Dr Elise Vernet is an adaptive optics specialist at ESO, and has overseen the development of the five giant mirrors that will collect light and transmit it to the telescope’s measuring equipment.
Each of the custom mirrors offered by ELT is a feat of optical design.
Dr. Vernet describes the 14-foot (4.25-meter) M2 convex mirror as a “piece of art.”
But perhaps the M1 and M4 mirrors best express the level of complexity and precision required.
The M1 primary mirror is the largest ever made for an optical telescope.
“It’s 39 million.” [128ft] In Qatar, it consists of: [798] “The mirror is made up of hexagonal parts, arranged so that it behaves like a perfect homogeneous mirror,” says Dr. Vernet.
The M1 will collect up to 100 million times more light than the human eye and should be able to maintain position and shape to a level of precision 10,000 times finer than a human hair.
The M4 mirror is the largest deformable mirror ever built and will be able to change shape 1,000 times per second to correct for atmospheric turbulence and vibrations of the telescope itself that can distort images.
Its flexible surface consists of six petals of a glass-ceramic material less than 2 mm (0.075 in) thick.
The petals were manufactured by Schott in Mainz, Germany, and then shipped to the engineering firm Safran Reosc outside Paris, where they were polished and assembled to a perfect mirror finish.
The manufacturing process of the five mirrors is nearing completion and they will soon be transported to Chile for installation.