The Giant Magellan Telescope, against the southern Milky Way, as it will appear when it's completed. (Image: Todd Mason/Mason Productions and GMTO Inc.)
The most challenging large astronomical mirror ever made has been completed.
The mirror – one of seven — will be part of the 25-meter Giant Magellan Telescope that will explore planets around other stars and the formation of stars, galaxies and black holes in the early universe.
The mirrors form the heart of the 25-meter Giant Magellan Telescope (GMT), providing more than 380 square meters, or 4,000 square feet, of light-collecting area. The Giant Magellan Telescope will be located on a remote mountaintop in the Chilean Andes. The telescope is slated to begin operations late in the decade.
A group of optical scientists and engineers working at the University of Arizona (UA) Steward Observatory Mirror Laboratory underneath the UA’s football stadium have been polishing an 8.4-meter (27 ½ feet) diameter mirror with an unusual, highly asymmetric shape.
The mirror has an unconventional shape because it is part of what ultimately will be a single 25-meter (82 feet) optical surface composed of seven circular segments, each 8.4 meters (27 ½ feet) in diameter. The mirror was cast at the mirror lab from 20 tons of glass.
By the standards used by optical scientists, the “degree of difficulty” for this mirror is 10 times that of any previous large telescope mirror.
The GMT partner institutions are the Australian National University, Astronomy Australia Limited, the Carnegie Institution for Science, Harvard University, the Korea Astronomy and Space Science Institute, The Smithsonian Institution, Texas A&M University, the University of Arizona, the University of Chicago and the University of Texas at Austin.
By Leonard David/UA press release