Keck Observatory is an astronomical observatory on Mauna Kea, a mountain on the island of Hawaii. It consists of two identical telescopes, Keck I and Keck II, which rank among the largest optical telescopes in the world. Keck I began science observations in 1993; Keck II, in 1996. The California Association for Research in Astronomy, a partnership of the University of California and the California Institute of Technology, runs the observatory. Its full name is the W. M. Keck Observatory.
Keck I and II collect and focus visible light waves and infrared (heat) waves from objects in space. One use of the telescopes is to analyze radiation coming to Earth from the farthest known galaxies.
Keck I and II are reflecting telescopes–that is, they use a large mirror to collect and focus light. The light-gathering mirror is a segmented mirror that consists of 36 smaller mirrors mounted together. The segments form a reflecting surface 33 feet (10 meters) in diameter.
An electronic sensing system holds the segments in place. If a segment gets out of position, sensors on its edges activate pistonlike devices called actuators on the back of the segment that move it into place.
In 2001, the two telescopes were joined to form the Keck Interferometer, which creates sharper images than either telescope alone (see Interferometer ). The observatory stopped using the interferometer in 2012 due to a lack of funding.
