A lens maker in Sagamihara, Kanagawa Prefecture, is busy finishing work on the “eye” of what will be the world’s largest telescope, now under construction near the summit of Mauna Kea in Hawaii.
The primary mirror of the Thirty Meter Telescope is scheduled to be completed in March 2022. It will be composed of 492 hexagonal mirrors, each 72 cm across. Ohara Inc. is supplying 574 mirrors, including some that will be used as replacements, by March 2020.
The TMT, with a 30-meter aperture, is larger than Japan's Subaru Telescope, one of the world's biggest to date. It is also near the top of the 4,205-meter-high volcano and entered service in 1999.