The Chang'e-4 probe, launched on December 8, 2018, touched down on the far side of the Moon on January 3, after traveling 26 days and 380,000 km in space. This marks the first soft-landing on the far side of the Moon, and the first time there has ever been communication between the Earth and the Moon's far side.
Because its revolution and rotation cycles are nearly identical, the Moon always has the same side facing the Earth. The far side is also called the dark side because it can never be directly observed from Earth.
The probe, which consists of a lander and a rover, started scientific exploration on January 11. The tasks of the Chang'e-4 mission include observing low frequency radio astronomy, surveying the terrain and landforms, detecting the mineral composition and shallow lunar surface structure, and measuring neutron radiation and neutral atoms.
The successful landing marks a historical breakthrough in human lunar exploration. It also reflects great progress in China's aerospace technology and improvement in the country's independent innovation capacity.
The success of the mission is also attributed to international collaboration. Of the 13 payloads onboard the Chang'e-4, four were developed by the Netherlands, Germany, Sweden and Saudi Arabia. The radioisotope heat source—a collaboration between Chinese and Russian scientists—will help the probe keep warm during the lunar night, equivalent to about 14 days on Earth when temperatures can fall to -180 degrees Celsius. The ground station that China built in Argentina has taken part in the monitoring and control of the mission from the South American country, while ground stations run by the European Space Agency will also offer support. The United States will assist the mission as well by monitoring the probe from the Lunar Reconnaissance Orbiter, a NASA robotic spacecraft currently orbiting the Moon.
There are few countries in the world capable of landing a lunar probe on the Moon. China is willing to provide opportunities for scientists from other countries to carry out lunar probes, hoping to contribute Chinese wisdom to the progress of human civilization under the principles of equality, mutual benefit, peaceful use and inclusiveness.