World's largest optical telescope, situated on Mauna Kea, Hawaii. It has a primary mirror 10 m/33 ft in diameter, unique in that it consists of 36 hexagonal sections, each controlled and adjusted by a computer to generate single images of the objects observed. It received its first images Nov 1990.
An identical telescope next to it, to be named Keck II, is due for completion 1996. Both telescopes are jointly owned by the California Institute of Technology and the University of California.