QUASAR

Giant Eye on the Sky
On 2 February, scientists at the European Southern Observatory's Paranal Observatory in Chile for the first time successfully linked together all four telescopes of the observatory's Very Large Telescope (VLT) array. In a technique called interferometry, light beams collected by each telescope are routed through tunnels and combined in a central laboratory. Researchers at Paranal tried such a linkup in March 2011 but failed. Together, the telescopes of the VLT array form the largest ground-based optical telescope in the world, with a diameter of 130 meters and high spatial resolution high enough to see details up to 25 times finer than the individual telescopes can.