Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016. (Photo: Xinhua)

Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016.

Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016.

Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016.

Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016.

Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016.

Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016.

Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016.

Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016.

Photo taken on Aug. 27, 2019 shows China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) in southwest China's Guizhou Province. China's FAST, the world's largest single-dish radio telescope, will greet the third anniversary of operation that began in September 2016.