Chinese Vice Premier Liu Yandong (3rd L) attends the launch ceremony of the Five-hundred-meter Aperture Spherical Telescope (FAST) in Pingtang, southwest China's Guizhou Province, Sept. 25, 2016. The FAST, the world's largest radio telescope, measuring 500 meters in diameter, was officially put into use on Sunday. (Xinhua/Jin Liwang)