Probe reveals secrets of previously unexplored far side of the Moon

A Chinese probe which became the first spacecraft to land on the far side of the Moon has found the lunar surface to be covered in a layer of loose deposits made up of rock and dust.

This layer, known as lunar regolith, was formed over billions of years by constant meteorite impacts on the surface of the Moon.

The findings, published in the journal Science Advances, reveal some of these loose deposits to be up to 39ft (12m) thick.

As most of the knowledge on lunar regolith comes from Nasa’s Apollo and the Soviet Union’s Luna missions to the near side of the Moon, scientists were, until now, uncertain whether these observations would hold true elsewhere on the lunar surface.

Dr Elena Pettinelli, a professor in the mathematics and physics department of Roma Tre University in Italy and one of the study authors, said: “These series of ejecta or deposits came from different impact craters that were created during the evolution of the Moon’s surface.

“It is quite interesting because we can see quite clearly the geological sequences of these events 40 metres below the surface.”

The Chang’e 4 (CE-4) spacecraft landed on the Von Karman crater on January 3 2019.

Its rover, Yutu-2, which can climb 20-degree hills and 8in (20cm) tall obstacles, was deployed 12 hours later to explore the landing site.

Previous landings have been on the near side of the Moon, which faces Earth.

The far side, which cannot be seen because it faces away from Earth, has been observed many times from lunar orbits but never explored on the surface.

Using data gathered from the first two days of Yutu-2’s exploration, the researchers identified coarse granular materials up to a depth of 79ft (24m) below the lunar surface.

They were able to combine the rover’s high-resolution images and ground-penetrating radar scans from 131ft (40m) below the surface to create a picture of the Moon’s “internal architecture”.

Although the radar signal could not be detected below 131ft (40m), the researchers speculate that these granular materials might extend deeper.