Editor's note:

The world's largest single-aperture spherical telescope, "FAST", starts operation in a karst valley in Pingtang county, Guizhou province, on Sunday. The size of 30 football fields, the 500-meter Aperture Spherical Telescope dwarfs Puerto Rico's 300-meter Arecibo Observatory. Construction began in March 2011 at a cost of 1.2 billion yuan ($179 million).

This scene taken from FAST's viewing platform shows the panorama of the 500-meter Aperture Spherical Telescope in Pingtang county, Guizhou province, Sept 24, 2016. [Photo/Xinhua]