Paranal Observatory's control room. Researchers working inside the control room for the Very Large Telescope (VLT) at Paranal Observatory in Cerro Paranal, Chile. The VLT comprises four 8.2-metre mirror telescopes (Antu, Kueyen, Melipal and Yepun). The images from each are combined by interferometry, giving an image equal to that obtained by one 16 metre diameter mirror. This makes the VLT one of the most powerful telescopes in the world. The mirrors are flexible and are constantly adjusted by the computers to compensate for errors. The VLT is operated by the European Southern Observatory. It is at an altitude of 2600 metres in the Atacama Desert, one of the driest places on Earth. This provides the VLT with excellent viewing conditions.