It is expected that the Chinese spacecraft will become the first to land on the "far side" of the moon, in a milestone for exploring the human space.
The craft aims to land in the unexplored South Pole-Aitken basin, the largest, oldest, deepest, crater on the moon's surface.
The robotic probe, Chang & # 39; e 4, entered an elliptical path around the moon at the weekend, receiving approximately 15 km (9 mi) of the surface. Control of the mission in China did not confirm time for a landing attempt, but state media reports suggested it would be early Thursday in Britain Thursday.
The spacecraft had previously photographed the long sides of the moon, but no one touched them there. If successful, Chang will mark a step forward to China's ambition to become the leading force in space exploration along with the US and Russia.
A technological hurdle in targeting the moon side that is constantly facing the Earth is the direct communication with the spacecraft is not possible. Therefore, the messages to and from Chang's 4 are transmitted via the Queqiao (Magpie Bridge) satellite, which is in the "halo orbit" on the other side of the moon.
The mission aims to make detailed measurements of the terrain and mineral composition of the Moon. It is believed that the Ictken's basin was formed during a huge collision very early in the history of the moon. The collision is likely to throw material from inside the moon, which means that Chang can provide new clues as to how the natural satellite has been formed.
The outside of the moon is also considered an attractive location for radio astronomy. The telescope located there will be protected from human radio activities, which could potentially be more sensitive to the radios coming from the sun or the signals from the deep space disappearing. Chang's 4 has an instrument for assessing the "electromagnetic purity" of the site as the first step to assess the possibility of installing a telescope there.
Lucy Green, space research scientist at University College London, said: "You are completely protected from all the emissions we produce on Earth so you can get data that we can not get elsewhere. the years of the potential of the telescope on the far side. This mission can pave the way for more serious development on that side. "
Since the ring cycle of the moon is the same as the cycle of rotation, the same side of the planetary body always faces the Earth. The other person, most of which can not be seen from the Earth, is called the distant side or "dark side" of the moon, not because it is dark, but because the majority of it is undisturbed.