You can get a great view of the stars in the Atacama Desert in Chile. There's seldom a rain cloud in the sky (it's one of the driest places on Earth), and it's far from any big cities and their accompanying light pollution and smog. That's why it's already home to a telescope or two, and the view will soon get a lot better. On a desert mountaintop, a U.S.-led international consortium has just broken ground on the Giant Magellan Telescope (GMT).

The first stages of construction will mostly involve putting in roads and power supplies. But when the telescope begins operating in 2021, GMT is expected to be the largest optical telescope on Earth--at least for a little while. It will produce images 10 times sharper than Hubble.

The GMT will combine seven giant mirrors to create a lens that's about 85 feet in diameter. By comparison, the world's current largest telescope of this type--the Great Canary Telescope in Spain--has an aperture of just 34 feet. And the space-based Hubble has a measly 8-foot mirror.