Technicians work at the assembly site of the single-aperture spherical telescope "FAST" in Qiannan of southwest China's Guizhou Province, July 27, 2015. Assembly of the telescope, with a dish the size of 30 football fields and located deep in the mountains of Guizhou, has got underway. When it is completed in 2016, the five hundred meter aperture spherical telescope (FAST) will be the world's largest, overtaking Puerto Rico's Arecibo Observatory, which is only 300 meters in diameter. (Photo: Xinhua/Jin Liwang)
