This is the first image of the new Chinese mega telescope

In the remote location of Qilian Shan, a high mountain in China’s Qinghai province, a powerful new telescope went into operation on September 17, Chinese news agency Xinhua reported. Last week, the Wide Field Survey Telescope (WFST), which can survey the entire Northern Hemisphere sky, released its first image: an image of the Andromeda Galaxy, our neighboring galaxy, more than two million light-years away.

Because the Andromeda Galaxy spans a significant portion of the sky, it is difficult for astronomical telescopes to simultaneously capture an accurate and complete view of the galaxy and its surroundings. The WFST, which combines a large field of view and high-resolution imaging capabilities, created the multi-color image from 150 images taken over several nights.

The survey telescope, developed by the China University of Science and Technology and the Crimson Mountain Observatory of the Chinese Academy of Sciences in Nanjing, has a primary mirror with a diameter of 2.5 meters. At the center is a camera with a large 765 megapixel image sensor. According to proprietary information, it is the largest facility in the Northern Hemisphere for time-domain measurements (“time-domain astronomy”) – that is, the study of cosmic objects that change during observation.

“When the WFST is fully operational, we will be able to detect some very faint and distant signals from the sky, including those from distant galaxies and clusters of galaxies outside the Milky Way,” said Lou Zheng, the observatory’s chief engineer.

The WFST can map the entire northern sky in just three nights. In addition to research into the Milky Way and the Local Group – a cluster of galaxies that include the Milky Way and the Andromeda Galaxy – an extensive inventory of the smaller celestial bodies in the solar system is also planned. The focus is mainly on asteroids close to Earth and – to ensure safety in space travel – meteoroids.

The telescope has been nicknamed ‘Mozi’ – after the ancient Chinese philosopher Mozi (also Mo-tsu or Latinized Micius), who is said to have been the first in history to conduct optical experiments. Over a period of six years, he will scan the night sky for fast-moving phenomena. A three-month pilot phase will begin in October to lay the foundation for the six-year mission, expected to begin in 2024.

One of the main goals of the new telescope will be to detect tens of thousands of supernovae. Astronomers hope that about 100 of these exploding stars will be found each year within a few days of their explosion, as the scientific journal Nature writes. Such events are difficult to detect for smaller telescopes because supernovae appear faint in their early phase. The WFST will be able to capture such supernova onsets by observing them in the near-ultraviolet region (wavelength 180 to 400 nanometers).

Observations at these and other wavelengths will also allow astronomers to study other transient phenomena in more detail. These include kilonovae – flashes of light that occur when two neutron stars merge – or tidal disruptions that occur when a star is pulled apart by a supermassive black hole.

Construction of the telescope began in July 2019. It is located 80 kilometers east of Lenghu on the 4,200-meter Peak C of the Saishenteng Shan. The area is known as China’s “Mars Camp” because of its eroded desert landscape that resembles the surface of the Red Planet. The WFST is just one of 35 optical and infrared observing telescopes being built, five of which, including the WFST, are already in use.

Mars Camp offers the benefits of clear night skies, stable atmospheric conditions, a dry climate and low light pollution. This means that it has the potential to become one of the most suitable locations for astronomical observations on the Eurasian continent.