that of the Keck Observatory and the use of a group of 8-meter (26') mirrors mounted to form a single unit. The US National Academy of Sciences made a suggestion that a 30-meter (100') telescope should be the focus of US astronomy interests and recommended that it be built within the decade. The University of California, along with Caltech, began development of a 30-meter telescope that same year. The California Extremely Large Telescope (CELT) began development, along with the Giant Magellan Telescope, the Giant Segmented Mirror Telescope (GSMT), and the Very Large Optical Telescope (VLOT). These studies would eventually become the Thirty Meter Telescope. The TMT would have nine times the collecting area of the older Keck telescope using slightly smaller mirror segments in a vastly larger group. Another telescope of a large diameter in the works is the Extremely Large Telescope (ELT) being built in northern Chile. The telescope is designed for observations from near-ultraviolet to mid-infrared (0.31 to 28 μm wavelengths). In addition, its adaptive optics system will help correct for image blur caused by the atmosphere of the Earth, helping it to reach the potential of such a large mirror. Among existing and planned extremely large telescopes, the TMT will have the highest elevation and will be the second-largest telescope once the ELT is built. Both use segments of small 1.44 metre (4'9") hexagonal mirrors—a design vastly different from the large mirrors of the Large Binocular Telescope (LBT) or the Giant Magellan Telescope (GMT). Each night, the TMT would collect 90 terabytes of data. The TMT has government-level support from the following countries: Canada, China, Japan and India. The United States is also contributing some funding, but less than the formal partnership. Proposed locations In cooperation with AURA, the TMT project completed a multi-year evaluation of six sites: Roque de los Muchachos Observatory, La Palma, Canary Islands, Spain Cerro Armazones, Antofagasta Region, Republic of Chile Cerro Tolanchar, Antofagasta Region, Republic of Chile Cerro Tolar, Antofagasta Region, Republic of Chile Mauna Kea, Hawaii, United States (This site was chosen and approval was granted in April 2013) San Pedro Mártir, Baja California, Mexico Hanle, Ladakh, India The TMT Observatory Corporation board of directors narrowed the list to two sites, one in each hemisphere, for further consideration: Cerro Armazones in Chile's Atacama Desert and Mauna Kea on Hawaii Island. On July 21, 2009, the TMT board announced Mauna Kea as