Scientists on Wednesday said they could be a step closer tosolving the riddle behind the Moon's formation, unveiling the most detailedsurvey yet of the far side of Earth's satellite.
In January, the Chinese spacecraft Chang'e-4 — named afterthe moon goddess in Chinese mythology — became the first ever craft to touchdown on the far side of the lunar surface.
Similar to other bodies in our Solar System, the Moon isbelieved to have gone through a phase during its formation when it waspartially or entirely composed of molten rock.
As it cooled, so the hypothesis goes, denser minerals sankto the bottom of the magma-ocean, while lighter materials gathered near thesurface to form its mantle.
The team landed its probe in the Von Karmen Crater in theAitken Basin at the Moon's South Pole — home to one of the largest impact cratersknown in the Solar System.
They detected materials such as olivine and low-calciumpyroxene that are rare elsewhere on the surface.
Authors of the study, which was published in the journalNature, suggest that these materials were ejected from the Moon's upper mantlewhen it was struck by a meteor.
"Our results supportthe lunar magma ocean theory, and demonstrate that the magma ocean hypothesiscan be used to describe the early evolution history of the Moon," Chunlai Li,from the Chinese Academy of Sciences, told AFP.
Unlike the near side of the moon that always faces the Earthand offers many flat areas to touch down on, the far side is mountainous andrugged.
The United States, Russia and China have all landed probeson the near side of the Moon, though neither NASA's Apollo missions nor theSoviet Union's Luna probes have ever returned samples of the lunar mantle.
Writing in a linked comment piece, Patrick Pinet, fromFrance's l'Institut de Recherche en Astrophysique et Planetologie, said Li'sfindings were "thrilling".
The results "might also affect our understanding of theformation and evolution of planetary interiors," Pinet wrote, saying that moreresearch on the far side of the Moon was "of the utmost importance."