Giant Magellan telescope’s third mirror set to be unveiled

Washington – The Giant Magellan Telescope’s third primary mirror is going to be unveiled at the University of Arizona’s Steward Observatory Mirror Lab on December 6, 2013.

The combined surface area of the three mirrors created to date surpasses that of any existing telescope and will enable astronomers to peer more deeply into space than ever before once the telescope is completed.

Patrick McCarthy, Giant Magellan Telescope Project Director, said that the technology used to design and construct the telescope is breathtaking, but the answers it may provide as to the beginnings of time itself will be staggering.

The first of a new generation of “extremely large telescopes,” or “ELTs,” the Giant Magellan Telescope will have a mirror array consisting of seven 27-foot- (8.4-meter-) diameter mirror segments.

The telescope is anticipated to begin operation in 2020 with four mirror segments completed, making it the largest telescope in the world. When its final stages of construction are complete, it will have ten times the resolution of the Hubble Space Telescope.

Each of the Giant Magellan Telescope’s mirrors is the product of cutting edge technology and processing. Cast in a custom-built rotating furnace that reaches approximately 2,100 degree Fahrenheit, they each weigh about 20 tons, yet their internal architecture features an intricate honeycomb pattern that allows them to regulate temperature quickly while remaining extremely rigid.

Additionally, each mirror is meticulously polished and evaluated to create a surface that is so smooth that no imperfection is taller or deeper than a twentieth of a wavelength of light — one millionth of an inch. Details of the mirror making process can be seen here.

The third mirror – dubbed “GMT3” – was cast in August at the Steward Observatory Mirror Lab.