An analysis of lunar samples returned by China’s Chang’e 5 lunar mission has produced a possible new answer to volcanism late in the moon’s history.
Lunar samples returned from the Apollo and Luna missions are all around 3 billion years old, but samples returned from Chang’e 5 in late 2020 confirmed remote sensing analysis that rocks in the region were relatively young, only 2 billion years old.
Scientists have previously speculated that either a relatively high water content or the presence of radioactive substances, heat producing elements in the lunar interior may have driven volcanism at a late stage in the moon’s life in some regions, but new Chang’e-5 data published in Nature appear to have ruled out such hypotheses.
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Researchers led by Chen Yi from the Institute of Geology and Geophysics of the Chinese Academy of Sciences (IGGCAS) found that a lower melting point for parts of the lunar mantle could be due to the presence of fusible components and easily melted, leading to young lunars. volcanism.
“The recent melting of the lunar mantle can be achieved either by increasing the temperature or by lowering the melting point. To better understand this problem, we need to estimate the temperature and pressure in which the young volcanism was created,” said Chen in a statement. statement (opens in a new tab).
The researchers conducted a series of fractional crystallization and lunar mantle melting simulations to compare 27 samples of basalt clasts from Chang’e 5 with basalts from Apollo. They found that young magma collected by Chang’e 5 had higher calcium oxide and titanium dioxide contents than older Apollo magmas. These are oceanic cumulates of late-stage lunar magma rich in calcium and titanium that melt more easily than the early cumulates.
“This is a fascinating result, indicating a significant contribution of oceanic accumulations of late-stage lunar magma to the Chang’e 5 volcanic formation,” said Dr. Su Bin, first author of the study.
The research presents evidence for the first viable mechanism to explain youthful volcanism on the Moon that is consistent with the newly returned Chang’e 5 samples and could aid in understanding the Moon’s thermal and magmatic evolution.
The study was published in the journal Science Advances (opens in a new tab) Friday (October 21).
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