The moon had volcanoes much more recent than we thought, says new study: ScienceAlert

Fifty years ago, NASA and the Soviet space program conducted the first monster return missions from the moon. This included moon rocks created by the Apollo astronauts and those obtained through robotic missions that were part of the Soviet Luna program.

The analysis of these rocks revealed much about the moon’s composition, formation, and geological history. In particular, scientists concluded that the rocks were formed by volcanic eruptions more than 3 billion years ago.

In recent years, there has been a resurgence in lunar exploration as NASA and other space agencies have sent robotic missions to the moon (in preparation for manned missions).

For example, China has sent multiple orbiters, landers and rovers to the moon as part of its Chang’e program, including monster return missions.

A new study led by planetary scientists from the Chinese Science Academy (CAS) analyzed samples obtained by the Chang’e-5 rover from 2 billion years ago.

Their research could provide valuable insight into how young volcanism shaped the lunar surface.

The research was conducted by a team from the Institute of Geology and Geophysics of the Chinese Academy of Sciences (IGGCAS), led by Su Bin, Yuan Jiangyan and Chen Yi – members of the IGGCAS Laboratory of LIthospheric Evolution and Earth and Planetary Physics.

They were joined by researchers from Nanjing University’s Lunar and Planetary Science Institute (LPSI) and the CAS Center for Excellence in Comparative Planetology. An article describing their findings appeared in the journal scientific progress on October 21.

Based on samples returned from the Apollo and Luna missions, scientists theorized that the moon has been geologically dead for the past 3 billion years.

However, the new samples of moon rock obtained by the Chang’e-5 mission (and returned to Earth in 2021) were only 2 billion years old, indicating that volcanic activity was occurring at least a billion years longer than previously expected.

Like a small rocky body, the heat that fueled the volcanism on the moon should have been lost long before these eruptions happened.

Previously, scientists speculated that late-stage volcanism may have been caused by increased water content or the decay of radioactive elements in the lunar mantle. However, the many analyzes performed on the samples obtained by the Chang’e-5 rover have ruled out this consensus.

Based on their analysis, the CAS researchers found that low-melting minerals in the mantle could have enabled compression, leading to young volcanism. Prof. dr. Chen explained in a recent CAS statement:

“Recent melting of the lunar mantle can be achieved by increasing the temperature or lowering the melting point,” he said. “To better understand this problem, we need to estimate the temperature and pressure at which the young volcanism originated.”

For their analysis, the CAS team ran a series of simulations of fractional crystallization and the melting of the lunar mantle, comparing 27 basalt clasts obtained by the Chang’e-5 mission with those from the Apollo missions.

They found that the young magma samples had higher calcium oxide and titanium oxide concentrations than older Apollo magma samples.

The presence of these minerals, which can be melted more easily than previous minerals that accumulate in the moon’s mantle, means that volcanism would have been gravitationally driven and cause material in the mantle to topple.

Their analysis revealed that the mantle’s compression could have occurred at similar depths, but at cooler temperatures that would still have produced volcanoes.

This research is no different from what planetary scientists have learned Mars in recent years. Billions of years agothe red planet had thousands of eruptions on the surface, some of which resulted in the largest volcanoes in the solar system (such as Olympus Mons).

Scientists suspected that Mars became geologically dead as its interior cooled. But recent findings indicate it can still occur limited volcanic activity.

This study presents the first viable explanation for young lunar volcanism compatible with the samples returned from the Chang’e-5 rover.

This study could inform future planetary studies of the moon’s thermal and geological evolution.

as Dr. Su indicated:

“This is a fascinating result, indicating a significant contribution of the late-stage lunar magma ocean cumulative to the Chang’e-5 volcanic formation. We found that the Chang’e-5 magma was produced at similar depths, but 80 degrees Celsius cooler than older Apollo magmas, meaning the lunar mantle experienced a sustained, slow cooling of 80 degrees Celsius from about 3 billion years to 2 billion years ago.”

This article was originally published by Universe today. Read the original article.