On January 3, 2019 China’s Chang’e-4 lunar rover made the first-ever soft landing on the far side of the moon. This is the first time an attempt is made to explore the far side of the moon. The rover sent back close-up images of the previously unexplored region.
The other side of the moon, which is not visible from Earth, is the far side of the moon. . It is also referred to as the “dark side of the moon,” even though it receives just as much sunlight as its Earth-facing side.
It takes exactly 28 days for the Moon to complete one rotation, and the same time to make one orbit around Earth. Since the moon’s revolution cycle is the same as its rotation cycle, the same side always faces Earth. This leads to a phenomenon called “tidal locking”. Tidal locking is the name given to the situation when an object’s orbital period matches its rotational period.
Chang’e-4 is named after a Chinese moon goddess. It comprises a lander and a rover. A lander has the capability of making soft landing on surface of bodies and a rover has the capability of moving on a body.
The probe was launched by a Long March-3B carrier rocket on December 8 from the Xichang Satellite Launch Centre in Sichuan Province.
What is special about this moon landing?
All previous Moon landings, manned and unmanned, have been on the near side. This is because the Moon would have blocked radio communication between its far side and Earth. To overcome this problem, the Chinese mission has used a “relay satellite”, called Queqaio (Magpie Bridge) which was launched in May 2018. Signals between the far side and Earth are transmitted via the relay satellite.
Previous images of far side
While Chang’e-4 is the first spacecraft to actually land on the far side, its images of that side are not the first. In 1959 itself, the Soviet spacecraft Luna 3 clicked photographs of the far side, from over 60,000 km away, and relayed these photographs.
What are the tasks of Chang’e-4?
The tasks of the Chang’e-4 mission include study of far side moon’s terrain, its mineral composition and its environment.
History of China’s lunar mission
China’s lunar programme began in 2004. Chang’e 4 is the fourth lunar probe launched by China. In Chinese legends, ‘Chang’ is the goddess of the moon.
Chang’e 3 landed on the moon in 2013. Chang’e 3 released the first Chinese lunar rover, Yutu, on the moon. It worked there for around 1,000 days.
Why far side is important
Chang’e-4 landed on January 3, 2019 in the Von Kármán Crater in the South Pole-Aitken Basin on the far side of the Moon. Chang’e-4 landed at an altitude of minus 6,000 m. The Von Kármán Crater in the SPA Basin is large impact crater. A study of the Moon’s craters will help in determining their compositions and ages, collisions between Earth and the Moon, and various other aspects of the early Solar System.