Inside the dome of the VLT

This view from inside one of the VLT dome shows the innumerable metallic struts and beams that encase and support the centrepiece: the VLT's main mirror. The mirror is work of superlative craftsmanship: 8.2 metres in diameter, but only 17.5 centimetres thick. It is polished so accurately that if you were to scale its diameter to that of the Earth's, its largest imperfection would be no greater than the size of a pebble.