The future Extremely Large Telescope

This architectural concept drawing of ESO’s planned Extremely Large Telescope (ELT) shows the world’s largest planned optical telescope gazing heavenwards. Slated to begin operations early in the next decade, the ELT will tackle the biggest scientific challenges of our time. A chief goal will be to track down Earth-like planets around other stars in the “habitable zones” where life could exist — one of the Holy Grails of modern observational astronomy. The ELT will also make fundamental contributions to cosmology by measuring the properties of the first stars and galaxies and probing the nature of dark matter and dark energy.

On top of this, astronomers are also planning for the unexpected — new and unforeseeable questions will surely arise from the discoveries made with the ELT. With a primary mirror measuring an astounding 39 metres across, the ELT will collect 25 times more light than one 8.2-metre telescope at ESO’s Very Large Telescope observatory in Chile, which is currently a world leader in terms of astronomical observational capacity.

The design for the ELT shown here was published in 2011 and is preliminary.