Editing List of astronomical observatories

{{short description|none}}
{| class=wikitable style="float: right; margin:5px;"
|-align="center"
|'''Legend'''
|-bgcolor=#CCCCCC
|'''[[Space observatory]]'''
|-bgcolor=#0000A0
|'''[[Gravitational-wave detector|{{white|Gravitational-wave detector}}]]'''
|-bgcolor=#0000FF
|'''[[Antimatter observatory|{{white|Antimatter observatory}}]]'''
|-bgcolor=#00FFFF
|'''[[Airborne observatory]]'''
|-bgcolor=#99CC99
|'''[[Radio telescope|Radio observatory]]'''
|-bgcolor=#00FF00
|'''[[Submillimetre astronomy|Microwave observatory]]'''
|-bgcolor=#FFFFFF
|'''[[Observatory#Ground-based observatories|Ground-based observatory]]'''
|-bgcolor=#FFFF99
|'''[[Solar telescope|Solar observatory]]'''
|-bgcolor=#FFCC66
|'''[[Neutrino detector]]'''
|-bgcolor=#FFCC00
|'''[[Cosmic-ray observatory]]'''
|-bgcolor=#f58242
|'''[[Educational observatory|{{white|Educational observatory}}]]'''
|}
This is a partial '''list of astronomical observatories''' ordered by name, along with initial dates of operation (where an accurate date is available) and location. The list also includes a final year of operation for many observatories that are no longer in operation. While other sciences, such as [[volcanology]] and [[meteorology]], also use facilities called observatories for research and observations, this list is limited to observatories that are used to observe celestial objects.

[[Observatory#Astronomical observatories|Astronomical observatories]] are mainly divided into four categories: space-based, airborne, ground-based, and underground-based.

Many modern telescopes and observatories are located in space to observe astronomical objects in [[wavelength]]s of the [[electromagnetic spectrum]] that cannot penetrate the Earth's atmosphere (such as [[ultraviolet]] radiation, [[X-rays]], and [[gamma rays]]) and are thus impossible to observe using ground-based telescopes.<ref>{{cite book
 | last = Chaisson| first = Eric|author2=McMillan, Steve | title = Astronomy Today, Fourth Edition| publisher = [[Prentice Hall]]| year = 2002}}</ref> Being above the atmosphere, these [[Space observatory|space observatories]] can also avoid the effects of [[atmospheric turbulence]] that plague ground based telescopes, although new generations of [[adaptive optics]] telescopes have since then dramatically improved the situation on the ground. The space high vacuum environment also frees the detectors from the ancestral [[Diurnal motion|diurnal cycle]] due to the atmospheric blue light background of the sky, thereby increasing significantly the observation time.

An intermediate variant is the [[airborne observatory]], specialised in the [[infrared]] wavelengths of the electromagnetic spectrum, that conduct observations above the part of the atmosphere containing [[water vapor]] that absorbs them, in the [[stratosphere]].

Historically, [[Observatory#Astronomical observatories|astronomical observatories]] consisted generally in a building or group of buildings where observations of [[astronomy|astronomical]] objects such as [[sunspot]]s, [[planets]], [[asteroids]], [[comet]]s, [[star]]s, [[nebula]]e, and [[galaxy|galaxies]] in the [[Visible spectrum|visible]] wavelengths of the electromagnetic spectrum were conducted. At first, for millennia, astronomical observations have been made with naked eyes. Then with the discovery of [[optics]], with the help of different types of [[refractor telescope]]s and later with [[reflector telescope]]s. Their use allowed to dramatically increase both the [[Optical telescope#Light-gathering power|collecting power]] and [[Angular resolution|limit of resolution]], thus the [[brightness]], level of detail and apparent [[angular size]] of distant celestial objects allowing them to be better studied and understood. Following the development of modern [[physics]], new ground-based facilities have been constructed to conduct research in the radio and [[microwave]] wavelengths of the electromagnetic spectrum, with [[radio telescope]]s and dedicated [[Submillimetre astronomy|microwave telescope]]s.

Modern [[astrophysics]] has extended the field of study of celestial bodies to non-electromagnetic vectors, such as [[neutrino]]s, [[neutron]]s and [[cosmic-ray|cosmic ray]]s or [[gravitational wave]]s. Thus, new types of observatories have been developed. [[Interferometer]]s are at the core of gravitational wave detectors. In order to limit the natural or artificial [[background noise]], most [[particle detector]] based observatories are built [[Underground mining (hard rock)#Development mining vs. production mining|deep underground]].

== Observatories ==
{{sticky header}}
{| class="wikitable sortable sticky-header"
|-
! width="40%" |Name
! width="5%" |Established
! width="30%" |Location
|-
|[[Georgian National Astrophysical Observatory|Abastumani Astrophysical Observatory]]
|1932
|[[Abastumani]], Georgia
|-
|[[Abu Reyhan-e Birooni Observatory]]<!-- http://www.shirazu.ac.ir/en/index.php?page_id=21&menu_id=1&menu_item_id=64 -->
|1976
|[[Shiraz University]], [[Shiraz]], Iran
|-
|[[Adirondack Public Observatory]]<!--https://www.adirondackskycenter.org/ -->
|
|[[Tupper Lake (town), New York|Tupper Lake, New York]], US
|-bgcolor=#CCCCCC
|[[Aditya-L1]]
|2023
|[[Sun-Earth L1]]
|-
|[[Adolphson Observatory]]
|2013
|[[Monmouth, Illinois]], US
|-
|[[Airdrie Public Observatory]]
|1896
|[[Airdrie, North Lanarkshire|Airdrie]], Scotland, UK
|-
|[[Aker Observatory]]
|1995
|[[Safford, Arizona]], US
|-
|[[Aldershot Observatory]]
|1906
|[[Aldershot]], [[Hampshire]], England, UK
|-bgcolor=#99CC99
|[[Algonquin Radio Observatory]]
|1959
|[[Algonquin Provincial Park]], Ontario, Canada
|-
|[[Allegheny Observatory]]
|1859
|[[Pittsburgh]], Pennsylvania, US
|-
|[[Ametlla de Mar Observatory]]
|1992
|[[l'Ametlla de Mar]], [[Catalonia]], Spain
|-bgcolor=#99CC99
|[[AMiBA]]
|2006
|[[Mauna Loa]], [[Hawaii]], US
|-
|[[Anderson Mesa Station]]
|1959
|[[Flagstaff, Arizona]], US
|-
|[[Andrushivka Astronomical Observatory]]
|2001
|[[Andrushivka]], [[Zhytomyr Oblast]], Ukraine
|-
|[[Angell Hall Observatory]]
|1927
|[[Ann Arbor, Michigan]], US
|-
|[[Ankara University Observatory]]
|1963
| [[Gölbaşı, Ankara]], Turkey
|-bgcolor=#FFCC66
|[[Antarctic Muon and Neutrino Detector Array]]
|2002
|[[Antarctica]]
|-bgcolor=#00FF00
|[[Antarctic Submillimeter Telescope and Remote Observatory]]
|1994–2005
|[[Antarctica]]
|-bgcolor=#FFCC66
|[[ANTARES (telescope)|ANTARES]]
|2008
|In the [[Mediterranean Sea]] near [[Toulon]], France
|-
|[http://www.apache-sitgreaves.org/ Apache-Sitgreaves Observatory]
|2005
|[[Heber-Overgaard, Arizona|Overgaard, Arizona]], US
|-
|[[Apache Point Observatory]]
|1985
|[[Sunspot, New Mexico]], US
|-bgcolor=#FFCC00
|[[Apatity Cosmic-Ray Station]]
|
|[[Apatity]], Russia
|-
|[[Apollo Observatory]]
|1969
|[[Dayton, Ohio]], US
|-
|[[Arcetri Observatory]]
|
|[[Arcetri]], [[Florence]], Italy
|-bgcolor=#99CC99
|[[Arecibo Observatory]] 
|1963
|[[Arecibo, Puerto Rico]], US
|-bgcolor=#99CC99
|[[Argentine Institute of Radio Astronomy]]
|1966
|[[Berazategui Partido]], [[Buenos Aires Province]], Argentina
|-
|[[Armagh Observatory]]
|1790
|[[Armagh]], UK
|-
|[[Aryabhatta Research Institute of Observational Sciences]]
|1954
|[[Nainital]], [[Uttarakhand]], India
|-
|[[Ashton Observatory]]
|1983
|[[Baxter, Iowa]], US
|-
|[[Asiago Astrophysical Observatory]]
|1942
|[[Asiago]], Italy
|-
|[[Rossall School|Assheton Observatory]]
|1860
|[[Lancashire]], UK
|- bgcolor=#CCCCCC
|[[Astron (spacecraft)|Astron]] ''(defunct)''
|1983–1989
|Highly eccentric Earth orbit
|-
|[[Astronomical Observatory Aurora]]
|2011
|[[Hechingen]], Germany
|-
|[[Astronomical Observatory of Lisbon]]
|1867
|[[Lisbon]], Portugal
|-
|[[Astronomy Centre]]
|1982
|[[Todmorden]], England
|-
|[[Astronomy Tower of the Sorbonne]]
|1885–1909 (only for amateur use since 1980)
|[[Paris]], France
|-
|[[Astrophysical Institute Potsdam]]
|1992
|[[Potsdam]], Germany
|-bgcolor=#00FF00
|[[Atacama Pathfinder Experiment|Atacama Pathfinder Experiment (APEX)]]
|2003
|[[Llano de Chajnantor Observatory]], Chile
|-bgcolor=#99CC99
|[[Australia Telescope Compact Array]]
|1988
|[[Narrabri]], Australia
|-
|[[Australian Astronomical Observatory]]
|1971
|[[Coonabarabran]], Australia
|-
|[[Badlands Observatory]]
|2000
|[[Quinn, South Dakota]], US
|-bgcolor=#FFCC66
|[[Baikal Deep Underwater Neutrino Telescope]]
|1993
|[[Baikal Lake]], Russia
|-
|Bangladesh Astronomical Observatory<ref>{{cite web |title=Bangladesh Astronomical Observatory |url=http://bao.com.bd |archive-url=https://web.archive.org/web/20200609160318/http://bao.com.bd/ |archive-date=2020-06-09 }}</ref>
|2015
|[[Dhaka]], Bangladesh
|-
|[[Baker Observatory]]
|1980
|[[Marshfield, Missouri]], US
|-bgcolor=#FFCC66
|[[Baksan Neutrino Observatory]]
|1977
|[[Prielbrusye]], [[Baksan Valley]], Russia
|-
|[[Ball State University Observatory]]
|
|[[Muncie, Indiana]], US
|-
|[[Barnard Observatory]] ''(defunct)''
|1859
|[[Oxford, Mississippi]], US
|-
|[[Bareket Observatory]]
|1990
|[[Maccabim]], Israel
|-
|[[Barnett Observatory]]
|1960
|[[Chesterfield, Derbyshire|Chesterfield]], England, UK
|-
|[[Bayfordbury Observatory]]
|1969
|[[Hertfordshire]], England, UK
|-
|[[Behlen Observatory]]
|1972
|[[Mead, Nebraska]], US
|-

|[[Beijing Astronomical Observatory]]
|1958
|[[Beijing]], China
|-
|[[Beijing Ancient Observatory]]
|1442
|[[Beijing]], China
|-
|[[Belgrade Observatory]]
|1887
|[[Belgrade]], Serbia
|-
|[[Belogradchik Observatory]]
|1961
|[[Belogradchik]], Bulgaria
|-
|Benito Loyola Observatory
|2024
|[[Virginia Beach, Virginia]], US
|-
|[[Benmore Peak|Benmore Peak Observatory]]
|1996
|[[Mackenzie Basin]], [[South Island]], New Zealand
|-
|[[BeppoSAX]] ''(defunct)''
|1996–2003
|[[Low Earth orbit]]
|-
|[[Bergisch Gladbach Observatory]]
|1995
|[[Bergisch Gladbach]], Germany
|-
|[[Berlin Observatory]]
|1711
|[[Berlin]], Germany
|-
|[[Besançon Observatory]]
|1882
|[[Besançon]], France
|-
|[[Beverly-Begg Observatory]]
|1922
|[[Dunedin]], [[South Island]], New Zealand
|-
|[[Bidston Hill#Bidston Observatory|Bidston Observatory]]
|1849
|[[Bidston]], England, UK
|-bgcolor=#FFFF99
|[[Big Bear Lake Solar Observatory]]
|1969
|[[Big Bear City, California]], US
|-
|[[Bisdee Tier Optical Astronomy Observatory]]
|2010
|Bisdee Tier, Spring Hill, [[Tasmania]], Australia
|-
|[[Black Moshannon Observatory]] ''(defunct)''
|1972
|[[Pennsylvania]], US
|-
|[[Marlborough College#The Blackett Observatory|Blackett Observatory]]
|1930s
|[[Wiltshire]], England, UK
|-
|[[Blue Mesa Observatory]] ''(defunct)''
|1967
|[[New Mexico]], US
|-
|[http://members.westnet.com.au/~asnewcomputers/ Boambee Observatory]
|1987
|[[Boambee, New South Wales]], Australia
|-
|[[Bohyunsan Optical Astronomy Observatory]] (BOAO)
|1996
| Youngchun, South Korea
|-
|[[BOOTES]]
|1985
|Spain
|-
|[[Bordeaux Observatory]]
|1878
|[[Floirac, Gironde|Floirac]], France
|-
|[[Bosscha Observatory]]
|1923
|[[Lembang]], [[West Java]], Indonesia
|-
|[[Boswell Observatory]] ''(defunct)''
|1883
|[[Crete, Nebraska]], US
|-
|[[Bowman Observatory]]
|1940
|[[Greenwich, Connecticut]], US
|-
|[[Boyden Observatory]]
|1889
|[[Bloemfontein]], South Africa
|-
|[[Bradstreet Observatory]]
|1996
|[[St. Davids, Pennsylvania]], US
|-
|[[Brackett Observatory]]
|1908
|[[Pomona College]], [[Claremont, California]], US<ref>{{cite web |title=Brackett Observatory |url=https://www.pomona.edu/academics/departments/physics-and-astronomy/facilities/brackett-observatory |website=Physics and Astronomy Department |publisher=[[Pomona College]] |access-date=13 November 2024 |language=en |date=18 January 2017}}</ref><ref>{{cite journal
 | title=The Frank P. Brackett Observatory Dedication
 | journal=[[Popular Astronomy (US magazine)|Popular Astronomy]]
 | volume=17 | pages=14–19 | date=January 1909
 | bibcode=1909PA.....17...14.}}</ref>
|-
|[[Bradley Observatory]]
|1950
|[[Decatur, Georgia]], US
|-
|[[Braeside Observatory]] ''(defunct)''
|1976
|[[Flagstaff, Arizona]], US
|-
|[[Brera Observatory]]
|1764
|[[Milan]], Italy
|-
|[[Bridgewater State University Observatory]]
|2012
|[[Bridgewater, Massachusetts]], US
|-
|[[Brooks Observatory]]
|
|[[Toledo, Ohio]], US
|-
|[[Brooks Astronomical Observatory]]
|1964
|[[Mount Pleasant, Michigan]], US
|-
|[[Brorfelde Observatory]]
|1953
|[[Holbæk]], Denmark
|-
|[[Bucharest Astronomical Observatory]]
|1910
|[[Bucharest]], Romania
|-
|[[Bucknell Observatory]]
|
|[[Lewisburg, Pennsylvania]], US
|-
|[[Burrell Memorial Observatory]]
|1940
|[[Berea, Ohio]], US
|-
|[[Byurakan Observatory]]
|1946
|[[Mount Aragats]], Armenia
|-
|[[Cagigal Observatory]]
|1888
|[[Caracas]], Venezuela
|-
|[[Cagliari Observatory]]
|1899
|[[Cagliari]], [[Sardinia]], Italy
|-bgcolor=#FFFFFF
|[[Calais Observatory]] ''(defunct)''
|1857
|[[Calais, Maine]], US
|-
|[[Calar Alto Observatory]]
|1975
|[[Almería]], Spain
|--bgcolor=#00FF00
|[[Caltech Submillimeter Observatory]] ''(defunct)''
|1986
|[[Mauna Kea]], [[Hawaii]], US
|-
|[[Cambridge Observatory]]
|1823
|[[Cambridge]], UK
|-
|[[Camille Flammarion Observatory]]
|1883
|[[Juvisy-sur-Orge]], France
|-
|[[UWS Rotary Observatory|Campbelltown Rotary Observatory]]
|2000
|[[Campbelltown, New South Wales|Campbelltown]], [[NSW]], Australia
|-
|[[Campo Imperatore Near-Earth Object Survey]]
|2001
|[[Campo Imperatore]], Italy
|-
|[[Canopus Hill Observatory]]
|
|[[Hobart]], Tasmania, Australia
|-
|[[Capilla Peak Observatory]]
|1947
|[[Albuquerque, New Mexico]], US
|-
|[[Capodimonte Observatory]]
|1812
|[[Naples]], Italy
|-
|[[Carter Observatory]]
|1937
|[[Wellington]], New Zealand
|-
|[[Catania Astrophysical Observatory]]
|
|[[Catania]], Italy
|-
|[[Cawthron Atkinson Observatory]]
|1883
|[[Nelson, New Zealand]]
|-
|[[Celestial Observatory]]
|
|[[Russellville, Arkansas]], US
|-
|[[Herrett Observatory|Centennial Observatory]]
|2004
|[[Twin Falls, Idaho]], US
|-
|[[Harvard-Smithsonian Center for Astrophysics|Center for Astrophysics {{!}} Harvard & Smithsonian]]
|1973
|[[Cambridge, Massachusetts]], US
|-
|[[Cerro Armazones Observatory]]
|1995
|[[Atacama Desert]], Chile
|-
|[[Cerro Tololo Inter-American Observatory]]
|1962
|[[Atacama Desert]], Chile
|-
|[[Cerro Pachón|Cerro Pachón Observatory]]
|2000
|[[Atacama Desert]], Chile
|-
|[[Chabot Space & Science Center]]
|1883
|[[Oakland, California]], US
|-
|[[Chamberlin Observatory]]
|1890
|[[Denver]], Colorado, US
|-
|[[Changchun Astronomical Observatory]]
|
|[[Changchun]], [[Jilin]] Province, China
|- bgcolor=#CCCCCC
|[[Chandra X-ray Observatory]]
|1999
|Highly eccentric [[Geocentric orbit|Earth orbit]]
|-
|[[Chianti Polifunctional Observatory]]
|2013
|[[San Donato in Poggio, Florence]], Italy
|-
|[[Chico Community Observatory]]
|2001
|[[Chico, California]], US
|-bgcolor=#99CC99
|[[Chilbolton Observatory]]
|1967
|[[Chilbolton]], UK
|-
|[[Cima Ekar Observing Station]]
|1966
|[[Asiago]], Italy
|-
|[[Cincinnati Observatory]]
|1843
|[[Cincinnati]], Ohio, US
|-
|[[City Observatory]], Edinburgh
|1818
|[[Edinburgh]], Scotland, UK
|-
|[[Clarke Observatory]]
|1897 / 1923
|[[Dunkirk, New York]] / [[Alliance, Ohio]], US
|-
|[[Class of 1951 Observatory]]
|1997
|[[Poughkeepsie (town), New York|Poughkeepsie, New York]], US
|-
|[[Cloudcroft Observatory]] ''(defunct)''
|1962
|[[New Mexico]], US
|-
|[[Coats Observatory]]
|1883
|[[Paisley, Renfrewshire|Paisley]], Scotland, UK
|-
|[[Coit Observatory]]
|
|[[Boston]], Massachusetts, US
|-
|[[Collins Observatory]]
|2003
|[[Corning (town), New York|Corning, New York]], US
|-
|[[Collm Observatory]]
|
|[[Leipzig]], Germany
|-
|[[Colombo University Observatory]]
| 1920s
|[[Colombo]], Sri Lanka
|-bgcolor=#CCCCCC
|[[Compton Gamma-Ray Observatory]] ''(defunct)''
|1991–2000
|[[Low Earth orbit]]
|-bgcolor=#FFFFFF
|[[ÇOMÜ Ulupınar Observatory]]
|2002
|[[Çanakkale]], Turkey
|-
|[[Concordia College Observatory]]
|
|[[Moorhead, Minnesota]], US
|-
|[[Consell Observatory]]
|1987
|[[Majorca]], Spain
|-
|[[Copenhagen University Observatory]]
|1861
|[[Copenhagen]], Denmark
|-
|[[Cordell–Lorenz Observatory]]
|
|[[Sewanee, Tennessee]], US
|-bgcolor=#CCCCCC
|[[Corot (space mission)|COROT]]
|2006
|[[Polar orbit]]
|-
|[[Cosmic Background Imager]] (CBI) ''(defunct)''
|1999
|[[Llano de Chajnantor Observatory]], Chile
|-
|[[Côte d'Azur Observatory]]
|1988
|France
|-
|[[Crane Observatory]]
|
|[[Topeka, Kansas]], US
|-
|[[Crawford Observatory]]
|1880
|[[Cork (city)|Cork]], Ireland
|-
|[[Creighton University Observatory]] ''(defunct)''
|1886–1955
|[[Omaha, Nebraska]], US
|-
|[[Crimean Astrophysical Observatory]]
|1945
|[[Nauchnyi]], Crimea
|-
|[[Črni Vrh Observatory]]
|1975
|[[Idrija]], Slovenia
|-
|[[Cupillari Observatory]]
|
|[[La Plume Township, Pennsylvania|La Plume, Pennsylvania]], US
|-
|[[Custer Observatory]]
|1927
|[[Southold, New York]], US
|-
|[http://thecyprusplanetarium.com/ The Cyprus Planetarium] & Observatory
|2023
|[[Nicosia]], Cyprus
|-
|[[Daniel S. Schanck Observatory]] ''(defunct)''
|1865
|[[Rutgers University]], [[New Brunswick, New Jersey]], US
|-
|[[Daniel Scholl Observatory]] ''(defunct)''
|1886–1966
|[[Lancaster, Pennsylvania]], US
|-
|Daocheng Solar Radio Telescope 
|2022
|Daocheng County, Garze Tibetan Autonomous Prefecture, Sichuan Province, China.
|-
|[[Dark Sky Observatory]]
|1981
|Phillips Gap, [[Wilkes County, North Carolina]], US
|- bgcolor=#CCCCCC
|[[Dark Matter Particle Explorer|Dark Matter Particle Explorer (DAMPE)]]
|2015
|500&nbsp;km [[Low Earth orbit|LEO]]
|-
|[[Darling's Observatory]] ''(defunct)''
|1917
|[[Duluth, Minnesota]], US
|-
|[[Dearborn Observatory]]
|1889
|[[Evanston, Illinois]], US
|-
|[[Detroit Observatory]]
|1854
|[[Ann Arbor, Michigan]], US
|-
|[[David Dunlap Observatory]]
|1935
|[[Richmond Hill, Ontario]], Canada
|-
|[[Dome C]]
|
|[[Antarctica]]
|-
|[[Dominion Observatory]]
|1905
|[[Ottawa]], [[Ontario]], Canada
|-
|[[Dominion Astrophysical Observatory]]
|1918
|[[Saanich, British Columbia]], Canada
|-bgcolor=#99CC99
|[[Dominion Radio Astrophysical Observatory]]
|1960
|[[Kaleden]], British Columbia, Canada
|-
|[[Dunsink Observatory]]
|1785
|[[Dublin]], Ireland
|-
|[[Durham University Observatory]]
|1839
|[[Durham, England|Durham]], UK
|-
|[[Dyer Observatory]]
|1953
|[[Brentwood, Tennessee]], US
|-bgcolor=#99CC99
|[[Effelsberg 100-m Radio Telescope]]
|1972
|[[Bonn]], Germany
|-
|[[Ege University Observatory]]
|1965
|[[Kemalpaşa]], [[İzmir]], Turkey
|- bgcolor=#CCCCCC
|[[Einstein Probe]]
|2024
|[[Low Earth orbit]]
|- bgcolor=#CCCCCC
|[[Einstein Observatory]] ''(defunct)''
|1978
|[[Low Earth orbit]]
|-
|[[Elginfield Observatory]]
|1969
|[[Middlesex Centre]], Ontario, Canada
|-
|[https://web.archive.org/web/20180513183657/http://sterlinghillminingmuseum.org/whatshere/ellis.php Ellis Observatory]
|2004
|[[Sterling Hill Mining Museum]], [[Ogdensburg, New Jersey]], US
|-
|[[Embry-Riddle Observatory]]
|2005
|[[Daytona Beach]], [[Florida]], US
|-
|[[Entoto Observatory Space Science Research Center]]
|2012
|[[Mount Entoto]], Ethiopia
|-
|[[Eskdalemuir Observatory]]
|1908
|[[Dumfries and Galloway]], Scotland, UK
|-bgcolor=#CCCCCC
|[[Euclid (spacecraft)|Euclid Telescope]]
|2023
|Earth–Sun {{L2}} [[Lagrangian point]]
|-
|[[European Southern Observatory]]
:*[[La Silla Observatory]]
:*[[New Technology Telescope]]
:*[[Llano de Chajnantor Observatory]]
:*[[Very Large Telescope]]
:*[[Paranal Observatory]]
:*[[European Extremely Large Telescope]]
|1962
*1969
*1989
*2005
*1998
*1999
*2026
|[[Atacama Desert]], Chile
|-
|[[Fabra Observatory]]
|1906
|[[Barcelona]], Spain
|-
|[[Fan Mountain Observatory]]
|1966
|[[Albemarle County]], [[Virginia]], US
|-bgcolor=#99CC99
|[[Five hundred meter Aperture Spherical Telescope|Five-hundred-meter Aperture Spherical Radio Telescope]]
|2013
|[[Duyun]], [[Pingtang]] County, [[Guizhou]] Province, China
|-
|[[Félix Aguilar Observatory]]
|1965
|[[San Juan, Argentina]]
|-
|[[Fernbank Observatory]]
|
|[[Atlanta]], Georgia, US
|- bgcolor=#CCCCCC
|[[Fermi Gamma-ray Space Telescope]]
|2008
|[[Low Earth orbit]]
|-
|[[Fick Observatory]]
|1966
|[[Boone, Iowa]], US
|-
|[[Five College Radio Astronomy Observatory]] ''(defunct)''
|1976–2011
|[[New Salem, Massachusetts]], US
|-
|[[Flarestar Observatory]]
|
|[[San Gwann]], Malta
|-
|[[Foggy Bottom Observatory]]
|1951
|[[Hamilton (village), New York|Hamilton, New York]], US
|-
|[[Foothill Observatory]]
|
|[[Los Altos Hills, California]], US
|-
|[[Clinton B. Ford Observatory|Ford Observatory]]
|1998
|[[Ithaca, New York|Ithaca]], [[New York (state)|New York]], US
|-
|[[Fox Observatory]]
|
|[[Sunrise, Florida]], US
|-
|[[Fox Park Public Observatory]]
|1999
|[[Potterville, Michigan]], US
|-
|[[Francis Marion University Observatory]]
|1982
|[[Florence, South Carolina]], US
|-
|[[Fred Lawrence Whipple Observatory]]
|1968
|[[Mount Hopkins (Arizona)|Mount Hopkins, Arizona]], US
|-
|[[Fremont Peak Observatory]]
|1986
|[[San Juan Bautista, California]], US
|-
|[[Frosty Drew Observatory]]
|1980s
|[[Charlestown, Rhode Island]], US
|-
|[[Fuertes Observatory]]
|1917
|[[Ithaca, New York]], US
|-bgcolor=#CCCCCC
|Galaxy Evolution Explorer ([[GALEX]])
|2003
|[[Caltech]], [[JPL|Jet Propulsion Laboratory]], California, US
|-bgcolor=#99CC99
|[[Gaocheng Astronomical Observatory]]
|1276
|[[Dengfeng]], [[Henan]], China
|-bgcolor=#99CC99
|[[Gauribidanur Radio Observatory]]
|1976
|[[Gauribidanur]], [[Karnataka]], India
|-
|[[Gemini Observatory]]
|1999
| Southern Operations Center: [[La Serena, Chile|La Serena]], Chile; Northern Operations Center: [[Hilo, Hawaii]], US
|-
|George Observatory
|1989
| [[Brazos Bend State Park]], near [[Houston, TX|Houston, Texas]], US
|-bgcolor=#99CC99
|[[Giant Meterwave Radio Telescope|Giant Meterwave Radio Telescope (GMRT)]]
|1995
|[[Pune]], [[Maharashtra]], India
|-
|[[Gifford Observatory]]
|1912
|[[Wellington]], New Zealand
|-
|[[Girawali Observatory]]
|2006
|[[Pune]], [[Maharashtra]], India
|-
|[[Glen D. Riley Observatory]]
|1973
|[[Naperville, Illinois]], US
|-
|[[Godlee Observatory]]
|1902
|[[Manchester]], England, UK
|-
|[[Goodsell Observatory]]
|1887
|[[Northfield, Minnesota]], US
|-
|[[Goethe Link Observatory]]
|1939
|[[Brooklyn, Indiana]], US
|-
|[[Goldendale Observatory State Park|Goldendale Observatory]]
|1973
|[[Goldendale, Washington]], US
|-
| [[Gornergrat Infrared Telescope|Gornergrat (HFSJG)]] ''(defunct)''
| 1967–2005
| [[Gornergrat]], Switzerland
|- bgcolor=#CCCCCC
|[[Granat]] ''(defunct)''
|1989–1999
|Highly eccentric [[Geocentric orbit|Earth orbit]]
|-
|[[Gran Telescopio Canarias]]
|2006
|[[Canary Islands]], Spain
|-
|[[Grant O. Gale Observatory]]
|1984
|[[Grinnell, Iowa]], US
|-bgcolor=#99CC99
|[[Green Bank Telescope]]
|
|[[Green Bank, West Virginia]], US
|-
|[[Green Point Observatory]]
|1961
|[[Sutherland, New South Wales]], Australia
|-
|[[Grenfell Campus|Grenfell Observatory]]
|2012
|Corner Brook, [[Newfoundland and Labrador]], Canada
|-
|[[Griffith Observatory]]
|1935
|Los Angeles, [[California]], US
|-
|[[Guillermo Haro Observatory]]
|1972
|[[Cananea]], [[Sonora]], Mexico
|-
|[[Gyarah Sidi]]
|
|[[Agra]], [[Uttar Pradesh]], India
|-bgcolor=#CCCCCC
|[[HALCA]] ''(defunct)''
|1997–2005
|Elliptical Earth-centered orbit
|-
|[[Haleakala Observatory]]
|
|[[Maui]], Hawaii, US
|-
|[[Halley Observatory]]
|1987
|[[Heesch (Netherlands)|Heesch]], Netherlands
|-
|[[Hamburg Observatory]]
|1803
|[[Hamburg]], Germany
|-bgcolor=#99CC99
|[[Hat Creek Radio Observatory]]
|1950s
|[[Shasta County, California]], US
|-
|[[Hard Labor Creek Observatory]]
|
|[[Atlanta]], Georgia, US
|- bgcolor=#CCCCCC
|[[Hard X-ray Modulation Telescope|Space Hard X-Ray Modulation Telescope (HXMT)]]
|2017
|550&nbsp;km [[Low Earth orbit|LEO]]
|-
|[[Hartung–Boothroyd Observatory]]
|1974
|[[Ithaca, New York]], US
|-bgcolor=#99CC99
|[[Hartebeesthoek Radio Astronomy Observatory]]
|1961
|[[Gauteng]], South Africa
|-
|[[Hartwell House, Buckinghamshire|Hartwell House]]
|1831
|[[Hartwell, Buckinghamshire|Hartwell]], Buckinghamshire, UK
|-
|[[Harvard College Observatory]]
|1839
|[[Cambridge, Massachusetts]], US
|-
|[[Haute-Provence Observatory]]
|1937
|[[Alpes-de-Haute-Provence]], France
|-
|[[Haystack Observatory]]
|1964
|[[Westford, Massachusetts]], US
|-
|[[Hector J Robinson Observatory]]
|1964
|[[Lincoln Park, Michigan]], US
|-bgcolor=#FFCC66
|[[Helium and Lead Observatory]]
|2012
|[[Sudbury, Ontario]], Canada
|-
|[[Helmos Observatory]]
|2007
|[[Mount Helmos (Aroania)|Mount Helmos]], Greece
|-
|[[Helsinki University Observatory]]
|1834
|[[Helsinki]]/[[Kirkkonummi]], Finland
|-
|[[Herrett Observatory]]
|2004
|[[Twin Falls, ID|Twin Falls, Idaho]], US
|-bgcolor=#CCCCCC
|[[Herschel Space Observatory]]
|2009
|[[List of objects at Lagrangian points#L2|Earth–Sun L2 point]]
|-
|[[Hidden Valley Observatory]]
|1960s
|[[Rapid City, South Dakota]], US
|-bgcolor=#FFFF99
|Hida Observatory, Kyoto University<ref>{{cite web |title=Astronomical Observatory, Kyoto University |url=https://www.kwasan.kyoto-u.ac.jp/index_en.html |website=www.kwasan.kyoto-u.ac.jp |access-date=13 November 2024 |archive-url=https://web.archive.org/web/20190329105408/https://www.kwasan.kyoto-u.ac.jp/index_en.html |archive-date=2019-03-29 |language=en}}</ref>
|1968
|[[Takayama, Gifu|Takayama]], [[Gifu Prefecture|Gifu]], Japan
|-
|[[Georgetown University Astronomical Observatory|Heyden Observatory]], [[Georgetown University]]
|1844
|[[Washington, DC|Washington, D.C.]], US
|-bgcolor=#FFCC00
|[[High Altitude Water Cherenkov Observatory]]
|2015
|[[Sierra Negra]], [[Puebla]], Mexico
|-bgcolor=#FFCC00
|[[High Energy Stereoscopic System]]
|2002
|[[Khomas Region]], Namibia
|-
|[[Highland Road Park Observatory]]
|1997
|[[Baton Rouge, Louisiana]], US
|- bgcolor=#CCCCCC
|[[Hinode (satellite)|Hinode]]
|2006
|[[Low Earth orbit]]
|-
|[[Hirsch Observatory]]
|1942
|[[Troy, New York]], US
|-
|[[Hobbs Observatory]]
|1974
|[[Fall Creek, Wisconsin]], US
|-
|[[Hoher List Observatory]]
|1954
|[[Daun, Germany]]
|-
|[[Holcomb Observatory and Planetarium]]
|1954
|[[Indianapolis]], Indiana, US
|-
|[[Hong Kong Observatory]]
|1883
|[[Tsim Sha Tsui]], [[Kowloon]], Hong Kong
|-
|[[Hoober Observatory]]
|1993
|[[Rotherham]], UK
|-
|[[Hopkins Observatory]]
|1838
|[[Williamstown, Massachusetts]], US
|-
|[[Howell Observatory]]
|
|[[Starkville, Mississippi]], US
|-
|[[Hradec Králové Observatory]]
|1961
|[[Hradec Králové]], Czech Republic
|-bgcolor=#FFFF99
|[[Huairou Solar Observing Station]]
|
|[[Beijing]], China
|- bgcolor=#CCCCCC
|[[Hubble Space Telescope]]
|1990
|[[Low Earth orbit]]
|-
|[[Tulse Hill|Huggins Observatory]] ''defunct''
|1856
|[[London]], England, UK
|-
|[[Hume Cronyn Memorial Observatory]]
|1940
|[[London, Ontario]], Canada
|-
|[[Hyde Memorial Observatory]]
|1977
|[[Lincoln, Nebraska]], US
|-bgcolor=#FFCC66
|[[IceCube Neutrino Observatory]]
|2010
|[[Amundsen–Scott South Pole Station]], Antarctica
|-
|[[Indian Astronomical Observatory]]
|2001
|[[Hanle (village)|Hanle]], [[Ladakh]], India
|-
|[https://www.humbleisd.net/page/insperity-humble-isd-observatory Insperity Observatory]
|2008
|[[Humble, Texas]], US
|-
|[[Instituto de Astrofísica de Canarias]]
|1975
|[[Canary Islands]], Spain
|- bgcolor=#CCCCCC
|[[INTEGRAL]]
|2002
|Highly eccentric [[Geocentric orbit|Earth orbit]]
|- bgcolor=#CCCCCC
|[[IRAS|Infrared Astronomical Satellite (IRAS)]] ''(defunct)''
|January–November 1983
|[[Geocentric orbit|Earth orbit]]
|- bgcolor=#CCCCCC
|[[Infrared Space Observatory|Infrared Space Observatory (ISO)]] ''(defunct)''
|1995–1998
|[[Geocentric orbit|Earth orbit]]
|-
|[[Innsbruck Observatory]]
|
|[[Innsbruck]], Austria
|-bgcolor=#99CC99
|[[IRAM 30m telescope]]
|1984
|[[Veleta (Sierra Nevada)|Pico Veleta]], Spain
|-bgcolor=#99CC99
|IRAM [[Plateau de Bure Interferometer]]
|1988
|[[Gap, Hautes-Alpes]], France
|-
|[[Iranian National Observatory]]
|2017
|[[Mount Gargash]], Iran
|-
|[[Isaac Newton Group of Telescopes]]
|1979
|[[La Palma]], Spain
|-
|[[Isaac Roberts' Observatory|Isaac Roberts' Observatory]] ''(defunct)''
|1890
|[[Crowborough]], UK
|-
|[[Iso-Heikkilä Observatory]] ''(defunct)''
|1935 (only [[amateur astronomy|amateur]] use since 1972)
|[[Turku]], Finland
|-
|[[Constantinople Observatory of Taqi ad-Din]]
|1577
|[[Constantinople]], Turkey
|-
|[[Istanbul University Observatory]]
|1936
|[[Istanbul]], Turkey
|-
|[[Istituto Ricerche Solari Locarno, IRSOL]]
|1960
|[[Locarno]], Switzerland
|-bgcolor=#CCCCCC
|[[IXPE]]
|2021
|[[Geocentric orbit|Earth orbit]]
|-bgcolor=#FFFFFF
|[[Jack C. Davis Observatory]]
|2002
|[[Carson City, Nevada]], US
|-
|[[Astronomical Observatory of the Jagiellonian University]]
|1792
|[[Kraków]], Poland
|-bgcolor=#00FF00
|[[James Clerk Maxwell Telescope]]
|1987
|[[Mauna Kea]], [[Hawaii]], US
|-
|[[James Gregory Telescope]]
|1962

|[[St. Andrews]], UK
|-bgcolor=#CCCCCC
|[[James Webb Space Telescope]]
|2021
|Earth–Sun {{L2}} [[Lagrangian point]]
|-
|[[University of Montevallo#The James Wylie Shepherd Observatory|James Wylie Shepherd Observatory]]
|2009
|[[Montevallo]], [[Alabama]], US
|-
|[[Jakarta Planetarium|Jakarta Observatory]]
|1968
|[[Jakarta]], Indonesia
|-
|[[Jantar Mantar (Jaipur)|Jantar Mantar]]
|1727
|[[Jaipur]], [[Rajasthan]], India
|-
|[[Jena Observatory]]
|1962
|[[Jena]], Germany
|-
|[[Jewett Observatory]]
|1953
|[[Pullman, Washington]], US
|-bgcolor=#99CC99
|[[Jodrell Bank Observatory]]
|1945
|[[Cheshire]], England, UK
|-
|[[JAC, Johor Astronomy Club|JAC Johor Astronomy]]
|2014
|[[Johor]], Malaysia
|-
|[[Jones Observatory]]
|1936
|[[Chattanooga, Tennessee]], US
|-
|[[Sarah L. Krizmanich Telescope|Jordan Hall of Science]]
|2006
|[[Notre Dame, Indiana]], US
|-
|[[Judson B. Coit Observatory]]
|
|[[Boston]], Massachusetts, US
|-bgcolor=#99CC99
|[[KAIRA]]
|2011
|[[Kilpisjarvi]], Finland
|-
|[[Khajeh Nasiredin Observatory]]
|~1980
| [[Tabriz University]], [[Tabriz]], Iran
|-bgcolor=#FFCC66
|[[Kamioka Observatory]]
|1983
|[[Hida, Gifu]], Japan
|-bgcolor=#FFFF99
|[[Kanzelhoehe Solar Observatory]]
|1943
|[[Villach]], Austria
|-
|[[Karl Schwarzschild Observatory]]
|1960
|[[Jena]], Germany
|-
|[[Keck Observatory]]
|1993
|[[Mauna Kea]], [[Hawaii]], US
|-
|[[Keeble Observatory]]
|1963
|[[Ashland, Virginia]], US
|-
|Keele [http://www.keele.ac.uk/observatory Observatory]
|1962
|[[Keele University]], England, UK
|-
|[[Kennon Observatory]]
|1939
|[[Oxford, Mississippi]], US
|-bgcolor=#CCCCCC
|[[Kepler Space Observatory]]
|2009
|Earth-trailing [[heliocentric orbit]]
|-
|[[Kevola Observatory]]
|1963
|[[Kevola, Finland]]
|-
|[[Kielder Observatory]]
|2008
|[[Kielder Forest]], [[Northumberland]], England, UK
|-
|[[King's Observatory]] ''(defunct)''
|1769
|[[Richmond, London|Greater London]], England, UK
|-
|[[Kirkwood Observatory]]
|1901
|[[Bloomington, Indiana]], US
|-
|[[Kitami Observatory]]
|1987
|[[Hokkaidō]], Japan
|-
|[[Kitt Peak National Observatory]]
|1958
|[[Tucson, Arizona]], US
|-
|[[Kleť Observatory]]
|1957
|[[České Budějovice]], Czech Republic
|-bgcolor=#FFFF99
|[[Kodaikanal Solar Observatory]]
|1899
|[[Palani]], [[Tamil Nadu]], India
|-
|[[Konkoly Observatory]]
|1871
|[[Budapest]], Hungary
|-
|[[Kopernik Observatory & Science Center]]
|1974
|[[Vestal, New York]], US
|-bgcolor=#00FF00
|[[KOSMA|KOSMA observatory]]
|1985–2010
|[[Gornergrat]], Switzerland
|-
| [[Kottamia Astronomical Observatory]]
| 1964
| [[Cairo Governorate]], Egypt
|-
| [[Kryoneri Observatory]]
| 1972
| [[Mount Kyllini]], Greece
|-
| [[Kuffner observatory]]
| 1884
| [[Vienna]], Austria
|-bgcolor=#00FFFF
|[[Kuiper Airborne Observatory]] (retired)
|1974
|14&nbsp;km in the [[stratosphere]]
|-
| Kwasan Observatory, Kyoto University<ref>{{cite web |title=Astronomical Observatory, Kyoto University |url=https://www.kwasan.kyoto-u.ac.jp/index_en.html |website=www.kwasan.kyoto-u.ac.jp |archive-url=https://web.archive.org/web/20190329105408/https://www.kwasan.kyoto-u.ac.jp/index_en.html |archive-date=2019-03-29 |language=en}}</ref>
| 1929
| [[Kyoto]], Japan
|-bgcolor=#ffffff
|[[Kvistaberg Observatory]]
|1948
|[[Bro, Stockholm|Bro]], Sweden
|-
|[[Kyung Hee Observatory]]
|1992
|[[Seoul]], South Korea
|-
|[[Laboratoire d'Astrophysique de Grenoble]]
|2001
|[[Grenoble]], France
|-
|[[Observatorio de La Cañada]] (La Cañada Observatory)
|2002
|[[Ávila]], Spain
|-
|[[Ladd Observatory]]
|1891
|[[Providence, Rhode Island]], US
|-
|[[Lake Afton Public Observatory]]
|1979
|[[Wichita, Kansas]], US
|-
|[[Lamont–Hussey Observatory]] ''(defunct)''
|1928
|[[Bloemfontein]], South Africa
|-
|[[Landessternwarte Heidelberg-Königstuhl]]
|1898
|[[Königstuhl (Odenwald)|Königstuhl]], [[Heidelberg]], Germany
|-
|[[Landolt Astronomical Observatory]]
|1939<ref>{{Cite web |date=September 1, 2022 |title=History of the Landolt Astronomical Observatory |url=https://www.lsu.edu/physics/about/landolt.php |access-date=September 1, 2022 |publisher=Louisiana State University Department of Physics & Astronomy}}</ref>
|[[Baton Rouge, Louisiana]], US
|-
|[[La Plata Astronomical Observatory]]
|1883
|[[La Plata]], Argentina
|-
|[[La Silla Observatory]]
|1969
|[[Atacama Desert]], Chile
|-bgcolor=#FFCC00
|[[Large High Altitude Air Shower Observatory|Large High Altitude Air Shower Observatory (LHAASO)]]
|2019
|[[Daocheng County]], Sichuan, China
|-
|[[LAMOST|Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST)]]
|2009
|[[Xinglong Station (NAOC)|Xinglong Station]], Hebei, China
|-
|[[Large Millimeter Telescope]]
|
|[[Sierra Negra]], [[Puebla]], Mexico
|-
|[[Las Brisas Observatory]]
|1979
|[[Colorado]], US
|-
|[[Las Campanas Observatory]]
|
|[[La Serena, Chile]]
|-
|[[Langkawi National Observatory]]
|2012
|[[Langkawi Island]], Malaysia
|-
|[[Las Cumbres Observatory Global Telescope]]
|2005
|[[Global network]]
|-
|[[Laws Observatory]]
|1880
|[[Columbia, Missouri]], US
|-
|[[Leander McCormick Observatory]]
|1885
|[[Mount Jefferson (Virginia)|Mount Jefferson]], [[Charlottesville, Virginia]], US
|-
|[[Lee Observatory]]
|1873
|[[American University of Beirut]], [[Beirut]], Lebanon
|-
|[[Leiden Observatory]]
|1633
|[[Leiden University]], [[Leiden]], Netherlands
|-
|[[Leipzig Observatory]]
|
|[[Leipzig]], Germany
|-
|[[Leoncito Astronomical Complex]]
|1986
|[[Calingasta]], [[San Juan, Argentina|San Juan]], Argentina
|-
|[[Levenhagen Observatory]]
|
|[[Seattle]], Washington, US
|-
|[[Lick Observatory]]
|1881
|[[Mount Hamilton (California)|Mount Hamilton]], [[San Jose, California]], US
|-
|[[LightBuckets]] (commercial observatory)
|2007
|[[Rodeo, New Mexico]], US
|-bgcolor=#0000A0
|[[LIGO|{{white|LIGO}}]]
|{{white|1999}}
|[[Hanford Site|{{white|Hanford Site, Washington, US}}]] & [[Livingston, Louisiana|{{white|Livingston, Louisiana, US}}]], US
|-
|[[Lindheimer Astrophysical Research Center]] ''(defunct)''
|1966–1995
|[[Evanston, Illinois]], US
|--bgcolor=#00FF00
|[[Llano de Chajnantor Observatory]]
|2005
|[[Atacama Desert]], Chile
|-
|[[Llano del Hato National Astronomical Observatory]]
|1975
|[[Mérida, Mérida|Mérida]], Venezuela
|-bgcolor=#99CC99
| [[Lockyer Observatory and Planetarium|Lockyer Technology Centre]]
| 2010
| [[Sidmouth]], [[Devon]], England, UK
|-bgcolor=#99CC99
|[[Long Wavelength Array]]
|2010
|[[Socorro, New Mexico]], US
|-
|[[Longa Vista Observatory]]
|2010
|[[Itatiba, SP]], Brazil
|-
|[[Lowell Observatory]]
:*[[Anderson Mesa Station]]
|1894
*1959
|[[Flagstaff, Arizona]], US
|-
|Lucknow (King of Oudh's) Observatory 
|1832–1848
|[[Lucknow]], India
|-
|[[Lulin Observatory]]
|1999
|Mount Lulin, Taiwan
|-
|[[Lund Observatory]]
|1749
|[[Lund]], Sweden
|-bgcolor=#FFCC00
|[[Luoxue Mountain Cosmic Rays Research Center]]
|1953
|[[Luoxue Mountain]], [[Yunnan]] Province, China
|-
|[[Lyon Observatory]]
|1878
|[[Saint-Genis-Laval]], France
|-
|[[Macalester College Observatory]]
|
|[[St. Paul, Minnesota|Saint Paul, Minnesota]], US
|-
|[[Macfarlane Observatory]] ''defunct''
|1757
|[[Glasgow]], Scotland, UK
|-
|[[Magdalena Ridge Observatory]]

* [[Magdalena Ridge Observatory#2.4-meter telescope|Magdalena Ridge Observatory Single Telescope]]
* [[Magdalena Ridge Observatory#Magdalena Ridge Optical Interferometer|Magdalena Ridge Observatory Interferometer]]
|2006

* 2008
* Under construction
|[[Socorro County, New Mexico]], US
|-
|[[Majorca Observatory]]
|1991
|[[Majorca]], Spain
|-
|[[Malakoff Tower]]
|1845
|[[Recife]], Brazil
|-
|[[Manastash Ridge Observatory]]
|1972
|[[Ellensburg, Washington]], US
|-
|[[Manuel Foster Observatory]] ''(defunct)''
|1903
|[[Santiago]], Chile
|-
|[[Maragheh observatory|Maragheh Observatory]]
|1259
|[[Maragheh]], Iran
|-
|[[Margaret M. Jacoby Observatory]]
|1978
|[[Warwick, Rhode Island]], US
|-
|[[Maria Mitchell Observatory]]
|1908
|[[Nantucket]], Massachusetts, US
|-
|[[Marina Towers Observatory]] ''(Not In Use)''
|1989
|Maritime Quarter, [[Swansea]], Wales, UK
|-
|[[Markree Observatory]] ''(defunct)''
|1837
|[[County Sligo]], Ireland
|-
|[[Marseille Observatory]]
|
|[[Marseille]], France
|-
|[[Martz Observatory]]
|
|[[Chautauqua County, New York]], US
|-
|[[Mauna Kea Observatory]]
|1967
|[[Mauna Kea]], [[Hawaii]], US
|-bgcolor=#FFFF99
|[[Mauna Loa Solar Observatory]]
|
|[[Hawaii]], US
|-
|[[Maynard F. Jordan Observatory]]
|1901
|[[Orono, Maine]], US
|-
|[[McDonald Observatory]]
|
|[[Davis Mountains]], [[Texas]], US
|-
|[[McKim Observatory]]
|1884
|[[Greencastle, Indiana]], US
|-bgcolor=#FFFF99
|[[McMath–Hulbert Solar Observatory]]
|1930
|[[Lake Angelus, Michigan]], US
|-
|[[MDM Observatory]]
|
|[[Kitt Peak]], [[Arizona]], US
|-
|[[Mead Observatory]]
|2001
|[[Columbus, Georgia|Columbus]], Georgia, US
|-
|[[Medicina Radio Observatory]]
|1965
|[[Medicina]], [[Bologna]], Italy
|-
|[[Mees Observatory]]
|
|[[Rochester, New York]], US
|-
|[[Mehalso Observatory]]
|
|[[Erie, Pennsylvania]], US
|-
|[[Melbourne Observatory]]
|1862
|[[Melbourne]], [[Victoria, Australia|Victoria]], Australia
|-
|[[Melton Memorial Observatory]]
|1928
|[[Columbia, South Carolina]], US
|-
|[[Mendenhall Observatory]]
|2002
|[[Stillwater, Oklahoma]], US
|-
|[[Menke Observatory]]
|1994
|[[Davenport, Iowa]], US
|-bgcolor=#99CC99
|[[Metsähovi Observatory]]
|1966
|[[Kirkkonummi]], Finland
|-bgcolor=#FFFF99
|[[Meudon Observatory]]
|1876
|[[Meudon]], France
|-
|[[Meyer–Womble Observatory]]
|1996
|[[Mount Evans, Colorado]], US
|-
|[[Michigan State University Observatory]]
|1969
|[[East Lansing, Michigan]], US
|-
|[[Observatoire Midi-Pyrénées]]<!--- sort under "Midi-Pyrénées" --->
<!--- :*Lannemezan : [[Centre de recherches atmosphériques de Campistrous]] (radar and atmospheric research) http://www.aero.obs-mip.fr/presentation/presenta.htm --->
:*[[Pic du Midi Observatory]]
<!--- :*[[Laboratoire astrophysique de Toulouse-Tarbes]] (instruments and computers) http://www.ast.obs-mip.fr/article1.html --->
:*[[Toulouse Observatory]]
|&nbsp;
:*1878
:*1733
|Headquarters: [[Toulouse]], France
*[[Pyrenees]], France
*[[Toulouse]], France
|-bgcolor=#FFCC00
|[[Milagro (experiment)|Milagro]]
|1999
|[[Los Alamos, New Mexico]], US
|-
|[[Miller Observatory]]
|1976
|[[Maiden, North Carolina]], US
|-
|[[Mills Observatory]]
|1938
|[[Dundee]], Scotland, UK
|-
|[https://www.mindseyeobservatory.org Mind's Eye Observatory IAU W42]
|2018
|[[Sebastian, Florida]], US
|-
|[[MMT Observatory]]
|1979
|[[Mount Hopkins (Arizona)|Mount Hopkins, Arizona]], US
|-
|[[Modine-Benstead Observatory]]
|1963
|[[Union Grove, Wisconsin]], US
|-
|[[Modra Observatory]]
|1988
|[[Modra]], Slovakia
|-
|[[Johan Maurits Mohr|Mohr Observatory]] ''(demolished)''
|1765–1780
|[[Jakarta]], Indonesia
|-
|[[Moletai Astronomical Observatory]]
|1969
|[[Moletai]], Lithuania
|-
|[[Molonglo Observatory Synthesis Telescope]] (MOST)
|1960
|[[Bungendore]], New South Wales, Australia
|-
|[[Mont Mégantic Observatory]]
|1978
|[[Mont Mégantic]], [[Québec]], Canada
|-
|[[Monterey Institute for Research in Astronomy]]<br />([[Oliver Observing Station]])
|1972<br />(1984)
| [[Chews Ridge Lookout#Astronomy use anchor|Chews Ridge, California]] &<br />[[Monterey, California]], US
|-
|Montevideo National Observatory
|
|[[Montevideo]], Uruguay, {{Coord|34|54.6|S|56|12.8|W}}
|-
|[[Moore Observatory]]
|1978
|[[Oldham County, Kentucky]], US
|-
|[[Morgan–Monroe Observatory]]
|1966
|[[Morgan–Monroe State Forest]], [[Indiana]], US
|-
|[[Morris Observatory]]
|1973
|[[North Manchester, Indiana]], US
|-
|[[Morrison Observatory]]
|
|[[Fayette, Missouri]], US
|-bgcolor=#FFCC00
|[[Moscow Cosmic-Ray Station]]
|
|[[Troitsk, Moscow Oblast|Troitsk]], Russia
|-
|[[Mount Stony Brook Observatory]]
|1968
|[[Stony Brook, New York|Stony Brook]], [[New York (state)|New York]], US
|-
|[[Mounds Observatory]]
|
|[[Tulsa, Oklahoma]], US
|-
|[[Mount Abu InfraRed Observatory]]
|1995
|[[Mount Abu]], [[Rajasthan]], India
|-
|[[Mount Burnett Observatory]]
|1972
|[[Mount Burnett, Victoria|Mount Burnett]], Victoria, Australia
|-
|[[Mount Cuba Astronomical Observatory]]
|
|[[Greenville, Delaware]], US
|-
|[[Mount Graham International Observatory]]
|1993
|[[Mount Graham]], Arizona, US
|-
|[[Mount John University Observatory]]
|1965
|[[Lake Tekapo]], [[South Island]], New Zealand
|-
|[[Mount Laguna Observatory]]
|1968
|[[San Diego]], California, US
|-
|[[Mount Lemmon Observatory]]
|
|[[Tucson, Arizona]], US
|-bgcolor=#99CC99
|[[Mount Pleasant Radio Observatory]]
|
|[[Tasmania]], Australia
|-
|[[Mount Stromlo Observatory]]
|1911
|[[Canberra]], Australia
|-
|[[Mount Suhora Observatory]]
|1987
|[[Gorce Mountains]], Poland
|-
|[[Mount Wilson Observatory]]
|1904
|[[Mount Wilson (California)|Mount Wilson]], [[Los Angeles County, California]], US
|-
|[[Mountain Skies Observatory]]
|1997
|[[Lyman, Wyoming]], US
|-bgcolor=#99CC99
|[[Mullard Radio Astronomy Observatory]]
|1957
|[[Cambridge]], England, UK
|-bgcolor=#99CC99
|[[Murchison Radio-astronomy Observatory]]
|2012
|[[Murchison (Western Australia)|Murchison, Western Australia]], Australia
|-
|[[Mykolaiv Observatory|Mykolaiv Astronomical Observatory]]
|1821
|[[Mykolaiv]], [[Mykolaiv Oblast]], Ukraine
|-
|[[Nachi-Katsuura Observatory]]
|
|[[Nachikatsuura]], Wakayama, Japan
|-bgcolor=#99CC99
|[[Nançay Radio Telescope]]
|1965
|[[Nançay]], France
|-
|[[Nanjing Astronomical Instruments Research Centre]]
|1958
|[[Nanjing]], [[Jiangsu]] Province, China
|-
|[[National Astronomical Observatory (Colombia)]]
|1803
|[[Bogotá]], Colombia
|-
|[[National Astronomical Observatory of Japan]]
|1988
|Headquarters: [[Mitaka, Tokyo]], Japan
|-
|[[National Astronomical Observatory (Mexico)]]
|1967
|[[Sierra San Pedro Mártir]], [[Baja California]], Mexico
|-
|[[National Observatory (Brazil)]]
|1827
|[[Rio de Janeiro]], Brazil
|-
|[[National Observatory of Athens]]
|1842
|[[Athens]], Greece
|-
|[[National Optical Astronomy Observatory]]
:*[[Cerro Tololo Inter-American Observatory]]
:*[[Gemini Observatory]]
:*[[Kitt Peak National Observatory]]
:*[[National Solar Observatory]]
|1982
|Headquarters: [[Tucson, Arizona]], US
|-
|[[National Optical Observatory]]
|
|[[Turkey]]
|-bgcolor=#99CC99
|[[National Radio Astronomy Observatory]]
:*[[Atacama Large Millimeter Array]]
:*[[Green Bank Telescope]]
:*[[Very Large Array]]
:*[[Very Long Baseline Array]]
|1957
|Headquarters: [[Charlottesville, Virginia]], US
|-
|[[National Research Institute of Astronomy and Geophysics]] (NRIAG)
|1903
|[[Helwan]], Egypt
|-bgcolor=#FFFF99
|[[National Solar Observatory]]
|1952
|[[Sunspot, New Mexico]], US & [[Kitt Peak]], Arizona, US
|-
|Naval Research Lab. Radio Sta.
|
|[[Sugar Grove, West Virginia|Sugar Grove]], West Virginia, US {{Coord|38|31.2|N|79|16.4|W}}
|-
|[[Naylor Observatory]]
|1971
|[[Harrisburg, Pennsylvania]], US
|-
|[[Neuchâtel Observatory]]
|1858
|[[Neuchâtel]], Switzerland
|-
|[[Nha Trang Observatory]]
|2017
|[[Nha Trang]], Vietnam
|-
|[[Nice Observatory]]
|1879
|[[Nice]], France
|-
|[[Napoleon III Telescope (University of Notre Dame)|Nieuwland Hall (Napoleon III Telescope)]]
|1959
|[[Notre Dame, Indiana]], US
|-
|[[Nizamia observatory|Nizamia Observatory]]
|1907
|[[Hyderabad]], India
|-
|[[Nordic Optical Telescope]]
| 1988
| [[Canary Islands]], Spain
|-bgcolor=#FFCC00
|[[Norilsk Cosmic-Ray Station]]
|
|[[Norilsk]], [[Krasnoyarsk Krai]], Russia
|-
|[[Norman Lockyer Observatory]]
|1912
|[[Sidmouth]], UK
|-
|[[Northern Arizona University Observatory]]
|
|[[Flagstaff, Arizona]], US
|-
|[[Northern Skies Observatory]]
|2009
|[[Peacham, Vermont]], US
|-
|[[Northolt Branch Observatory]]
|2015
|[[London]], England, UK
|-
|[[Northolt Branch Observatory 2, Shepherd's Bush]]
|2016
|London, England, UK
|-
|[[Northolt Branch Observatory 3, Blandford Forum]]
|2017
|London, England, UK
|-
|[[North Georgia Astronomical Observatory]]
|
|[[Dahlonega]], Georgia, US
|-
|[[North Otago Astronomical Society Observatory]]
|
|[[Oamaru]], [[South Island]], New Zealand
|-
|[[Nyrölä Observatory]]
|1997
|[[Jyväskylän maalaiskunta]], Western Finland Province, Finland
|-
|[[OAC (Observatorio Astronómico de Córdoba)]]
|1871
|[[Córdoba, Argentina|Córdoba]], Argentina
|-
|OAO (Observatorio de Aras de los Olmos)
|2008
|[[Aras de los Olmos]], [[Valencia]], Spain
|-
|[[O'Brien Observatory]]
|1961
|[[Marine on St. Croix, Minnesota]], US
|-
|[http://www.astroqueyras.com/ Observatoire du Pic de Château-Renard]
|1974
|[[Saint-Véran]], France
|-
|[https://web.archive.org/web/20080511173449/http://www.observatorio.unal.edu.co/ Observatorio Astronómico Nacional (Colombia)]
|1803
|[[Bogotá]], Colombia
|-
|[[Observatorio Astronomico Nacional Tonantzintla]]
|1961
|[[Tonantzintla]], Mexico
|-
|[[Observatorio Solar Carl Sagan]]
|2000
|[[Hermosillo]], [[Sonora]], Mexico
|-
|[[Observatory House]] ''(defunct)''
|1789
|[[Slough]], UK
|-
|[[Observatory of the rue Serpente]] ''(defunct)''
|1890–1968
|[[Paris]], France
|-
|[[Oil Region Astronomical Observatory]]
|
|[[Venango County, Pennsylvania]], US
|-
|[[Onan Observatory]]
|1990
|[[Norwood Young America, Minnesota]], US
|-
|[[Ondokuz Mayıs University Observatory]]
|2006
|[[Samsun]], Turkey
|-
|[[Ondřejov Observatory]]
|1898
|[[Ondřejov (Prague-East District)|Ondřejov]], Czech Republic
|-bgcolor=#99CC99
|[[Onsala Space Observatory]]
|1949
|[[Onsala]], Sweden
|-bgcolor=#99CC99
|[[Ooty Radio Telescope]]
|1970
|[[Ooty]], [[Tamil Nadu]], India
|-
|[[Orchard Hill Observatory]]
|1965
|[[Amherst, Massachusetts]], US
|-
|[[Orioloromano Observatory]]
|2007
|[[Oriolo Romano]], Italy
|-bgcolor=#CCCCCC
|[[Orion 1 and Orion 2 Space Observatories|Orion 1]] (defunct)
|1971
|[[Low Earth orbit]]
|-bgcolor=#CCCCCC
|[[Orion 1 and Orion 2 Space Observatories|Orion 2]] (defunct)
|1973
|[[Low Earth orbit]]
|-
|[[Orion Ranch Observatory]]
|2009
|[[Bertram, Texas]], US
|-
|[[Orwell Park School|Orwell Park School Observatory]]
|1848
|[[Nacton]], UK
|-
|[[Ostrowik Observatory]]
|1952
|[[Ostrowik, Otwock County|Ostrowik]], Poland
|-
|[[Otter Creek Observatory]]
|1995
|[[Meade County, Kentucky]], US
|-bgcolor=#FFCC00
|[[Oulu Cosmic-Ray Station]]
|
|[[Oulu]], Finland
|-bgcolor=#99CC99
|[[Owens Valley Radio Observatory]]
|1958
|[[Bishop, California]], US
|-
|[[Pachmarhi Telescope Array|Pachmarhi Array of Cerenkov Telescopes (PACT)]]
|1986
|[[Pachmarhi]], [[Madhya Pradesh]], India
|-
|[[Palisades-Dows Observatory]]
|1987
|[[Cedar Rapids, Iowa]], US
|-
|[[PAGASA Observatory|PAGASA Astronomical Observatory]]
|1954
|[[Quezon City]], Philippines
|-
|[[Palermo Observatory]]
|1790
|[[Palermo]], Sicily, Italy
|-
|[[Palomar Observatory]]
|1948
|[[Palomar Mountain]], [[California]], US
|-
|[[Panzano Observatory]]
|1640
|[[Bologna]], Italy
|-
|[[Paranal Observatory]]
|1999
|[[Cerro Paranal]], [[Atacama Desert]], Chile
|-
|[[Paris Observatory]]
|1667
|Paris, France
|-bgcolor=#99CC99
|[[Parkes Observatory]]
|1961
|[[Parkes, New South Wales|Parkes]], Australia
|-
|[[Paul Robinson Observatory]]
|1965
|[[High Bridge, New Jersey]], US
|-
|[[Peach Mountain Observatory]]
|1950
|[[Dexter, Michigan]], US
|-
|[[Penteli Observatory]]
|1937
|[[Penteli, Greece|Penteli]], [[Attica (region)|Attica]], Greece
|-
|[[Perkins Observatory]]
|1931
|[[Delaware, Ohio]], US
|-
|[[Perth Observatory]]
|1896
|[[Perth, Western Australia|Perth, Australia]]
|-
|[[Peterberg Observatory]]
|1977
||[[Saarland]], Germany
|-
|[[Pic du Midi de Bigorre|Pic du Midi Observatory]]
|1878
|[[Pic du Midi de Bigorre|Pic du Midi]], [[Pyrenees]], France
|-
|[[Pico dos Dias Observatory]]
|1981
|[[Minas Gerais]], Brazil
|-
|[[Piera Observatory]]
|1968
|[[Barcelona]], Spain
|-bgcolor=#FFCC00
|[[Pierre Auger Observatory]]
|2004
|[[Malargüe]], Argentina
|-
|[[Pine Bluff Observatory]]
|1958
|[[Cross Plains (town), Wisconsin|Cross Plains, Wisconsin]], US
|-
|[[Pine Mountain Observatory]]
|1965
|[[Bend, Oregon]], US
|-
|[[Pistoia Mountains Astronomical Observatory]]
|1990
|[[Pian dei Termini]] (near [[San Marcello Pistoiese]]), Italy
|-bgcolor=#99CC99
|[[Institute of Astronomy, NCU|Piwnice Ovservatory]]
|1945
|[[Piwnice, Kuyavian-Pomeranian Voivodeship|Piwnice]] near Toruń, Poland
|-
|[[Planetarium and Astronomical Observatory in Grudziądz]]
|1972
|[[Grudziądz, Kujawsko-Pomorskie]], Poland
|-
|[https://sna.international Plateau Astronomique de La Couronne]
|2024
|[[Cordes-sur-Ciel]], [[Tarn (department)|Tarn]], France
|-
|[[Pollock Astronomical Observatory]]
|2004
|[[Hunting Valley, Ohio]], US
|-
|[[Portage Lake Observatory]] ''(defunct)''
|1948
|[[Dexter, Michigan]], US
|-
|[[Poznań Observatory]]
|1919
|[[Poznań]], Poland
|-
|[[Prishtina Observatory]]
|1997
|[[Pristina Municipality]], Kosovo
|-bgcolor=#CCCCCC
|[[PROBA-3]]
|2024
|[[Low Earth orbit]]
|-
|[[Puckett Observatory]]
|1977
|[[Ellijay, Georgia]], US
|-
|[[Pula Observatory]]
|1869
|[[Pula]], Croatia
|-
|[[Pulkovo Observatory]]
|1839
|[[Pulkovskiye Heights]], Russia
|-
|[[Purple Mountain Observatory]]
|1929
|[[Nanjing]], [[Jiangsu]] Province, China
|- bgcolor=#CCCCCC
|[[Queqiao]] 
|2018
|[[Lagrange point|Earth-Moon L<sub>2</sub>]]
|- bgcolor=#CCCCCC
|[[Queqiao-2]] 
|2024
|[[Lunar orbit]]
|-
|[[Quito Astronomical Observatory]]
|1873
|[[La Alameda Park, Quito]], Ecuador
|-
|[[Radcliffe Observatory]]
|1772
|[[Oxford]], England. Moved to [[Durban]], South Africa in 1939
|-
|[[Rainwater Observatory]]
|
|[[French Camp, Mississippi]], US
|-
|[[Ralph A. Worley Observatory]]
|1964
|[[Shreveport, Louisiana]], US
|-
|[http://www.dancaton.physics.appstate.edu/Observatories/RSO/RSO.htm Rankin Science Observatory]
|1963
|[[Appalachian State University]], [[Boone, North Carolina]], US
|-
|[[Rancho Mirage Library and Observatory]]
|2018
|[[Rancho Mirage, California]], US
|-
|[[Rattlesnake Mountain Observatory]] ''(defunct)''
|1971
|[[Hanford Reach National Monument]], [[Washington (state)|Washington]], US
|-
|Real Instituto y Observatorio de la Armada (Spain)
|1793
|[[San Fernando, Cádiz]], Spain
|-
|[[Red Barn Observatory]]
|2006
|[[Ty Ty, Georgia|Ty Ty]], Georgia, US
|-
|[[Red Buttes Observatory]]
|1994
|[[Laramie, Wyoming]], US
|-
|[[Riley Observatory]]
|1974
|[[Naperville, Illinois]], US
|-
|[[RIT Observatory]]
|
|[[Rochester, New York]], US
|-
|[[Ritter Observatory]]
|
|[[Toledo, Ohio]], US
|-
|[[Robert A. Schommer Observatory]]
|
|[[Rutgers University]], [[New Brunswick, New Jersey]], US
|-
|[[Robert Brownlee Observatory]]
|
|[[Lake Arrowhead, California]], US
|-
|[[Robinson Observatory]]
|
|[[Orlando, Florida]], US
|-
|[[Robotic Lunar Observatory]] ''(defunct)''
|1995
|[[Flagstaff, Arizona]], US
|-bgcolor=#FFFF99
|[[MSAD 17#Schools|Roger Twitchell Observatory]]<ref name=Twitchell1>{{cite web|url= https://www.msad17.org/page/twitchell-observatory/ |title = Twitchell Observatory {{vbar}} MSAD 17 |website= MSAD17.org | publisher = [[Maine Department of Education]] |access-date= December 30, 2022}}</ref>
|1972
|[[Paris, Maine]], US
|-
|[[Rogers Observatory]]
|1981
|[[Traverse City, Michigan]], US
|-
|[[Rolnick Observatory]]
|
|[[Westport, Connecticut]], US
|-
|[[Rome Observatory]]
|1938
|Italy
|-
|[[Roseland Observatory]]
|1998
|[[St Stephen-in-Brannel]], [[UK]]
|-
|[[Rossall School|Rossall School Observatory]]
|
|[[Rossall]], UK
|-
|[[Rothney Astrophysical Observatory]]
|1984
|[[Priddis, Alberta]], Canada
|-
|[[Royal Observatory, Greenwich]]
|1675
|[[Greenwich]], England, UK
|-
|[[Royal Observatory, Edinburgh]]
|1896
|[[Edinburgh]], Scotland, UK
|-
|[[Roque de los Muchachos Observatory]]
|1979 (officially inaugurated in 1985)
|[[La Palma]], [[Canary Islands]], Spain.
|-
|[[Rosemary Hill Observatory]]
|
|[[Bronson, Florida]], US
|-
|[[Rozhen Observatory]]
|1981
|Peak [[Rhodope Mountains|Rozhen]], Bulgaria
|-
|[[Rutherford Observatory]]
|1920s
|[[New York City]], New York, US
|-bgcolor=#FFFF99
|[http://www.csun.edu/sfo/index.html San Fernando Observatory (SFO)]
|1976
|[[Sylmar, California]], US
|-
|[[Sankt Andreasberg Observatory]]
|2014
|[[Sankt Andreasberg]], Germany
|-
|[[Sayan Spectrographic Cosmic Ray Complex]]
|
|[[Irkutsk]], Russia
|-
|[[SFA Observatory]]
|1976
|[[Nacogdoches, Texas]], US
|-
|[[Sagamore Hill Radio Observatory]]
|1963
|[[Hamilton, Massachusetts]], US
|-
|[https://limaastro.com Schoonover Observatory]
|1964
|[[Lima, Ohio]], US
|-
|[[Shattuck Observatory]]
|1854
|[[Hanover, New Hampshire]], US
|-
|[[Sherwood Observatory]]
|1972
|[[Mansfield]], UK
|-
|[[Seven Hills Observatory]]
|1996
|[[Kearney, Nebraska]], US
|-
|[[Shamakhi Astrophysical Observatory]]
|1958
|[[Shamakhi]], [[Azerbaijan]]
|-
|[[Shanghai Astronomical Observatory]]
|1962
|[[Shanghai]], China
|-
|[[Sherzer Observatory]]
|1878
|[[Ypsilanti, Michigan]], US
|-
|[[Sheshan Astronomical Observatory]]
|1900
|[[Shanghai]], China
|-
|[[Siding Spring Observatory]]
|1924
|[[Siding Spring Observatory|Siding Spring]], New South Wales, Australia
|-bgcolor=#FFFF99
| [[Lockyer Observatory and Planetarium|Sidmouth Observatory]]
| 1912
| [[Sidmouth]], [[Devon]], England, UK
|-
|[[Sierra Nevada Observatory]]
|1981
|[[Sierra Nevada, Spain|Sierra Nevada]], Spain
|-
|[[Silesian Planetarium|Silesian Planetarium and Astronomical Observatory]]
|1955
|[[Chorzów]] / [[Katowice]], [[Silesia]], Poland
|-
|[[Simeiz Observatory]]
|1906
|[[Simeiz]], [[Crimea]], Ukraine
|-
|[[Skalnaté Pleso Observatory]]
|1953
|[[Vysoké Tatry (town)|Vysoké Tatry]], Slovakia
|-
|[[Skinakas Observatory]]
|1984
|[[Crete]], Greece
|-
|[[Skylab]]
|1973
|[[Low Earth orbit]]; re-entered in 1979
|-
|[[Smith Observatory]]
|1880s
|[[Beloit, Wisconsin]], US
|-
|[[Smithsonian Astrophysical Observatory]]
|1890
|[[Cambridge, Massachusetts]], US
|-
|[[Sobaeksan Optical Astronomy Observatory]]
|1978
|[[Sobaeksan]], South Korea
|-
|[[Sola Fide Observatory]]
|1990s
|[[Austin, Minnesota]], US
|-bgcolor=#CCCCCC
|[[Solar and Heliospheric Observatory|Solar and Heliospheric Observatory (SOHO)]]
|1996
|Earth–Sun [[Lagrange Point|L1 point]]
|-bgcolor=#CCCCCC
|[[Space program of China#List of projects|Solar Space Telescope]]
|2009
|709&nbsp;km [[Sun-synchronous orbit|SSO]]; life: 3 years
|-
|[[Sommers–Bausch Observatory]]
|1949
|[[Boulder, Colorado]], US
|-
|[[Sonnenborgh Observatory]]
|1853
|[[Utrecht (city)|Utrecht]], Netherlands
|-
|[[Sonoma State Observatory]]
|1976
|[[Rohnert Park, California]], US
|-
|[[South African Astronomical Observatory]]
:*Cape Town
:*Sutherland
|
*1820
*1972
|[[Observatory, Cape Town]], South Africa
*[[Sutherland, Northern Cape]], South Africa
|-
|[[Southern Astrophysical Research Telescope|Southern Astrophysical Research Telescope (SOAR)]]
|2004
|[[Cerro Pachón]], Chile
|-bgcolor=#99CC99
|[[South Pole Telescope]]
|2007
|Antarctica
|-bgcolor=#CCCCCC
|[[Spanish National Observatory]]
|1790
|[[Madrid]], Spain
|-
|[[Special Astrophysical Observatory of the Russian Academy of Science]]s
|1966
|[[Zelenchukskaya]], near [[Arkhyz]], [[Caucasus Mountains]], Russia
|-
|[[Sperry Observatory]]
|1967
|[[Cranford, New Jersey]], US
|-bgcolor=#CCCCCC
|[[SPHEREx]]
|2025
|Sun-synchronous [[Geocentric orbit|Earth orbit]]
|-bgcolor=#CCCCCC
|[[Spitzer Space Telescope]]
|2003
|[[Heliocentric orbit]]
|-
|[[Springfield Science Museum|Springfield Observatory]]
|1968
|[[Springfield, Massachusetts]], US
|-
|[[Sproul Observatory]]
|1911
|[[Swarthmore, Pennsylvania]], US
|-
|[[Stardome Observatory]]
|1967
|[[Auckland]], [[North Island]], New Zealand
|-
|[[Starkenburg Observatory]]
|1970
|[[Heppenheim]], Germany
|-
|[[Štefánik's Observatory]]
|1928
|[[Prague]], Czech Republic
|-
|[[Stellafane Observatory]]
|1920
|[[Springfield, Vermont]], US
|-bgcolor=#f58242
|[https://StellarVistaObservatory.org Stellar Vista Observatory]
|2019
|[[Kanab, Utah]], US
|-
|[https://stephensobservatory.org/ Stephens Memorial Observatory]
|1901
|[[Hiram, Ohio]], US
|-
|[[Steward Observatory]]
:*[[MMT Observatory]]
:*[[Mount Graham International Observatory]]
:*[[Mount Lemmon Observatory]]
|1916
|[[Tucson, Arizona]], US
|-
|[[Bennington College|Stickney Observatory]]<ref>{{Cite web|url=https://observatory.bennington.edu/|title=Stickney Observatory at Bennington College|website=Stickney Observatory at Bennington College}}</ref>
|1950s
|[[Bennington, Vermont]], US
|-
|[[Stjerneborg]]
|1581
|[[Hven]], Sweden
|-
|[[Stockholm Observatory]]
|1749
|[[Stockholm]], Sweden
|-
|[[Stokesville Observatory]]
|1970s
|[[Virginia]], US
|-
|[[Stone, Buckinghamshire|Stone Observatory]]
|1853
|[[Stone, Buckinghamshire]], UK
|-
|[[Stonyhurst Observatory]]
|1838
|[[Lancashire]], England
|-
|[[Observatory of Strasbourg|Strasbourg Observatory]]
|1881
|[[Strasbourg]], France
|-bgcolor=#00FFFF
||[[Stratospheric Observatory for Infrared Astronomy]]
|2006
|14&nbsp;km in Earth [[stratosphere]]
|-
|[[Stull Observatory]]
|1966
|[[Alfred (town), New York|Alfred, New York]], US
|-
|[[Stuttgart Observatory]]
|1920
|[[Stuttgart]], Germany
|-bgcolor=#00FF00
|[[Submillimeter Array]]
|1987
|[[Mauna Kea]], [[Hawaii]], US
|-
|[[St. Thomas Observatory]]
|2009
|[[Saint Paul, Minnesota]], US
|- bgcolor=#CCCCCC
|[[Space Variable Objects Monitor]]
|2004
|[[Low Earth orbit]]
|-bgcolor=#FFCC66
|[[Sudbury Neutrino Observatory]]
|1999
|[[Greater Sudbury|Sudbury]], [[Ontario]], Canada
|-
|[[Sunriver Observatory]]
|1990
|[[Sunriver, Oregon]], US
|- bgcolor=#CCCCCC
|[[Swift Gamma-Ray Burst Mission]]
|2004
|[[Low Earth orbit]]
|-
|[[Swiss Observatory Polychron and Astronomy]]
|2019
|[[Geneva]], Switzerland
|-
|[[Sydney Observatory]]
|1858
|[[Sydney]], Australia
|-
|[[Table Mountain Observatory]]
|
|[[Angeles National Forest]], [[Wrightwood, California]], US
|-
|[[Tacubaya Observatory]]
|1882
|[[Tacubaya]], [[Mexico City]], Mexico
|-bgcolor=#99CC99
|[[Taeduk Radio Astronomy Observatory]]
|1986
|[[Taejon]], South Korea
|-
|[[Tamke-Allan Observatory]]
|1998
|[[Roane County, Tennessee]], US
|-
|[[Tartu Observatory]]
|1964
|[[Tartumaa]], Estonia
|-
|[[Teide Observatory]]
|1964
|[[Tenerife]], [[Canary Islands]], Spain
|-
|[[Ten Acre Observatory]]
|
|[[Tribbey, OK|Tribbey, Oklahoma]], US
|-
|[[Terskol Peak Observatory]]
|1989
|Terskol, [[Kabardino-Balkaria]], Russia
|-
|[[Thai National Observatory]]
|2013
|[[Doi Inthanon National Park|Doi Inthanon]], [[Chiang Mai]], Thailand
|-
|[https://thedamobservatory.com The Dam Observatory]
|2017
|[[Heart Butte Dam|Lake Tschida]], [[North Dakota]], US
|-
|[[The Heights Observatory]]
|1989
|[[The Heights School (Australia)|The Heights School]], South Australia, Australia
|-
|[[Texas A&M Astronomical Observatory]]
|
|[[College Station, Texas]], US
|-
|[[Theodore Jacobsen Observatory]]
|1895
|[[Seattle, WA|Seattle, Washington]], US
|-
|[[Thompson Observatory]]
|1968
|[[Beloit, Wisconsin]], US
|-bgcolor=#FFCC00
|[[Tien Shan Astronomical Observatory]]
|
|[[Almaty]], Kazakhstan
|-
|[[Tuorla Observatory]]
|1952
|[[Piikkiö]], Finland
|-
|[[Trieste Observatory]]
|
|[[Trieste]], Italy
|-
|[[Troodos Observatory]]
|2023
|[[Agridia]], [[Troodos Mountains]], Cyprus
|-bgcolor=#CCCCCC
|[[Trottier Observatory]]
|2015
|[[Simon Fraser University]], [[Burnaby]], Canada
|-
|[[Turin Observatory]]
|1759
|[[Pino Torinese]], Italy
|-bgcolor=#FFFF99
|[[Udaipur Solar Observatory]]
|
|[[Udaipur]], Rajasthan, India
|-bgcolor=#99CC99
|[[Ukrainian T-shaped Radio telescope, second modification]]
|1972
|[[Shevchenkove, Shevchenkove Raion|Shevchenkove]], Ukraine
|-
|[[Ulugh Beg Observatory]]
|1420s
|[[Samarkand]], Uzbekistan
|-
|[[University of Alabama Observatory]]
|1950
|[[Tuscaloosa, Alabama]], US
|-
|[[Old University of Alabama Observatory|University of Alabama Observatory (Old)]]
|1849–1890s
|Tuscaloosa, Alabama, US
|-
|[[UNA Observatory|University of North Alabama Observatory]]
|
|[[Florence, Alabama]], US
|-
|[[University of Illinois Observatory|University of Illinois Astronomical Observatory]]
|1896
|[[Urbana, Illinois]], US
|-
|[[University of London Observatory]]
|1929
|London, England, UK
|-
|[[University of Maryland Observatory]]
|
|[[College Park, Maryland]], US
|-
|[[University of Michigan-Dearborn Observatory]]
|2007
|[[Dearborn, Michigan]], US
|-
|[[University of New Hampshire Observatory]]
|1985
|[[Durham, New Hampshire]], US
|-
|[[University of Oklahoma Observatory]]
|
|[[Norman, Oklahoma]], US
|-
|[[University of Puerto Rico at Humacao|University of Puerto Rico at Humacao Observatory]]<ref>{{Cite journal |last=Muller |first=R. J. |date=Summer 1994 |title=The Humacao University Observatory |url=http://adsabs.harvard.edu/full/1994IAPPP..56...43M |journal=International Amateur-Professional Photoelectric Photometry Communication |volume=56 |issue=43 |page=43 |bibcode=1994IAPPP..56...43M}}</ref>
|1985
|[[Humacao, Puerto Rico]], US
|-
|[[University of Valencia Astronomical Observatory]]
|1909
|[[Valencia]], Spain
|-
|[[Uppsala Astronomical Observatory]]
|1741
|[[Uppsala]], Sweden
|-
|[[Urania (Antwerp)]]
|
|[[Hove, Belgium]]
|-
|[[Urania (Berlin)]]
|
|Berlin, Germany
|-
|[[Urania (Vienna)]]
|1909
|[[Vienna]], Austria
|-
|[[Urania Observatory (Zürich)]]
|1907
|[[Zürich]], Switzerland
|-
|[[Uraniborg]]
|1572–1597 ''(demolished)''
|[[Hven]], Sweden
|-
|[[Urumqi Astronomical Observatory]]
|1957
|[[Urumqi]], [[Xinjiang]], China
|-
|[[United States Naval Observatory|U.S. Naval Observatory (USNO)]]<ref>{{Cite web|date=2016-08-15|title=Records of the U.S. Naval Observatory|url=https://www.archives.gov/research/guide-fed-records/groups/078.html|access-date=2021-04-14|website=National Archives|language=en}}</ref>
*[[United States Naval Observatory#History|Depot of Charts and Instruments (U.S. Navy) (precursor, renamed to USNO)]]
*[[United States Naval Observatory Flagstaff Station|U.S. Naval Observatory (Flagstaff Station)]]
|1844
*1830–1844
*1955
|[[Washington, D.C.]], US
*[[Washington, D.C.]], US
*[[Flagstaff, Arizona]], US
|-
|[[Valongo Observatory]]
|1881
|[[Rio de Janeiro]], Brazil
|-
|[[Vainu Bappu Observatory]]
|1968
|[[Kavalur]], [[Tamil Nadu]], India
|-
|Astronomical observatory of Aosta Valley
|2003
|[[Nus, Aosta Valley]], Italy
|-
|[[Van Vleck Observatory]]
|1914
|[[Middletown, Connecticut]], US
|-
|[[Vanderbilt University Observatory]]
|
|[[Nashville, Tennessee]], US
|-
|[[Vartiovuori Observatory]] ''(defunct)''
|1819–1834
|[[Turku]], Finland
|-
|[[Vassar College Observatory]] ''(defunct)''
|1865
|[[Poughkeepsie (town), New York|Poughkeepsie, New York]], US
|-
|[[Vatican Observatory]]
:*[[Vatican Advanced Technology Telescope]]
|1891
*1993
|Headquarters: [[Castel Gandolfo]], Italy
:*[[Mount Graham]], Arizona, US
|-
|[[Veen Observatory]]
|1970
|[[Lowell, Michigan]], US
|-
|[[Vega–Bray Observatory]]
|1990
|[[Benson, Arizona]], US
|-bgcolor=#99CC99
|[[Ventspils Starptautiskais Radioastronomijas Centrs]]
|
|[[Irbene]], Latvia
|-
|[[Vernonia Peak Observatory]]
|
|[[Vernonia, Oregon]], US
|-bgcolor=#99CC99
|[[Very Large Array]]
|1980
|[[Socorro, New Mexico]], US
|-bgcolor=#99CC99
|[[Very Long Baseline Array]]
|1993
|Various locations on Earth
|-
|[[Vienna Observatory]]
|1753
|[[Vienna]], Austria
|-
|[[Vilnius University Observatory]]
|1753
|[[Vilnius University]], Lithuania
|-
|[[Višnjan Observatory]]
|1978
|[[Višnjan]], Croatia
|-
|[[Observatory Vsetín|Vsetín Observatory]]
|1950
|[[Vsetín]], Czech Republic
|-bgcolor=#99CC99
|[[Warkworth Radio Observatory]]
|2008
|[[Warkworth, New Zealand]]
|-
|[[Warner Observatory]] ''(defunct)''
|1882
|[[Rochester, New York|Rochester]], [[New York (state)|New York]], US
|-
|[[Warner and Swasey Observatory]]
|1919
|[[Cleveland]], Ohio, US
|-
|[[Warren Rupp Observatory]]
|1985
|[[Mansfield, Ohio]], US
|-
|[[University of Warsaw Observatory]]
|1825
|[[Warsaw]], Poland
|-
|[[Washburn Observatory]]
|1881
|[[Madison, Wisconsin]], US
|-
|[[Wast Hills Observatory]]
|1982
|[[Birmingham]], England, UK
|-
|[[Weaver Student Observatory]]
|1998
|[[Monterey, California]], US
|-
|[[Weitkamp Observatory]]
|1955
|[[Westerville, Ohio]], US
|-
|[[West Mountain Observatory]]
|1981
|[[West Mountain (Utah)|West Mountain, Utah]], US
|-
|[[Whakatane Astronomical Society]]
|1964
|[[Whakatāne]], New Zealand
|-
|[[Whitin Observatory]]
|1901
|[[Wellesley, Massachusetts]], US
|-
|[[Widener University Observatory]]
|2004
|[[Chester, Pennsylvania]], US
|-
|[[Wilder Observatory]]
|1903
|[[Amherst, Massachusetts]], US
|-
|[[Willard L. Eccles Observatory]]
|2009
|[[Frisco Peak]], [[Utah]], US
|-
|[[William Brydone Jack Observatory]]
|1851
|[[Fredericton]], [[New Brunswick]], Canada
|-
|[[Williams Observatory]]
|1990
|[[Boiling Springs, North Carolina]], US
|-
|[[Winer Observatory]]
|1983
|[[Sonoita, Arizona]], US
|-
|[[Winfree Observatory]]
|1900
|[[Lynchburg, Virginia]], US
|-
|[[Wise Observatory]]
|1971
|[[Negev]], Israel
|-
|[[Witte Observatory]]
|1984
|[[Mediapolis, Iowa]], US
|-
|[[WIYN Observatory]]
|1994
|[[Kitt Peak]], Arizona, US
|-
|[[Wyoming Infrared Observatory]]
|1975
|[[Laramie, Wyoming]], US
|-
|[[Xiangfen Astronomical Observatory]]
|data-sort-value="-2100"|2100 BCE
|[[Xiangfen County]], [[Linfen]], [[Shanxi]] Province, China
|-
|[[Xinglong Station (NAOC)]]
|
|[[Xinglong County]], [[Chengde]], [[Hebei]] province, China<ref>{{cite web|url=http://english.nao.cas.cn/resources/gallery/202103/t20210321_266312.html|date=2021-03-21|title=Xinglong Observing Station|archive-url=https://web.archive.org/web/20230123094650/http://english.nao.cas.cn/resources/gallery/202103/t20210321_266312.html|archive-date=2023-01-23}}</ref>
|-
|[[Xinjiang Astronomical Observatory]]
|1968
|[[Urumqi]], [[Xinjiang]], China
|-bgcolor=#CCCCCC
|[[XMM-Newton]]
|1999
|Highly eccentric [[Geocentric orbit|Earth orbit]]
|-bgcolor=#CCCCCC
|[[XRISM]]
|2023
|[[Geocentric orbit|Earth orbit]]
|-bgcolor=#CCCCCC
|[[XPoSat]]
|2024
|[[Geocentric orbit|Earth orbit]]
|-
|[[Xujiahui Astronomical Observatory]]
|1872
|[[Shanghai]], China
|-bgcolor=#FFCC00
|[[Arctic Space Weather Center]]
|
|[[Yakutsk]], Russia
|-
|[[Yale Student Observatory]]
|
|[[New Haven, Connecticut]], US
|-bgcolor=#FFCC00
|[[Yangbajing International Cosmic-Ray Observatory]]
|
|[[Yangbajing]] Valley, [[Tibet Autonomous Region|Tibet]], China
|-
|[[Yantra Mandir (Delhi)|Yantra Mandir]]
|1724
|[[New Delhi]], [[Delhi]], India
|-bgcolor=#FFCC00
|[[Yerevan Cosmic-Ray Station]]
|
|[[Yerevan]], Armenia
|-
|[[Yerkes Observatory]]
|1897
|[[Williams Bay, Wisconsin]], US
|-
|[[York University Observatory]]
|1969
|[[Toronto]], [[Ontario]], Canada
|-
|[[Yuba City Astronomical Observatory]]
|2010
|[[Yuba City, California]], US
|-
|[[Yunnan Astronomical Observatory]]
|1957
|[[Kunming]], [[Yunnan]], China
|-
|[[Zimmerwald Observatory]]
|1956
|[[Zimmerwald]], Switzerland
|-
|[[Zadko Observatory]]
|2009
|[[Gingin, Western Australia|Gingin]], Australia
|}

== See also ==
{{div col|colwidth=30em}}
* [[Lists of telescopes]]
* [[:Category:Astronomical observatories by country]]
* [[History of the telescope]]
* [[List of astronomical instrument makers]]
* [[List of highest astronomical observatories]]
* [[List of largest optical reflecting telescopes]]
* [[List of largest optical refracting telescopes]]
* [[List of observatory codes]]
* [[List of planetariums]]
* [[List of radio telescopes]]
* [[List of telescope types]]
* [[Science tourism]]
* [[Space observatory]]
* [[Timeline of telescopes, observatories, and observing technology]]
{{div col end}}

== References ==
{{Reflist}}

== External links ==
* [http://www.astro.uni-bonn.de/~pbrosche/hist_astr/ha_obs.html History of Astronomy: Observatories and other places]
* [http://cleardarksky.com/cgi-bin/find_clock.py?keys=%22%5C%28observatoire%5C%7Cobservatory%5C%7Cobservatories%5C%29%22&type=text&doit=Find Observatories with Clear Sky Clocks]
* [https://gostargazing.co.uk/observatories-in-the-uk/ Map of observatories in the United Kingdom]

{{DEFAULTSORT:List Of Astronomical Observatories}}
[[Category:Astronomical observatories|*]]
[[Category:Lists of buildings and structures|Observatories]]
[[Category:Astronomy-related lists|Observatories]]