China’s Chang’e 4 mission, the first to perform a soft landing on the far side of the Moon, has shed light on the chemical and mineralogical composition of the lunar mantle, an advance that could unravel the mystery of the evolution of Earth and its natural satellite.

What was the speciality of Chang’e 4 probe?

The Chang’e 4 probe — named after a Chinese moon goddess — made the world’s first soft landing on the moon’s “dark side” on January 3, a major step in China’s ambitions to become a space superpower. The rover Yutu-2 then rolled off the lander to explore its surroundings.

What does the new findings say?

Using data obtained by the visible and near infrared spectrometer installed on Yutu-2, a research team led by Li Chunlai, with the National Astronomical Observatories of China under the Chinese Academy of Sciences, found that the lunar soil in the landing area of the Chang’e-4 probe contains olivine and pyroxene which came from the lunar mantle deep inside the Moon.

The first important scientific discovery of the Chang’e 4 probe was published online in the latest issue of the academic journal Nature.

The Moon comprises a core, mantle and crust, like the Earth. With the evolution of lunar magma, the light plagioclase rose to the upper layer to form the lunar crust, while the heavier olivine and pyroxene sank to form the lunar mantle, Li said. “But since the lunar crust is very thick, and there has been no volcanic activity and plate movement on the Moon for billions of years, it’s hard to find materials from the lunar mantle on the surface,” Li told state-run Xinhua news agency.

The rover landed inside a 180 kilometer wide impact bowl called Von Karman crater. But that smaller crater lies within the 2,300 kilometer wide South Pole Aitken (SPA) Basin, which covers nearly a quarter of the Moon's circumference.

The results could now help scientists understand the chemical and mineralogical composition of the mantle, which could shed light on the origins and evolution of the moon itself, it said. The team members also want to find out more about what happened after the asteroid collided with the Moon and formed the SPA Basin.

Scientists predict that the hole in the surface may have been filled by molten rock — forming a “melt sheet” within the impact bowl, which complicates the picture of this region’s geology.

Analysis showed the lunar soil in the landing area contains a large amount of olivine, low-calcium pyroxene and a small amount of high-calcium pyroxene, which are very likely from the lunar mantle, Li said.