<P> Largest does not always equate to being the best telescopes, and overall light gathering power of the optical system can be a poor measure of a telescope's performance . Space - based telescopes, such as the Hubble Space Telescope, take advantage of being above the Earth's atmosphere to reach higher resolution and greater light gathering through longer exposure time . Location in the northern or southern hemisphere of the Earth can also limit what part of the sky can be observed . </P> <P> This list is ordered by optical aperture, which has historically been a useful gauge of limiting resolution, optical area, physical size, and cost . Multiple mirror telescopes that are on the same mount, may have a working beam combiner, and can form an image may be ranked by an equivalent aperture to this reported by sources . HET - style or fixed telescopes are ranked by an equivalent aperture also . </P> <Table> Reflecting telescopes <Tr> <Th> Name </Th> <Th> Image </Th> <Th> Effective aperture m </Th> <Th> Aper . in </Th> <Th> Mirror type </Th> <Th> Nationality / Sponsors </Th> <Th> Site </Th> <Th> Built </Th> </Tr> <Tr> <Td> Gran Telescopio Canarias (GTC) </Td> <Td> </Td> <Td> 7001104000000000000 ♠ 10.4 m </Td> <Td> 409" </Td> <Td> Segmented, 36 </Td> <Td> Spain (90%), Mexico, USA </Td> <Td> Roque de los Muchachos Obs., Canary Islands, Spain </Td> <Td> 2006 / 9 </Td> </Tr> <Tr> <Td> Hobby - Eberly Telescope (HET) 11 m × 9.8 m mirror </Td> <Td> </Td> <Td> 7001100000000000000 ♠ 10 m </Td> <Td> 394" </Td> <Td> Segmented, 91 </Td> <Td> USA, Germany </Td> <Td> McDonald Observatory, Texas, USA </Td> <Td> 1997 </Td> </Tr> <Tr> <Td> Keck 1 </Td> <Td> </Td> <Td> 7001100000000000000 ♠ 10 m </Td> <Td> 394" </Td> <Td> Segmented, 36 </Td> <Td> USA </Td> <Td> Mauna Kea Observatories, Hawaii, USA </Td> <Td> </Td> </Tr> <Tr> <Td> Keck 2 </Td> <Td> </Td> <Td> 7001100000000000000 ♠ 10 m </Td> <Td> 394" </Td> <Td> Segmented, 36 </Td> <Td> USA </Td> <Td> Mauna Kea Observatories, Hawaii, USA </Td> <Td> </Td> </Tr> <Tr> <Td> Southern African Large Telescope (SALT) 11 m × 9.8 m mirror </Td> <Td> </Td> <Td> 7000920000000099999 ♠ 9.2 m </Td> <Td> 362" </Td> <Td> Segmented, 91 </Td> <Td> South Africa, USA, UK, Germany, Poland, New Zealand </Td> <Td> South African Astronomical Obs., Northern Cape, South Africa </Td> <Td> 2005 </Td> </Tr> <Tr> <Td> Large Binocular Telescope (LBT) Phased - array optics for combined 11.9 m </Td> <Td> </Td> <Td> 7000840000000000000 ♠ 8.4 m × 2 </Td> <Td> 330" × 2 </Td> <Td> Multiple mirror, 2 </Td> <Td> USA, Italy, Germany </Td> <Td> Mount Graham International Observatory, Arizona, USA </Td> <Td> </Td> </Tr> <Tr> <Td> Subaru (JNLT) </Td> <Td> </Td> <Td> 7000820009999999999 ♠ 8.2 m </Td> <Td> 323" </Td> <Td> Single </Td> <Td> Japan </Td> <Td> Mauna Kea Observatories, Hawaii, USA </Td> <Td> 1999 </Td> </Tr> <Tr> <Td> VLT UT1--Antu </Td> <Td> </Td> <Td> 7000820009999999999 ♠ 8.2 m </Td> <Td> 323" </Td> <Td> Single </Td> <Td> ESO Countries, Chile </Td> <Td> Paranal Observatory, Antofagasta Region, Chile </Td> <Td> 1998 </Td> </Tr> <Tr> <Td> VLT UT2--Kueyen </Td> <Td> </Td> <Td> 7000820009999999999 ♠ 8.2 m </Td> <Td> 323" </Td> <Td> Single </Td> <Td> ESO Countries, Chile </Td> <Td> Paranal Observatory, Antofagasta Region, Chile </Td> <Td> 1999 </Td> </Tr> <Tr> <Td> VLT UT3--Melipal </Td> <Td> </Td> <Td> 7000820009999999999 ♠ 8.2 m </Td> <Td> 323" </Td> <Td> Single </Td> <Td> ESO Countries, Chile </Td> <Td> Paranal Observatory, Antofagasta Region, Chile </Td> <Td> 2000 </Td> </Tr> <Tr> <Td> VLT UT4--Yepun </Td> <Td> </Td> <Td> 7000820009999999999 ♠ 8.2 m </Td> <Td> 323" </Td> <Td> Single </Td> <Td> ESO Countries, Chile </Td> <Td> Paranal Observatory, Antofagasta Region, Chile </Td> <Td> 2001 </Td> </Tr> <Tr> <Td> Gemini North (Gillett) </Td> <Td> </Td> <Td> 7000810000000000000 ♠ 8.1 m </Td> <Td> 318" </Td> <Td> Single </Td> <Td> USA, UK, Canada, Chile, Australia, Argentina, Brazil </Td> <Td> Mauna Kea Observatories, Hawaii, USA </Td> <Td> 1999 </Td> </Tr> <Tr> <Td> Gemini South </Td> <Td> </Td> <Td> 7000810000000000000 ♠ 8.1 m </Td> <Td> 318" </Td> <Td> Single </Td> <Td> USA, UK, Canada, Chile, Australia, Argentina, Brazil </Td> <Td> Cerro Pachón (CTIO), Coquimbo Region, Chile </Td> <Td> 2001 </Td> </Tr> <Tr> <Td> MMT (1 x 6.5 m) </Td> <Td> </Td> <Td> 7000650000000000000 ♠ 6.5 m </Td> <Td> 256" </Td> <Td> Single </Td> <Td> USA </Td> <Td> F.L. Whipple Obs., Arizona, USA </Td> <Td> 2000 </Td> </Tr> <Tr> <Td> Magellan 1 (Walter Baade) </Td> <Td> </Td> <Td> 7000650000000000000 ♠ 6.5 m </Td> <Td> 256" </Td> <Td> Honeycomb </Td> <Td> USA </Td> <Td> Las Campanas Obs., Coquimbo Region, Chile </Td> <Td> 2000 </Td> </Tr> <Tr> <Td> Magellan 2 (Landon Clay) </Td> <Td> </Td> <Td> 7000650000000000000 ♠ 6.5 m </Td> <Td> 256" </Td> <Td> Honeycomb </Td> <Td> USA </Td> <Td> Las Campanas Obs., Coquimbo Region, Chile </Td> <Td> 2002 </Td> </Tr> <Tr> <Td> BTA - 6 </Td> <Td> </Td> <Td> 7000600000000000000 ♠ 6 m </Td> <Td> 238" </Td> <Td> Single </Td> <Td> USSR / Russia </Td> <Td> Special Astrophysical Obs., Karachay--Cherkessia, Russia </Td> <Td> </Td> </Tr> <Tr> <Td> Large Zenith Telescope (LZT) </Td> <Td> </Td> <Td> 7000600000000000000 ♠ 6 m </Td> <Td> 236" </Td> <Td> Liquid </Td> <Td> Canada, France, United States </Td> <Td> Maple Ridge, British Columbia, Canada </Td> <Td> 2003 </Td> </Tr> <Tr> <Td> Hale Telescope (200 inch) </Td> <Td> </Td> <Td> 7000508000000000000 ♠ 5.08 m </Td> <Td> 200" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Palomar Observatory, California, USA </Td> <Td> 1948 </Td> </Tr> <Tr> <Td> LAMOST 7000490000000000000 ♠ (6.67 m × 6.05 m + 5.72 m × 4.40 m corrector; effective aperture 3.6--4.9 m) </Td> <Td> </Td> <Td> 4.9 m--3.6 m </Td> <Td> 193" </Td> <Td> Segmented (37 + 24) </Td> <Td> PRC (China) </Td> <Td> Beijing Astronomical Obs., Xinglong, China </Td> <Td> 2008 </Td> </Tr> <Tr> <Td> MMT (original optics: 6 × 1.8 m) → see above record for current 6.5 m mirror </Td> <Td> </Td> <Td> 7000470000000000000 ♠ 4.7 m (6 × 1.8 m) </Td> <Td> 186" </Td> <Td> Segmented, 6 </Td> <Td> USA </Td> <Td> F.L. Whipple Obs., Arizona, USA </Td> <Td> 1979--1998 </Td> </Tr> <Tr> <Td> Discovery Channel Telescope </Td> <Td> </Td> <Td> 7000430000000000000 ♠ 4.3 m </Td> <Td> 169" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Lowell Observatory, Happy Jack, Arizona, USA </Td> <Td> 2012 </Td> </Tr> <Tr> <Td> William Herschel Telescope </Td> <Td> </Td> <Td> 7000420000000000000 ♠ 4.2 m </Td> <Td> 165" </Td> <Td> Single </Td> <Td> UK, Netherlands, Spain </Td> <Td> Roque de los Muchachos Obs., Canary Islands, Spain </Td> <Td> </Td> </Tr> <Tr> <Td> SOAR </Td> <Td> </Td> <Td> 7000410009999999999 ♠ 4.1 m </Td> <Td> 161" </Td> <Td> Single </Td> <Td> USA, Brazil </Td> <Td> Cerro Pachón (CTIO), Coquimbo Region, Chile </Td> <Td> 2002 </Td> </Tr> <Tr> <Td> VISTA </Td> <Td> </Td> <Td> 7000410009999999999 ♠ 4.1 m </Td> <Td> 161" </Td> <Td> Single </Td> <Td> ESO Countries, Chile </Td> <Td> Paranal Observatory, Antofagasta Region, Chile </Td> <Td> 2009 </Td> </Tr> <Tr> <Td> Victor M. Blanco Telescope </Td> <Td> </Td> <Td> 7000400000000000000 ♠ 4 m </Td> <Td> 157" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Cerro Tololo Inter-American Obs., Coquimbo Region, Chile </Td> <Td> 1976 </Td> </Tr> <Tr> <Td> Nicholas U. Mayall 4 m </Td> <Td> </Td> <Td> 7000400000000000000 ♠ 4 m </Td> <Td> 158" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Kitt Peak National Obs., Arizona, USA </Td> <Td> 1973 </Td> </Tr> <Tr> <Td> Anglo - Australian Telescope (AAT) </Td> <Td> </Td> <Td> 7000389000000000000 ♠ 3.89 m </Td> <Td> 154" </Td> <Td> Single </Td> <Td> Australia, UK </Td> <Td> Australian Astronomical Obs., New South Wales, Australia </Td> <Td> </Td> </Tr> <Tr> <Td> 3.67 m AEOS Telescope (AEOS) </Td> <Td> </Td> <Td> 7000367000000000000 ♠ 3.67 m </Td> <Td> 145" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Air Force Maui Optical Station, Hawaii, USA </Td> <Td> </Td> </Tr> <Tr> <Td> 3.6 m Devasthal Optical Telescope (DOT) </Td> <Td> </Td> <Td> 7000360000000000000 ♠ 3.60 m </Td> <Td> 141" </Td> <Td> Single </Td> <Td> India </Td> <Td> ARIES Devasthal Observatory, Nainital, India </Td> <Td> 2016 </Td> </Tr> <Tr> <Td> Telescopio Nazionale Galileo (TNG) </Td> <Td> </Td> <Td> 7000358000000000000 ♠ 3.58 m </Td> <Td> 138" </Td> <Td> Single </Td> <Td> Italy </Td> <Td> Roque de los Muchachos Obs., Canary Islands, Spain </Td> <Td> 1997 </Td> </Tr> <Tr> <Td> New Technology Telescope (NTT) </Td> <Td> </Td> <Td> 7000358000000000000 ♠ 3.58 m </Td> <Td> 142" </Td> <Td> Single </Td> <Td> ESO countries </Td> <Td> La Silla Observatory, Coquimbo Region, Chile </Td> <Td> </Td> </Tr> <Tr> <Td> Canada - France - Hawaii Telescope (CFHT) </Td> <Td> </Td> <Td> 7000358000000000000 ♠ 3.58 m </Td> <Td> 141" </Td> <Td> Single </Td> <Td> Canada, France, USA </Td> <Td> Mauna Kea Observatories, Hawaii, USA </Td> <Td> 1979 </Td> </Tr> <Tr> <Td> ESO 3.6 m Telescope </Td> <Td> </Td> <Td> 7000357000000000000 ♠ 3.57 m </Td> <Td> 140" </Td> <Td> Single </Td> <Td> ESO countries </Td> <Td> La Silla Observatory, Coquimbo Region, Chile </Td> <Td> 1977 </Td> </Tr> <Tr> <Td> MPI - CAHA 7000350000000000000 ♠ 3.5 m </Td> <Td> </Td> <Td> 3.5 m </Td> <Td> 138" </Td> <Td> Single </Td> <Td> West Germany, Spain </Td> <Td> Calar Alto Obs., Almería, Spain </Td> <Td> 1984 </Td> </Tr> <Tr> <Td> USAF Starfire 3.5 m </Td> <Td> </Td> <Td> 7000350000000000000 ♠ 3.5 m </Td> <Td> 138" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Starfire Optical Range, New Mexico, USA </Td> <Td> 1994 </Td> </Tr> <Tr> <Td> WIYN Telescope </Td> <Td> </Td> <Td> 7000350000000000000 ♠ 3.5 m </Td> <Td> 138" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Kitt Peak National Obs., Arizona, USA </Td> <Td> 1994 </Td> </Tr> <Tr> <Td> Space Surveillance Telescope </Td> <Td> </Td> <Td> 7000350000000000000 ♠ 3.5 m </Td> <Td> 138" </Td> <Td> Single </Td> <Td> USA </Td> <Td> White Sands Missile Range, New Mexico, USA </Td> <Td> 2011 </Td> </Tr> <Tr> <Td> Astrophysical Research Consortium (ARC) </Td> <Td> </Td> <Td> 7000348000000000000 ♠ 3.48 m </Td> <Td> 137" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Apache Point Obs., New Mexico, USA </Td> <Td> 1994 </Td> </Tr> <Tr> <Td> Shane Telescope </Td> <Td> </Td> <Td> 7000305000000000000 ♠ 3.05 m </Td> <Td> 120" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Lick Observatory, California, USA </Td> <Td> 1959 </Td> </Tr> <Tr> <Td> NASA Infrared Telescope Facility </Td> <Td> </Td> <Td> 3.0 m </Td> <Td> 120" </Td> <Td> Single </Td> <Td> USA </Td> <Td> Mauna Kea Observatory, Hawaii, USA </Td> <Td> 1979 </Td> </Tr> <Tr> <Td> NASA - LMT → retired, private </Td> <Td> </Td> <Td> 7000300000000000000 ♠ 3 m </Td> <Td> 118" </Td> <Td> Liquid </Td> <Td> USA </Td> <Td> NASA Orbital Debris Obs., New Mexico, USA </Td> <Td> 1995--2002 </Td> </Tr> <Tr> <Td_colspan="8"> See List of large optical reflecting telescopes for continuation of list </Td> </Tr> </Table> <Tr> <Th> Name </Th> <Th> Image </Th> <Th> Effective aperture m </Th> <Th> Aper . in </Th> <Th> Mirror type </Th> <Th> Nationality / Sponsors </Th> <Th> Site </Th> <Th> Built </Th> </Tr>

Where is the world's largest optical telescope located