The moon is tidally locked to Earth, rotating at the same rate that it orbits our planet, so the far side - or the "dark side" - is never visible from Earth. Previous spacecraft have seen the far side of the moon, but none has landed on it.
China launched the Chang'e-4 probe earlier this month, carried by a Long March-3B rocket. It includes a lander and a rover to explore the surface of the moon.
Xinhua said that the probe had entered an elliptical lunar orbit at 08.55 Beijing time, which brought it at its closest point just 15 kilometres away from the surface of the moon. The Chang'e-4 first entered a lunar orbit on Dec. 12. The tasks of the Chang'e-4 include astronomical observation, surveying the moon's terrain, landform and mineral composition, and measuring the neutron radiation and neutral atoms to study the environment on the far side of the moon. China aims to catch up with Russia and the United States to become a major space power by 2030.