Named after the Chinese goddess of the moon, China’s lunar lander Chang’E 4 landed on the far side of the moon and was the first to do so. This historic event went a long way in probing the mystery of the far side of the moon, and might help clarify how the moon evolved.
A theory emerged in the 1970s that in the moon’s infancy, an ocean made of magma covered its surface. As the molten ocean began to calm and cool, lighter minerals floated to the top, while heavier components sank. The top crusted over in a sheet of mare basalt, encasing a mantle of dense minerals, such as olivine and pyroxene.
As asteroids and space junk crashed into the surface of the moon, they cracked through the crust and kicked up pieces of the lunar mantel.
“Understanding the composition of the lunar mantel is critical for testing whether a magma ocean ever existed, as postulated,” said corresponding author Li Chunlai, a professor of the National Astronomical Observatories of Chinese Academy of Sciences (NAOC). “It also helps advance our understanding of the thermal and magmatic evolution of the moon.”
The evolution of the moon may provide a window into the evolution of Earth and other terrestrial planets, according to Li, because its surface is relatively untouched compared to, say, the early planetary surface of Earth.
Li and his team landed CE-4 in the moon’s South Pole-Aitken (SPA) basin, which stretches about 2,500 kilometers—about half the width of China. CE-4 collected spectral data samples from the flat stretches of the basin, as well as from other smaller but deeper impact craters within the basin.
Find out more on phys.org.
(Image Credit: NAOC/ CNSA)