Historic Telescopes

Optical observatory · Chile

La Silla was ESO's first observatory, a pioneering site on the edge of the Atacama Desert still productive in exoplanet and survey science.

Optical observatory · United States (California)

Mount Wilson Observatory in California is where Edwin Hubble discovered the expansion of the universe, using the 100-inch Hooker Telescope.

Radio observatory · United States (Puerto Rico)

Arecibo Observatory in Puerto Rico operated a 305-metre radio dish — for decades the largest single-dish radio telescope — until its collapse in 2020.

Optical reflector · 5.1 m

The 200-inch Hale Telescope at Palomar was the largest in the world for decades and remains a workhorse of optical astronomy.

Optical reflector · 2.5 m

The 100-inch Hooker Telescope at Mount Wilson was used by Edwin Hubble to discover that the universe is expanding.