Gallery: The Top 10 Telescopes of All Time

Gemini Observatory

Two eyes are better than one. The Gemini Observatory's twin optical/infrared telescopes are an ocean apart, yet together they can access the entire sky. Gemini South is located at almost 9,000 feet in the Chilean Andes; Gemini North (pictured) sits atop the dormant volcano Mauna Kea, home to an international community of telescopes peering at the night skies through Hawaii's excellent atmosphere.

Seven countries own Gemini, whose scientists make it a point to keep the telescope's technology fresh -- the observatories even have a "sputtering chamber" that applies silver coatings on the Gemini mirrors to increase their infrared capabilities.

European Southern Observatory

The observatory's 3.5-meter scope, the dryly named New Technology Telescope, was the first telescope in the world to have a computer-controlled main mirror. Even amateur scopes now have that technology. The ESO's suite of telescopes in Chile's Atacama Desert also includes the Very Large Telescope array (pictured), Europe's flagship observatory. The ESO is also home to Europe's portion of the Atacama Large Millimeter/sub-Millimeter Array, known as ALMA, an intercontinental collaboration with North America, east Asia and Chile. ALMA will be the highest observatory on Earth and the world's most advanced radio astronomy observatory. Which takes us to the next top observatory ...