The European Extremely Large Telescope (E-ELT)

The European Extremely Large Telescope (E-ELT)

The European Extremely Large Telescope (E-ELT) is a ground-based extremely large telescope for the optical/near-infrared range, that is being planned by the European Southern Observatory (ESO). Early designs included a filled single aperture mirror with a diameter of 42 metres and area of about 1300 m2, with a secondary mirror with a diameter of 5.9 m. However, in 2011 a proposal was put forward to reduce its size by 13% to 978 m2, for a 39.3 m diameter primary mirror and a 4.2 m diameter secondary mirror. This reduces the projected costs from 1.275 billion to 1.055 billion euros and should allow the telescope to be finished sooner. However, it will likely make it harder for the telescope to image Earthlike exoplanets, though that goal is still possible.