Three tiny glass beads, from a sample of 3,000 taken from the Moon, have revealed evidence of recent volcanic activity. Previous scientific estimates suggested volcanic activity ended more than 2 billion years ago, but a new study suggests far, far more recent eruptions. Volcanoes on our lunar satellite were still spewing lava while dinosaurs walked the Earth.
Valuable cargo
The samples, picked up by the Chinese Chang’e 5 mission in 2020, are the first Moon rocks brought to Earth since the 1970s. Over the next four years, a team from the Institute of Geology and Geophysics at the Chinese Academy of Sciences in Beijing painstakingly analyzed the minute beads, each smaller than a pinhead. On Sept. 5, they published their findings.
Scientists remove samples from Chang’e 5. Photo: National Astronomical Observatories, CAS
They only identified three beads with a volcanic origin “based on their textures, chemical compositions, and sulfur isotopes.” The remaining 2,997 were likely the result of meteorite impacts.
Though these aren’t the first volcanic beads discovered on the Moon, they are certainly the most interesting. Previous samples date back billions of years, to the formation of lunar maria, enormous basaltic plains formed by lava flowing into craters. Meanwhile, “uranium-lead dating of the three volcanic glass beads [from 2020] shows that they formed 123 million, ±15 million, years ago,” the report explains.
What was driving volcanic activity for so long?
However, existing models of the Moon’s evolution suggest that its interior should have cooled beyond volcanism long before the formation of these glass beads.
As is often the case, researchers are left with more questions than answers. Perhaps the recently discovered Moon cave will help scientists understand what caused this surprisingly recent volcanic activity…
