When the Giant Magellan Telescope goes online around 2020, it will be the first of a new generation of massive telescopes that will be able to look back and see the earliest objects in the Universe. The GMT will also be able to directly image exoplanets up to one million times fainter than their host stars.

The telescope’s third 8.4-meter mirror was cast on August 24, 2013, at the University of Arizona’s Steward Observatory Mirror Lab. The completed telescope will use seven mirrors to give it an effective aperature of 24.5 meters (80 -feet). When completed, it should briefly hold the title for the largest optical telescope in the world.