This diagram made on October 20, 2022 shows the thermal and magmatic evolution of the Moon. A Chinese group analyzed lunar samples returned by China’s Chang’e-5 mission and proposed a new mechanism for how young volcanoes formed on the cooling moon 2 billion years ago. [Institute of Geology and Geophysics of the Chinese Academy of Sciences/Handout via Xinhua]
BEIJING – A Chinese group analyzed lunar samples returned by China’s Chang’e-5 mission and proposed a new mechanism for how young volcanoes formed on the cooling moon 2 billion years ago.
Scientists previously speculated that high water content or radioactive elements in the lunar interior could have triggered volcanism late in the Moon’s life. But the Chang’e-5 data found its mantle source region dry and lacking in heat-producing substance.
The study, published Saturday in the journal Science Advances, showed that depression of the melting point of the mantle due to the presence of fusible and easily meltable components could generate young lunar volcanism.
Researchers from the Institute of Geology and Geophysics of the Chinese Academy of Sciences (IGGCAS) examined 27 Chang’e-5 basalt clasts to calculate the original ingredients of these samples.
They found that young magma from the Chang’e-5 source could have higher contents of calcium oxide and titanium dioxide than magmas in older samples returned by the Apollo missions.
China’s Chang’e-5 probe has revealed surprisingly young volcanic activity, only 2 billion years old, dismissing the theory that the Moon has been geologically dead since the formation of Apollo samples at least 3,000 years ago millions of years
“The recent melting of the lunar mantle can be achieved by increasing the temperature or lowering the melting point,” said the paper’s corresponding author, IGGCAS researcher Chen Yi.
The study shows that the late-stage lunar magma ocean accumulated in the Chang’e-5 samples is rich in calcium and titanium. It melts more easily than the early build-ups.
A researcher from the Institute of Geology and Geophysics of the Chinese Academy of Sciences (IGGCAS) analyzes lunar samples returned by China’s Chang’e-5 mission in Beijing, capital of China, on October 14, 2022 A Chinese group analyzed lunar samples returned by China’s Chang’e-5 mission and proposed a new mechanism for how young volcanoes formed on the cooling moon 2 billion years ago. [Institute of Geology and Geophysics of the Chinese Academy of Sciences/Handout via Xinhua]
The scientists proposed that these fusible components added to the lunar interior could have efficiently reduced the melting temperature of the mantle and thus triggered young lunar volcanism.
“We found that the Chang’e-5 magma was produced at similar depths, but 80 degrees Celsius cooler than the older Apollo magmas,” said the paper’s first author, Su Bin of IGGCAS.
“This means that the lunar mantle experienced a slow and sustained cooling of 80 degrees Celsius from about 3 billion years to 2 billion years ago,” Su said.
The work presents evidence for a viable mechanism to explain young volcanism on the Moon that is compatible with the recently returned Chang’e-5 samples, the researchers say.
“This study can help planetary scientists better understand the thermal and magmatic evolution of the Moon,” Chen said.