W. M. Keck Observatory
Keck's twin 10-meter, 8-story, 300-ton telescopes are as famous for their design as their discoveries. Each primary mirror is composed of 36 hexagonal segments that work together as one single piece of glass -- a revolutionary engineering feat that allows for massive mirrors. The Keck telescopes, perched on Mauna Kea, remain the world's largest optical and infrared telescopes. They have helped scientists make some amazing discoveries: the presence of galaxies at the edge of the universe; studying supernovas to determine the universe's expansion rate; the nature of gamma-ray bursts and, most recently, planets around other stars.