Mount Wilson Observatory

Mount Wilson Observatory is a research facility at an elevation of 5715 feet (1742 meters) in the San Gabriel Mountains, featuring multiple solar telescopes and reflector instruments. The facility houses both historic and modern equipment for observing stars, planets, and the sun.

George Ellery Hale established the facility in 1904 with Carnegie Institution funding, initially as a solar observation station for Yerkes Observatory. The site expanded over the following decades with the construction of larger telescopes to study the night sky.

Edwin Hubble used the 100-inch Hooker telescope in the 1920s to make fundamental discoveries about galaxy distances and the expansion of the universe. His work here led to a completely new understanding of cosmic scale and the movement of distant star systems.

The facility offers regular visiting hours during spring and summer with telescope viewings, guided tours, concerts, and educational programs. Access requires driving up a winding mountain road that may close during poor weather conditions.

The CHARA interferometer array consists of six telescopes that work together to measure stellar diameters with extreme precision. This arrangement uses the principle of interferometry to achieve an effective resolution equivalent to a single much larger telescope.

Location: Los Angeles County

Inception: 1904

Elevation above the sea: 1,742 m

Website: https://mtwilson.edu

GPS coordinates: 34.22503,-118.05719

Latest update: December 14, 2025 17:47