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Palomar Mountain, California

Palomar Observatory

A world-class observatory in the California desert. 

The Palomar Observatory was once the world’s largest astronomical observatory, and remains one of the world’s finest.

Nestled in the mountains of Southern California north of San Diego, the Palomar Observatory was built by famed astrophysicist George Ellery Hale, whose home in Pasadena featured its own observatory for his personal use.

Palomar was the second location of three at which Hale constructed what would be, at the time, the world’s largest observatory – a record which was only broken by Hale each time during his era. The Palomar Observatory is still a working location to this day, aiding scientists from Caltech and all over the world in their search for new insights and information somewhere in the starry depths of the sky.

The observatory operates several telescopes, including the famous 200-inch Hale Telescope (5.1 m) and the 48-inch Samuel Oschin Telescope (1.2 m). In addition, other instruments and projects have been hosted at the observatory, such as the Palomar Testbed Interferometer and the historic 18-inch Schmidt telescope (0.46 m), Palomar Observatory’s first telescope, dating from 1936.