DR FRED ESPENAK / SCIENCE PHOTO LIBRARY DR FRED ESPENAK / SCIENCE PHOTO LIBRARY
The Keck telescopes. The Keck I (right, white) and Keck II telescopes on the dormant volcano Mauna Kea in Hawaii. Keck I was completed in April 1992, but its twin will not be operational until the end of 1996. They are the largest optical telescopes in the world. Each has a main mirror made of 36 1.8 metre hexagonal mirrors, forming a unique sur- face with a total diameter of 10 metres. Each of the 36 mirrors has a specific shape and is mounted on computer-controlled motors that maintain its correct position during use. Keck I and II will be used together as an optical interferometer, where the signals received by the two telescopes are combined in a computer for improved accuracy.
Model release not required. Property release not required.