Installation was completed on the world's largest radio telescope on Sunday as the last of 4,450 panels was fitted into the centre of the big dish.
Hoisting of the last triangular panel to the reflector, which is the size of 30 football fields, began at 10.47 a.m. and lasted about an hour. It was a landmark step for the telescope's planned launch of operations in September, Xinhua news agency reported.
About 300 people, including builders, experts, science fiction enthusiasts and reporters, witnessed the installation at Karst Valley in the southwestern province of Guizhou.
"The telescope is of great significance for humans to explore the universe and extraterrestrial civilisations," said Liu Cixin, a renowned science fiction writer.
"I hope scientists can make epoch-making discoveries," said Liu, who won the 2015 Hugo Award for Best Novel.
Scientists will begin debugging and trial observation of the 500 metre Aperture Spherical Telescope (FAST), said Zheng Xiaonian, deputy head of the National Astronomical Observation (NAO) under the Chinese Academy of Sciences, which built the telescope.
The project has the potential to search for more strange objects to better understand the origin of the universe and boost the global hunt for extraterrestrial life, said Zheng. It will be the global leader for the next 10 to 20 years.
In the first two or three years after its completion, the telescope will undergo further adjustment, and during that period Chinese scientists will use it for early-stage research.
After that, it will be open to scientists worldwide, said Peng Bo, director of the NAO Radio Astronomy Technology Laboratory.
Upon completion, the telescope will dwarf Puerto Rico's Arecibo Observatory, which is 300 metres in diameter. It will also be 10 times more sensitive than the steerable 100-metre telescope near Bonn in Germany, he said.
Work on the 1.2-billion-yuan ($180 million) FAST project began in 2011.