We see a lot of "world's largest" claims around here. And this isn't even the first one for a telescope. But this one is actually for the world's biggest optical telescope, and that somehow makes it easier to grasp the magnitude of. At a cost of 1.1 billion Euros, it doesn't come cheap, but the European Extremely Large Telescope (ELT) has just been given the go ahead -- and truly lives up to its name. The mirror it uses will measure 39 meters across (four times that of typical mirrors,) comprising nearly 800 hexagonal pieces, and will swallow 12 times more light than the current biggest in existence. This, of course, means that it will be able to peep galaxies much farther away, and those in the process of formation in much more clarity. The project was approved by the European Southern Observatory council, which got the nod from ten countries in the continent, with others provisionally giving the thumbs up pending government backing. The telescope itself, however, will be located atop Chile's Cerro Armazones mountain in the Atacama Desert once completed.