The rise of a giant (I): nightly inside view
Birds eye view of the elaborate 3-dimensional model of the Extremely Large Telescope developed to determine expected performance during observing conditions. With a 40-meter-class diameter primary mirror, the present baseline, its total rotating mass is 5500 tons. The two platforms on each side of the structure hold large instruments. The telescope features a novel, innovative design, based on 5 mirrors. The primary 40-metre-class mirror is composed about 800 segments, each 1.45 m wide, while the secondary mirror is as large as 4.2 metres in diameter. A tertiary mirror, 3.75 metres in diameter, relays the light to the adaptive optics system, composed of two mirrors: a 2.5-m mirror supported by 5000 or more actuators so as to be able to distort its own shape a thousand times per second, and one 2.7 m in diameter that allows for the final image corrections. This five mirror approach results in an exceptional image quality, with no significant aberrations in the field of view.
The video shows a nightly inside view.
The design for the ELT shown here was published in 2009 and is preliminary.Crédit: