The McMath-Pierce Solar Telescope at Kitt Peak National Observatory in Arizona, USA, looks like a monumental piece of modern art. A great white, inverted-V like concrete structure rises 110 feet up towards the sky from which a shaft slants two hundred feet to the ground. At the top of the tower is a 3-mirror heliostat which collects the sun’s light and directs it down the diagonal tunnel which continues for another three hundred feet into the mountain, forming an underground tunnel. At the base of the tunnel is a 34-inch parabolic mirror that captures the image of the sun. Built in 1962, it is the world's largest solar instrument as well as the largest unobstructed aperture optical telescope, with a diameter of 1.6 meters. Although designed to study the sun, it is so sensitive that it can even observe bright stars in the night.

Aerial view of the McMath-Pierce Solar Telescope. Photo credit: prezi.com