MAUNA KEA OBSERVATORIES

The Mauna Kea Observatories (MKO) are an independent collection of astronomical research facilities located on the summit of Mauna Kea on the Big Island of Hawai'i, USA. The facilities are located in a 500-acre (2.0 km²) special land use zone known as the "Astronomy Precinct", which is located in the Mauna Kea Science Reserve. The Astronomy Precinct was established in 1967 and is located on land protected by the Historical Preservation Act for its significance to Hawaiian culture.

The location is ideal because of its dark skies, good astronomical seeing, low humidity and position above most of the water vapor in the atmosphere, clean air, good weather and almost equatorial location.

Because of its height and excellent seeing, this site supports by far the largest astronomical facility in the world. It is operated by the Institute for Astronomy of the Univ. of Hawaii. The largest telescopes are the 33-ft (10-m) W. M. Keck telescopes (Keck I and II), each consisting of an array of 36 segmented mirrors; a computer adjusts each small mirror many times per second so that a single image is formed of the object under study. Keck I began observations in 1993, Keck II in 1996. The Subaru telescope, featuring a 327-in. (8.3-m) one-piece mirror, was formerly called the Japanese National Large Telescope. The 320-in. (8.1-m) Gemini telescope is one of an identical pair, the other being constructed atop Chile's Cerro Pachon. Together they will provide complete unobstructed optical and infrared coverage of both the northern and southern skies. Other instruments include the Canada-France-Hawaii telescope (142 in./3.6 m), the United Kingdom Infrared telescope (150 in./3.8 m), and the Infrared Telescope Facility (120 in./3 m), as well as two telescopes—the Caltech Submillimeter Observatory and the James Clerk Maxwell Telescope—used for observations in the submillimeter portion of the electromagnetic spectrum. Also part of the complex is the Hawaii Antenna of the Very Long Baseline Array, which is used for observations in radio astronomy.