China’s Chang’e-6 on Tuesday (June 25) became the world’s first spacecraft to bring back samples from the part of the Moon that the Earth never gets to see. “Chang’e-6 is the first mission in human history to return samples from the far side of the moon,” Long Xiao, a planetary geologist at China University of Geosciences, wrote to The New York Times in an email. “This is a major event for scientists worldwide,” he added, and “a cause for celebration for all humanity.” Here is a look at why scientists want to explore the far side of the Moon, and the details about the Chang’e-6 mission. Why explore the far side of the Moon? The Moon’s far side is often referred to as the dark side because it cannot be seen from the Earth, not because it does not catch the Sun’s rays. The Moon is tidally locked with the Earth and therefore, we see only one side of the Moon, also known as the near side. The far side has been under the spotlight in recent years as it is very different from the near side. “It has a thicker crust, more craters and fewer maria, or plains where lava once flowed,” according to a report by The New York Times. Examining the samples from the far side can help scientists solve mysteries about the origin and evolution of the Moon — till now, scientists have only been able to analyse samples from the near side. The far-side samples can also give answers to the longstanding question: why is it different from the near side? “[G]oing to the far side, getting samples and doing different kinds of geophysical measurements is really important to figuring out this really long, long-standing mystery,” Brett Denevi, a planetary geologist at the Johns Hopkins University’s Applied Physics Lab, told CNN. What was the Chang’e-6 mission? The Chang’e-6 was a 53-day-long mission. After reaching the Moon’s orbit, the mission’s orbiter circled the natural satellite while its lander descended into the 2,500-kilometre-wide South Pole-Aitken basin on the lunar surface. “The impact that created the basin — among the largest in the history of the solar system — is thought to have dug up material from the lunar mantle. If that material can be retrieved, scientists can learn more about the history of the Moon’s insides,” The NYT report said. After collecting samples through scooping and drilling, the lander launched an ascent vehicle, which transferred the samples to the orbiter’s service module. This module then returned to the Earth. China is the only country to achieve a soft-landing on the far side of the Moon. In 2019, its Chang’e-4 mission landed on the region and explored the Moon’s Von Karman crater with the help of a rover. (With inputs from The NYT)
