Full Steam Ahead for ELT’s Giant Primary Mirror
Construction of a crucial part of ESO’s Extremely Large Telescope (ELT) is starting — the gigantic main mirror.
At 39 metres in diameter, the ELT’s primary mirror dwarfs the mirrors of all other telescopes.
It will be composed of 798 individual hexagonal segments, each 1.4-metres across.
They will be polished incredibly precisely…
...so if each segment were the size of France, its surface irregularities would be no higher than a ladybird!
Together, the 798 segments will collect tens of millions of times more light than the human eye.
Contracts have now been awarded to SCHOTT in Germany and Safran Reosc in France for the manufacture of the segments.