Figure 3-31 The 10-m Keck Telescopes Located on the dormant (and hopefully extinct) Mauna Kea volcano in Hawaii, these huge twin telescopes each consist of 36 hexagonal mirrors measuring 1.8 m (5.9 ft) across. Each Keck telescope has the light-gathering, resolving, and magnifying ability of a single mirror 10 m in diameter. Inset: View down the Keck I telescope. The hexagonal apparatus near the top of the photograph shows the housing for the 1.4-m secondary mirror.