Very Large Telescope (VLT) at night, Chile. The bright object at centre is the Moon, slightly to its upper left is the ringed planet Saturn, while rocky Mercury sits to the lower left. The dusty Milky Way spans the width of the image. 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.