The Fred Lawrence Whipple Observatory, formerly known as Mount Hopkins Observatory, is located on Mount Hopkins, Arizona, at an altitude of 2,600 meters and operated by the Smithsonian Institution. Its main instrument is the Multiple Mirror Telescope (MMT). The Observatory also operates a number of smaller instruments including a 1.2-meter diameter imaging optical telescope; the 1.5-meter Tillinghast optical spectroscopic telescope; the HAT (Hungarian-made Automated Telescope) array of five optical telescopes, and the MINERVA array of four 70-centimeter optical telescopes.

 

Multiple Mirror Telescope

The Multiple Mirror Telescope (MMT) is a 6.5-meter telescope located at an altitude of 2,606 meters (8,550 feet) on the summit of Mount Hopkins, the second highest peak in the Santa Rita Range of the Coronado National Forest, about 55 km south of Tucson, Arizona, on the grounds of the Fred Lawrence Whipple Observatory. In 1998, the large single mirror replaced six identical 1.8-meter mirrors on a common mount (with a combined light-collecting power of a 4.5-meter mirror), which had been in use since 1979. Just before it was upgraded, the old MMT was used in a pioneering demonstration of nulling interferometry to image the dust cloud around Betelgeuse. The MMT is a joint venture of the University of Arizona, which operates the MMT, and the Smithsonian Institution.