SCHOTT has produced its 500th ZERODUR mirror blanks for the M1 primary mirror of the European Southern Observatory’s Extremely Large Telescope (ELT), the company announced.

The ELT is expected to become operational in 2027, and it will be the world’s largest visible and infrared light telescope in the world. It is currently under construction on Cerro Armazones in Chile’s Atacama Desert.

“We are very proud to help shape the future of astronomy by supporting the European Southern Observatory in their important work on the ELT,” said Thomas Werner, head of the ELT project at SCHOTT.

The telescope features five-mirror optical designs that will allow it to unveil the universe in unprecedented detail, states the European Space Observatory (ESO). The five mirrors, M1, M2, M3, M4 and M5, each have different shapes, sizes and roles. The ESO claims that the ELT will gather 100,000,000 times more light than the human eye, will be 8,000,000 times stronger than Galileo’s telescope and 20 times more powerful than a Very Large Telescope (VLT) unit telescope.

Along with the M1 mirror blanks, ZERODUR will also feature on the ELT’s convex M2 mirror (4.2 meters), concave M3 mirror (3.8 meters), and adaptive M4 mirror (2.4 meters).

SCHOTT signed a contract with ESO in 2017 to supply a total of 949 ZERODUR® mirror blanks for the ELT’s M1 primary mirror (including 798 mirror blanks, 133 spares and 18 prototype segments). Overall, SCHOTT has worked alongside the ESO on the ELT for more than 15 years, said Dr. Thomas Westerhoff, head of the ZERODUR special business unit at SCHOTT.

ZERODUR mirror blanks help large telescopes gather light from the night sky that is far away. Since they have an extremely low thermal expansion, the mirror blanks can reflect light in a highly precise manner, even under extreme temperature shifts. In the ELT, they will also help correct for distortions to the starlight from the Earth’s atmosphere, which means that it will be able to provide images 16 times sharper than the Hubble Space Telescope.

“The whole team here at SCHOTT is very excited and proud to help shape the future of astronomy by supporting the European Southern Observatory with its important work on the Extremely Large Telescope,” Westerhoff said. “The stunning images of the deep universe from the James Webb Telescope are already fascinating, and we can’t wait to see even more details with the ELT in the future.”