Cerro Paranal moonrise

Paranal Observatory pictured with Cerro Paranal in the background. The mountain is home to one of the most advanced ground-based telescopes in the world, the VLT. The VLT telescope consists of four unit telescopes with mirrors measuring 8.2 metres in diameter and work together with four smaller Auxiliary Telescopes to make interferometric observations. Each of the 8.2-m diameter Unit Telescopes can also be used individually. With one such telescope, images of celestial objects as faint as magnitude 30 can be obtained in a one-hour exposure. This corresponds to seeing objects that are four billion (four thousand million) times fainter than what can be seen with the unaided eye.