Chinese scientists have made a groundbreaking discovery regarding the composition of materials on the back of the moon, unveiling significant differences from samples collected on its near side. The new samples brought back by the Chang’e-6 mission consist of a mix of basaltes and rocks ejected by impacts, which is a stark contrast to the mainly basalt volcanic rocks previously studied.
Researchers believe that these materials may have formed from a combination of lunar soil and recently ejected rocks due to the presence of numerous fresh craters in the landing area. This revelation came less than three months after the samples were returned to Earth, with the study authors noting the “obvious differences” between these new lunar materials and those obtained from the near side dating back to 1969.
Notably, the samples from the far side contain more light components like glass and field sparks compared to the CHAG’E-5 samples from the near side. These samples also exhibit a lower density, indicating a loose and porous structure.
According to a study published in the journal National Science Review by the Chinese Academy of Sciences, the lunar soil is described as loose, with a fluffier structure when in its natural state on the moon’s surface.
The significance of these new samples for scientific research cannot be overstated, as they offer insights into the history of volcanism on the far side of the moon, the composition of lunar regolith, and potentially even the deeper layers of the lunar mantle.
China has emerged as the first and only country to successfully retrieve samples from the far side of the moon through the Chang’e-6 mission, bringing back over 1.9 kg of lunar soil from the South Pole-Aitken basin, the largest, deepest, and oldest impact crater on the moon.
Prior to the Chang’e-6 mission, the far side of the moon remained largely unexplored, with all previous missions—spanning 10 expeditions from the US, Soviet Union, and China—collecting samples solely from the near side.
The landing site of Chang’e-6 is of particular significance, offering opportunities to delve into the early history of impacts on the moon, understand the composition of its subsurface layers, and investigate the asymmetries between the near and far sides of the moon. This discovery has the potential to reshape our understanding of the moon’s origin and evolution.
Although the initial results are preliminary, they have already expanded our comprehension of the moon’s internal structure and evolution. Scientists anticipate that further exploration will help address fundamental questions concerning the formation of the solar system and planetary systems at large.