Xinhua pictures of the year 2018

Researchers check the surface of a four-meter-aperture optical mirror developed by Changchun Institute of Optics, Fine Mechanics, and Physics of the Chinese Academy of Sciences in Changchun, northeast China's Jilin Province, Aug. 21, 2018. China has developed a high accuracy four-meter-aperture optical mirror, an important tool for deep space and astronomical observation. (Xinhua/Xu Chang)