NEW YORK — Recent research has determined that volcanism on the moon’s far side was active billions of years ago, similar to the volcanic activity observed on the side visible from Earth. Researchers have examined lunar soil samples collected by China’s Chang’e-6 mission, noted for being the first to bring back material from the less-studied far side of the moon.

Analysis by two independent research teams revealed volcanic rock fragments that are approximately 2.8 billion years old, with one specimen dating back even further, around 4.2 billion years. According to Christopher Hamilton, a planetary volcanology expert at the University of Arizona who was not part of the study, acquiring samples from this previously unexplored area is crucial because it provides data that has been lacking until now.

While scientists have known that the near side of the moon has active volcanoes with similar historical timelines, earlier research including findings from NASA’s Lunar Reconnaissance Orbiter had only hinted at a potentially active volcanic history on the moon’s far side. The recent samples confirm that this remote region did indeed experience significant volcanic activity.

These findings were published in scientific journals including Nature and Science. China’s lunar exploration efforts have included various missions. In 2020, the Chang’e-5 mission successfully returned lunar rocks from the near side, marking the first collection of moon samples since the Apollo and Soviet lunar missions of the 1970s. Notably, the Chang’e-4 mission achieved a historic moment by landing on the moon’s far side in 2019.

The far side of the moon features an array of craters and lacks the expansive dark plains formed by lava flows, which are prevalent on the near side. The reasons behind the stark contrast between the two hemispheres of the moon remain an enigmatic subject, as expressed by Qiu-Li Li, a co-author of the study from the Chinese Academy of Sciences.

Li emphasized that the new research indicates a series of volcanic eruptions that took place over a span exceeding 1 billion years on the moon’s far side. Further studies will be essential to explore the duration and nature of this prolonged volcanic activity.