ESO Open House Day 2011

The full-size replica of the E-ELT’s 39.3-metre mirror is completed after four hours of assembly by children, adults and ESO volunteers at ESO’s Open House Day 2011 in Garching bei München. The mock-up was made of 798 cardboard hexagons, each around 1.4 metres across. The E-ELT will be the largest optical/infrared telescope in the world.