The Chinese rover is exploring the interior of the far side of the moon

The Chinese spacecraft Yutu 2 has been on the far side of the moon since January 2019 and has been playing overtime for several years now, collecting various very interesting measurements. More recently, researchers have used the rover’s penetrating radar to investigate the composition of the upper layer of the lunar surface down to a depth of 300 metres, something that had not been done before.

Under the dark side of the moon

Yutu 2 is a rover developed by the China National Space Administration (CNSA) as part of the mission Chang 4. It was launched in December 2018, and aims to study the geology, topography, mineral composition, and surface structure of the far side of the Moon, in addition to conducting scientific experiments.

For operation, the car is equipped with several tools, incl Lunar Penetrating Radar (LPR). This is designed to make measurements of the subsurface of the Moon using radar waves in order to obtain information about the structure and composition of the subsurface layers of the Moon.

Specifically, the LPR is equipped with two channels that operate on different frequencies. On the one hand, a low frequency channel They emit long wavelength radar waves. These have the ability to deeper penetration on the Moon, because they are less likely to be reflected by the surface layers. This approach makes it possible to explore deeper layers. The second channel is used higher frequency Shorter radar waves tend to reflect more from the surface layers. Therefore, it provides information about properties closer to the surface.

In 2020, the Yutu-2 team has already used LPR to map the upper 40 meters of the lunar surface. Recently, the mission team pushed the limits of the instrument by diving into it Its depth is more than three hundred meters. Details of this work have been published in the journal JGR planets.

Testimony of ancient lunar volcanism

This new data indicates that forty meters The upper parts of the lunar surface are made up of several layers of dust, earth, and broken rock. It was hidden among these items buried hole. The debris surrounding this formation is therefore likely to be ejecta (debris from the impact). Below, the researchers outline Five distinct layers of lava The moon seeps into the landscape over time. The thickness of each layer is quite variable, ranging from 20 to 70 metres. Obviously, the thicker layers are the deeper.

According to the team, this data seems consistent with what we know about the ancient volcanic activity of the moon. We know that our natural satellite once existed Geologically very active And that lava was flowing on its surface. The famous lunar seas, which are nothing more than large basalt plains, testify to this ancient activity, as does the Von Karmann crater in the Antarctic-Aitken Basin, where Chang’e 4 landed.

The data presented here correspond to a series of basaltic eruptions that occurred billions of years ago. Concretely, these new measures show that this process has been achieved slowed down over time. Indeed, the fact that layers of igneous rocks thin as they approach the surface of the Moon indicate this Lava eruptions were less significant over time. In other words, the Moon was slowly cooling, gradually releasing its last lava flows.