Chang'e-5 Mission Discovers Moon's Faint Yet Enduring Magnetic Field
A recent study of samples from the Chang'e-5 mission has uncovered evidence of the moon's weak yet enduring magnetic field. The findings highlight the moon's geological history and its ability to maintain this subtle magnetic force over time. Researchers are delving into the implications of these results for our understanding of the moon's internal structure and the broader dynamics of planetary bodies.
TroibNews 
A recent analysis of samples from China's Chang'e-5 mission has unveiled that the moon had a weak yet active dynamo magnetic field around 2 billion years ago.
Grasping the strength, structure, and evolution of the lunar magnetic field is essential for deciphering its internal structure, thermal history, and surface conditions.
The research team, led by scientists from the Institute of Geology and Geophysics at the Chinese Academy of Sciences, examined nine basalt samples gathered by Chang'e-5 from the Oceanus Procellarum region in the moon's mid-latitudes.
These samples present a rare chance to investigate the moon's magnetic history spanning from 3 to 1 billion years ago, a time frame that is still not well understood. This lack of exploration prompts an intriguing consideration of whether the moon underwent a sustained "dynamo" effect.
The analysis indicates that during this period, the moon's dynamo magnetic field was weak, with measurements between 2 to 4 microteslas—less than 10 percent of Earth's current magnetic strength, as reported in a study published Thursday in Science Advances, which featured the findings as the cover story.
This discovery addresses a significant gap in our comprehension of the moon's magnetic evolution, suggesting that the lunar dynamo persisted into its middle years, according to Cai Shuhui, a corresponding author of the paper.
The researchers also proposed that ongoing thermal convection in the moon's deep interior may have contributed additional heat for volcanic activities before the complete loss of the magnetic field.
The mechanisms that sustained the magnetic field could include processes such as the crystallization of the lunar core, its wobble, and the sinking of dense primordial materials, according to the findings.
The weak magnetic field observed in the Chang'e-5 samples indicates the existence of a protective magnetic shield during this era, which serves as a reference point for studying space weathering and the presence of volatile materials, such as water, on the lunar surface during the moon's midlife, noted Cai.
Furthermore, the research team recently published a study in the journal Nature, revealing an unexpected increase in the strength of the moon's magnetic field 2.8 billion years ago, based on rock samples gathered from the moon's far side by the Chang'e-6 lunar probe.
Together, these two studies imply that the moon's magnetic field not only endured into its midlife but may have also experienced fluctuations during that period, as per Cai.
In November 2024, an IGG team reported two significant volcanic events on the moon's far side, occurring 2.8 billion years ago and 4.2 billion years ago. Another study confirmed that the low-titanium samples collected by Chang'e-6 are approximately 2.83 billion years old, providing further evidence of volcanic activity on the moon's far side.
On June 25 of the previous year, the Chang'e-6 lunar probe returned to Earth with 1,935.3 grams of lunar samples from the moon's previously unexplored far side. Similarly, the Chang'e-5 probe, which returned on December 17, 2020, retrieved 1,731 grams of lunar samples, primarily consisting of rocks and soil from the lunar surface.
Ian Smith contributed to this report for TROIB News
Grasping the strength, structure, and evolution of the lunar magnetic field is essential for deciphering its internal structure, thermal history, and surface conditions.
The research team, led by scientists from the Institute of Geology and Geophysics at the Chinese Academy of Sciences, examined nine basalt samples gathered by Chang'e-5 from the Oceanus Procellarum region in the moon's mid-latitudes.
These samples present a rare chance to investigate the moon's magnetic history spanning from 3 to 1 billion years ago, a time frame that is still not well understood. This lack of exploration prompts an intriguing consideration of whether the moon underwent a sustained "dynamo" effect.
The analysis indicates that during this period, the moon's dynamo magnetic field was weak, with measurements between 2 to 4 microteslas—less than 10 percent of Earth's current magnetic strength, as reported in a study published Thursday in Science Advances, which featured the findings as the cover story.
This discovery addresses a significant gap in our comprehension of the moon's magnetic evolution, suggesting that the lunar dynamo persisted into its middle years, according to Cai Shuhui, a corresponding author of the paper.
The researchers also proposed that ongoing thermal convection in the moon's deep interior may have contributed additional heat for volcanic activities before the complete loss of the magnetic field.
The mechanisms that sustained the magnetic field could include processes such as the crystallization of the lunar core, its wobble, and the sinking of dense primordial materials, according to the findings.
The weak magnetic field observed in the Chang'e-5 samples indicates the existence of a protective magnetic shield during this era, which serves as a reference point for studying space weathering and the presence of volatile materials, such as water, on the lunar surface during the moon's midlife, noted Cai.
Furthermore, the research team recently published a study in the journal Nature, revealing an unexpected increase in the strength of the moon's magnetic field 2.8 billion years ago, based on rock samples gathered from the moon's far side by the Chang'e-6 lunar probe.
Together, these two studies imply that the moon's magnetic field not only endured into its midlife but may have also experienced fluctuations during that period, as per Cai.
In November 2024, an IGG team reported two significant volcanic events on the moon's far side, occurring 2.8 billion years ago and 4.2 billion years ago. Another study confirmed that the low-titanium samples collected by Chang'e-6 are approximately 2.83 billion years old, providing further evidence of volcanic activity on the moon's far side.
On June 25 of the previous year, the Chang'e-6 lunar probe returned to Earth with 1,935.3 grams of lunar samples from the moon's previously unexplored far side. Similarly, the Chang'e-5 probe, which returned on December 17, 2020, retrieved 1,731 grams of lunar samples, primarily consisting of rocks and soil from the lunar surface.
Ian Smith contributed to this report for TROIB News
