Also known as the ‘dark side of the moon’, the ‘far side of the moon’ is the hemisphere of the Moon that always faces away from Earth. Rugged with a multitude of impact craters, it is home to one of the largest craters in the Solar System, the South Pole–Aitken basin. However, all the manned and unmanned soft landings have taken place on the near side of the Moon and this side of the moon remained the most sidelined one in terms of landings until ‘China’s Chang’e 4 spacecraft’ made the first landing on this untravelled surface on January 3, 2019.
Previous lunar landers have landed on the Earth-facing side, but this is the first time any craft has landed successfully on the unexplored and rugged far side. The Chang’e-4 was launched from Xichang Satellite Launch Centre in China on 7 December and arrived in lunar orbit on 12 December.It was then directed to lower itself towards the Moon, being careful to identify and avoid obstacles and finally it landed on its target on January 3,2019.
The Chang’e-4 probe is mainly aiming to explore a place called the Von Kármán crater, located within the much larger South Pole-Aitken (SPA) Basin, thought to have been formed by a giant impact early in the Moon’s history.Being one of the largest impact craters in the Solar System and the largest, deepest and oldest basin on the Moon, this huge structure is over 2,500km (1,550 miles) in diameter and 13km deep.
Instruments onboard the Chang’e lander and rover will also aim to study the local lunar geology, probe the moon’s interior, and analyse the solar wind, a stream of high-energy particles that flow from the sun. The lander also carries a container with six live species from Earth – cotton, rapeseed, potato, fruit fly, yeast and arabidopsis (a flowering plant) , in order to form a mini biosphere there. In this way, Onboard experiments will also test how well plants grow in the weak lunar gravity.
According to Chinese state media, The ‘Arabidopsis’ plant may produce the first flower on the Moon.
The lander also has an imaging spectrometer to identify minerals.Scientists believe that the far side could be an excellent place to perform radio astronomy, because it is shielded from the radio noise of Earth. The spectrometer will also aim to test this idea.The lander is communicating with Earth using a relay satellite, as with no view of Earth, there is no way to establish a direct radio link.
This mission is a part of a larger Chinese programme of lunar exploration.The far side of the moon is of particular scientific interest as it is heavily pockmarked by deep craters, more than the nearside, where a succession of lava flows have obscured many of the earliest impacts. Scientists are still trying to understand why there are differences between the two faces of the moon and may be, this lander will help them to find some of the answers.
According to Prof Andrew Coates, a space scientist at UCL’s Mullard Space Science Laboratory, this lunar lander of China is one of the greatest technological accomplishment that has ever taken place !