In 1969, Neil Armstrong uttered the famous words, “That’s one small step for man, one giant leap for mankind,” as he took the first steps onto the moon, sparking the interest of millions across the world.
Despite the fascination of humans with the moon, the first landing on the far side of the moon occurred only recently with China’s Chang'e-4 mission. This mission was launched in an attempt to learn more about the evolution and origins of the moon.
Astronomers have postulated since the 1970s, shortly after the first landing on the moon, that the moon was once covered in a magma ocean. The cooling of this magma ocean allowed lighter minerals to rise to the surface, resulting in the formation of a basalt crust on top of a mineral mantle. Scientists have theorized that this mantle is partially composed of pyroxene and olivine; however, scientists have found scarce evidence to reveal the composition of the lunar mantle. According to Li Chunlai, a professor of the National Astronomical Observatories of the Chinese Academy of Sciences, determining the composition of the mantle is “critical for testing whether a magma ocean ever existed.”
China’s successful landing of the Chang’e-4 rover on the far side of the moon has opened up possibilities of discovering the lunar mantle’s composition. Chang’e-4 landed in the Von Karman crater on January 3, 2019, thereafter deploying the Yutu-2 rover, which is responsible for exploring the South Pole-Aitken Basin. This basin, the biggest and oldest crater on the far side of the moon, is an impact crater that was formed by the collision of an object with the moon. At the moment, Yutu-2 is in the process of searching for pieces of the mantle that have surfaced from the crater in order to determine their composition.
Since this landing, researchers and scientists have been collecting data and pictures from the Chang’e-4 mission for almost six months. Yutu-2 will remain in the South Pole-Aitken basin in order to acquire samples from the crater floor, which will then be tested to determine what they are composed of. Some of these samples could potentially be sent to researchers on Earth. So far, data samples from the rover’s expeditions have proved the presence of olivine and pyroxene in the crust. This has caused scientists to theorize that equal amounts of the two minerals could exist in the crust. However, researchers are still not certain of the mantle’s composition and will continue to analyze the data collected in order to approach a conclusion.
Although humans have explored and researched the moon for decades, many of the moon’s mysteries are yet to be uncovered. Learning more about the moon through missions similar to the Chang’e-4 mission will aid not only scientists’ understanding of the moon, but will also advance their understanding of Earth’s evolution and the universe.