반사경 제작 중인 세계 최대의 망원경 E-ELT 2017.05.24. 19:40 (This diagram shows the novel 5-mirror optical system of ESO's Extremely Large Telescope (ELT). Before reaching the science instruments the light is first reflected from the telescope's giant concave 39-metre segmented primary mirror (M1), it then bounces off two further 4-metre-class mirrors, one conve..