Keck Observatory consists of two 10 meter adaptive optics reflector telescopes near summit of Mauna Kea in Hawaii, at an elevation of 4,145 m (13,600 ft). When they went into operation in the 1990s, they represented a substantial increase in the size of optical telescopes and as of 2019, 10 meters remains largest class of individual optical telescopes in operation. The two can operate as an optical interferometer with a baseline of 85 meters, known as the Keck Interferometer (KI). The observatory is named for W. M. Keck whose foundation funded it. Its instruments include:
Some previously listed instruments:
The Keck Planet Imager and Characterizer (KPIC) is extreme adaptive optics upgrade under development to enhance the capabilities of the infrared instruments in imaging exoplanets.