Shepherding the stars and cultivating the moon: the third anniversary of Chang'e 4's lunar landing

January 3rd marked the third anniversary of Chang'e-4's landing on the moon. At the same time, the Yutu-2 lunar rover once again refreshed its "online time", becoming the lunar rover with the longest working time on the moon in human history. As of January 3rd, Chang'e-4 was "checking in" on the far side of the moon for the 38th lunar day, with a total of more than 3,000GB of detection data; the Queqiao relay satellite has been in orbit for more than 1,300 days; and the Yutu-2 lunar rover has traveled nearly 1 kilometer.

At the beginning of the new year on Earth, on the moon, 380,000 kilometers away, a little rabbit is still working "step by step". It carefully pricks up its "ears", opens its "eyes" wide, and walks and explores, conscientiously carrying out a great adventure on the back of the moon. It is the Yutu-2 lunar rover. The Chang'e-4 lander and the Queqiao relay satellite accompanying it are also sticking to their respective positions to carry out exploration missions. The "three-person team on the back of the moon" cooperates tacitly and works together to uncover the secrets of the moon.

On January 3, 2019, my country's Chang'e-4 probe successfully landed on the far side of the moon, becoming the first spacecraft in human history to soft-land and conduct patrol exploration on the far side of the moon, revealing the mystery of the other side of the moon.

Figure 1. Chang'e 4 landing on the moon (GIF, source see watermark)

In the video recording the landing process of Chang'e-4, we can clearly see the dust being blown away directly under the lander at the moment of landing (Figure 1); the Yutu-2 lunar rover slowly drove down from the lander and began its patrol and exploration on the back side of the moon, carving the first eye-catching rut on the back side of the moon (Figure 2).

Figure 2. The silhouette of Yutu-2 and the tracks on the lunar surface

(Image source: China National Space Administration)

The track is more than 600 meters long and is still extending forward with the footsteps of Yutu. From the video and photos, we can see that the surface of the moon is not hard rock, but covered with a layer of loose soil, which scientists call "lunar soil."

Review of Chang'e 4 mission

May 21, 2018

▲On May 21, 2018, the Chang'e-4 relay satellite "Queqiao" was successfully launched from the Xichang Satellite Launch Center, marking my country's successful first step in the lunar back landing project. "Queqiao" created many world firsts: the first dedicated relay communication satellite outside the Earth's orbit in human history, the first relay satellite connecting the Earth and the Moon, and the first satellite to adopt a Halo orbit at the Earth-Moon L2 point.

December 8, 2018

▲The Chang'e-4 lunar probe was launched from the Xichang Satellite Launch Center.

January 3, 2019

▲Chang'e-4 successfully landed in the Von Karman crater in the Aitken Basin on the far side of the moon. This mission achieved the first soft landing of a human probe on the far side of the moon.

▲Chang'e 4 sent back the first close-up image of the far side of the moon.

▲The Chang'e-4 lander and rover separated successfully, and "Yutu-2" left the first mark of a human probe on the back of the moon.

January 11, 2019

▲The Chang'e-4 lander operated normally at noon on the moon, and the terrain camera successfully completed 360-degree panoramic shooting.

▲The Chang'e-4 lander and Yutu-2 rover worked normally and successfully took photos of each other with the support of the Queqiao relay satellite. The Chang'e-4 mission was a complete success.

January 30, 2019

▲Chang'e-4 safely passed the first lunar night and started work on the second lunar day. This is the first time that my country's lunar exploration project has obtained temperature detection data on the lunar night.

February 15, 2019

▲The landing site of Chang'e 4 was named Tianhe Base.

February 15, 2020

▲The shallow underground structure on the far side of the moon was revealed for the first time. This is also the first time that humans have unveiled the mystery of the underground structure on the far side of the moon.

Chang'e-4's third anniversary

Comprehensive sources: Xinhua News Agency, China Academy of Space Technology, China Lunar Exploration Project, General Design Department of the Fifth Academy of China Aerospace Science and Technology Corporation