Chang'e 5 sampling on the moon (rendering image). Photo courtesy of Lunar Exploration and Aerospace Engineering Center
A study of Chang'e-5 lunar samples showed that the Chang'e-5 landing area experienced at least four volcanic magma eruptions, and the magma flux in the area increased significantly during the late lunar volcanism. This result is conducive to further improving the understanding of the history of lunar volcanism and internal thermal evolution.
The research was completed by the Planetary Environment and Evolution Research Team of the National Space Science Center of the Chinese Academy of Sciences in cooperation with Peking University and other units. The relevant results were recently published in the international academic journal "Journal of Geophysical Research: Planets".
The Chang'e-5 landing site is located in the northeastern region of the Ocean's Cripple Terrain on the lunar front, an area considered to be one of the youngest basalt units on the lunar surface. "The study of the thickness of the basalt in the Chang'e-5 landing area and its eruption rate is of great significance for exploring the history of lunar volcanism and internal thermal evolution," said Du Jun, the first author of the article and a special research assistant at the National Space Science Center of the Chinese Academy of Sciences.
The research results show that the Chang'e-5 landing area has experienced at least four volcanic magma eruptions, with median thicknesses of 230 meters, 70 meters, 4 meters, and 36 meters, respectively. Further research found that the magma eruption flux in this region increased significantly in the late lunar volcanic activity about 2 billion years ago, with an increase of about 2 orders of magnitude.
The maintenance mechanism of late lunar volcanism has always been a hot issue in lunar scientific research. Previous studies have suggested that the abundance of heat-generating elements in the Cripple terrane of the Ocean of Storms on the front of the moon is the main reason for the still active volcanic activity in the late lunar period. However, the latest sample research results show that the basalt in the Chang'e 5 landing area is not Krip basalt.
In this regard, the study proposes a possibility that the heat-generating elements in the Cripple Terrain of the Storm Ocean did provide a heat source for the partially molten region of the lunar mantle, but during the rapid rise of magma from the lunar mantle to the lunar surface, It may not have time to fully mix with the Krep components in the Cripple terrane of the Storm Ocean, resulting in not much Krep matter measured in the Chang'e-5 lunar samples.
"Further excavation research on the Chang'e-5 lunar samples is expected to provide new constraints for the existing lunar thermochemical and kinetic models, thereby providing strong evidence for explaining the duration and scale of lunar volcanism." Du Jun said.
