Chang’e 4, China’s latest space mission, a lander, left Earth’s surface on December 7, 2018. The lander is scheduled to attempt the first-ever landing on the unexplored side of the moon, between January 1 and 3, in 2019.
Most of our knowledge about the far side of the moon comes from satellites that orbit around the moon and capture pictures. The first time mankind was able to see the far side of the moon was in 1959 when the Soviet Union’s space probe, Luna 3, first photographed the far side of the moon. Because of these photographs, scientists realized that the near side is remarkably different from the far side.
The Far Side
The side of the moon that never faces the earth is called the far side of the moon. You might wonder why we cannot see the far side of the moon even though it rotates? The moon does rotate, but Earth’s tidal forces have slowed down the moon’s speed so that the moon rotates at about the same speed it revolves around the Earth. This phenomenon is called tidal locking.
Both sides of the moon have distinctive characteristics. For instance, the near side of the moon is covered in large basaltic plains, which are made of igneous rocks formed by the cooling of lava rich in magnesium and iron. These plains are called lunar maria. On the contrary, there are very few of these maria present on the far side of the moon. Also, through pictures, scientists have observed that the far side of the moon has significantly more craters than the near side.
Challenges and Goals
No other country has yet landed on the far side of the moon because of the mission’s complexity.
When a spaceship is on the other side of the moon, it loses its ability to communicate with Earth. To overcome this obstacle, China will use a relay satellite named Queqiao that was launched on May 20, 2018. The satellite's position will allow it to receive signals from Chang'e 4 when it lands and communicate with the Chinese space centers.
Through this spacecraft, China hopes to learn more about the secrets of the moon. After Chang’e 4’s landing on the moon, it will perform a radiation reading. Then it will send that data back to the Earth via the relay satellite. The spacecraft is also equipped with materials that will allow it to conduct low-frequency radio experiments.
Additionally, Chang’e 4 will conduct an experiment on the moon to see if the moon is capable of sustaining life. The lander will try to grow potato plants from seeds. It is also carrying silkworm eggs to see if they can survive on the moon. Chang’e 4 will help humanity understand the little-known side of our closest neighbor in space.
Sources: Smithsonianmag, Space.com. Medium, PBS, bgr.com, Wikipedia