Historic observatories are places of awe and discovery where modern astronomy was born, and humankind’s understanding of the physical universe emerged.

The Alliance of Historic Observatories (AHO) acts as a vehicle for global collaboration in research, inspiration and engagement, and preservation of historical resources.

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Objectives

Develop strategies for preserving and sharing our legacies with future generations.

Share methods to preserve the infrastructure of historic observatories.

Tell our stories as a model for how the observatories inspire people around the world to foster greater literacy in science.

Become model institutions of youth STEM programs.

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Founding Observatories

Griffith Observatory

est. 1935

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Griffith Observatory
est. 1935
Los Angeles, CA, USA
City of Los Angeles

The most viewed telescope in the world (> 7 million people)

12-inch/9½-inch telescopes (0.3m/0.25m refractors, 1935/55)
Coelostat and Solar Telescopes (1935)

Ed Krupp (director)

Website History Visiting Observing Programs Exhibits Events

Lick Observatory

est. 1888

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Lick Observatory
est. 1888
Mt. Hamilton, CA, USA
University of California Observatories

Largest refractor in the world (1888)
The world's first permanently occupied mountain-top observatory

36-inch James Lick ("Great Lick") Refractor (0.9m, 1888)
36-inch Crossley Reflector (0.9m, 1879/1896)
20-inch Carnegie Double Astrograph (0.5m refractors, 1941)
22-inch Tauchmann Reflector (0.5m, 1954)
120-inch Shane Telescope (3m reflector, 1959)
Coudé Auxiliary Telescope (0.6m reflector, 1969)

Matthew Shetrone (deputy director)

Website History Research
Visiting Observing Programs Tour Live Cams Archives Events

Lowell Observatory

est. 1894

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Lowell Observatory
est. 1894
Flagstaff, AZ, USA

Discovery of Pluto (1930)

24-inch Clark Telescope (0.6m refractor, 1896)
13-inch A. L. Lowell Astrograph (0.3m refractor, 1929)

W. Lowell Putnam (trustee)

Website History Research
Visiting Stargazing Programs Exhibits Archives Events News

Mt. Wilson Observatory

est. 1904

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Mount Wilson Observatory
est. 1904
Mt. Wilson, CA, USA
Mount Wilson Institute

Largest telescopes in the world (1908 and 1917)
Discovery of the cosmic expansion

100-inch Hooker Telescope (2.5m reflector, 1917)
60-inch telescope (1.5m reflector, 1908)
60-ft (18m) Snow Solar Telescope (1905)
150-ft (46m) solar tower (1912)

Timothy Thompson (science director)

Website History Visiting Observing Programs Events Live Cams Tour

Palomar Observatory

est. 1948

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Palomar Observatory
est. 1948
Palomar Mountain, CA, USA
Caltech

Largest telescope in the world (1949)
Largest Schmidt in the world (1948)
Palomar sky surveys (1958 and 2000)
Discovery of quasars (1963)
Discovery of Eris (2005) and other TNOs

200-inch Hale Telescope (5m reflector, 1949)
48-inch Samuel Oschin Telescope (1.2m Schmidt, 1948)
18-inch telescope (0.46m Schmidt, 1936)
60-inch telescope (1.5m reflector, 1970)

Andy Boden (deputy director)

Website History Research Visiting Tour Exhibits Live Cams Archives News

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AHO Meetings

AHO observatories meet every fall, typically for a couple of days, to discuss and plan alliance matters, exchange ideas, share experiences, and celebrate the achievements of our members. Vatican Observatory hosted the latest meeting in October 2024. Click here for more details.