The World’s Largest Telescope

As the world celebrates the International Year of Astronomy in 2009, it’s only natural for astronomers to ponder the next generation of “light buckets” – enormous telescopes that can see ever-deeper into the cosmos. Of course, much hype surrounds the planned successor to the Hubble Space Telescope, known as the James Webb Space Telescope, set for launch in 2014. But some astronomers insist there’s still a vital role for new ground-based telescopes. At U of T, astronomers Ray Carlberg and Roberto Abraham are among those involved in the development of the so-called “Thirty-Meter Telescope” to be built atop Hawaii’s Mauna Kea volcano. When completed in 2018, the facility will have nine times the light-collecting area of any existing optical telescope. Abraham says both The James Webb and Thirty-Meter telescopes are needed because each has its own strengths and weaknesses

Because it will avoid the obscuring effect of the Earth’s atmosphere, the James Webb Telescope will be able to detect objects that ground-based scopes might miss. But astronomers will turn to extremely large telescopes on the ground to investigate these objects further, and learn about their composition. The Thirty-Meter Telescope “is almost required to exploit the discoveries that you make with the James Webb Space Telescope,” says Abraham.

Using both kinds of telescopes will yield a more complete understanding of astrophysical objects, from planetary systems in our celestial back yard, to remote, ancient galaxies.