Mount Wilson Observatory

Mount Wilson Observatory sits at 1,742 metres in the San Gabriel Mountains near Pasadena, California, a site that has shaped the history of modern astronomy since 1904.

About Mount Wilson Observatory

George Ellery Hale founded the observatory in 1904, after earlier efforts by University of Southern California co-founder Edward Falles Spence to establish a telescope on the mountain went unfinished. The Carnegie Institution of Washington first funded it as the Mount Wilson Solar Observatory, leasing the land from the owners of the Mount Wilson Hotel; the lease notably required that the site allow public access, a condition that still shapes the observatory's public-facing role today.

History

Mount Wilson's 60-inch telescope was completed in 1908 and was, at the time, the largest operational telescope in the world. It was surpassed by the observatory's own 100-inch Hooker telescope, completed in 1917, which held the title of the world's largest telescope until 1949. In 1989, the Carnegie Institution transferred the observatory to the non-profit Mount Wilson Institute, which continues to operate it.

Telescopes & research

Alongside the Hooker and 60-inch telescopes, the site holds the Snow solar telescope (1905), the 60-foot solar tower (1908), and the 150-foot solar tower (1912). Its newest major instrument, the CHARA array built by Georgia State University, became fully operational in 2004 and was the largest optical interferometer in the world at completion. Los Angeles's growing light pollution and the atmospheric inversion layer that traps smog over the city have limited deep-space work, but that same steady air makes Mount Wilson excellent for interferometry, and CHARA continues to carry out important stellar research today.

Location & getting there

The observatory sits on Mount Wilson, a 1,742-metre peak in the San Gabriel Mountains northeast of Los Angeles and close to Pasadena, reached by mountain road above the city.

Visiting Mount Wilson Observatory

Public access has been part of Mount Wilson since its original 1904 lease. The site runs public programs, particularly in spring and summer; check the official Mount Wilson Observatory website for current tour times, tickets, and seasonal access before visiting.

See your named star from here

Few observatories have a history as tied to the discovery of the wider universe as Mount Wilson, home to telescopes that reshaped our understanding of galaxies and stars. Name a star and find its exact position in the star catalogue.