W. M. Keck Observatory

The W. M. Keck Observatory is part of the Mauna Kea Observatory on the summit of the 4200 meter high dormant volcano Mauna Kea on the island of Hawai'i.

It houses two identical mirror telescopes, each of which has a ( composed of 36 smaller hexagonal segments ) primary mirror 10 meters in diameter and which were the largest optical telescopes in the world until July 2007. They were replaced by the Gran Telescopio Canarias, the mirror diameter is 10.4 m. The mirror support these telescopes were manufactured by Schott AG in Mainz Zerodur glass ceramic. The Keck I telescope was put into operation in 1993, the Keck II telescope followed in 1996. Both telescopes can also be operated together as an optical interferometer. Keck I and Keck II adaptive optics feature.

The foundation dates back to a donation from the WM Keck Foundation in the amount of 140 million U.S. dollars. The observatory is operated by the California Institute of Technology, the University of California and the U.S. space agency NASA together.