When we look up at the moon in the sky, we are actually looking, for the most part, at the exact same side of the Earth’s natural satellite. As the moon revolves around our world, it keeps one hemisphere constantly facing the Earth’s surface: the “near” side. The opposing “far” side, of which only about 18% could be glimpsed at times, remained a curious mystery to observers until finally seen in full by Soviet lunar probes and orbiting American astronauts. But no close examination has been done to the lunar far side, with all lunar landings having been done on the near side; until now.
USA Today tells us that on Thursday, January 3 of the New Year 2019, China landed a lunar exploration probe on the far side of the moon. It is the first time a spacecraft was sent onto that lunar area. Chang’e 4 was reported by China Central TV (CCTV) on its noon newscast to have touched down with a soft landing at 10:26 AM (Beijing time) Thursday. This lunar mission is a follow-up to Chang’e 3, which landed in the lunar “sea” of Mare Imbrium in 2013, or 37 years since the last lunar landing on the moon by Soviet lander Luna 24 on 1976.
Chang’e 4 was launched into space on its voyage to the moon via a Long March 3B rocket back in December 8, 2018 from the Xichang Satellite Launch Center, southern China. It reached the moon on December 12 and began a slow orbit up to the 30th in preparation for landing. Similar to Chang’e 3, the probe’s multi-objective function includes studies of the lunar surface, measuring surface temperature, chemical compositions of the moon’s soil and study cosmic rays. The last is notable as, on the lunar far side cosmic radiation can be more accurately studied.
Preparations done by the CNSA for the Chang’e 4 mission included the launch of the Queqiao relay satellite in May of last year, facilitating communications between Earth and the probe once it has touched down on the far side. Like its predecessors and planned successors, Chang’e 4 is named after the Chinese moon goddess of the same name, and its Queqiao communications relay satellite refers to the Chinese folktale of the Cowherd and Weaver Girl (the stars Altair and Vega).
Future Chang’e missions by the CNSA include Chang’e 5, scheduled for this year and planned to be China’s first lunar exploration mission with a returning component, carrying soil and rock samples on a return capsule.
Image from Xinhua News Agency