In the year 2020, seven of the largest mirrors on Earth — 20 tons each — will come together in a 22-story, rotating building located at the Las Campanas Observatory in the southern Atacama Desert of Chile. They will form the Giant Magellan Telescope, a feat of science, technology, engineering and math that will have ten times the resolution of the Hubble Space Telescope.
In this video from July 2013, Dr. Wendy Freedman, Chairman GMT, and Dr. Pat McCarthy, Director GMT, explain the astounding challenge of creating this precise, powerful, and wondrous machine. Read more at Phys.org.
In the archives: more telescope-related vids.
Update: Via Wikipedia, the telescope is now due for completion in 2025.