A Chinese spacecraft is expected to be the first ever land on the Moon's "far side", in a milestone for human space exploration.
The craftsmanship aims to land in the unexplored south pole Aitken basin, the largest, oldest, deepest crater on the lunar surface.
The robot probe, Chang 4, came in an elliptical way around the moon over the weekend and came as close as 15 km from the surface. China's mission control has not confirmed a time for the touchdown attempt, but reports in state-run media suggested it would be early Thursday morning in Britain.
Spacecraft has taken pictures of the lunar long side before, but no farmer has ever touched down there. If successful, Chang & # 39; ll mark a step toward China's ambition to become a leading force in space research with the US and Russia.
A technological obstacle in the target side of the moon, which constantly turns away from Earth, is that direct communication with the spacecraft is not possible. So messages to and from Chang 4 are relayed by the Queqiao (Magpie Bridge) satellite, which is in a "halo circuit" across the moon.
The mission is to take detailed measurements of the moon's terrain and mineral composition. The Aitken basin is believed to have been formed during a gigantic collision very early in the history of the moon. The collision is likely to have thrown material from the lunar interior, which means that Chang & # 39; s new traces of how the natural satellite was formed.
The distant side of the moon is also seen as an attractive place for radio astronomy. A telescope lying there would be shielded from human radioactivity, potentially making it more sensitive to radio bursts coming from the sun or weakening signals from the deep space. Changing 4 carries an instrument for "electromagnetic cleanliness" of the location as a first step to assess the possibility of placing a telescope there.
Lucie Green, a space researcher at University College London, said: "You are completely shielded from all the emissions we produce on Earth so you can get data that we couldn't get anywhere else. There has been a lot of talk over the years the possibility of having a telescope on the far side. This mission could pave the way for more serious development on that side. "
Since the Moon's revolution cycle is the same as its rotational cycle, the same side of planetary body always stands above the ground. The other face, most of which cannot be seen from Earth, is called the lunar distant side or "dark side", not because it is dark, but because most of it is uncharted.