Moments after sunset the giant eyes of Cerro Paranal Observatory prepare for a night of exploration in the barren Atacama Desert. With its amazing dark, steady, and transparent sky, Paranal is home to some of the world's leading telescopes. Operated by the European Southern Observatory (ESO) the Very Large Telescope (VLT) is located on Paranal, composed of four 8-meter telescopes and smaller auxiliary telescopes, each 1.8 m in aperture (left), which are important elements of the VLT interferometer.