NASA’s Apollo samples reveal the Moon’s explosive volcanic past

Volcanic glass beads from Apollo 17 reveal the Moon’s explosive past, thanks to new high-tech analysis.

The last full-crewed mission to the Moon was aboard Apollo 17 in 1972, over five decades ago.

Back then, astronaut Harrison “Jack” Schmitt noticed a bright orange soil that turned out to be rich in volcanic glass beads, formed during ancient fire-fountain eruptions.

Found among the grey dust, these tiny spheres were a visual and scientific anomaly, formed 3.3 to 3.6 billion years ago.

Each bead is less than 1 mm wide and is recognized as a miniature record of ancient lunar activity.

“They’re some of the most amazing extraterrestrial samples we have,” says Ryan Ogliore, lead researcher and associate professor of physics in Arts & Sciences at Washington University in St. Louis.

Researchers today use new tech, such as NanoSIMS 50, atom probe tomography, and electron microscopy, to uncover new evidence from the Apollo 17 mission.

Many of these tools were unimaginable at the time the samples were collected, offering a fresh scientific lens.

“We’ve had these samples for 50 years, but we now have the technology to fully understand them,” marvelled Ogliore.

The beads formed when molten material from lunar volcanoes was ejected and cooled instantly in space.

Interestingly, this process resembles Hawaiian fire-fountain eruptions, but under vacuum conditions.

Notably, this results in beads that are orange, black, and chemically unlike anything found on Earth.

Their shape, composition, and colour make them geological fingerprints of lunar eruptions.

“The very existence of these beads tells us the Moon had explosive eruptions,” explained Ogliore.

The study was published in Icarus and involved Brown University and Washington University in St. Louis.