Very Large Telescope (VLT)

The Very Large Telescope (VLT) is located at the Paranal Observatory in Chile's Atacama desert, and is the world's most advanced optical telescope. It comprises four 8.2 metre reflecting telescopes and three auxiliary 1 metre telescopes that can move about.

The VLT produces extremely sharp images using a special technique called optical inferometry (i.e. combining the light from all telescopes) and can capture light from the faintest and most remote objects in the Universe.

The four VLT domes 
Credit: ESO/VLT

Some facts about the telescope:

  • Observatory location: Cerro Paranal, Atacama Desert, Chile
  • Height above sea level: 2,635 meters (8,645 feet)
  • Moving Mass: 200 metric tonnes (each unit)
  • Mirror diameter: 8.2 metres (each unit)

The photograph above shows the four main enclosures that make up the VLT.

With all four telescopes working together, the total light collecting power is equivalent to a 16 metre single telescope - thus making the VLT the largest "effective" optical telescope in the world.

Image of Horsehead Nebula
Credit: ESO/VLT

The advantage of using all four telescopes together is that distant objects that appear close together can be separated by a special technique called interferometry. This technique is required if astronomers are going to observe exoplanets orbiting stars in their search for life in the Universe.

This spectacular image shows the Horsehead Nebula; a massive dark cloud of dust and gas which is currently providing material for the birth of lots of brand new stars. You cannot see most of those stars because the cloud is so thick and blocks out most of the light. This image was taken with the VLT on 25 January 2002