In China, a number of projects are being developed that would help answer the question of the uniqueness or massive distribution of biological life in the universe. One such project involves the search for Earth’s twins around sun-like planets in relative proximity to our star system using a space telescope. If the project is approved, a suitable telescope could be built and launched into space in 2027.

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Chinese scientists have selected about a hundred stars as candidates for the search for super-Earths in their habitable zone – where temperatures are moderate and water can be in liquid form. All selected stars are no further than 32 light years away from us. Each of the candidate stars is similar in characteristics to our Sun in order to consider the probability of the emergence of life near them high enough (taking into account the flow of heat, radiation, gravity and other factors).

To date, more than 5,000 exoplanets (planets outside the solar system) have been discovered by one method or another. Most of them are much larger than the Earth and are outside the habitable zone. The Chinese project Closeby Habitable Exoplanet Survey (CHES) will search for exoplanets with the mass of the Earth or a little more and located in any orbit. Why is it important?

Today, astronomical observation tools allow us to confidently detect only those exoplanets that cross the disk of the star of the observed system. This is only 0.5% of all possible orbits. In other words, there may be many more planets even where they have not yet been discovered. The finest measurements of the position of stars in the sky should help in their search. No matter how small a planet is compared to a star, it still has a gravitational effect on its star.

This means that stars with planetary systems are constantly making small movements in the sky. Having fixed these movements, it is possible to accurately calculate the size of a planet invisible from such a distance and calculate its orbit. And this orbit can be practically any inclination in relation to our field of view.

The new laser measurement technique underlying the CHES telescope will be 10 times more accurate than any modern system for such purposes. The measurement accuracy is such that the system will allow the Earth to distinguish the movement of an object on the Moon by one millimeter. If the telescope project is approved by experts this year, it can be launched into space in five years. Scientists plan to locate the CHES telescope at the L2 Lagrange point at a distance of 1.5 million km from the Earth. This is where the James Webb telescope is now located.

The CHES telescope is not the only Chinese project to look for signs of biological life in the universe. The Chinese scientific community is studying at least three more proposals related to the discovery of exoplanets. Thus, the Earth 2.0 project will use seven telescopes to study exoplanets in the Milky Way galaxy, with a transit approach similar to the Kepler telescope, but with a field of view 10 times larger. Like CHES, Earth 2.0 is also due for review in June and, if approved, is scheduled to launch in 2026-2027.

The Miyin project, which plans to use several small telescopes to search for habitable planets, is in the conceptual development stage. There is also a very ambitious space telescope called HABITATS (HABItable Terrestrial planetary ATmospheric Surveyor). This device with a 6-meter aperture is designed to detect molecules of water, oxygen and ozone in the atmosphere of exoplanets and should start working within 15–20 years.