Mauna Kea Observatory

Mauna Kea Observatory, astronomical research facility, located on Hawaii’s dormant volcano Mauna Kea, at an altitude of 4,205 m (13,796 ft). Mauna Kea offers nighttime viewing with minimal interference from human light sources. The observatory, founded in 1967, is affiliated with the University of Hawaii but has a number of internationally sponsored instruments. See also Observatory; Astronomy.

The observatory complex contains all of the necessities for astronomers who spend time at the observatory. Mauna Kea has dormitories and cafeterias at an altitude of about 3,000 m (about 9,000 ft), below the summit area of the observatory where the telescopes are located. Mauna Kea Observatory is so high that astronomers usually spend at least a day at the lower area before visiting the summit to allow their bodies to acclimate to the altitude.

Mauna Kea Observatory is home to many telescopes, sponsored by many nations. Most of Mauna Kea’s telescopes are optical telescopes, meaning that they gather light that is visible to humans. The largest optical telescopes on Mauna Kea include the twin United States Keck telescopes, both of which have 1,000-cm (394-in) primary mirrors. The huge mirrors are actually made up of many small segments whose movements are coordinated electronically. The Keck telescopes are among the largest optical telescopes in the world and are run by the California Institute of Technology (Caltech), the University of California, and the National Aeronautics and Space Administration (NASA). The Japanese Subaru optical telescope that was completed in 1998 has a primary mirror 830 cm (327 in) in diameter.

The Gemini North telescope, an international telescope almost as large as the Subaru telescope, began scientific work on Mauna Kea in 2000. The Gemini North telescope has an 810-cm (320-in) primary mirror. It has a sister telescope, Gemini South, near La Serena, Chile. Both telescopes are run by a consortium of scientists and institutions from the United States, the United Kingdom, Canada, Chile, Australia, Argentina, and Brazil.

Mauna Kea is also home to telescopes that gather light that humans cannot see. Mauna Kea holds infrared, submillimeter, and radio telescopes. All three types of telescopes are designed for radiation with wavelengths longer than those of visible light. Infrared radiation has slightly longer wavelengths than visible light has. Submillimeter radiation encompasses the far end of the infrared band and the beginning of the microwave band of radiation. Radio waves have the longest wavelength of all radiation. Mauna Kea hosts a member of the Very Long Baseline Array (VLBA), a network of radio telescopes that spans the United States. The VLBA telescope on Mauna Kea has a dish diameter of 2,500 cm (980 in). See also Infrared Astronomy; Radio Astronomy.