New analysis from China’s Chang’e 5 mission has revealed compelling evidence that the Moon experienced volcanic activity far more recently than previously believed.
This groundbreaking discovery suggests that volcanic eruptions may have occurred as recently as 120 million years ago, overturning long-held assumptions that the Moon has been geologically inactive for over a billion years. The results, published in Science, come from the detailed study of volcanic glass beads collected by the Chang’e 5 lander, which indicate a much younger volcanic history than previously thought.
Evidence from Chang’e 5 Samples: Young Volcanic Glass on the Moon
The Chang’e 5 mission, which successfully returned lunar samples to Earth in December 2020, provided scientists with the first new material from the Moon since the 1970s. The mission retrieved 3.82 pounds (1,731 grams) of lunar soil from a region known as Oceanus Procellarum. In these samples, researchers discovered tiny glass beads, which are formed by volcanic activity. After meticulously studying around 3,000 glass beads, scientists identified three that were of volcanic origin.
The age of these beads, determined through uranium-lead dating, was the most surprising finding. The dating showed that these beads were formed just 123 million years ago, with a margin of error of 15 million years. This is relatively recent in geological terms, especially considering the Moon’s age of about 4.5 billion years. The high precision of these measurements has stunned scientists. "The fact that these volcanic glass beads were formed during the time when dinosaurs roamed Earth is astonishing," said Dr. Bi-Wen Wang, lead author from the Institute of Geology and Geophysics at the Chinese Academy of Sciences. The presence of these young volcanic beads has caused researchers to rethink their understanding of the Moon's volcanic history, suggesting that the Moon may have been volcanically active far longer than previously assumed.
Challenging Established Theories of Lunar Geology
For decades, scientists believed that the Moon had cooled and become geologically inactive over a billion years ago. Because the Moon is much smaller than Earth, it was thought to have lost its internal heat more quickly, leading to the cessation of volcanic activity by about 3 billion years ago. This assumption was supported by the age of the basaltic plains, the dark areas visible on the Moon’s surface, which were formed by lava flows during its early history. However, the discovery of much younger volcanic glass contradicts this narrative and suggests that volcanic activity persisted well into the Moon's more recent geological past.
The key to this continued volcanism might lie in the heat-generating elements present within the Moon’s mantle. Elements such as uranium, thorium, and potassium generate heat through radioactive decay, which could have kept parts of the lunar mantle hot enough to produce magma for longer than previously thought. According to Dr. Wang, "The young age of these volcanic beads shows us that the Moon may not be as different from Earth as we once thought." This discovery suggests that the Moon may have had magma chambers deep beneath its surface that remained active well into its later history, potentially fueled by these radioactive elements.
Implications for a Revised Timeline of Lunar Volcanism
This discovery significantly alters the timeline of volcanic activity on the Moon. Previous studies suggested that the Moon’s volcanic activity peaked between 3 and 3.8 billion years ago, creating the vast mare or basalt plains visible today. The Chang’e 5 findings suggest that volcanic activity did not cease abruptly but instead may have continued sporadically, with eruptions occurring as recently as 120 million years ago. This new timeline has profound implications for our understanding of how the Moon evolved over time.
Recent discoveries of irregular mare patches (IMPs), which appear to have formed less than 100 million years ago, hinted at more recent volcanic activity. These patches, observed through crater counting techniques, suggested that some form of volcanism could have occurred more recently than believed. However, until now, there had been no direct laboratory evidence to confirm these findings. The discovery of volcanic glass beads from Chang’e 5 provides definitive proof that volcanic activity occurred long after the Moon was thought to have become geologically dormant.
Dr. Yuri Amelin and Dr. Qing-Zhu Yin, who commented on the findings in a Science editorial, praised the precision and care involved in the analysis, describing it as "a needle in a haystack" search to identify volcanic material among the thousands of beads. They noted that “the effort … put into finding the volcanic ‘needle’ in the impact-generated ‘haystack’ has paid off.” This meticulous work has revealed not only the existence of young volcanic activity but also pointed to new areas of research regarding the Moon’s geological evolution.
Could the Moon Still be Volcanically Active?
The discovery of such recent volcanic activity raises the question of whether the Moon could still have active magma chambers today. Although the Moon has been cooling for billions of years, the presence of radioactive elements in its interior could continue to provide enough heat to sustain volcanic activity, albeit on a much smaller scale. Dr. Wang and his team believe that further research and modeling studies will be needed to determine whether the Moon could still be producing magma today.
"This raises the question of whether the Moon is still producing magma today," the study noted, highlighting the need for further exploration and observation. With new missions planned by NASA, including the Artemis program, and additional international lunar missions, scientists may soon have more opportunities to investigate whether volcanic activity could still be ongoing beneath the Moon’s surface.
The Future of Lunar Exploration
The discovery of recent volcanism on the Moon underscores the need for continued exploration and study of our nearest celestial neighbor. With plans to return humans to the Moon through NASA’s Artemis missions, scientists are eager to explore areas that could offer more insights into the Moon’s volcanic history. Future missions may target regions of interest, such as volcanic vents or the Oceanus Procellarum, where the Chang’e 5 mission collected its samples.
As Dr. Wang pointed out, "The Moon’s volcanic history is far more complex than we previously thought." The Chang’e 5 findings not only reshape our understanding of the Moon’s past but also open new avenues of research into how volcanic activity might still be influencing the lunar surface today. This discovery is likely to guide future missions as scientists seek to learn more about the Moon’s geological processes and how they compare to those of other rocky planets, including Earth.