NASA's Hubble telescope to be challenged by China's Xuntian telescope in 2023; Here's how

After challenging the West on the space station front, China is now aiming to launch its own space telescope by 2023 to make new cosmic discoveries. Named the Chinese Space Station Telescope (CSST), or Xuntian, meaning 'survey to heavens', the telescope is said to compete against NASA's Hubble telescope and might even outrun it in some aspects. According to Liu Jifeng, deputy director of the National Astronomical Observatories Of China (NAOC), the Xuntian telescope is as big as a three-storied building.

(The Hubble Space Telescope; Image: NASA)

He revealed that the telescope has a two-meter-wide aperture, which is slightly smaller than Hubble (2.4m) but has a field of view 350 times larger than the American telescope, CGTN reported. It is worth noting, however, that the Hubble telescope was launched in 1990 and runs on the technology of the past, whereas the Chinese observatory will use modern technology and hence would yield better results.

China compares Xuntian with Hubble

Further revealing details about the Chinese space telescope, Jifeng said that since Hubble has a smaller field of view, it has only scanned a relatively smaller area of the sky. A field of view defines the area of the sky observed by a telescope at a given time. The Chinese official said that Hubble's field of view is no bigger than 1% of the average size of a fingernail held at arm's length, whereas the Xuntian telescope will cover a slightly larger area and provide sharper images. 

Zhan Hu, project scientist of the CSST Optical Facility said as per CGTN, "It has an advantage for survey observations since it can scan a large part of the universe fairly quickly". As per Hu, the Chinese space telescope will be equipped with nine instruments and will photograph 40% of the sky by observing billions of galaxies and their positions, shapes and brightness. The purpose of this, Hu said, is to determine how the evolution of these galaxies took place. In addition to this, the telescope will also be used to unravel the most mysterious subjects in astronomy - dark energy and dark matter - which make up around 95% of the observable universe.

The China National Space Administration (CNSA), Beijing's space agency, has decided to install the telescope in the same orbit as its space station- Tiangong, whose construction will be completed by the end of 2022. Notably, Zhan has said that the Xuntian telescope will likely be the largest space observatory scanning the cosmos in the near-ultraviolet and visible light.