Just about every amateur astronomer has wondered what it'd be like to have an even-bigger telescope — we call it "aperture envy" — and professional astronomers are no different.
So the pros were understandably thrilled last week to learn that a telescope with an aperture of 30 meters (nearly 100 feet) is moving from wishful thinking to not-too-distant reality. That's because the Gordon and Betty Moore Foundation has pledged $200 million over the next nine years to aid construction of a giant eye called the Thirty Meter Telescope.
Building on experience gained with previous segmented-mirror designs, the TMT will employ 492 hexagonal mirrors, each about 1.44 meters (57 inches) across its corners, arrayed together into a 30-meter-wide f/1 primary mirror. Six artificial guide stars, created by lasers illuminating spots in the upper atmosphere, will allow the telescope to continuously cancel out the image-degrading effects of atmospheric turbulence.
It's hard to imagine a telescope this big. This 140-ton giant will gather eight times more light than any other telescope — heck, even its secondary mirror is 10 feet across!
A site for the TMT hasn't been chosen; five locations in Chile, Hawaii, and Mexico are being studied, though Cerro Armazones in northern Chile is the one being used for planning purposes. Construction should begin in 2009, with "first light" expected in 2016.
If you're an aspiring astrophysicist wondering where to go to college, note that TMT is a collaboration involving Caltech, the University of California, AURA (a consortium of universities), and ACURA (AURA's Canadian counterpart). Caltech and the UC system, which previously joined forces to build the Keck telescopes, have each committed $50 million toward the TMT, and their astronomers will get the lion's share of observing time.
And, just in case you're wondering, the TMT won't have an eyepiece.