W. M. Keck Observatory

The W. M. Keck Observatory is an astronomical facility in Hawaii, United States, with two telescopes each featuring a ten-meter-wide primary mirror. Both structures sit at an elevation of 4,145 meters (13,600 feet) near the summit of Mauna Kea and house different scientific instruments for observing the night sky.

The Howard B. Keck Foundation donated 70 million dollars in 1985 for construction of the first telescope, which received first light in 1990. A second telescope was added a few years later, expanding the research capabilities of the facility.

Scientists from around the world apply regularly for observing time on the two telescopes, with research contributing to mapping distant galaxies and studying exoplanets. The facility works closely with other observatories on the mountain and shares data from nightly observation runs.

The location at extreme altitude means thin air and cold temperatures, so visitors should dress warmly and watch for possible symptoms of altitude sickness. Access to the summit area requires a four-wheel-drive vehicle and the road may close depending on weather conditions.

Each primary mirror consists of 36 hexagonal segments working together through active optics technology to function as a single reflecting surface. This segmented design allows for very large mirror diameters that would be impractical as a single piece.

Location: Hawaii

Elevation above the sea: 4,145 m

Diameter: 10 m

Part of: Mauna Kea Observatories

Address: 65-1120 Mamalahoa Highway, Kamuela, HI 96743

Website: https://keckobservatory.org

GPS coordinates: 19.82630,-155.47441

Latest update: December 14, 2025 17:24