E-ELT SITE

Towards a site for the E-ELT

The E-ELT programme office is studying a number of potential sites for the E-ELT observatory. A decision on the site is foreseen in Spring 2010. After down-selecting sites during the last couple of years, only a handful of locations are still being considered.
The site selection advisory committee issued a recommendation in early 2010 (see ESO announcement 1013). The ESO Council will make a decision on the E-ELT baseline site, taking into account the recommendations of the Site Selection Advisory Committee and all other relevant aspects.

site testing Vernin

The site selection process

Various aspects needed to be considered in the site selection process. Parameters taken into account were not restricted to 'sky quality', but included more general scientific aspects, as well as parameters essential for construction and operations. For example, aspects that the project looked at include:

  • Atmospheric parameters: number of clear nights, infrared properties (height, temperature, precipitable water vapour, etc), seeing, atmospheric turbulence profile, mean coherence length and time, outer scale length, etc.
  • Scientific synergy aspects: which facilities will (be) support(ed by) the E-ELT (e.g. VLT/VLTI, ALMA, surveys such as LSST, JWST, SKA, etc) and where are they located?
  • Construction aspects: a flat surface on solid ground equivalent to several football fields is needed, over 1500 containers will need to be delivered to the construction site from all over the world, construction will last several years – what is the impact on construction cost and schedule of the location?
  • Logistical aspects: for its operations, the observatory will require up to 10 MW of power – is a power grid conveniently close? Where will the water come from? Where will the ca. 150 staff live (on site and privately)?

The site selection process was supported by FP6 activities described in an SPIE paper.
A Site Selection Advisory Committee (SSAC) was formed and was advising the ESO Director General who reports to council.

Impressions of some of the stuided sites

From left to right: Roque de los Muchachos (Canary Islands), Ventarrones (Chile), Aklim (Morocco), and Macon (Argentina).
Further pictures of the sites can be found in the Gallery.