Scientists have discovered evidence of ancient volcanic activity on the far side of the moon, a region vastly different in geology from the side visible from Earth. US and Chinese researchers analysed samples collected by China’s Chang’e-6 mission, revealing volcanic basalt fragments dating back more than 4.2 billion years.
The findings, published in Nature and Science on Friday, shed new light on the moon’s volcanic history. While volcanic activity on the near side has been well-documented, the far side, often called the “dark side,” remains less understood.
Radiometric dating of the samples, led by the Chinese Academy of Sciences, also uncovered evidence of a “surprisingly young” eruption about 2.83 billion years ago—much younger than any volcanic activity previously identified on the near side.
“This is an incredibly exciting study,” wrote Professor Qiuli Li from the Institute of Geology and Geophysics in a peer review. “It will be of immense importance to the lunar and planetary science community.”
The samples, the first ever retrieved from the far side, were collected during the nearly two-month-long Chang’e-6 mission, which included deploying a small rover to photograph the rocky surface. Although called the “dark side,” this region receives sunlight but remains hidden from Earth’s view due to the moon’s tidally locked orbit. The moon takes approximately 27 days to rotate and orbit Earth, ensuring the same side always faces us.
The far side was first photographed in 1959 by the Soviet spacecraft Luna 3. Since then, higher-quality images and videos, including a NASA video showing Earth in the background, have provided more detailed views of the region. The Chang’e-6 mission marks another milestone in lunar exploration, offering unprecedented insights into the moon’s volcanic and geological history.