The Extremely Large Telescope

UK involvement in the ELT


  • The chosen site of Cerro Armazones will undergo a massive transformation in the next few years.
  • Armazones is 20 km from the existing VLT site on Cerro Paranal and as such the site infrastructure takes account and advantage of the existing Paranal infrastructure.
  • At 3064 m altitude the site does not pose logistical problems for operations and of course has met the exacting science requirements for site selection.
  • A suitable platform for the telescope can be generated on Armazones. The removal of approximately 300,000 cubic metres of rock will be needed to create a platform of approximately 150 m x 150 m.
  • During the construction phase a temporary camp will be created at the foot of Armazones for the construction contractors and the ESO team overseeing the work.
  • A purpose built road will connect the platform to the base camp and then on to the main highway and from there to Paranal.
  • During actual telescope operations the ELT will form part of the Paranal facility and logistics management (including accommodation) and engineering resources (including integration facilities) will all be based there.
  • Paranal and Armazones will get a Chilean grid connection for electricity as part of an agreement between ESO and the Chilean government.
  • The minimal operation on Armazones will have facilities for mirror coating, general storage, fire-fighting and a small accommodation unit for reception and duty personnel.

Cerro ArmazonesThis aerial view shows beautifully the Chilean Atacama Desert around the ESO Paranal Observatory, home to the Very Large Telescope (seen at the bottom right). Close to the VLT, one can see the dome of the VISTA survey telescope, and to the right, the Paranal Residence and basecamp. The high peak in the distance is the 6739-metre high volcano belonging to the Andes, Llullaillaco. Also in the image, to the middle left, one can see an isolated peak with a curvy road leading to its summit. This is Cerro Armazones, the selected home for the future Extremely Large Telescope (ELT).

Credit: ESO/M. Tarenghi