China Wants to Search for Habitable Planets to 'Expand Our Living Space'

China wants to start hunting down habitable exoplanets with a dedicated satellite with a view to "expand our living space" within the cosmos. The proposed mission will be the first to search for habitable planets beyond our solar system with a space-based telescope.

The project, named the Closeby Habitable Exoplanet Survey (CHES) would make use of a space telescope with a 3.9 foot aperture that would be placed in a point in space not far from Earth known as the L2 point, the same location as NASA's new James Webb Space Telescope, Chinese state-run news outlet CGTN reported on Thursday.

China is currently in the process of expanding its space program, having announced an ambitious five year plan in a report released in January. This included plans to explore the boundary of the solar system.

The CHES telescope would then explore around 100 stars similar to the sun at a distance of around 32 light years. The scientists who have proposed the project hope that around 50 Earth-like exoplanets—planets located outside of the solar system—could be discovered in habitable zones around their host stars.

The project is still a proposal for now and it's not certain that it will be carried out.

A stock illustration depicts an exoplanet in space. Scientists have found more than 5,000 planets outside of the solar system. dima_zel/Getty

However, preliminary investigations for the project have been conducted by a team from several Chinese research institutions, supported by the Chinese Academy of Sciences.

Ji Jianghui, a professor from the Purple Mountain Observatory of the Chinese Academy of Sciences and principal investigator of the CHES mission, told CGTN that the project will aim to answer questions about how planets might become habitable and whether life exists elsewhere in the universe.

"The discovery of the nearby habitable worlds will be a great breakthrough for humankind, and will also help humans visit those Earth twins and expand our living space in the future," Ji told CGTN.

The telescope will detect other planets using a method known as astrometry, a tried and tested way of finding other worlds.

Astrometry involves looking at a star and measuring how much it wobbles compared to other stars around it. If a star is wobbly, that suggests that it has a planet or multiple planets orbiting it, because these planets exert a small gravitational force on the star which causes it to move slightly. Scientists can use this method to work out the mass of exoplanets as well.

Artist representation of Trappist-1f, one of the potentially habitable planets announced by NASA in 2017. China has proposed a mission to launch a satellite to search for habitable planets. NASA/JPL-Caltech/T. Pyle IPAC

Exoplanet research is a rapidly-advancing field of astronomy. Scientists only discovered the first exoplanets in the 1990s, and since then the number of known worlds outside the solar system has shot up to more than 5,000.

Known exoplanets include small, rocky worlds like Earth to gas giants even bigger than Jupiter. Their conditions range hugely. Some of the worlds are thought to orbit within their star's habitable zone, and others have conditions so nightmarishly inhospitable that it would be impossible for life as we know it to survive there.

In 2017, NASA announced the discovery of a solar system just 40 light years away called Trappist-1. This system was home to seven rocky exoplanets similar to Earth, three of which were found to be located in the habitable zone—meaning they could potentially host liquid water on the surface.

It is currently impossible to send humans to planets beyond our solar system. It would take approximately 39 years traveling at the speed of light to reach the Trappist-1 system. According to, if a spacecraft were to travel at the same speed as Voyager 1—around 38,200 mph—it would take roughly 685,000 years to get there.