In the late 13th century, Chinese astronomer, engineer and mathematician Guo Shoujing started his work rebuilding and improving the astronomy instruments in Dadu, the capital city of the Yuan Dynasty (1271-1368).

With the new instruments, Guo collected the most accurate data in his time on changing seasons, and rotation and orbit of the Earth. He even led an unprecedented massive astronomical observation.

Seven hundred years passed, now Chinese scientists are carrying out a massive sky survey with a telescope named after him, the Guo Shoujing Telescope, or the Large Sky Area Multi-Object Fiber Spectroscopic Telescope.