An engineer of China's Five-hundred-meter Aperture Spherical Radio Telescope (FAST) shows the website to submit applications for observations, southwest China's Guizhou Province, March 31, 2021. China's Five-hundred-meter Aperture Spherical Radio Telescope (FAST), the world's largest single-dish and most sensitive radio telescope, officially opened to the world starting Wednesday. (Xinhua/Ou Dongqu)
