W. M. Keck Observatory

Near the summit of Mauna Kea in Hawaii, the W. M. Keck Observatory operates two high-altitude optical and near-infrared telescopes, each with a 10-meter segmented primary mirror. Developed from a 1977 concept and funded first by a major gift from Howard B. Keck, Keck I began science observations in 1993 and Keck II followed in 1996; at their completion, they were the world’s largest optical reflecting telescopes. Their defining segmented-mirror and active-optics system solved the problem of giant mirrors sagging under their own weight. With powerful instruments, adaptive optics, and a former interferometer, Keck became one of the world’s most productive observatories and influenced later giant-telescope designs.

Paauilo, Hawaii · United States