Mount Wilson Observatory - 60 Inch (1.5 M) Telescope

60 Inch (1.5 M) Telescope

George Ellery Hale received the 60 inches (1.5 m) mirror blank, cast by Saint-Gobain in France, in 1896 as a gift from his father, William Hale. It was a glass disk 7+1⁄₂ inches (190 mm) thick and weighing 1,900 pounds (860 kg). However it was not until 1904 that Hale received funding from the Carnegie Institution to build an observatory. Grinding began in 1905 and took two years. The mounting and structure for the telescope was built in San Francisco and barely survived the 1906 earthquake. Transporting the pieces to the top of Mount Wilson was an enormous task. "First light" was December 8, 1908. It was at the time the largest operational telescope in the world.

The 60 inch reflector became one of the most productive and successful telescopes in astronomical history. Its design and light-gathering power allowed the pioneering of spectroscopic analysis, parallax measurements, nebula photography, and photometric photography. Though surpassed in size by the Hooker telescope nine years later, the Hale telescope remained one of the largest in use for decades.

In 1992, the 60 inch telescope was fitted with an early adaptive optics system, the Atmospheric Compensation Experiment (ACE). The 69-channel system improved the potential resolving power of the telescope from 0.5-1.0 arc sec to 0.07 arc sec. ACE was developed by DARPA for the Strategic Defense Initiative system, and the National Science Foundation funded the civilian conversion.

Today, the 60 inch telescope is used for public outreach. Eyepieces are fitted to its focus instead of instruments. It is the largest telescope in the world devoted to the general public. As of June 2009, the cost for a half-night of observation is $900, $1700 for a full night.