| Hankasalmi Observatory.jpg | Arto Oksanen | CC BY-SA 3.0 |
| Hanle observatory.jpg | Alin Dev | Public domain |
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| Hans-Nüchter-Sternwarte Luftaufnahme 02.jpg | Jan-Gode Pösnecker | CC BY-SA 4.0 |
| Harquahala Peak Solar Observatory, La Paz County, Arizona.jpg | Stephen M.Richard | CC BY-SA 4.0 |
| Hartung-Boothroyd Observatory, Ithaca, NY (June 8 2004).jpg | Richard C.S. "Doc" Kinne | CC BY-SA 2.5 |
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| Haterumajima Observatory Tower.jpg | Yasu ( talk ) | CC BY-SA 3.0 |
| Hauraki suburb, 1992.jpg | Unknown | CC BY 4.0 |
| Hawaiian Volcano Observatory, Hawaiʻi Volcanoes National Park, Hawaii (4528702285).jpg | Ken Lund from Reno, Nevada, USA | CC BY-SA 2.0 |
| HAWC from LMT Aug 19 2014 01.jpg | Jordanagoodman | CC BY-SA 4.0 |
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| HelwanJapGardenBuddhas.jpg | Roland Unger | CC BY-SA 3.0 |
| HerefordArizonaObservatory-HAO1&2-BruceGary-20100724.jpg | Bruce L. Gary | CC0 |
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| Herschel Space Observatory.jpg | NASA | Public domain |
| HESS II gamma ray experiment five telescope array.jpg | Klepser , DESY, H.E.S.S. collaboration | CC BY-SA 3.0 |
| HET Dome.jpg | Unknown author | CC BY-SA 3.0 |
| HevzdarenVartovkaBanskaBystrica.jpg | Matej Grochal | CC BY-SA 4.0 |
| Hiddensee-overview2.jpg | Sebastian Negraszus | CC BY-SA 3.0 |
| Higginson Tower - 01.jpg | Cantons-de-l'Est | CC BY-SA 4.0 |
| Himalayan chandra telescope.jpg | Harikrishnank123 | CC BY-SA 3.0 |
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| Hisaki-sprint-a-artistconcept2013.png | Nesnad | CC BY-SA 3.0 |
| HK experiment overview.jpg | Jan Kisiel (Silesia U.) for the Hyper-Kamiokande collaboration | CC BY 4.0 |
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| Holcomb Observatory and Planetarium 2012.jpg | Richie Diesterheft | CC BY-SA 2.0 |
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| Horn Antenna-in Holmdel, New Jersey.jpeg | NASA | Public domain |
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| Hubble 2009 close-up.jpg | NASA | Public domain |
| Hunyadi János utca 23-25., az Érseki Főgimnázium (ma Szent István Gimnázium) tetején a Haynald-Obszervatórium (Csillagda) kupolái a meteorológiai megfigyelő állomástól nézve. Fortepan 100304.jpg | FOTO:Fortepan — ID 100304 : Adományozó/Donor: Jezsuita Levéltár. archive copy at the Wayb… | CC BY-SA 3.0 |
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| HXMT rendering.jpg | Institute of High Energy Physics, Chinese Academy of Sciences | CC BY 4.0 |
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| In-construction KAGRA gravitational-wave detector.jpg | Christopher Berry | CC BY-SA 4.0 |
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| Interior view of dome and TAO refractor telescope, used for hand-on viewing at Stargazes and classes.jpg | Fieldsde | Public domain |
| International Axion Observatory logo.jpg | Deadeater.42 | CC0 |
| Intérieur du Préau des Accoules.jpg | MGHX | CC BY-SA 4.0 |
| IRAM 30m Sierra Nevada - sky.jpg | JuanJaén | CC BY-SA 2.0 |
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| Isaac Newton Telescope, La Palma, Spain.jpg | The original uploader was Worldtraveller at English Wikipedia . | CC BY-SA 3.0 |
| Isaac Roberts's observatory.jpg | Unknown | Public domain |
| Ishigaki tenmondai.jpg | Paipateroma | CC BY-SA 3.0 |
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| Iso-Heikkilan tahtitorni talvi.jpg | Unknown author | CC BY 2.5 |
| IstanbulUniversityObservatory03.JPG | CeeGee | CC BY-SA 4.0 |
| IUE 2.jpg | NASA | Public domain |
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| Jagiellonian University, Astronomical Observatory, Radio telescope RT-8, 171 Orla street, Krakow, Poland.jpg | Radoslaw Ziomber | CC BY-SA 3.0 |
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| James Cook Observatory Front View.jpg | Angusb111 | CC BY-SA 4.0 |
| James Cox - Spyglass - 2009.24 - Cleveland Museum of Art.tif | James Cox | CC0 |
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| Jena Volkssternwarte Urania.jpg | Reise Reise | CC BY-SA 4.0 |
| Jennifer Chalsty Planetarium.jpg | Tzim78 | CC BY 4.0 |
| Jerusaelm Birdswatch Center1.jpg | User:Ranbar | CC BY-SA 3.0 |
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| Jiufeng Seismic Station (20170906131245).jpg | N509FZ | CC BY-SA 4.0 |
| JKSW.jpg | Johann-Kern-Sternwarte Wertheim e.V. | Attribution |
| Jodrell Bank 42ft telescope.jpg | Mike Peel ; Jodrell Bank Centre for Astrophysics, University of Manchester. | CC BY-SA 4.0 |
| Jodrell Bank Mark II 5.jpg | Mike Peel ; Jodrell Bank Centre for Astrophysics, University of Manchester Michael Peel | CC BY-SA 4.0 |
| Johannes Kepler Observatory Linz.jpg | H. Raab ( User:Vesta ) | CC BY-SA 4.0 |
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| Kalyazin 64-m dish ESA382896.jpg | European Space Agency | CC BY-SA 3.0 igo |
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| KeckTelescopes-hi.png | T. Wynne / JPL | Public domain |
| Kennon Observatory.jpg | Brandonrush ( talk ) | Public domain |
| Kepler EQ.svg | Fred the Oyster | CC BY-SA 4.0 |
| Kepler Space Telescope spacecraft model 2.png | NASA | Public domain |
| Kepler-Schul Graz observatory.jpg | MartinOrSomething | CC BY-SA 3.0 |
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| Kharkiv Observatory, Main Building.jpg | Oleksiy.golubov | CC BY-SA 4.0 |
| Khureltogoot.jpg | https://www.flickr.com/photos/tengis/ | CC BY 2.0 |
| Kielder Observatory - geograph.org.uk - 1219650.jpg | Phil Thirkell | CC BY-SA 2.0 |
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| Kinnordy, Kirriemuir (geograph 3063483).jpg | M J Richardson | CC BY-SA 2.0 |
| KirkwoodObservatory.jpg | Durin at English Wikipedia | CC BY-SA 3.0 |
| Kiss György Csillagda.jpg | Szenasi | CC BY-SA 4.0 |
| Kitt Peak (7554295742).jpg | Jeremy Keith from Brighton & Hove, United Kingdom | CC BY 2.0 |
| Kitt Peak National Observatory in the Quinlan Mountains, 2023.jpg | KPNO/NOIRLab/NSF/AURA/T. Slovinský | CC BY 4.0 |
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| Kiwanis Chico Community ObservatoryB.jpg | Derek Curry | CC BY-SA 2.0 |
| KL tower1.JPG | Formulax | CC BY-SA 2.0 |
| Knockin Radio Telescope - geograph.org.uk - 1627663.jpg | Hans Linnet | CC BY-SA 2.0 |
| Kodaikanal Solar Observatory-a.jpg | Marcus334 at English Wikipedia ( Original text: Indian Institute of Astrophysics ) | CC BY 2.5 |
| Kokudochiriin.jpg | 麒麟坊 | CC BY-SA 3.0 |
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| KorpusAO KM8.jpg | Igoressen | CC BY-SA 4.0 |
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| KPPO LOGO 4.jpg | Brucewaters | CC BY-SA 4.0 |
| Kremsmünster Stift Sternwarte-8993.jpg | Isiwal | CC BY-SA 4.0 |
| Kroller-sternwarte.jpg | Karl Hofstetter / Karl Hofstetter | CC BY-SA 3.0 |
| Kryzhanivka observatory.jpg | Minami Himemiya | CC BY-SA 2.5 |
| Kuala-Lumpur Malaysia Planetarium Negara-03.jpg | CEphoto, Uwe Aranas | CC BY-SA 3.0 |
| Kuffner Observatory Vienna.jpg | H. Raab ( User:Vesta ) | CC BY-SA 3.0 |
| Kumamoto Tsukawara Ancient Tomb Park 09.JPG | hyolee2 | CC BY-SA 3.0 |
| Kuppel der Sternwarte Singen.jpg | DerSiggiReal | CC BY-SA 3.0 |
| Kurashiki Observatory.jpg | あかしょうびん | CC BY-SA 4.0 |
| Kvant-1 (1995-02-06) cropped.jpg | NASA | Public domain |
| Kvistabergs observatorium.jpg | Annika Peterson. | CC BY-SA 4.0 |
| Könyves Kálmán High School 05.JPG | VinceB | CC BY-SA 3.0 |
| L'antico osservatorio astronomico di Brera a Milano.jpg | Paolobon140 | CC BY-SA 4.0 |
| L'observatoire astronomique de Strasbourg (41534417322).jpg | Valentin R. from France | CC0 |
| L'observatoire Copernic dans la province de Namur, près de Dinant, en 2020..jpg | Michaël Bemelmans | CC BY-SA 4.0 |
| La Posta Observatory.jpg | Unknown author | Public domain |
| La Silla Aerial View.jpg | ESO/C.Madsen | CC BY 4.0 |
| La Specola - Padua.jpg | Jiří Dobrý | CC BY-SA 4.0 |
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| La zizzola d'inverno.JPG | Valeria Baldelli | CC BY-SA 3.0 |
| Lab Infiernillo.jpg | Jhuenante | CC BY-SA 4.0 |
| Lac des Pises - Observatoire astronomique.jpg | GrandCelinien | CC BY-SA 3.0 |
| Ladd Observatory crop.jpg | Ladd Observatory | CC BY-SA 3.0 |
| Lagrange mission ESA414888.png | European Space Agency | CC BY-SA 3.0 igo |
| LAMOST telescope org.jpg | Paul Hilscher | CC BY-SA 3.0 |
| Land's End Observatory, July 2012.jpg | Paj60wiki | CC BY-SA 3.0 |
| Landsort Bird Observatory at Öja, April 2009.jpg | Calandrella | CC0 |
| Large 1911 0277.jpg | Unknown author | CC BY 4.0 |
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| Large SMG00084935.jpg | National Maritime Museum | CC BY 4.0 |
| Large Synoptic Survey Telescope 3 4 render 2013.png | LSST Project Office | CC BY-SA 4.0 |
| LargeBinoTelescope NASA½.jpg | Mohamed Osama AlNagdy, 2010-12-13 | Copyrighted free use |
| LasCampanasObservatory.jpg | Cédric Foellmi | CC BY 2.5 |
| LAT SO.jpg | Flucerod | CC BY-SA 4.0 |
| LATMOS LHASTEC - 013.jpg | X-Javier | CC BY-SA 4.0 |
| Lazkuako behatokia1.jpg | Xirkan | CC BY-SA 4.0 |
| LBT Pinaleno Mountains.40936.JPG | Wars | CC BY-SA 3.0 |
| LCS Node 20110823 018.jpg | John Martinez | CC0 |
| LDEO Comer Building.jpg | Ronnie Anderson, LDEO Original uploader was Kkostel at en.wikipedia | GFDL |
| Le marégraphe de Marseille en venant du David.jpg | XDurang | CC BY-SA 4.0 |
| Leander McCormick Observatory.jpg | Rob | CC BY 2.0 |
| Ledeč nad Sázavou, observatory.jpg | Pavel Hrdlička (Czech Wikipedia user Packa ) | CC BY-SA 4.0 |
| Leitner observatory.jpg | Namkota | CC BY-SA 4.0 |
| Lick Observatory Refractor.jpg | myyorgda | CC BY 2.0 |
| Lick-Refraktor 3130169128.jpg | Michael from San Jose, California, USA | CC BY 2.0 |
| Lilienthaler Sternwarte.jpg | Unknown author Unknown author | Public domain |
| Lille observatoire face.jpg | Velvet | CC BY-SA 4.0 |
| Lindheimer Observatory Northwestern Univ 10.jpg | WikiPedant | CC BY-SA 4.0 |
| LISA-waves.jpg | NASA | Public domain |
| Litchfield observatory, by Seward, H. W. (H. Walton), d. 1871.jpg | Seward, H. W. (H. Walton), d. 1871 -- Photographer | Public domain |
| Litoměřice, Jezuitská hvězdárna.jpg | Stanislav Dusík | CC BY-SA 4.0 |
| Liverpool Telescope facility exterior.jpg | Elme | CC BY-SA 2.0 |
| LLAMA Gorund Zero.jpg | Guigue | CC BY-SA 3.0 |
| LNA - Telescópio IAG 0,6 m - panoramio.jpg | b.lastorina | CC BY-SA 3.0 |
| Lofar onsala 20110706.jpg | Onsala rymdobservatorium/Leif Helldner | CC BY-SA 3.0 |
| LOFAR Superterp.jpg | LOFAR / ASTRON | CC BY 3.0 |
| LoianoAstronomicalObservatory60cm.png | Vasile C. | Public domain |
| Longitudinal section of the LBNE Beamline facility in the MI-10, Shallow beamline configuration.png | V. Papadimitriou, R. Andrews, M. Campbell, A. Chen, S. Childress, C. D. Moore, Fermilab,… | CC BY 3.0 |
| Loomis 2.jpg | SilentMatt Psychedelic | CC BY-SA 4.0 |
| Lossy-page1-6940px-Lord Rosse's Great Reflecting Telescope, at Parsonstown, Ireland RMG F8661 (cropped).jpg | Working Men's Educational Union | Public domain |
| Lovell Telescope (5417).jpg | Nilfanion | CC BY-SA 4.0 |
| Lovell Telescope 5.jpg | Mike Peel ; Jodrell Bank Centre for Astrophysics, University of Manchester | CC BY-SA 4.0 |
| Lovell Telescope.jpg | Mike Peel ; Jodrell Bank Centre for Astrophysics, University of Manchester | CC BY-SA 4.0 |
| Lowell Observatory NRIS-66000172-Pluto Astrograph2-Flagstaff Arizona.jpg | Packbj | CC BY-SA 4.0 |
| LSW-Heidelberg.jpg | Mhdman at English Wikipedia | CC BY-SA 3.0 |
| Lubomir Astronomical Observatory (19).jpg | Rafał M. Socha (Azymut) | CC BY-SA 4.0 |
| Lulin Observatory interior.jpg | LiCheng Shih | CC BY 2.0 |
| Lundsobserv.jpg | Popperipopp | Public domain |
| Lustbühel Observatory.jpg | H. Raab ( User:Vesta ) | CC BY-SA 4.0 |
| LUVOIR-A transparent.png | NASA/GSFC | Public domain |
| LUVOIR-B transparent.png | NASA/GSFC | Public domain |
| LWA logo.png | Long Wavelength Array consortium | CC BY-SA 4.0 |
| Lynx X-ray observatory.jpg | NASA | Public domain |
| Macalester College Observatory.jpg | McGhiever | CC BY-SA 4.0 |
| Madhava Observatory at Calicut University.jpg | Navaneeth Krishnan S | CC BY-SA 3.0 |
| Madras Observatory 1880.jpg | ru:Погсон, Норман Роберт | Public domain |
| Magdalena Observatory.JPG | Astarre | CC BY-SA 3.0 |
| Magellan-Telescopes-at-LCO-2014-04-19.jpg | Jan Skowron | CC BY-SA 3.0 |
| MAGIC Telescope - La Palma.JPG | Raedts | CC BY-SA 3.0 |
| Mailhat.jpg | Diego Giraudi | CC BY-SA 3.0 |
| Main building of Royal Observatory, Cape of Good Hope.jpg | Janus Brink | CC0 |
| Manilaobservatryjf2024 09.JPG | Ramon FVelasquez | CC BY-SA 3.0 |
| Mannheim Sternwarte 20100809.jpg | Rudolf Stricker | Attribution |
| Maquete satellite MVL-300 (Mikhailo Lomonosov) DSC 0071.JPG | Pline | CC BY-SA 4.0 |
| Maquette de Gaia salon du Bourget 2013 DSC 0191.JPG | Pline | CC BY-SA 3.0 |
| Maragheh observatory1.jpg | aydin tabrizi | CC BY-SA 4.0 |
| MariaMitchellObservatory NantucketMA.jpg | Versageek | CC BY-SA 3.0 |
| Marko Mount John Observatory New Zealand.jpg | Mark Oliver Dittrich. Released into public domain on his behalf. | Public domain |
| Markree-castle-by-night-2.jpeg | The original uploader was Suckindiesel at English Wikipedia . | CC BY-SA 2.0 |
| Matsushiro Seismological Observatory major tunnel entrance 1.jpg | photo: Qurren ( talk ) Taken with Canon IXY 10S (Digital IXUS 210) | CC BY-SA 3.0 |
| Mauna Kea Summit 2021-06-16 33 (cropped).jpg | Leijurv | CC BY-SA 4.0 |
| Mauna Loa Solar Observatory.jpg | University Corporation for Atmospheric Research | Public domain |
| MaunaKea Subaru.jpg | Denys (fr) | CC BY 3.0 |
| MAXIMA Balloon.jpg | The original uploader was Sheliak at English Wikipedia . | CC BY 2.5 |
| McDonald Observatory.jpg | Jason Quinn | Public domain |
| McKim Observatory, western side.jpg | Nyttend | Public domain |
| MDM Hiltner Telescope.jpg | BorkaGoose at English Wikipedia | Public domain |
| MDM McGraw Hill Telescope.jpg | BorkaGoose at English Wikipedia | Public domain |
| Medienkuppel planetarium mallorca.jpg | Danyel André | CC BY-SA 3.0 de |
| Medium SMG00030462.jpg | Science Museum Photo Studio | CC BY-SA 4.0 |
| Medium SMG00030657.jpg | Science Museum Photo Studio | CC BY-SA 4.0 |
| Medium SMG00043907.jpg | Wellcome Collection | CC BY 4.0 |
| Medium SMG00043908.jpg | Mr Thomas H. Court | CC BY 4.0 |
| MeerKAT prototype dish in 2014-2.jpg | Photograph by Mike Peel ( www.mikepeel.net ). | CC BY-SA 4.0 |
| Meet Pandora, NASA’s Newest Exoplanet Explorer (SVS14747 - Pandora Still 1 0000 Ultra).png | NASA's Scientific Visualization Studio - University of Maryland College Park/Francis Redd… | Public domain |
| Menara as.jpg | Johnsonooijunsheng at English Wikipedia | CC BY-SA 3.0 |
| Mercator telescope.jpg | Johannes Z Wolff | Public domain |
| Meteorological instruments on Milešovka 2021-11-06 01.jpg | Jana Plavec | CC BY-SA 4.0 |
| Meteorologisches Observatorium Lindenberg.jpg | André Knöfel | CC BY-SA 3.0 |
| MetsahoviRadioObservatory 2009 12.jpg | Jan Wagner | CC BY-SA 3.0 |
| Meudon Observatory (3559558087) (cropped).jpg | Jean-Marc Astesana from Voisins le Bretonneux, France | CC BY-SA 2.0 |
| Michigan State University Observatory (1888).webp | Anonymous Unknown author | CC BY-SA 4.0 |
| Michigan State University Observatory 1273.jpg | Paul R. Burley | CC BY-SA 4.0 |
| MicroObservatory Donald.jpg | CTIO/NOIRLab/NSF/AURA | CC BY 4.0 |
| Mikulášovice čp. 1002 01.jpg | Gumideck | CC BY-SA 4.0 |
| Mill hill observatory 2009.JPG | Grim23 ( talk ) | CC BY-SA 3.0 |
| Mills Cross, Fleurs 002.png | CSIRO | CC BY 4.0 |
| Millsobservtwo.jpg | Cyrillic at English Wikipedia | CC BY-SA 3.0 |
| Millstone Hill Radar - Haystack Observatory - DSC04017.JPG | Daderot | CC0 |
| Millstone Hill Radar - Haystack Observatory - DSC04019.JPG | Daderot | CC0 |
| Milmaru Observatory Tower.jpg | Minseong Kim | CC BY-SA 4.0 |
| Milwaukee Astronomical Society Observatory Grounds - August, 2021.jpg | Milwaukeeastronomer | CC BY-SA 4.0 |
| MINERvA Neutrino Detector 2011.jpg | KeysPhotography.com | CC BY-SA 4.0 |
| Mir-27.jpg | NASA | Public domain |
| Mitzpe Revivim - Revivim 3.jpg | Danny Gershoni | CC BY-SA 4.0 |
| MLO-1-npaci.jpg | Streltzer at en.wikipedia | Public domain |
| MMT Observatory.jpg | Pyronordicman | CC BY-SA 4.0 |
| Model of the Planck Satellite.jpg | Photograph by Mike Peel ( www.mikepeel.net ). | CC BY-SA 4.0 |
| Modine-Benstead-Observatory.jpg | Tiraehd | CC BY-SA 4.0 |
| Molata de Casa Vieja.JPG | Martingala | CC BY-SA 3.0 |
| Molonglotele.jpg | No machine-readable author provided. Rnt20 assumed (based on copyright claims). | CC BY-SA 3.0 |
| Molėtai Astronomical Observatory.JPG | MindaugasMacijauskas at English Wikipedia | Public domain |
| MonoCraters LongValley.gif | USGS | Public domain |
| Mont d'Arbois Astronomie observatory, Saint-Gervais-les-Bains, 2025.jpg | DimiTalen | CC0 |
| Montpellier - Tour de la Babote.jpg | Christophe.Finot | CC BY-SA 2.5 |
| Montpellier jardin plantes2.jpg | The original uploader was Vpe at French Wikipedia . | CC BY-SA 2.0 fr |
| Montserrat Volcano Observatory.jpg | David Stanley from Nanaimo, Canada | CC BY 2.0 |
| Moscow observatory 1900.jpg | Unknown author Unknown author | Public domain |
| MosOblast Schyolkovo District radio telescope 08-2016.jpg | A.Savin | FAL |
| Mount Abu Observatory.JPG | CorrectKnowledge | CC BY-SA 3.0 |
| Mount Cuba Astronomical Observatory.jpg | Paulo Henrique Silva de Santana | CC BY 2.0 |
| Mount Hopkins Santa Rita Mountains AZ USA.10247.jpg | Wars | CC BY-SA 3.0 |
| Mount Pleasant Radio Telescope.jpg | Noodle snacks | CC BY-SA 3.0 |
| Mount Stony Brook Observatory - ground view.jpg | ComplexRational | CC BY-SA 4.0 |
| MSE on Maunakea at sunset.png | Doug Simons, Executive Director, CFHT | CC BY-SA 4.0 |
| Mt Stromlo Obs2.jpg | Unknown author | CC BY-SA 3.0 |
| Mukai Chiaki Children's Science Museum.jpg | photo: Qurren ( talk ) Taken with Canon IXY 430F (Digital IXUS 245 HS) | CC BY-SA 3.0 |
| Museum of Space Sendai.jpg | Sakoppi | CC BY-SA 4.0 |
| Mårtsboobservatoriet.jpg | Igbal | CC BY-SA 4.0 |
| München Universitätssternwarte.JPG | Unknown author | CC BY-SA 3.0 |
| Münster, Gievenbeck, Alte Sternwarte -- 2020 -- 0729.jpg | Dietmar Rabich | CC BY-SA 4.0 |
| Nakajima Park Sapporo14n4272.jpg | 663highland | CC BY 2.5 |
| Nancay radiotelescope miroir primaire.jpg | No machine-readable author provided. Nguyenld assumed (based on copyright claims). | CC BY-SA 3.0 |
| Nanten2.jpg | Matthew Petroff | CC BY-SA 4.0 |
| Nançay Décamétrique.jpg | Denys | CC BY-SA 3.0 |
| Nançay Observatory D.jpg | Wouter Hagens | CC BY-SA 4.0 |
| NAOJ mitaka.jpg | Osamu Iwasaki from Tokyo, Japan | CC BY-SA 2.0 |
| NAOP.jpg | Unknown author | CC BY-SA 3.0 |
| NASA C-141A KAO.jpg | NASA http://vathena.arc.nasa.gov/curric/space/lfs/kao_abov.jpg | Public domain |
| NASA DFRC Lear 24 in flight.jpg | Jim Ross | Public domain |
| NASA SOHO spacecraft.png | Cgruda | Public domain |
| National Bolivian Observatory 1.jpg | S. Korotkiy | CC BY-SA 3.0 |
| National Observatory of Llano del Hato.jpg | Juan Tello | CC BY 2.0 |
| National Solar Observatory, Sacramento Peak, New Mexico.jpg | Flickr user: Jöshua Barnett https://www.flickr.com/people/angel_malachite/ | CC BY 2.0 |
| Nauchny and CrAO-Crimea Ukraine.jpg | Kirx at English Wikipedia | CC BY-SA 3.0 |
| Naval Observatory LOC npcc.00094.jpg | National Photo Company Collection | Public domain |
| Neschwitz Bird Observatory.jpg | Conny | CC BY-SA 3.0 |
| Neuchâtel, observatoire 4.JPG | Elleka | CC BY-SA 3.0 |
| Neue Sternwarte am Hausberg 2.jpg | Michael Burgholzer | CC BY-SA 4.0 |
| Neufang-Sternwarte.jpg | Störfix | CC BY-SA 3.0 de |
| NEVOD.jpg | Brateevsky | CC BY-SA 3.0 |
| New Horizons LORRI.jpg | Unknown author Unknown author | Public domain |
| New Keeble Observatory from NE.jpg | Hungrydog55 | CC BY-SA 4.0 |
| New Plymouth Observatory, New Plymouth, Nueva Zelanda - panoramio.jpg | Nelson Pérez | CC BY-SA 3.0 |
| New view UVEX3.png | Unknown author Unknown author | Public domain |
| Niac2020 bandyopadhyay.jpg | Saptarshi Bandyopadhyay | Public domain |
| NICER graphic still (plain).png | NASA/Goddard Space Flight Center Conceptual Image Lab | Public domain |
| Nichihara Observatory.jpg | Srats | CC BY-SA 3.0 |
| Night time observations using the MACE Telescope.jpg | Press Information Bureau (PIB) | GODL-India |
| Nishimino Observatory.JPG | Alpsdake | CC BY-SA 4.0 |
| NizamiaObservatory2.jpg | Sriharsha | CC BY-SA 2.0 |
| NOAA - Alert observatory.jpg | National Oceanic & Atmospheric Administration | Public domain |
| Nobeyama radio observatory 2009.jpg | Wiiii | CC BY-SA 3.0 |
| Nobeyama Radio Observatory 45-m Telescope.jpg | 03 at Japanese Wikipedia | CC BY-SA 3.0 |
| Nobeyama Radio Polarimeters.jpg | 03 at Japanese Wikipedia | CC BY-SA 3.0 |
| Nobeyama Radioheliograph.jpg | 03 at Japanese Wikipedia | CC BY-SA 3.0 |
| Norikura Solar Observatory、乗鞍コロナ観測所、8128356.JPG | 松岡明芳 | CC BY 3.0 |
| Norman Lockyer Observatory 228.jpg | Paul Lang | CC BY-SA 3.0 |
| Northern Ireland - Armagh Observatory College Hill Armagh - 20220623113653.jpg | Csyogi | CC BY-SA 4.0 |
| Northern leg of LIGO interferometer on Hanford Reservation.JPG | Umptanum | CC BY-SA 3.0 |
| Northumberland Astronomical Society.jpg | Simon Cobb | CC0 |
| Not telescope sunset 2001.jpg | Bob Tubbs | Public domain |
| NuSTAR spacecraft model.png | NASA/JPL-Caltech | Public domain |
| Ny-Alesund Airport 6.JPG | Superchilum | CC BY-SA 3.0 |
| Nyrölä Observatory.JPG | Antti Leppänen | CC BY-SA 3.0 |
| NZ160315 Milford Sound 09.jpg | Oren Rozen | CC BY-SA 3.0 |
| O'Brien Observatory.jpg | Cass0114 | CC BY-SA 3.0 |
| OADM dron.jpg | Pgiloadm | CC BY-SA 4.0 |
| OAN40mRT.jpg | Pancho-san | CC BY 2.5 |
| Oanton.jpg | Gsrdzl | Public domain |
| OAO-B.jpg | NASA | Public domain |
| Obs 1.jpg | Besnier.m | CC BY 2.5 |
| Obs-Paris-coupole-Arago.jpg | Unknown author | CC BY-SA 3.0 |
| Observatoire - Grenoble.JPG | Milky | FAL |
| Observatoire - Juvisy-sur-Orge (FR91) - 2025-10-11 - 6.jpg | Chabe01 | CC BY-SA 4.0 |
| Observatoire 00606.JPG | G.Garitan | CC BY 3.0 |
| Observatoire astronomique d'Aniane.jpg | Lothur | CC BY-SA 3.0 |
| Observatoire Astronomique de Mont-Soleil.jpg | Green slash | CC BY-SA 3.0 |
| Observatoire besancon 2011.jpg | Euldulle | CC BY-SA 4.0 |
| Observatoire de Cointe+reflet-080408.jpg | Xofc | CC BY 3.0 |
| Observatoire de Genève - Panorama 4.JPG | Adrien Coffinet, dit SenseiAC | CC BY-SA 3.0 |
| Observatoire de l'Abbé Moreux.jpg | Faboss29 | CC BY-SA 3.0 |
| Observatoire de l'Espace du Cnes.jpg | Philaz Fogue | CC BY-SA 4.0 |
| Observatoire de la Capitale 13.JPG | Jeangagnon | CC BY-SA 3.0 |
| Observatoire de la Sorbonne, Paris 2014.jpg | Dennis G. Jarvis | CC BY-SA 2.0 |
| Observatoire de Nice.jpg | ClaireL28 | CC BY-SA 3.0 |
| Observatoire de Paris 2, 14 July 2012 (2).jpg | Sylvain Naudin from La Riche | CC BY-SA 2.0 |
| Observatoire de Toulouse.jpg | Didier Descouens | CC BY-SA 3.0 |
| Observatoire des Baronnies provençales.jpg | Romain Bousson | CC BY-SA 4.0 |
| Observatoire du Cégep de Trois-Rivières 01.JPG | Fralambert | CC BY-SA 3.0 |
| Observatoire du pic de Chateaurenard.jpg | Eritrichium | CC BY-SA 4.0 |
| Observatoire François Xavier Bagnoud.jpg | Christian David | CC BY-SA 4.0 |
| Observatoire fédéral d'astrophysique04.JPG | Eminoro & Simon Villeneuve | CC BY-SA 3.0 |
| Observatoire Lyon Coudee.JPG | Denys (fr) | CC BY 3.0 |
| Observatoire Vallot 1890.jpg | Unknown author Unknown author | Public domain |
| Observatoire-ependes.jpg | Martignoni | CC BY-SA 4.0 |
| Observator1.jpg | Геннадій Мойсенко | GFDL |
| OBSERVATORI ASTRONÒMIC DE CASTELLTALLAT - IB-340.jpg | Isidre blanc | CC BY-SA 4.0 |
| Observatori de Pujalt.jpg | Martí8888 | CC BY-SA 4.0 |
| Observatori del Montsec - panoramio.jpg | jordi domènech | CC BY-SA 3.0 |
| Observatori Fabra - Vista des del Tibidabo - 1.jpg | Arnaugir | CC BY-SA 3.0 |
| Observatoriet 2011.JPG | I99pema | CC BY-SA 3.0 |
| Observatoriet i Oslo.jpg | Jan-Tore Egge | CC BY-SA 4.0 |
| Observatoriet slottsskogen 2.jpg | User Per Johansson on sv.wikipedia | CC BY-SA 3.0 |
| Observatorija, Palanga.JPG | Vilensija | CC BY-SA 3.0 |
| Observatorio 20150124.jpg | Juan lacruz | CC BY-SA 4.0 |
| Observatorio Asociación Entrerriana de Astronomía.jpg | Carloszelayeta | CC BY-SA 4.0 |
| Observatorio Astronomico da Paraiba.JPG | Arktrus2 | CC BY-SA 3.0 |
| Observatorio Astronómico de El Garraf.jpg | Luis14122 | CC BY-SA 4.0 |
| Observatorio Astronómico de Forcarei.jpg | Gabriel González from Pontevedra, España | CC BY 2.0 |
| Observatorio Astronómico de La Hita, telescopio T77.jpg | Malopez 21 | CC BY-SA 4.0 |
| Observatorio Astronómico de Mercedes.jpg | Observatorio astronómico de mercedes | CC BY-SA 4.0 |
| Observatorio Astronómico de Montevideo (IAVA) 03.jpg | JacobinoWunsh | CC BY-SA 4.0 |
| Observatorio Astronómico del CURE.jpg | Asterismo | CC BY-SA 3.0 |
| Observatorio Astronómico Educativo Turístico UNMSM - M.D. Maranganí.jpg | Luis Arturo Romero Granados | CC BY-SA 4.0 |
| Observatorio astronómico El Roble.jpg | Juan Pablo Gardeweg | CC0 |
| Observatorio Ckoirama, primer observatorio del Estado de Chile.jpg | Rodrigo Maluenda Romero | CC BY-SA 4.0 |
| Observatorio Cotobade 2.jpg | Adrián Estévez ( Estevoaei ) | CC BY-SA 4.0 |
| Observatorio de la Agrupación Astronómica de Sabadell.JPG | Vetranio | CC BY-SA 3.0 |
| Observatorio de Natal-(1903).jpg | Unknown author Unknown author | Public domain |
| Observatorio do Valongo em julho de 2016.jpg | Helio Jaques Rocha Pinto | CC BY-SA 4.0 |
| Observatorio Eta Carinae durante el día.jpg | Fedaro | CC BY-SA 3.0 |
| Observatorio Geofísico de Almería 20220416 01.jpg | Ismael Olea | CC BY 4.0 |
| Observatorio Hipatia de Tepezalá 03.jpg | Luis Alvaz | CC BY-SA 4.0 |
| Observatorio inca de oro.jpg | NICORSOLE | CC BY-SA 4.0 |
| Observatorio la silla ntt.JPG | Masteruk | CC BY-SA 3.0 |
| Observatorio nacional sede centro.jpg | Andrés Muñoz Castillo | CC BY 3.0 |
| Observatorio Ramon Maria Aller - 07.JPG | Xosema | CC BY-SA 4.0 |
| Observatorio-cba.jpg | Máximo E. Calderón | CC BY-SA 3.0 |
| Observatorio-Deva.jpg | David Álvarez López | CC BY 2.0 |
| Observatorio02.jpg | Wikipuerto | CC BY-SA 3.0 |
| Observatorioantares.jpg | Andrevruas | CC BY 3.0 |
| ObservatorioAstronomicoLosMolinos0.jpg | Fernando da Rosa (Fedaro) | CC BY-SA 3.0 |
| Observatoriomadridfrente.jpg | Fanattiq | CC BY 3.0 |
| Observatorium Kanzelhoehe.jpg | Poetziw | GFDL |
| Observatorium Zimmerwald 01.jpg | Arkelin | CC BY 4.0 |
| Observatorium-erkrath1.JPG | Heiko Tomaszewski -- Darkstar1970 20:04, 19 August 2007 (UTC) | CC BY-SA 3.0 |
| Observatorul Bosianu (2).JPG | Alstyle | CC BY-SA 3.0 ro |
| Observatory (Zvenigorod) Wikiexpedition (2017-04-01) by Andreykor 15.jpg | Andreykor | CC BY-SA 4.0 |
| Observatory ACK - Pristina.jpg | SUHEJLO | CC BY-SA 4.0 |
| Observatory and She Shan Basilica 20050410.jpg | Christopher | CC BY 2.0 |
| Observatory at former Penllergare Estate - geograph.org.uk - 1764608.jpg | Nigel Davies | CC BY-SA 2.0 |
| Observatory Cerro Murphy 2023 credit Araucaria Project.png | PKarczmarek | CC BY-SA 4.0 |
| Observatory House, 25 Windsor Road, Slough.jpg | Richard Kelly | CC BY-SA 4.0 |
| Observatory in Odessa.jpg | Kateryna Kulish | CC BY 4.0 |
| Observatory jena grossschwabhausen germany july 2022.jpg | Thuringius | CC0 |
| Observatory kirchheim thuringia.jpg | Thuringius | Public domain |
| Observatory Taurus-1 Surpakov Belarus.jpg | S. Korotkiy | Public domain |
| Observatory, Alexandra park.jpg | Marc A Gibbs | CC BY-SA 4.0 |
| Observatory, Kryoneri, Corinth, Greece.jpg | DiGi (Gikas Dimitris) Γκίκας Δημήτριος. Original uploader was DiGi at el.wikipedia | Attribution |
| ObservatoryTiflis.jpg | Не известный автор | Public domain |
| Observatório Astronómico da Faculdade de Ciências da Universidade do Porto.jpg | Ricardo Saraiva de Almeida | CC BY-SA 4.0 |
| Observatório Astronómico da Universidade de Coimbra, em 2025 - Foto 15.jpg | Threeohsix | CC BY-SA 4.0 |
| Observatório Astronômico - UFRGS.jpg | Ricardo André Frantz ( User:Tetraktys ) | CC BY-SA 3.0 |
| Observatório de capricórnio - panoramio (1).jpg | enioprado | CC BY-SA 3.0 |
| Observatório Nacional - Rio de Janeiro, Brasil 140 (4118162565).jpg | Jonas de Carvalho from Rio de Janeiro, Brasil | CC BY-SA 2.0 |
| Observatório Príncipe Alberto de Mónaco - Horta - Portugal (52153148150).jpg | Vitor Oliveira from Torres Vedras, PORTUGAL | CC BY-SA 2.0 |
| Observatórium Lomnický štít 1.jpg | Bubamara | CC BY-SA 3.0 |
| Obserwatorium Astronomiczne Uniwersytetu Warszawskiego 2021.jpg | Adrian Grycuk | CC BY-SA 3.0 pl |
| Obserwatorium astronomiczne.JPG | Michał Franiasz | CC BY 3.0 |
| Old observatory tower, Falmouth (2220083837).jpg | Tim Green from Bradford | CC BY 2.0 |
| Old Perth Observatory, seen from Central Park, January 2021 01.jpg | Calistemon | CC BY-SA 4.0 |
| Old University of Alabama Observatory 02.jpg | Alex Bush | Public domain |
| Oldobservatory12Presov3.JPG | Ing.Mgr.Jozef Kotulič | CC BY-SA 3.0 |
| Ole Roemer observatoriet aarhus.jpg | Nico-dk ( talk ) 15:48, 3 April 2009 (UTC) / Nils Jepsen | CC BY-SA 3.0 |
| OMA Americana SP Brasil foto2.JPG | Carlosar | Public domain |
| Omni-Theatre, Singapore Science Centre, Nov 05.JPG | Unknown author | Copyrighted free use |
| OMP Toulouse.JPG | Esspe | CC BY-SA 3.0 |
| Onboard Photo - Astro-1 Ultraviolet Telescope in Cargo Bay.jpg | NASA | Public domain |
| Ondřejov - radioteleskop na radarové louce (2).jpg | Luká | CC BY-SA 4.0 |
| Ondřejov 65cm Telescope.jpg | H. Raab ( User:Vesta ) | CC BY-SA 3.0 |
| Ondřejov Astron Observ DSCN0564.JPG | Original uploader was Sokoljan at cs.wikipedia | CC BY-SA 3.0 |
| One of the individual telescopes of the Minerva project.jpg | NASA | Public domain |
| One-Mile Telescope.jpg | Rror | CC BY-SA 3.0 |
| Onsala rymdobservatorium.JPG | Moralist | CC BY 3.0 |
| Onsala Twin Telescopes.jpg | Askmatl | CC BY-SA 4.0 |
| Onsala-20m-antenn.jpg | Peterkz | CC BY 4.0 |
| Ooty Radio Telescope.jpg | Own work | CC BY 3.0 |
| Orbiting Astronomical Observatory 2.jpg | NASA | Public domain |
| Orbiting Astronomical Observatory.jpg | Unknown author | Public domain |
| Orchard Hill Observatory.jpg | Ktr101 | CC BY-SA 4.0 |
| ORFEUS-SPAS II grows larger as Columbia moves closer during rendezvous (STS080-719-005).jpg | NASA | Public domain |
| Orgov telescope (cutted).jpg | Norayr | CC BY-SA 4.0 |
| Oriolo Romano Observatory.jpg | Orioloromano deep sky | Public domain |
| Osservatorio astronomico d'Abruzzo.jpg | . The original uploader was Faprimol at Italian Wikipedia . | CC BY 3.0 |
| Osservatorio astronomico dell'università di siena (dipartimento di fisica) 01.jpg | Sailko | CC BY 3.0 |
| Osservatorio Astronomico di Capodimonte, Naples.jpg | H. Raab ( User:Vesta ) | CC BY-SA 4.0 |
| Osservatorio Astronomico di Cima Rest - panoramio (10).jpg | Gianluca Cogoli | CC BY 3.0 |
| Osservatorio astronomico di Isnello 01.jpg | Davide Mauro | CC BY-SA 4.0 |
| Osservatorio astronomico di Luserna San Giovanni.jpg | Saracambellotti | CC BY-SA 4.0 |