Worlds most advanced giant telescope mirror is completed

first_imgWhat does it take to build the Giant Magellan Telescope (GMT), which will one day the be the largest telescope on Earth, and produce images 10 times sharper than the Hubble? The answer is a lot of smart people, a build site that’s high up and away from light pollution (preferably a mountaintop in the Chilean Andes) and a set of very large, precisely fabricated mirrors.Scientists at the University of Arizona and in California recently completed the first of seven 27.5-foot mirrors to be used in the GMT, and that task was a feat of engineering by itself. Since the mirrors will be mounted together into a single 82-foot optical surface, each of the outer six has to be made into a perfectly curved shape. The final products can’t be off by more than 1/20 of a wavelength of green light, or about 25 nanometers, and creating them is rated at ten times the difficulty of any previous large telescope mirror.Although the GMT team still has six more huge mirrors to make (the second was cast in January and the third will be cast in August 2013), completing the first was a big milestone. Now that it’s clear that the fabrication equipment and techniques are up to the task, the team can move toward the GMT’s 2019 completion goal with a little more confidence.Eventually each completed mirror will be mounted into its own support cell inside the telescope, and a complex mechanism will ensure that all seven stay perfectly aligned. Once in place, light from distant objects will reflect off the big mirrors, up to seven smaller secondary mirrors, and down through the opening in the center mirror to be recorded by cameras below. The concentrated light can then be measured to determine how far away the objects are and what they are made of.GMTO via uanews.orglast_img

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