China is launching a space mission in a few days to bring rock samples from the unseen side of the Moon

​China will launch in the first days of May one of the most important space missions in its history: Chang’e-6, which aims to bring, for the first time, samples of rock and soil from the unseen side of the Moon. In the following years, the missions will become even more complicated, with the goal being to take “taikonauts” to the Moon by 2030.

The Chang’e-6 mission is scheduled to launch this week and will last 53 days. It will be complicated, because the goal is to bring to Earth materials from the hidden side of the Moon, and the difficulties are many. The probe aims to collect 2 kg of lunar samples.

In preparation for this mission, China also launched a signal relay satellite in March. Queqiao-2 will orbit the Moon and relay signals to and from the Chang’e-6 mission.

This satellite will also be used for the Chang’e-7 and 8 missions scheduled for 2026 and 2028 – missions that aim to begin exploring the lunar south pole in search of frozen water.

China brought samples from the visible side of the Moon back to Earth in 2020, proving that its technology is viable. The quantity was important: 1.73 kg.

The Lunar South Pole is considered to be an essential area for future exploration, in the idea of ​​establishing an inhabited outpost on the Moon, as the polar ice could support the operation of future space bases, without the need for extremely expensive resources to be brought in by on Earth.

What is the hidden face of the moon like?

This hidden face is very different from the one that is visible. The face we see is composed of vast plains of cooled lava called “maria” (Latin for seas). The far face is full of craters because it was hit by asteroids.

The lack of volcanic activity on the far side of the Moon means that there are many craters there that have not long been covered by lava flows, preserving material from the early stages of the Moon’s formation.

A Chinese probe, Chang’e 4, landed there in 2019.

It was an image blow for China, a country that wanted to show that its space program has become a world-class one, the success being an important one from a technical point of view, but also symbolically. The Yutu 2 rover sent back information about the ground in that crater after using a ground-scanning radar.

NASA’s Lunar Reconnaissance Orbiter has also sent many photos in recent years.

Why does the moon have a hidden face

Why can’t we see the entire surface of the Moon from Earth? The Moon always presents the same face to the Earth and this means that part of the Moon always remains hidden from our eyes. But it would be a mistake to call that side “dark side of the moon”, as the title of a famous Pink Floyd album sounded.

This hidden, rugged face of the Moon was first photographed by a Soviet space probe called Luna 3 in 1959 and was first seen directly by humans in 1968 by the astronauts of the American Apollo 8 mission.

One and the same side of the Moon is visible from Earth because the Moon has a synodic period equal to its period of revolution (27.3 days), a phenomenon called synchronous rotation. The complementary part is therefore invisible from Earth, and nothing was known about it until it was photographed over 60 years ago.

Synchronous rotation describes the rotation of one celestial body around another, where the period of rotation of the satellite is equal to the orbital period around the body it is rotating with respect to, and therefore always points the same hemisphere towards the body it is rotating with respect to.

Sources: Reuters, South China Morning Post