The world's largest radio telescope, Five-hundred-meter Aperture Spherical Telescope (FAST) (Photo/Provided by FAST project office, National Astronomical Observatories, Chinese Academy of Sciences)

2. FAST telescope

The world's largest radio telescope, Five-hundred-meter Aperture Spherical Telescope (FAST), was put into use in a mountainous region of southwestern China's Guizhou province on Sept. 25, 2016.

FAST was built in a hollow that formed 45 million years ago, following the collapse of a karst cave. Work on the nearly 1.2-billion-RMB ($180 million) project started in 2011, 17 years after it was proposed by Chinese astronomers. FAST's tasks include the observation of pulsars as well as the exploration of interstellar molecules and interstellar communication signals.

To ensure the telescope's performance, more than 8,000 people were relocated to make way for the project, which requires radio silence within a 5-kilometer radius. Visitors to the zone must turn off their mobile phones.