On the summit of a remote mountain, about 4,200 metres above sea level, a large dome is taking shape. It will soon be one of the most powerful observatories on Earth.
More than 30 telescopes will dot the peaks of Saishiteng Mountain in China's northwest Qinghai province. It is one of the world's best stargazing sites, thanks to its high altitude, dry weather and lack of light pollution.
The dome will house a 2.5-metre telescope which will be one of the world's most powerful tools to observe the northern sky. It should be up and running by the end of this year.
The observatory will map the Milky Way to understand the evolution of stars. It will also look for events in the deep universe, such as the collision of black holes.
