Site of Thirty Meter Telescope to be Summit of Mauna Kea, Hawaii. (July 22, 2009)

It was announced yesterday that Mauna Kea rather than Cerro Armazones in Chile's Atacama desert got the nod to be home of what is to be the world's largest telescope, the Thirty Meter Telescope (TMT). Expected "First Science" is June 2018, i.e. a  year or so after that of the 24.5 meter Giant Magellan Telescope (GMT) at Las Campanas Observatory, Chile.

The current consortium for the TMT consists of the California Institute of Technology, the University of California, and the Association of Canadian Universities for Research in Astronomy. So far they have raised US$300 million of the estimated US$1 billion that will be needed. The consortium is hoping that the U.S. government, private foundations, and new foreign partners will come up with the additional funding.

The TMT will be sited at global coordinates of 19°49′14.39″N   155°28′05.04″W while the GMT will be at 29°00′54″S   70°41′32″W a separation of almost 50^o of latitude. So while the regions of the sky that will be observed will overlap, there also will be significant singular contributions.

The telescopes' designs are quite different with the GMT consisting of seven 8.4 meter segments (left) while the TMT's primary mirror will be made up of 492  1.4 meter, individual hexagonal mirrors (right).