2013-02-18T13:58:03Z ivo://x-invalid-test/KeckObs 2008-04-04T16:43:32Z 2 Keck ivo://x-invalid-test/KeckObs W. M. Keck Observatory, CARA S. Thest sthest@keck.hawaii.edu optical astronomy optical interferometry The Keck Observatory's instruments are the twin Keck Telescopes, the world's largest optical and infrared telescopes. Each stands eight stories tall and weighs 300 tons, yet operates with nanometer precision. At the heart of each Keck Telescope is a revolutionary primary mirror. Ten meters in diameter, the mirror is composed of 36 hexagonal segments that work in concert as a single piece of reflective glass. http://www.keckobservatory.org/ Organisation General Research Keck Telescopes Keck Telescope