The European Extremely Large Telescope (ELT) is a revolutionary scientific project for a 40m-class telescope that will allow us to address many of the most pressing unsolved questions about our Universe.

The ELT will be the largest optical/near-infrared telescope in the world and will gather 13 times more light than the largest optical telescopes existing today. The ELT will be able to correct for the atmospheric distortions (i.e., fully adaptive and diffraction-limited) from the start, providing images 16 times sharper than those from the Hubble Space Telescope. The ELT will vastly advance astrophysical knowledge by enabling detailed studies of planets around other stars, the first galaxies in the Universe, super-massive black holes, and the nature of the Universe's dark sector (more).

The ELT project is included in the European Strategy Forum on Research Infrastructures (ESFRI) List of Opportunities. It has also been ranked in the 2010-2025 ASTRONET European strategic planning as one of two clear top priorities for future ground-based astronomical infrastructures.

The project has completed the ELT's detailed design, which passed the Final Design Review successfully in September 2010. Between the end of 2010 and the summer of 2011 the ELT project extended the detailed design phase in order to consider the recommendations of the ELT Design Review. The main goals were the reduction of risk by optimising the cost and constraining the schedule in order to ensure that ESO can further expand its leading role in astronomy by constructing the world’s first extremely large telescope.

In June 2011 ESO Council endorsed a revised baseline design for the ELT. This led to a significant cost saving and to a reduction of risk on major items such as the secondary mirror.

Preparatory construction work on some of the ELT's first elements has commenced in early 2012 (more).

In December 2012 ESO Council fully approved the ELT Programme (more, more, even more, still more). On-site work began in March 2014, with a groundbreaking event in June 2014 (more).

In December 2014 ESO Council approved the construction of the ELT in two phases, and authorised spending on Phase 1. The construction of the ELT is now in full swing.

Also in December 2014 a new policy for the awarding of GTO time on the ELT was approved by Council at its meeting. See the Policy Document.

The ELT is planned to start operations as an integrated part of the Paranal Observatory in 2025.

The European Extremely Large Telescope — the World’s Biggest Eye on the Sky