The world's largest radio telescope has officially opened to the world to aid global research. Footage, filmed in Pingtang County in Guizhou Province on March 31, shows the exterior of the 500-metre aperture spherical radio telescope (FAST) known as "Sky Eye." Observation invitations were sent to scientists across the world. About 10 percent of FAST's observation time, which is around 450 hours, is expected to be allocated to foreign scientists. Foreign scientists can submit their applications online and the observation time cannot be more than 100 hours. The results will be announced on July 20 and observations will start in August. The video was provided by local media with permission.