Gemini Northern Telescope

When this 26.6ft telescope is paired with its twin in Chile, they are able to cover almost the entire sky. In 2014, Gemini used speckle imaging to help confirm the existence of Kepler 186f, the first known Earth-sized planet orbiting within a sun's habitable zone. The two telescopes are operated jointly by the US, Canada, Brazil, Argentina and Chile, with percentage of observation time distributed based on each country's financial contribution. First light: 1999.