China Moon mission lands Chang’e-4 spacecraft on far side

What to know?

• China has successfully landed a robotic spacecraft on the far side of the Moon, the first ever such attempt and landing.
• The un-crewed Chang’e-4 probe touched down in the South Pole-Aitken Basin.
• It is carrying instruments to analyse the unexplored region’s geology, as well to conduct biological experiments.
• The landing is being seen as a major milestone in space exploration.
• There have been numerous missions to the Moon in recent years, but the vast majority have been to orbit, fly by or impact. The last crewed landing was Apollo 17 in 1972.

Why is this Moon landing so significant?

• Previous Moon missions 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; it arrived in lunar orbit on 12 December.
• It was then directed to lower itself toward the Moon, being careful to identify and avoid obstacle.
• The Chang’e-4 probe is 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.
• This huge structure is over 2,500km (1,550 miles) in diameter and 13km deep, one of the largest impact craters in the Solar System and the largest, deepest and oldest basin on the Moon.
• The event responsible for carving out the SPA basin is thought to have been so powerful, it punched through the Moon’s crust and down into the zone called the mantle. 

What else might we learn from this mission?

• Chang’e-4’s static lander is carrying two cameras; a German-built radiation experiment called LND; and a spectrometer that will perform low-frequency radio astronomy observations.
• Scientists believe the far side could be an excellent place to perform radio astronomy, because it is shielded from the radio noise of Earth. The spectrometer work will aim to test this idea.

Other equipment/experiments include:

• A panoramic camera
• A radar to probe beneath the lunar surface
• An imaging spectrometer to identify minerals
• An experiment to examine the interaction of the solar wind (a stream of energised particles from the Sun) with the lunar surface

The mission is part of a larger Chinese programme of lunar exploration. The first and second Chang’e missions were designed to gather data from orbit, while the third and fourth were built for surface operations.