A philanthropic donation of $25 million has provided a boost to one of two projects competing for future US sponsorship of a giant ground-based telescope.
The Thirty Meter Telescope (TMT) project and the Giant Magellan Telescope (GMT) project are competing for National Science Foundation support, with a decision expected later this year. The TMT would go on Mauna Kea in Hawaii, and the GMT would be a 24.5 meter telescope on Cerro Las Campanas in Chile. The National Academy of Sciences’ Astro2010 decadal review recommended that the US National Science Foundation (NSF) cover 25% of the cost of one of the two projects. Depending on their fundraising, either or both may be able to go ahead without the NSF funding, but the selection of one may appear to other funding sources to weaken the case for another in the class.
Now the GMT has won a $25 million donation from George Mitchell, the founder of Mitchell Energy & Development Corporation. The relatively large one-off donation only brings the GMT some of the way closer to its target of $700 million, with $255.5 million already raised.
The GMT will be made of seven 8.4 meter mirrors arranged with six in a hexagon and one in the middle. In contrast the TMT is based on the design of the 10 meter Keck telescopes in Hawaii, which are made of many more smaller mirrors. Paul Schechter, an astronomer at MIT who works with the Magellan Telescopes, says he believes the GMT will work better. Schechter says the Hawaii site may be better than the Chilean one, that the Magellan design gives sharper images than the Keck for the same quality of atmosphere. “It’s much less complicated mirror and the telescope works better,” he says.
The European Southern Observatory is also planning a giant telescope, the one billion euro European Extremely Large Telescope, which will be 42 meters across and located at Cerro Armazones in Chile.
Image: Giant Magellan Telescope – GMTO Corporation