SCHOTT is part of the new mega project of the European Southern Observatory (ESO): the Extremely Large Telescope, ELT for short, that will have a main mirror 39 meters in diameter and is currently being built in Chile. These dimensions will make it the largest ground-based optical telescope in the world for visible and near-infrared light ... We are “extremely” happy to be part of it!

On this platform, you will find news, stay informed about important milestones of the project and get exciting and exclusive insights into our contribution to the new mega telescope. Follow us on social media too!
4-meter mirror blank cast for the ELT project

4-meter mirror blank cast for the ELT project


The ELT team of SCHOTT Advanced Optics cast the 4.25-meter secondary mirror substrate (M2) for the Extremely Large Telescope (ELT) mid of May.
ELT site Chile: Land of extremes

ELT site Chile: Land of extremes


After careful consideration, the ESO selected Chile as the site of the world’s largest telescope. Optimal conditions for astronomical observation were required.
SCHOTT New CNC machine

“Extremely” precise


New CNC machine enables highly accurate processing of mirror components for the Extremely Large Telescope (ELT).

Capacity expansion in record time


Interview about the challenges of constructing the second ZERODUR® glass-ceramic melting tank and perfect teamwork.

The optical system of the ELT and the role of ZERODUR®


This infographics shows the novel 5-mirror optical system of ESO's Extremely Large Telescope (ELT) and the position of the ZERODUR® mirror substrates.
SCHOTT contract M2 & M3 mirror

Unexplored depths: the world’s largest telescope will peer out into space with technology from Mainz


SCHOTT has been awarded a contract for the production of mirror substrates for the secondary (M2) and tertiary mirrors (M3) of the Extremely Large Telescope. M2 will be the largest convex mirror ever produced.