VLT Auxiliary Telescope at night, Paranal Observatory in Chile. Two human silhouettes are also visible at the foreground. Visible in the night sky is the Milky Way galaxy (running vertically at left). At centre right is the Large Magallenic Cloud. Above it is the bright star Canopus. The reddish green glow along the horizon is airglow, caused by the Earth's atmosphere. The VLT is the world?檚 most advanced optical and infrared observatory. It consists of four large Unit Telescopes, each with a mirror 8.2 metres across, and four smaller Auxiliary Telescopes, with mirrors 1.8 metres in diameter.