Active optics experiment at ESO

In 1987, active optics was a concept under experiment at ESO headquarters in Garching, Germany. Active optics uses motorised telescope supports, like those seen here, below a thin and deformable mirror to correct for changes in shape caused by gravity. This, then, allowed optical telescope mirrors to become larger. After this successful experiment, active optics was deployed on ESO’s New Technology Telescope (NTT) in 1990 and has been used on many telescopes since.