Every discovery starts with a cloudless night. To an astronomer, broadening horizons means reaching for the stars.
But if you’re spending your nights stargazing, you're happy for any help you can get. Only one thing’s better than a large telescope aperture: an even larger telescope aperture. Brown dwarves, red giants, black holes, perhaps even extraterrestrial lifeforms – what may have started as a school project today might quickly wind up as an entry in tomorrow’s history books.
This and no less is what the scientists at the Extremely Large Telescope (ELT) are hoping for. The telescope, that SCHOTT is helping to build in Chile’s Atacama Desert, should be making those aliens nervous. Humanity’s largest-ever eye has great expectations to fulfil once it’s completed in 2024: no less than finding proof of life in space.
The leap in progress of the giant telescope can be compared to Galileo Galilei’s 400 years ago, when he became the first person to use not only his unaided eye but also a spyglass to observe the starry sky.
To discover new worlds, you need to push the limits of perfection. For the ELT, this means a millionth of a millimetre can make a difference. The material used for the mirrors will become the key to a sharp view of the Universe. The monumental project is possible only thanks to mirror substrates made of ZERODUR® and its thermal expansion coefficient approaching zero.
For space telescopes, ZERODUR® can go on a diet – weight loss guaranteed. The mirrors can be
lightweighted by a factor approacing ninety percent, a property no less important than the fact that the material is prctically impervious to the rigors of space launch.
From Chile to Mallorca, from Hawaii to Hebei – the world’s largest and most powerful telescopes rely on proven mirror substrates of exceptional quality.
SCHOTT has supplied them with monolithic mirror blanks made of ZERODUR® glass-ceramic with diameters of up to 8.2 metres. That’s roughly the length of two average compact cars.
But large is still a far cry from gigantic. However, several substrates combined results in a giant segmented telescope. The ELT’s thirty-nine-metre primary mirror employs 798 hexagonal segments. 798 times perfection, 798 tailored fits, 798 times quality that scientists can rely on.
Incidentally, SCHOTT has prior experience in extra-terrestrial performances. In 1969, optical glass made in Mainz was aboard the first manned moon landing. In 2014, special glass in the panoramic camera fitted to the comet lander Philae for the Rosetta mission was still delivering spectacular photos even after ten years’ exposure to cosmic radiation.
The same applies to camera systems with innovative filter solutions, such as those used to survey Earth. Even the astronomers at the mega-telescope in Chile should be effortlessly visible. Clouds shouldn’t cause much trouble either, by the way. The skies are clear there 360 nights a year. A stargazer’s paradise.