Giant Magellan Telescope 2nd mirror casting

A short video of the Steward Observatory Mirror Lab furnace spinning during the casting of the second 8.4 meter mirror for the Giant Magellan Telescope. Hard to believe but the furnace is turning approximately 4.8 mph at the time of this video. When completed, this mirror will join 6 others to form a 24.5 meter light gathering surface. Visit to learn all about this project, or to learn about the creation of the world’s largest telescope mirrors.