-in-hand with the quaternary mirror, have also been completed and are in testing. </p> <div class="mw-heading mw-heading4"><h4 id="Quinary_mirror">Quinary mirror</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=9" title="Edit section: Quinary mirror"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The 2.7-by-2.2-metre (8.9 by 7.2 ft) quinary mirror is a tip-tilt mirror used to refine the image using <a href="/wiki/Adaptive_optics" title="Adaptive optics">adaptive optics</a>. The mirror will include a fast tip-tilt system for image stabilization that will compensate perturbations caused by wind, atmospheric turbulence, and the telescope itself before reaching the ELT instruments.<sup id="cite_ref-52" class="reference"><a href="#cite_note-52"><span class="cite-bracket">[</span>52<span class="cite-bracket">]</span></a></sup> </p><p>As of early 2024 the six component petals had been fabricated and are being brazed into a single unit.<sup id="cite_ref-SPIE2024_39-2" class="reference"><a href="#cite_note-SPIE2024-39"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="ELT_dome_and_structure">ELT dome and structure</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=10" title="Edit section: ELT dome and structure"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading4"><h4 id="Dome_construction">Dome construction</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=11" title="Edit section: Dome construction"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:ELT_concept.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/35/ELT_concept.jpg/260px-ELT_concept.jpg" decoding="async" width="260" height="184" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/35/ELT_concept.jpg/390px-ELT_concept.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/35/ELT_concept.jpg/520px-ELT_concept.jpg 2x" data-file-width="6000" data-file-height="4255" /></a><figcaption>ELT concept</figcaption></figure> <p>The ELT dome will have a height of nearly 74 metres (243 ft) from the ground and a diameter of 86 metres (282 ft),<sup id="cite_ref-53" class="reference"><a href="#cite_note-53"><span class="cite-bracket">[</span>53<span class="cite-bracket">]</span></a></sup> making it the largest dome ever built for a telescope. The dome will have a total mass of around 6,100 tonnes (13,400,000 lb), and the telescope mounting and tube structure will have a total moving mass of around 2,800 tonnes (6,200,000 lb). </p><p>For the observing slit, two main designs were under study: one with two sets of nested doors, and the current baseline design, i.e. a single pair of large sliding doors. This pair of doors has a total width of 45.3 metres (149 ft). </p><p>ESO signed a contract for its construction,<sup id="cite_ref-54" class="reference"><a href="#cite_note-54"><span class="cite-bracket">[</span>54<span class="cite-bracket">]</span></a></sup> together with the main structure of the telescopes, with the Italian ACe Consortium, consisting of <a href="/wiki/Astaldi" title="Astaldi">Astaldi</a> and Cimolai<sup id="cite_ref-55" class="reference"><a href="#cite_note-55"><span class="cite-bracket">[</span>55<span class="cite-bracket">]</span></a></sup> and the nominated subcontractor, Italy's EIE Group.<sup id="cite_ref-56" class="reference"><a href="#cite_note-56"><span class="cite-bracket">[</span>56<span class="cite-bracket">]</span></a></sup> The signature ceremony took place on 25 May 2016<sup id="cite_ref-57" class="reference"><a href="#cite_note-57"><span class="cite-bracket">[</span>57<span class="cite-bracket">]</span></a></sup> at ESO's Headquarters in Garching bei München, Germany. </p><p>The dome is to provide needed protection to the telescope in inclement weather and during the day. A number of concepts for the dome were evaluated. The baseline concept for the 40-metre-class ELT dome is a nearly hemispherical dome, rotating atop a concrete pier, with curved laterally-opening doors. This is a re-optimisation from the previous design, aimed at reducing the costs, and it is being revalidated to be ready for construction.<sup id="cite_ref-58" class="reference"><a href="#cite_note-58"><span class="cite-bracket">[</span>58<span class="cite-bracket">]</span></a></sup> </p><p>One year after signing the contract, and after the laying of the first stone ceremony in May 2017, the site was handed over to ACe, signifying the beginning of the construction of the dome's main structure. </p> <div class="mw-heading mw-heading4"><h4 id="Astronomical_performance">Astronomical performance</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=12" title="Edit section: Astronomical performance"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In terms of astronomical performance the dome is required to be able to track about the 1-degree <a href="/wiki/Zenith" title="Zenith">zenithal</a> avoidance locus as well as preset to a new target within 5 minutes. This requires the dome to be able to accelerate and move at angular speeds of 2 degrees/s (the linear speed is approximately 5 km/h or 4.6 ft/s).<sup id="cite_ref-59" class="reference"><a href="#cite_note-59"><span class="cite-bracket">[</span>59<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size mw-halign-center" typeof="mw:File/Thumb"><a href="/wiki/File:Size_comparison_between_the_E-ELT_and_other_telescope_domes.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/59/Size_comparison_between_the_E-ELT_and_other_telescope_domes.jpg/840px-Size_comparison_between_the_E-ELT_and_other_telescope_domes.jpg" decoding="async" width="840" height="159" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/59/Size_comparison_between_the_E-ELT_and_other_telescope_domes.jpg/1260px-Size_comparison_between_the_E-ELT_and_other_telescope_domes.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/59/Size_comparison_between_the_E-ELT_and_other_telescope_domes.jpg/1680px-Size_comparison_between_the_E-ELT_and_other_telescope_domes.jpg 2x" data-file-width="11496" data-file-height="2172" /></a><figcaption>Size comparison between the ELT and other telescope domes</figcaption></figure> <p>The dome is designed to allow complete freedom to the telescope so that it can position itself whether it is opened or closed. It will also permit observations from the zenith down to 20 degrees from the horizon. </p> <div class="mw-heading mw-heading4"><h4 id="Windscreen">Windscreen</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=13" title="Edit section: Windscreen"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>With such a large opening, the ELT dome requires the presence of a windscreen to protect the telescope's mirrors (apart from the secondary), from direct exposure to the wind. The baseline design of the windscreen minimises the volume required to house it. Two spherical blades, either side of the observing slit doors, slide in front of the telescope aperture to restrict the wind. </p> <div class="mw-heading mw-heading4"><h4 id="Ventilation_and_air-conditioning">Ventilation and air-conditioning</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=14" title="Edit section: Ventilation and air-conditioning"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The dome design ensures that the dome provides sufficient ventilation for the telescope not to be limited by <a href="/wiki/Astronomical_seeing" title="Astronomical seeing">dome seeing</a>. For this the dome is also equipped with louvers, whereby the windscreen is designed to allow them to fulfill their function. </p><p>Computational fluid dynamic simulations and wind tunnel work are being carried out to study the airflow in and around the dome, as well as the effectiveness of the dome and windscreen in protecting the telescope. </p><p>Besides being designed for water-tightness, air-tightness is also one of the requirements as it is critical to minimise the air-conditioning load. The air-conditioning of the dome is necessary not only to thermally prepare the telescope for the forthcoming night but also in order to keep the telescope optics clean. </p><p>The air-conditioning of the telescope during the day is critical and the current specifications permit the dome to cool the telescope and internal volume by 10 °C (18 °F) over 12 hours. </p> <div class="mw-heading mw-heading2"><h2 id="Science_goals">Science goals</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=15" title="Edit section: Science goals"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><span><video id="mwe_player_0" poster="//upload.wikimedia.org/wikipedia/commons/thumb/e/ec/E-ELT_Trailer.ogv/260px--E-ELT_Trailer.ogv.jpg" controls="" preload="none" data-mw-tmh="" class="mw-file-element" width="260" height="147" data-durationhint="202" data-mwtitle="E-ELT_Trailer.ogv" data-mwprovider="wikimediacommons" resource="/wiki/File:E-ELT_Trailer.ogv"><source src="//upload.wikimedia.org/wikipedia/commons/e/ec/E-ELT_Trailer.ogv" type="video/ogg; codecs="theora, vorbis"" data-width="720" data-height="406" /><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/e/ec/E-ELT_Trailer.ogv/E-ELT_Trailer.ogv.144p.mjpeg.mov" type="video/quicktime" data-transcodekey="144p.mjpeg.mov" data-width="256" data-height="144" /><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/e/ec/E-ELT_Trailer.ogv/E-ELT_Trailer.ogv.240p.vp9.webm" type="video/webm; codecs="vp9, opus"" data-transcodekey="240p.vp9.webm" data-width="426" data-height="240" /><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/e/ec/E-ELT_Trailer.ogv/E-ELT_Trailer.ogv.360p.vp9.webm" type="video/webm; codecs="vp9, opus"" data-transcodekey="360p.vp9.webm" data-width="638" data-height="360" /><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/e/ec/E-ELT_Trailer.ogv/E-ELT_Trailer.ogv.360p.webm" type="video/webm; codecs="vp8, vorbis"" data-transcodekey="360p.webm" data-width="638" data-height="360" /></video></span><figcaption>The official trailer for the ELT showing the preliminary design.</figcaption></figure> <p>The ELT will search for extrasolar planets—planets orbiting other stars. This will include not only the discovery of planets down to Earth-like masses through indirect measurements of the wobbling motion of stars perturbed by the planets that orbit them, but also the direct imaging of larger planets and possibly even the characterisation of their atmospheres.<sup id="cite_ref-brochure_60-0" class="reference"><a href="#cite_note-brochure-60"><span class="cite-bracket">[</span>60<span class="cite-bracket">]</span></a></sup> The telescope will attempt to image Earthlike <a href="/wiki/Exoplanets" class="mw-redirect" title="Exoplanets">exoplanets</a>.<sup id="cite_ref-govert_2-2" class="reference"><a href="#cite_note-govert-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p><p>Furthermore, the ELT's suite of instruments will allow astronomers to probe the earliest stages of the formation of planetary systems and to detect water and organic molecules in protoplanetary discs around stars in the making. Thus, the ELT will answer fundamental questions regarding planet formation and evolution.<sup id="cite_ref-E-ELT_Alone_6-1" class="reference"><a href="#cite_note-E-ELT_Alone-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </p><p>By probing the most distant objects the ELT will provide clues to understanding the formation of the first objects that formed: primordial stars, primordial galaxies and black holes and their relationships. Studies of extreme objects like black holes will benefit from the power of the ELT to gain more insight into time-dependent phenomena linked with the various processes at play around compact objects.<sup id="cite_ref-brochure_60-1" class="reference"><a href="#cite_note-brochure-60"><span class="cite-bracket">[</span>60<span class="cite-bracket">]</span></a></sup> </p><p>The ELT is designed to make detailed studies of the first galaxies. Observations of these early galaxies with the ELT will give clues that will help understand how these objects form and evolve. In addition, the ELT will be a unique tool for making an inventory of the changing content of the various elements in the Universe with time, and to understand star formation history in galaxies.<sup id="cite_ref-E-ELT_First_61-0" class="reference"><a href="#cite_note-E-ELT_First-61"><span class="cite-bracket">[</span>61<span class="cite-bracket">]</span></a></sup> </p><p>One of the goals of the ELT is the possibility of making a direct measurement of the acceleration of the Universe's expansion. Such a measurement would have a major impact on our understanding of the Universe. The ELT will also search for possible variations in the fundamental physical constants with time. An unambiguous detection of such variations would have far-reaching consequences for our comprehension of the general laws of physics.<sup id="cite_ref-E-ELT_First_61-1" class="reference"><a href="#cite_note-E-ELT_First-61"><span class="cite-bracket">[</span>61<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Instrumentation">Instrumentation</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=16" title="Edit section: Instrumentation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:The_First_E-ELT_Instruments.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5d/The_First_E-ELT_Instruments.jpg/260px-The_First_E-ELT_Instruments.jpg" decoding="async" width="260" height="141" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5d/The_First_E-ELT_Instruments.jpg/390px-The_First_E-ELT_Instruments.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5d/The_First_E-ELT_Instruments.jpg/520px-The_First_E-ELT_Instruments.jpg 2x" data-file-width="4000" data-file-height="2168" /></a><figcaption>The first ELT instruments<sup id="cite_ref-62" class="reference"><a href="#cite_note-62"><span class="cite-bracket">[</span>62<span class="cite-bracket">]</span></a></sup></figcaption></figure> <p>The telescope will have several science instruments and will be able to switch from one instrument to another within minutes. The telescope and dome will also be able to change positions on the sky and start a new observation in a short time. </p><p>Four of its instruments, the first generation, will be available at or shortly after first light, while two others will begin operations later. Throughout its operation other instruments can be installed.<sup id="cite_ref-63" class="reference"><a href="#cite_note-63"><span class="cite-bracket">[</span>63<span class="cite-bracket">]</span></a></sup> </p><p>The first generation includes four instruments: MICADO, HARMONI and METIS, along with the adaptive optics system MORFEO. </p> <ul><li><b>HARMONI</b>: The High Angular Resolution Monolithic Optical and Near-infrared Integral field spectrograph (HARMONI) will function as the telescope's workhorse instrument for spectroscopy.<sup id="cite_ref-HARMONI_Webpage_64-0" class="reference"><a href="#cite_note-HARMONI_Webpage-64"><span class="cite-bracket">[</span>64<span class="cite-bracket">]</span></a></sup></li> <li><b>METIS</b>: The Mid-infrared ELT Imager and Spectrograph (METIS) will be a mid-infrared imager and spectrograph.<sup id="cite_ref-METIS_Webpage_65-0" class="reference"><a href="#cite_note-METIS_Webpage-65"><span class="cite-bracket">[</span>65<span class="cite-bracket">]</span></a></sup></li> <li><b>MICADO</b>: The Multi-AO (adaptive optics) Imaging Camera for Deep Observations (MICADO) will be the first dedicated imaging camera for the ELT and will work with the Multiconjugate adaptive Optics Relay For ELT Observations, (<b>MORFEO</b>, formerly <b>MAORY</b>).<sup id="cite_ref-MICADO_Webpage_66-0" class="reference"><a href="#cite_note-MICADO_Webpage-66"><span class="cite-bracket">[</span>66<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-MORFEO_Webpage_67-0" class="reference"><a href="#cite_note-MORFEO_Webpage-67"><span class="cite-bracket">[</span>67<span class="cite-bracket">]</span></a></sup></li></ul> <p>The second generation of instruments consists of MOSAIC and ANDES. </p> <ul><li><b>MOSAIC</b>: A proposed multi-object spectrograph which will allow astronomers to trace the growth of galaxies and the distribution of matter from shortly after the Big Bang to the present day.<sup id="cite_ref-MOSAIC_Webpage_68-0" class="reference"><a href="#cite_note-MOSAIC_Webpage-68"><span class="cite-bracket">[</span>68<span class="cite-bracket">]</span></a></sup></li> <li><b>ANDES</b> (formerly <b>HIRES</b>): The ArmazoNes high Dispersion Echelle Spectrograph will be used to search for indications of life on Earth-like exoplanets, find the first-born stars of the universe, test for possible variations of the fundamental constants of physics, and measure the acceleration of the Universe's expansion.<sup id="cite_ref-HIRES_Webpage_69-0" class="reference"><a href="#cite_note-HIRES_Webpage-69"><span class="cite-bracket">[</span>69<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Comparison">Comparison</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=17" title="Edit section: Comparison"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure typeof="mw:File/Thumb"><a href="/wiki/File:Comparison_optical_telescope_primary_mirrors.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Comparison_optical_telescope_primary_mirrors.svg/350px-Comparison_optical_telescope_primary_mirrors.svg.png" decoding="async" width="350" height="366" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Comparison_optical_telescope_primary_mirrors.svg/525px-Comparison_optical_telescope_primary_mirrors.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Comparison_optical_telescope_primary_mirrors.svg/700px-Comparison_optical_telescope_primary_mirrors.svg.png 2x" data-file-width="512" data-file-height="536" /></a><figcaption>Comparison of nominal sizes of apertures of the Extremely Large Telescope and some notable optical telescopes</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:E-ELT_and_VLT_vs_Colosseum.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c4/E-ELT_and_VLT_vs_Colosseum.jpg/350px-E-ELT_and_VLT_vs_Colosseum.jpg" decoding="async" width="350" height="144" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c4/E-ELT_and_VLT_vs_Colosseum.jpg/525px-E-ELT_and_VLT_vs_Colosseum.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c4/E-ELT_and_VLT_vs_Colosseum.jpg/700px-E-ELT_and_VLT_vs_Colosseum.jpg 2x" data-file-width="2710" data-file-height="1112" /></a><figcaption>ELT compared to the <a href="/wiki/Very_Large_Telescope" title="Very Large Telescope">VLT</a> and the <a href="/wiki/Colosseum" title="Colosseum">Colosseum</a></figcaption></figure> <p>One of the <a href="/wiki/List_of_largest_optical_reflecting_telescopes" title="List of largest optical reflecting telescopes">largest optical telescopes</a> operating today is the <a href="/wiki/Gran_Telescopio_Canarias" title="Gran Telescopio Canarias">Gran Telescopio Canarias</a>, with a 10.4-metre (34 ft) aperture and a light-collecting area of 74 m<sup>2</sup> (800 sq ft). Other planned <a href="/wiki/Extremely_large_telescope" title="Extremely large telescope">extremely large telescopes</a> include the <a href="/wiki/Giant_Magellan_Telescope" title="Giant Magellan Telescope">Giant Magellan Telescope</a> with a mirror diameter of 25 m (82 ft) and area of 368 m<sup>2</sup> (3,960 sq ft), and the <a href="/wiki/Thirty_Meter_Telescope" title="Thirty Meter Telescope">Thirty Meter Telescope</a> with a diameter of 30 m (98 ft), and an area of 655 m<sup>2</sup> (7,050 sq ft). Both of these are also targeting the second half of the 2020 decade for completion. These two other telescopes roughly belong to the same next generation of optical ground-based telescopes.<sup id="cite_ref-GMT_Overview_70-0" class="reference"><a href="#cite_note-GMT_Overview-70"><span class="cite-bracket">[</span>70<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-About_TMT_71-0" class="reference"><a href="#cite_note-About_TMT-71"><span class="cite-bracket">[</span>71<span class="cite-bracket">]</span></a></sup> Each design is much larger than previous telescopes.<sup id="cite_ref-govert_2-3" class="reference"><a href="#cite_note-govert-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p><p>The size of the ELT has been reduced from its original design. Even with that reduction, the ELT is significantly larger than both other planned extremely large telescopes.<sup id="cite_ref-govert_2-4" class="reference"><a href="#cite_note-govert-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> It has the aim of observing the universe in greater detail than the <a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubble Space Telescope</a> by taking images 15 times sharper, although it is designed to be complementary to space telescopes, which typically have very limited observing time available.<sup id="cite_ref-esoscience_25-1" class="reference"><a href="#cite_note-esoscience-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> The ELT's 4.2-metre <a href="/wiki/Secondary_mirror" title="Secondary mirror">secondary mirror</a> is the same size as the primary mirror on the <a href="/wiki/William_Herschel_Telescope" title="William Herschel Telescope">William Herschel Telescope</a>, the second largest optical telescope in Europe. </p> <table class="wikitable sortable" style="text-align: center;"> <tbody><tr> <th>Name</th> <th>Aperture<br />diameter (m)</th> <th>Collecting<br />area (m²)</th> <th>First light</th> <th>Ref </th></tr> <tr> <td align="left"><b>Extremely Large Telescope (ELT)</b></td> <td>39.3</td> <td>978</td> <td>2028</td> <td><sup id="cite_ref-72" class="reference"><a href="#cite_note-72"><span class="cite-bracket">[</span>72<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td align="left"><a href="/wiki/Thirty_Meter_Telescope" title="Thirty Meter Telescope">Thirty Meter Telescope</a> (TMT)</td> <td>30.0</td> <td>655</td> <td>?</td> <td> </td></tr> <tr> <td align="left"><a href="/wiki/Giant_Magellan_Telescope" title="Giant Magellan Telescope">Giant Magellan Telescope</a> (GMT)</td> <td>25.4</td> <td>368</td> <td>2029</td> <td><sup id="cite_ref-73" class="reference"><a href="#cite_note-73"><span class="cite-bracket">[</span>73<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td align="left"><a href="/wiki/Large_Binocular_Telescope" title="Large Binocular Telescope">Large Binocular Telescope</a> (LBT) </td> <td>2 x 8.4 (22.8) </td> <td>111 </td> <td>2005 </td> <td> </td></tr> <tr> <td align="left"><a href="/wiki/Southern_African_Large_Telescope" title="Southern African Large Telescope">Southern African Large Telescope</a> (SALT)</td> <td>11.1 × 9.8</td> <td>79</td> <td>2005</td> <td> </td></tr> <tr> <td align="left"><a href="/wiki/Hobby%E2%80%93Eberly_Telescope" title="Hobby–Eberly Telescope">Hobby–Eberly Telescope</a> (HET) </td> <td>11.1 × 9.8 </td> <td>79 </td> <td>1996 </td> <td> </td></tr> <tr> <td align="left"><a href="/wiki/Gran_Telescopio_Canarias" title="Gran Telescopio Canarias">Gran Telescopio Canarias</a> (GTC)</td> <td>10.4</td> <td>74</td> <td>2007</td> <td> </td></tr> <tr> <td align="left"><a href="/wiki/Keck_Telescopes" class="mw-redirect" title="Keck Telescopes">Keck Telescopes</a></td> <td>10.0</td> <td>76</td> <td>1990, 1996</td> <td> </td></tr> <tr> <td align="left"><a href="/wiki/Very_Large_Telescope" title="Very Large Telescope">Very Large Telescope</a> (VLT)</td> <td>8.2</td> <td>50 (×4)</td> <td>1998–2000</td> <td> </td></tr> <tr> <td colspan="4" style="font-size: 0.85em; padding: 6px 0 4px 4px;">Notes: Future first-light dates are provisional and likely to change. </td></tr></tbody></table> <p>The ELT under ideal conditions has an angular resolution of 0.005 <a href="/wiki/Arcsecond" class="mw-redirect" title="Arcsecond">arcsecond</a> which corresponds to separating two light sources 1 <a href="/wiki/Astronomical_unit" title="Astronomical unit">AU</a> apart from 200 <a href="/wiki/Parsec" title="Parsec">pc</a> (650 ly) distance, or two light sources 30 cm (12 in) apart from roughly 12,000 km (7,500 mi) distance. At 0.03 arcseconds, the contrast is expected to be 10<sup>8</sup>, sufficient to search for exoplanets.<sup id="cite_ref-74" class="reference"><a href="#cite_note-74"><span class="cite-bracket">[</span>74<span class="cite-bracket">]</span></a></sup> The <a href="/wiki/Naked_eye" title="Naked eye">unaided human eye</a> has an angular resolution of 1 arcminute which corresponds to separating two light sources 30 cm apart from 1 km distance.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (October 2024)">citation needed</span></a></i>]</sup> </p> <div style="clear:both;" class=""></div> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=18" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1184024115">.mw-parser-output .div-col{margin-top:0.3em;column-width:30em}.mw-parser-output .div-col-small{font-size:90%}.mw-parser-output .div-col-rules{column-rule:1px solid #aaa}.mw-parser-output .div-col dl,.mw-parser-output .div-col ol,.mw-parser-output .div-col ul{margin-top:0}.mw-parser-output .div-col li,.mw-parser-output .div-col dd{page-break-inside:avoid;break-inside:avoid-column}</style><div class="div-col" style="column-width: 21em;"> <ul><li><a href="/wiki/Lists_of_telescopes" title="Lists of telescopes">Lists of telescopes</a></li> <li><a href="/wiki/List_of_largest_optical_reflecting_telescopes" title="List of largest optical reflecting telescopes">List of largest optical reflecting telescopes</a></li> <li><a href="/wiki/List_of_optical_telescopes" title="List of optical telescopes">List of optical telescopes</a></li> <li><a href="/wiki/Large_Binocular_Telescope" title="Large Binocular Telescope">Large Binocular Telescope</a></li> <li><a href="/wiki/European_Solar_Telescope" title="European Solar Telescope">European Solar Telescope</a> (planned completion in 2025)</li> <li><a href="/wiki/Gran_Telescopio_Canarias" title="Gran Telescopio Canarias">Gran Telescopio Canarias</a></li> <li><a href="/wiki/Overwhelmingly_Large_Telescope" title="Overwhelmingly Large Telescope">Overwhelmingly Large Telescope</a></li> <li><a href="/wiki/List_of_astronomical_observatories" title="List of astronomical observatories">List of astronomical observatories</a></li> <li><a href="/wiki/List_of_highest_astronomical_observatories" title="List of highest astronomical observatories">List of highest astronomical observatories</a></li> <li>Other observatories in Chile: <ul><li><a href="/wiki/Llano_de_Chajnantor_Observatory" title="Llano de Chajnantor Observatory">Llano de Chajnantor Observatory</a> <ul><li><a href="/wiki/Atacama_Large_Millimeter_Array" title="Atacama Large Millimeter Array">Atacama Large Millimeter Array</a></li></ul></li> <li><a href="/wiki/Paranal_Observatory" title="Paranal Observatory">Paranal Observatory</a> <ul><li><a href="/wiki/Very_Large_Telescope" title="Very Large Telescope">Very Large Telescope</a></li></ul></li> <li><a href="/wiki/Cerro_Armazones_Observatory" class="mw-redirect" title="Cerro Armazones Observatory">Cerro Armazones Observatory</a></li> <li><a href="/wiki/La_Silla_Observatory" title="La Silla Observatory">La Silla Observatory</a></li> <li><a href="/wiki/Cerro_Tololo_Inter-American_Observatory" title="Cerro Tololo Inter-American Observatory">Cerro Tololo Inter-American Observatory</a></li></ul></li></ul> </div> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Extremely_Large_Telescope&action=edit&section=19" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-columns references-column-width" style="column-width: 30em ;"> <ol class="references"> <li id="cite_note-NYT-20240308-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-NYT-20240308_1-0">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output 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Retrieved <span class="nowrap">16 April</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=ESO+MOSAIC+Webpage&rft_id=https%3A%2F%2Fwww.eso.org%2Fpublic%2Fteles-instr%2Felt%2Felt-instr%2Fmosaic%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AExtremely+Large+Telescope" class="Z3988"></span></span> </li> <li id="cite_note-HIRES_Webpage-69"><span class="mw-cite-backlink"><b><a href="#cite_ref-HIRES_Webpage_69-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.eso.org/public/teles-instr/elt/elt-instr/hires/">"ESO HIRES Webpage"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">16 April</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=ESO+HIRES+Webpage&rft_id=https%3A%2F%2Fwww.eso.org%2Fpublic%2Fteles-instr%2Felt%2Felt-instr%2Fhires%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AExtremely+Large+Telescope" class="Z3988"></span></span> </li> <li id="cite_note-GMT_Overview-70"><span class="mw-cite-backlink"><b><a href="#cite_ref-GMT_Overview_70-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110609023406/http://www.gmto.org/overview.html">"GMT Overview – Giant Magellan Telescope"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.gmto.org/overview.html">the original</a> on 9 June 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">15 June</span> 2011</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=GMT+Overview+%E2%80%93+Giant+Magellan+Telescope&rft_id=http%3A%2F%2Fwww.gmto.org%2Foverview.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AExtremely+Large+Telescope" class="Z3988"></span></span> </li> <li id="cite_note-About_TMT-71"><span class="mw-cite-backlink"><b><a href="#cite_ref-About_TMT_71-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110808172454/http://www.tmt.org/about-tmt">"About TMT – Thirty Meter Telescope"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.tmt.org/about-tmt">the original</a> on 8 August 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">15 June</span> 2011</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=About+TMT+%E2%80%93+Thirty+Meter+Telescope&rft_id=http%3A%2F%2Fwww.tmt.org%2Fabout-tmt&rfr_id=info%3Asid%2Fen.wikipedia.org%3AExtremely+Large+Telescope" class="Z3988"></span></span> </li> <li id="cite_note-72"><span class="mw-cite-backlink"><b><a href="#cite_ref-72">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://elt.eso.org/about/timeline/">"Extremely Large Telescope – Timeline"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">11 July</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Extremely+Large+Telescope+%E2%80%93+Timeline&rft_id=https%3A%2F%2Felt.eso.org%2Fabout%2Ftimeline%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AExtremely+Large+Telescope" class="Z3988"></span></span> </li> <li id="cite_note-73"><span class="mw-cite-backlink"><b><a href="#cite_ref-73">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.universetoday.com/150506/the-giant-magellan-telescopes-6th-mirror-has-just-been-cast-one-more-to-go/">"Giant Magellan Telescope – 6th mirror cast"</a>. 12 March 2021<span class="reference-accessdate">. Retrieved <span class="nowrap">11 July</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Giant+Magellan+Telescope+%E2%80%93+6th+mirror+cast&rft.date=2021-03-12&rft_id=https%3A%2F%2Fwww.universetoday.com%2F150506%2Fthe-giant-magellan-telescopes-6th-mirror-has-just-been-cast-one-more-to-go%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AExtremely+Large+Telescope" class="Z3988"></span></span> </li> <li id="cite_note-74"><span class="mw-cite-backlink"><b><a href="#cite_ref-74">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.eso.org/sci/libraries/SPIE2010/7735-84.pdf">EPICS: direct imagine of exoplanets with the E-ELT</a></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a 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href="/wiki/Space_Telescope_European_Coordinating_Facility" title="Space Telescope European Coordinating Facility">Space Telescope European Coordinating Facility</a></li></ul> </div></td><td class="noviewer navbox-image" rowspan="4" style="width:1px;padding:0 0 0 2px"><div><span typeof="mw:File"><a href="/wiki/File:ESO_member_states.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/21/ESO_member_states.svg/80px-ESO_member_states.svg.png" decoding="async" width="80" height="109" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/21/ESO_member_states.svg/120px-ESO_member_states.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/21/ESO_member_states.svg/160px-ESO_member_states.svg.png 2x" data-file-width="336" data-file-height="458" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="text-align: center;;width:1%">Telescopes</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Atacama_Large_Millimeter_Array" title="Atacama Large Millimeter Array">ALMA</a></li> <li><a href="/wiki/Atacama_Pathfinder_Experiment" title="Atacama Pathfinder Experiment">APEX</a></li> <li><a class="mw-selflink selflink">ELT</a> <small><i>(under construction)</i></small></li> <li><a href="/wiki/ESO_3.6_m_Telescope" title="ESO 3.6 m Telescope">ESO 3.6m</a></li> <li><a href="/wiki/Swiss_1.2-metre_Leonhard_Euler_Telescope" title="Swiss 1.2-metre Leonhard Euler Telescope">EULER</a> <span style="font-size:85%;">(national)</span></li> <li><a href="/wiki/Next-Generation_Transit_Survey" title="Next-Generation Transit Survey">NGTS</a> <span style="font-size:85%;">(project)</span></li> <li><a href="/wiki/New_Technology_Telescope" title="New Technology Telescope">NTT</a></li> <li><a href="/wiki/MPG/ESO_telescope" title="MPG/ESO telescope">MPG/ESO</a></li> <li><a href="/wiki/Overwhelmingly_Large_Telescope" title="Overwhelmingly Large Telescope">OWL</a> <span style="font-size:85%;">(cancelled)</span></li> <li><a href="/wiki/VISTA_(telescope)" title="VISTA (telescope)">VISTA</a></li> <li><a href="/wiki/Very_Large_Telescope" title="Very Large Telescope">VLT</a></li> <li><a href="/wiki/VLT_Survey_Telescope" title="VLT Survey Telescope">VST</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align: center;;width:1%">Telescope<br />instruments</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ESO_3.6_m_Telescope" title="ESO 3.6 m Telescope">ESO 3.6 m Telescope</a></li> <li><a href="/wiki/Swiss_1.2-metre_Leonhard_Euler_Telescope" title="Swiss 1.2-metre Leonhard Euler Telescope">CORALIE</a></li> <li><a href="/wiki/ESPRESSO" title="ESPRESSO">ESPRESSO</a></li> <li><a href="/wiki/Gamma-Ray_Burst_Optical/Near-Infrared_Detector" title="Gamma-Ray Burst Optical/Near-Infrared Detector">GROND</a></li> <li><a href="/wiki/High_Accuracy_Radial_Velocity_Planet_Searcher" title="High Accuracy Radial Velocity Planet Searcher">HARPS</a></li> <li><a href="/wiki/K-band_multi-object_spectrograph" title="K-band multi-object spectrograph">KMOS</a></li> <li><a href="/wiki/Multi_Unit_Spectroscopic_Explorer" class="mw-redirect" title="Multi Unit Spectroscopic Explorer">MUSE</a></li> <li><a href="/wiki/PIONIER_(VLTI)" class="mw-redirect" title="PIONIER (VLTI)">PIONIER</a></li> <li><a href="/wiki/Spectro-Polarimetric_High-Contrast_Exoplanet_Research" title="Spectro-Polarimetric High-Contrast Exoplanet Research">SPHERE</a></li> <li><a href="/wiki/Visible_Multi-Object_Spectrograph" class="mw-redirect" title="Visible Multi-Object Spectrograph">VIMOS</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align: center;;width:1%">Miscellany</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/Astronomy_%26_Astrophysics" title="Astronomy & Astrophysics">Astronomy & Astrophysics</a></i></li> <li><a href="/wiki/ESO_Hotel" title="ESO Hotel">ESO Hotel</a></li> <li><a href="/wiki/Xavier_Barcons" title="Xavier Barcons">Xavier Barcons</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow hlist" colspan="3" style="text-align: center;"><div> <ul><li><b><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:European_Southern_Observatory" title="Category:European Southern Observatory">Category</a></b></li> <li><b><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Symbol_portal_class.svg" class="mw-file-description" title="Portal"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/16px-Symbol_portal_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/23px-Symbol_portal_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/31px-Symbol_portal_class.svg.png 2x" data-file-width="180" data-file-height="185" /></a></span> <a href="/wiki/Portal:Astronomy" title="Portal:Astronomy">Portal:Astronomy</a>/<a href="/wiki/Portal:Space" class="mw-redirect" title="Portal:Space">Space</a></b></li> <li><b><span class="noviewer" typeof="mw:File"><span title="Commons page"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span> <a href="https://commons.wikimedia.org/wiki/Category:European_Southern_Observatory" class="extiw" title="commons:Category:European Southern Observatory">Commons</a></b></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Astronomical_observatories_in_Chile301" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Astronomical_observatories_in_Chile" title="Template:Astronomical observatories in Chile"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Astronomical_observatories_in_Chile" title="Template talk:Astronomical observatories in Chile"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Astronomical_observatories_in_Chile" title="Special:EditPage/Template:Astronomical observatories in Chile"><abbr 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Chajnantor Observatory">Llano de Chajnantor</a> (<a href="/wiki/Atacama_Pathfinder_Experiment" title="Atacama Pathfinder Experiment">APEX</a></li> <li><a href="/wiki/Atacama_Large_Millimeter_Array" title="Atacama Large Millimeter Array">ALMA</a></li> <li><a href="/wiki/Atacama_Submillimeter_Telescope_Experiment" title="Atacama Submillimeter Telescope Experiment">ASTE</a></li> <li><a href="/wiki/POLARBEAR" title="POLARBEAR">HTT</a></li> <li><a href="/wiki/NANTEN2_Observatory" title="NANTEN2 Observatory">NANTEN2</a></li> <li><a href="/wiki/QUIET" title="QUIET">QUIET</a>)</li> <li><a href="/wiki/Paranal_Observatory" title="Paranal Observatory">Paranal</a> (<a href="/wiki/Very_Large_Telescope" title="Very Large Telescope">VLT</a>)</li> <li><a href="/wiki/University_of_Tokyo_Atacama_Observatory" title="University of Tokyo Atacama Observatory">TAO</a></li> <li><a href="/wiki/Southern_Wide-field_Gamma-ray_Observatory" title="Southern Wide-field Gamma-ray Observatory">SWGO</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Atacama_Region" title="Atacama Region">Atacama Region</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Las_Campanas_Observatory" title="Las Campanas Observatory">Las Campanas</a> <ul><li><a href="/wiki/Magellan_Telescopes" title="Magellan Telescopes">Magellan Telescopes</a></li> <li><a href="/wiki/Giant_Magellan_Telescope" title="Giant Magellan Telescope">Giant Magellan Telescope</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Coquimbo_Region" title="Coquimbo Region">Coquimbo Region</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cerro_Pach%C3%B3n" title="Cerro Pachón">Cerro Pachón</a> (<a href="/wiki/Gemini_Observatory" title="Gemini Observatory">Gemini</a></li> <li><a href="/wiki/Vera_C._Rubin_Observatory" title="Vera C. Rubin Observatory">Vera C. Rubin</a></li> <li><a href="/wiki/Southern_Astrophysical_Research_Telescope" title="Southern Astrophysical Research Telescope">SOAR</a>)</li> <li><a href="/wiki/Cerro_Tololo_Inter-American_Observatory" title="Cerro Tololo Inter-American Observatory">Cerro Tololo</a></li> <li><a href="/wiki/La_Silla_Observatory" title="La Silla Observatory">La Silla</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Santiago_Metropolitan_Region" title="Santiago Metropolitan Region">Santiago Metropolitan Region</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/National_Astronomical_Observatory_(Chile)" title="National Astronomical Observatory (Chile)">National Astronomical Observatory</a></li> <li><a href="/wiki/Cerro_El_Roble_Observatory" class="mw-redirect" title="Cerro El Roble Observatory">Cerro El Roble</a></li> <li><a href="/wiki/Manuel_Foster_Observatory" title="Manuel Foster Observatory">Manuel Foster</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:Astronomical_observatories_in_Chile" title="Category:Astronomical observatories in Chile">Category</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Exoplanet_search_projects402" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="3"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Exoplanet_search_projects" title="Template:Exoplanet search projects"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Exoplanet_search_projects" title="Template talk:Exoplanet search projects"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Exoplanet_search_projects" title="Special:EditPage/Template:Exoplanet search projects"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Exoplanet_search_projects402" style="font-size:114%;margin:0 4em"><a href="/wiki/List_of_exoplanet_search_projects" title="List of exoplanet search projects">Exoplanet search projects</a></div></th></tr><tr><td class="navbox-abovebelow" colspan="3"><div> <ul><li><a href="/wiki/Exoplanetology" class="mw-redirect" title="Exoplanetology">Exoplanetology</a></li> <li><a href="/wiki/Exoplanet" title="Exoplanet">Exoplanet</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Ground-based</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Anglo-Australian_Planet_Search" title="Anglo-Australian Planet Search">AAPS</a></li> <li><a href="/wiki/Automated_Planet_Finder" title="Automated Planet Finder">APF</a></li> <li><a href="/wiki/Swiss_1.2-metre_Leonhard_Euler_Telescope" title="Swiss 1.2-metre Leonhard Euler Telescope">CORALIE</a></li> <li><a href="/wiki/East-Asian_Planet_Search_Network" title="East-Asian Planet Search Network">EAPSNet</a></li> <li><a href="/wiki/ELODIE_spectrograph" title="ELODIE spectrograph">ELODIE</a></li> <li><a class="mw-selflink-fragment" href="#Instrumentation">EPICS</a></li> <li><a href="/wiki/ESPRESSO" title="ESPRESSO">ESPRESSO</a></li> <li><a href="/wiki/Fiber-optic_Improved_Next-generation_Doppler_Search_for_Exo-Earths" title="Fiber-optic Improved Next-generation Doppler Search for Exo-Earths">FINDS Exo-Earths</a></li> <li><a href="/wiki/Geneva_Extrasolar_Planet_Search" title="Geneva Extrasolar Planet Search">Geneva</a> <ul><li><a href="/wiki/High_Accuracy_Radial_Velocity_Planet_Searcher" title="High Accuracy Radial Velocity Planet Searcher">HARPS</a></li> <li><a href="/wiki/HARPS-N" title="HARPS-N">HARPS-N</a></li></ul></li> <li><a href="/wiki/Gemini_Planet_Imager" title="Gemini Planet Imager">GPI</a></li> <li><a href="/wiki/HATNet_Project" title="HATNet Project">HATNet</a></li> <li><a href="/wiki/Hunt_for_Exomoons_with_Kepler" title="Hunt for Exomoons with Kepler">HEK</a></li> <li><a href="/wiki/HiCIAO" class="mw-redirect" title="HiCIAO">HiCIAO</a></li> <li><a href="/wiki/HIRES" class="mw-redirect" title="HIRES">HIRES</a></li> <li><a href="/wiki/Kilodegree_Extremely_Little_Telescope" title="Kilodegree Extremely Little Telescope">KELT</a></li> <li><a href="/wiki/Lick%E2%80%93Carnegie_Exoplanet_Survey" title="Lick–Carnegie Exoplanet Survey">LCES</a></li> <li><a href="/wiki/Magellan_Planet_Search_Program" title="Magellan Planet Search Program">Magellan</a></li> <li><a href="/wiki/MARVELS" class="mw-redirect" title="MARVELS">MARVELS</a></li> <li><a href="/wiki/MASCARA" title="MASCARA">MASCARA</a></li> <li><a href="/wiki/MEarth_Project" title="MEarth Project">MEarth</a></li> <li><a href="/wiki/MicroFUN" title="MicroFUN">MicroFUN</a></li> <li><a href="/wiki/Miniature_Exoplanet_Radial_Velocity_Array" title="Miniature Exoplanet Radial Velocity Array">MINERVA</a> <ul><li><a href="/wiki/MINERVA-Australis" title="MINERVA-Australis">Australis</a></li></ul></li> <li><a href="/wiki/Microlensing_Observations_in_Astrophysics" title="Microlensing Observations in Astrophysics">MOA</a></li> <li><a href="/wiki/N2K_Consortium" title="N2K Consortium">N2K</a></li> <li><a href="/wiki/Next-Generation_Transit_Survey" title="Next-Generation Transit Survey">NGTS</a></li> <li><a href="/wiki/New_Mexico_Exoplanet_Spectroscopic_Survey_Instrument" title="New Mexico Exoplanet Spectroscopic Survey Instrument">NESSI</a></li> <li><a href="/wiki/Optical_Gravitational_Lensing_Experiment" title="Optical Gravitational Lensing Experiment">OGLE</a></li> <li><a href="/wiki/Okayama_Planet_Search_Program" title="Okayama Planet Search Program">OPSP</a></li> <li><a href="/wiki/PlanetPol" title="PlanetPol">PlanetPol</a></li> <li><a href="/wiki/Project_1640" title="Project 1640">Project 1640</a></li> <li><a href="/wiki/PRL_Advanced_Radial-velocity_All-sky_Search" title="PRL Advanced Radial-velocity All-sky Search">PARAS</a></li> <li><a href="/wiki/Strategic_Explorations_of_Exoplanets_and_Disks_with_Subaru" title="Strategic Explorations of Exoplanets and Disks with Subaru">SEEDS</a></li> <li><a href="/wiki/Search_for_extraterrestrial_intelligence" title="Search for extraterrestrial intelligence">SETI</a></li> <li><a href="/wiki/SOPHIE_%C3%A9chelle_spectrograph" title="SOPHIE échelle spectrograph">SOPHIE</a></li> <li><a href="/wiki/SPECULOOS" title="SPECULOOS">SPECULOOS</a></li> <li><a href="/wiki/Spectro-Polarimetric_High-Contrast_Exoplanet_Research" title="Spectro-Polarimetric High-Contrast Exoplanet Research">SPHERE</a></li> <li><a href="/wiki/Wide_Angle_Search_for_Planets" title="Wide Angle Search for Planets">SuperWASP</a></li> <li><a href="/wiki/Systemic_(amateur_extrasolar_planet_search_project)" title="Systemic (amateur extrasolar planet search project)">Systemic</a></li> <li><a href="/wiki/Trans-Atlantic_Exoplanet_Survey" title="Trans-Atlantic Exoplanet Survey">TrES</a></li> <li><a href="/wiki/XO_Telescope" class="mw-redirect" title="XO Telescope">XO Telescope</a></li> <li><a href="/wiki/ZIMPOL/CHEOPS" title="ZIMPOL/CHEOPS">ZIMPOL/CHEOPS</a></li></ul> </div></td><td class="noviewer navbox-image" rowspan="3" style="width:1px;padding:0 0 0 2px"><div><span typeof="mw:File"><a href="/wiki/File:HST_SWEEPS_Detail_2006.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5b/HST_SWEEPS_Detail_2006.jpg/80px-HST_SWEEPS_Detail_2006.jpg" decoding="async" width="80" height="80" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5b/HST_SWEEPS_Detail_2006.jpg/120px-HST_SWEEPS_Detail_2006.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5b/HST_SWEEPS_Detail_2006.jpg/160px-HST_SWEEPS_Detail_2006.jpg 2x" data-file-width="800" data-file-height="800" /></a></span><br /><span typeof="mw:File"><a href="/wiki/File:Keplerspacecraft-FocalPlane-cutout.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Keplerspacecraft-FocalPlane-cutout.svg/80px-Keplerspacecraft-FocalPlane-cutout.svg.png" decoding="async" width="80" height="46" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Keplerspacecraft-FocalPlane-cutout.svg/120px-Keplerspacecraft-FocalPlane-cutout.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Keplerspacecraft-FocalPlane-cutout.svg/160px-Keplerspacecraft-FocalPlane-cutout.svg.png 2x" data-file-width="716" data-file-height="416" /></a></span><br /><span typeof="mw:File"><a href="/wiki/File:LombergA1024.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/be/LombergA1024.jpg/80px-LombergA1024.jpg" decoding="async" width="80" height="60" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/be/LombergA1024.jpg/120px-LombergA1024.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/be/LombergA1024.jpg/160px-LombergA1024.jpg 2x" data-file-width="1596" data-file-height="1206" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Space missions</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Past</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/MOST_(satellite)" class="mw-redirect" title="MOST (satellite)">MOST</a> <span style="font-size:85%;">(2003–2019)</span></li> <li><a href="/wiki/Sagittarius_Window_Eclipsing_Extrasolar_Planet_Search" title="Sagittarius Window Eclipsing Extrasolar Planet Search">SWEEPS</a> <span style="font-size:85%;">using <a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">HST</a></span> <span style="font-size:85%;">(2006)</span></li> <li><a href="/wiki/CoRoT" title="CoRoT">CoRoT</a> <span style="font-size:85%;">(2006–2013)</span></li> <li><a href="/wiki/EPOXI" title="EPOXI">EPOXI</a> <span style="font-size:85%;">using <i><a href="/wiki/Deep_Impact_(spacecraft)" title="Deep Impact (spacecraft)">Deep Impact</a></i></span> <span style="font-size:85%;">(2008–2013)</span></li> <li><a href="/wiki/Kepler_space_telescope" title="Kepler space telescope">Kepler</a> <span style="font-size:85%;">(2009–2018)</span> <ul><li><span style="font-size:85%;"><a href="/wiki/List_of_exoplanets_discovered_by_the_Kepler_space_telescope" title="List of exoplanets discovered by the Kepler space telescope">detected exoplanets</a></span></li></ul></li> <li><a href="/wiki/ASTERIA_(spacecraft)" title="ASTERIA (spacecraft)">ASTERIA</a> <span style="font-size:85%;">(2017–2020)</span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Current</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/Gaia_(spacecraft)" title="Gaia (spacecraft)">Gaia</a></i> <span style="font-size:85%;">(2013–present)</span></li> <li><a href="/wiki/Transiting_Exoplanet_Survey_Satellite" title="Transiting Exoplanet Survey Satellite">TESS</a> <span style="font-size:85%;">(2018–present)</span></li> <li><a href="/wiki/CHEOPS" title="CHEOPS">CHEOPS</a> <span style="font-size:85%;">(2019–present)</span></li> <li><i><a href="/wiki/Hayabusa2" title="Hayabusa2">Hayabusa2</a></i> <span style="font-size:85%;">(2021–present)</span></li> <li><a href="/wiki/James_Webb_Space_Telescope" title="James Webb Space Telescope">James Webb Space Telescope</a> <span style="font-size:85%;">(2021–present)</span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Planned</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/PLATO_(spacecraft)" title="PLATO (spacecraft)">PLATO</a></i> <span style="font-size:85%;">(2026)</span></li> <li><a href="/wiki/ARIEL" title="ARIEL">ARIEL</a> <span style="font-size:85%;">(2029)</span></li> <li><a href="/wiki/Nancy_Grace_Roman_Space_Telescope" title="Nancy Grace Roman Space Telescope">Nancy Grace Roman Space Telescope</a> <span style="font-size:85%;">(mid-2020s)</span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Proposed</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Exoplanetary_Circumstellar_Environments_and_Disk_Explorer" title="Exoplanetary Circumstellar Environments and Disk Explorer">EXCEDE</a></li> <li><a href="/wiki/Habitable_Exoplanet_Imaging_Mission" class="mw-redirect" title="Habitable Exoplanet Imaging Mission">HabEx</a></li> <li><a href="/wiki/Large_Interferometer_For_Exoplanets" title="Large Interferometer For Exoplanets">LIFE</a></li> <li><a href="/wiki/Large_Ultraviolet_Optical_Infrared_Surveyor" title="Large Ultraviolet Optical Infrared Surveyor">LUVOIR</a></li> <li><a href="/wiki/Nautilus_Deep_Space_Observatory" title="Nautilus Deep Space Observatory">Nautilus Deep Space Observatory</a></li> <li><a href="/wiki/New_Worlds_Mission" title="New Worlds Mission">New Worlds Mission</a></li> <li><a href="/wiki/Origins_Space_Telescope" title="Origins Space Telescope">OST</a></li> <li><a href="/wiki/PEGASE" title="PEGASE">PEGASE</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Cancelled</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/Darwin_(spacecraft)" title="Darwin (spacecraft)">Darwin</a></i></li> <li><a href="/wiki/EChO" title="EChO">EChO</a></li> <li><i><a href="/wiki/Eddington_(spacecraft)" title="Eddington (spacecraft)">Eddington</a></i></li> <li><a href="/wiki/Space_Interferometry_Mission" title="Space Interferometry Mission">Space Interferometry Mission</a></li> <li><a href="/wiki/Terrestrial_Planet_Finder" title="Terrestrial Planet Finder">Terrestrial Planet Finder</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Methods_of_detecting_exoplanets" title="Methods of detecting exoplanets">Detection methods</a></li> <li><a href="/wiki/Discoveries_of_exoplanets" title="Discoveries of exoplanets">Discoveries of exoplanets</a></li> <li><a href="/wiki/Habitable_zone_for_complex_life" title="Habitable zone for complex life">Habitable zone for complex life</a></li> <li><a href="/wiki/Lists_of_exoplanets" class="mw-redirect" title="Lists of exoplanets">Lists of exoplanets</a> <ul><li><a href="/wiki/List_of_nearest_exoplanets" title="List of nearest exoplanets">nearest</a></li></ul></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="3"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <b><a href="/wiki/Category:Exoplanet_search_projects" title="Category:Exoplanet search projects">Category</a></b></li> <li><span class="noviewer" typeof="mw:File"><span title="Commons page"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span> <a href="https://commons.wikimedia.org/wiki/Category:Exoplanet_search_projects" class="extiw" title="commons:Category:Exoplanet search projects"><b>Commons</b></a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Astronomy559" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2" style="text-align: center;"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Astronomy_navbox" title="Template:Astronomy navbox"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Astronomy_navbox" title="Template talk:Astronomy navbox"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Astronomy_navbox" title="Special:EditPage/Template:Astronomy navbox"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Astronomy559" style="font-size:114%;margin:0 4em"><a href="/wiki/Astronomy" title="Astronomy">Astronomy</a></div></th></tr><tr><td class="navbox-abovebelow" colspan="2" style="text-align: center;"><div> <ul><li><span class="nowrap"><a href="/wiki/Outline_of_astronomy" title="Outline of astronomy">Outline</a></span></li> <li><span class="nowrap"><a href="/wiki/History_of_astronomy" title="History of astronomy">History</a></span> <ul><li><span class="nowrap"><a href="/wiki/Timeline_of_astronomy" title="Timeline of astronomy">Timeline</a></span></li></ul></li> <li><span class="nowrap"><a href="/wiki/Astronomer" title="Astronomer">Astronomer</a></span></li> <li><span class="nowrap"><a href="/wiki/Astronomical_symbols" title="Astronomical symbols">Astronomical symbols</a></span></li> <li><span class="nowrap"><a href="/wiki/Astronomical_object" title="Astronomical object">Astronomical object</a></span></li> <li><span class="nowrap"><a href="/wiki/Glossary_of_astronomy" title="Glossary of astronomy">Glossary</a></span></li> <li><span class="nowrap"><a href="/wiki/List_of_topics_in_space" title="List of topics in space">... in space</a></span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align: center;;width:1%">Astronomy by</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal; text-align: center;">Manner</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><span class="nowrap"><a href="/wiki/Amateur_astronomy" title="Amateur astronomy">Amateur</a></span></li> <li><span class="nowrap"><a href="/wiki/Observational_astronomy" title="Observational astronomy">Observational</a></span></li> <li><span class="nowrap"><a href="/wiki/Sidewalk_astronomy" title="Sidewalk astronomy">Sidewalk</a></span></li> <li><span class="nowrap"><a href="/wiki/Space_telescope" title="Space telescope">Space telescope</a></span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal; text-align: center;">Celestial subject</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><span class="nowrap"><a href="/wiki/Galactic_astronomy" title="Galactic astronomy">Galactic</a> / <a href="/wiki/Extragalactic_astronomy" title="Extragalactic astronomy">Extragalactic</a></span></li> <li><span class="nowrap"><a href="/wiki/Solar_System" title="Solar System">Local system</a></span> <ul><li><span class="nowrap"><a href="/wiki/Sun" title="Sun">Solar</a></span></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal; text-align: center;">EM methods</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><span class="nowrap"><a href="/wiki/Radio_astronomy" title="Radio astronomy">Radio</a></span></li> <li><span class="nowrap"><a href="/wiki/Submillimetre_astronomy" title="Submillimetre astronomy">Submillimetre</a></span></li> <li><span class="nowrap"><a href="/wiki/Infrared_astronomy" title="Infrared astronomy">Infrared</a> (<span style="font-size:85%;"><a href="/wiki/Far-infrared_astronomy" title="Far-infrared astronomy">Far-infrared</a></span>)</span></li> <li><span class="nowrap"><a href="/wiki/Visible-light_astronomy" title="Visible-light astronomy">Visible-light <span style="font-size:85%;">(optical)</span></a></span></li> <li><span class="nowrap"><a href="/wiki/Ultraviolet_astronomy" title="Ultraviolet astronomy">Ultraviolet</a></span></li> <li><span class="nowrap"><a href="/wiki/X-ray_astronomy" title="X-ray astronomy">X-ray</a></span> <ul><li><span class="nowrap"><a href="/wiki/History_of_X-ray_astronomy" title="History of X-ray astronomy">History</a></span></li></ul></li> <li><span class="nowrap"><a href="/wiki/Gamma-ray_astronomy" title="Gamma-ray astronomy">Gamma-ray</a></span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal; text-align: center;">Other methods</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><span class="nowrap"><a href="/wiki/Neutrino_astronomy" title="Neutrino astronomy">Neutrino</a></span></li> <li><span class="nowrap"><a href="/wiki/Cosmic_ray_astronomy" title="Cosmic ray astronomy">Cosmic rays</a></span></li> <li><span class="nowrap"><a href="/wiki/Gravitational-wave_astronomy" title="Gravitational-wave astronomy">Gravitational radiation</a></span></li> <li><span class="nowrap"><a href="/wiki/High-energy_astronomy" title="High-energy astronomy">High-energy</a></span></li> <li><span class="nowrap"><a href="/wiki/Radar_astronomy" title="Radar astronomy">Radar</a></span></li> <li><span class="nowrap"><a href="/wiki/Spherical_astronomy" title="Spherical astronomy">Spherical</a></span></li> <li><span class="nowrap"><a href="/wiki/Multi-messenger_astronomy" title="Multi-messenger astronomy">Multi-messenger</a></span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;font-weight:normal; text-align: center;"><a href="/wiki/Cultural_astronomy" title="Cultural astronomy">Culture</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><span class="nowrap"><a href="/wiki/Australian_Aboriginal_astronomy" title="Australian Aboriginal astronomy">Australian Aboriginal</a></span></li> <li><span class="nowrap"><a href="/wiki/Babylonian_astronomy" title="Babylonian astronomy">Babylonian</a></span></li> <li><span class="nowrap"><a href="/wiki/Chinese_astronomy" title="Chinese astronomy">Chinese</a></span></li> <li><span class="nowrap"><a href="/wiki/Egyptian_astronomy" title="Egyptian astronomy">Egyptian</a></span></li> <li><span class="nowrap"><a href="/wiki/Ancient_Greek_astronomy" title="Ancient Greek astronomy">Greek</a></span></li> <li><span class="nowrap"><a href="/wiki/Hebrew_astronomy" title="Hebrew astronomy">Hebrew</a></span></li> <li><span class="nowrap"><a href="/wiki/Indian_astronomy" title="Indian astronomy">Indian</a></span></li> <li><span class="nowrap"><a href="/wiki/Inuit_astronomy" title="Inuit astronomy">Inuit</a></span></li> <li><span class="nowrap"><a href="/wiki/Maya_astronomy" title="Maya astronomy">Maya</a></span></li> <li><span class="nowrap"><a href="/wiki/Astronomy_in_the_medieval_Islamic_world" title="Astronomy in the medieval Islamic world">Medieval Islamic</a></span></li> <li><span class="nowrap"><a href="/wiki/Persian_astronomy" title="Persian astronomy">Persian</a></span></li> <li><span class="nowrap"><a href="/wiki/Astronomy_in_Serbia" title="Astronomy in Serbia">Serbian</a></span> <ul><li><span class="nowrap"><a href="/wiki/Serbian_folk_astronomy" title="Serbian folk astronomy">folk</a></span></li></ul></li> <li><span class="nowrap"><a href="/wiki/Tibetan_astronomy" title="Tibetan astronomy">Tibetan</a></span></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="text-align: center;;width:1%"><a href="/wiki/Optical_telescope" title="Optical telescope">Optical<br />telescopes</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><span class="nowrap"><a href="/wiki/List_of_optical_telescopes" title="List of optical telescopes">List</a></span></li> <li><span class="nowrap"><a href="/wiki/Category:Telescopes" title="Category:Telescopes">Category</a></span></li> <li><span class="nowrap"><a href="/wiki/Extremely_large_telescope" title="Extremely large telescope">Extremely large telescope</a></span></li> <li><span class="nowrap"><a class="mw-selflink selflink">Extremely Large Telescope</a></span></li> <li><span class="nowrap"><a href="/wiki/Gran_Telescopio_Canarias" title="Gran Telescopio Canarias">Gran Telescopio Canarias</a></span></li> <li><span class="nowrap"><a href="/wiki/Hale_Telescope" title="Hale Telescope">Hale Telescope</a></span></li> <li><span class="nowrap"><a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubble Space Telescope</a></span></li> <li><span class="nowrap"><a href="/wiki/W._M._Keck_Observatory" title="W. M. Keck Observatory">Keck Observatory</a></span></li> <li><span class="nowrap"><a href="/wiki/Large_Binocular_Telescope" title="Large Binocular Telescope">Large Binocular Telescope</a></span></li> <li><span class="nowrap"><a href="/wiki/Southern_African_Large_Telescope" title="Southern African Large Telescope">Southern African Large Telescope</a></span></li> <li><span class="nowrap"><a href="/wiki/Very_Large_Telescope" title="Very Large Telescope">Very Large Telescope</a></span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align: center;;width:1%">Related</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><span class="nowrap"><a href="/wiki/Archaeoastronomy" title="Archaeoastronomy">Archaeoastronomy</a></span></li> <li><span class="nowrap"><a href="/wiki/Astrobiology" title="Astrobiology">Astrobiology</a></span></li> <li><span class="nowrap"><a href="/wiki/Astrochemistry" title="Astrochemistry">Astrochemistry</a></span></li> <li><span class="nowrap"><a href="/wiki/Astroinformatics" title="Astroinformatics">Astroinformatics</a></span></li> <li><span class="nowrap"><a href="/wiki/Astrophysics" title="Astrophysics">Astrophysics</a></span></li> <li><span class="nowrap"><a href="/wiki/Astrology_and_astronomy" title="Astrology and astronomy">Astrology and astronomy</a></span></li> <li><span class="nowrap"><a href="/wiki/Astrometry" title="Astrometry">Astrometry</a></span></li> <li><span class="nowrap"><i><a href="/wiki/Astronomers_Monument" title="Astronomers Monument">Astronomers Monument</a></i></span></li> <li><span class="nowrap"><a href="/wiki/Astroparticle_physics" title="Astroparticle physics">Astroparticle physics</a></span></li> <li><span class="nowrap"><a href="/wiki/Binoculars" title="Binoculars">Binoculars</a></span></li> <li><span class="nowrap"><a href="/wiki/Constellation" title="Constellation">Constellation</a></span> <ul><li><span class="nowrap"><a href="/wiki/IAU_designated_constellations" title="IAU designated constellations">IAU</a></span></li></ul></li> <li><span class="nowrap"><a href="/wiki/Photometry_(astronomy)" title="Photometry (astronomy)">Photometry</a></span></li> <li><span class="nowrap"><a href="/wiki/Planetarium" title="Planetarium">Planetarium</a></span></li> <li><span class="nowrap"><a href="/wiki/Planetary_geology" title="Planetary geology">Planetary geology</a></span></li> <li><span class="nowrap"><a href="/wiki/Physical_cosmology" title="Physical cosmology">Physical cosmology</a></span></li> <li><span class="nowrap"><a href="/wiki/Quantum_cosmology" title="Quantum cosmology">Quantum cosmology</a></span></li> <li><span class="nowrap"><a href="/wiki/List_of_astronomers" title="List of astronomers">List of astronomers</a></span> <ul><li><span class="nowrap"><a href="/wiki/List_of_French_astronomers" title="List of French astronomers">French</a></span></li> <li><span class="nowrap"><a href="/wiki/Astronomy_in_the_medieval_Islamic_world#Notable_astronomers" title="Astronomy in the medieval Islamic world">Medieval Islamic</a></span></li> <li><span class="nowrap"><a href="/wiki/List_of_Russian_astronomers_and_astrophysicists" title="List of Russian astronomers and astrophysicists">Russian</a></span></li> <li><span class="nowrap"><a href="/wiki/List_of_women_astronomers" title="List of women astronomers">Women</a></span></li></ul></li> <li><span class="nowrap"><a href="/wiki/Telescope" title="Telescope">Telescope</a></span> <ul><li><span class="nowrap"><a href="/wiki/X-ray_telescope" title="X-ray telescope">X-ray telescope</a></span></li> <li><span class="nowrap"><a href="/wiki/History_of_the_telescope" title="History of the telescope">history</a></span></li> <li><span class="nowrap"><a href="/wiki/Lists_of_telescopes" title="Lists of telescopes">lists</a></span></li></ul></li> <li><span class="nowrap"><a href="/wiki/Zodiac" title="Zodiac">Zodiac</a></span></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2" style="text-align: center;"><div> <ul><li><span class="nowrap"><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:Astronomy" title="Category:Astronomy">Category</a></span></li> <li><span class="nowrap"><span class="noviewer" typeof="mw:File"><span title="Commons page"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" 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