An international study featuring scientists from Curtin University's School of Earth and Planetary Sciences and Space Science and Technology Centre offers new insights into the Moon's history and provide a better understanding of what lies beneath its cratered surface.
Researchers from Curtin University, Nanjing University and The Australian National University analysed tiny, green glass beads collected by Chang'e-5 - the Chinese National Space Administration mission to the Moon.
Typically, lunar glass beads are formed from impacts that melt surface rocks.
However, the beads in this study were found to have unusually high levels of magnesium, which Professor Alexander Nemchin from the School of Earth and Planetary Sciences said was evidence of a potentially deeper origin.
"These high-magnesium glass beads may have formed when an asteroid smashed into rocks that originated from the mantle deep within the Moon," Professor Nemchin said.
"This is exciting, because we've never sampled the mantle directly before: the tiny glass beads offer us a glimpse of the Moon's hidden interior."
Co-author Professor Tim Johnson, also from Curtin's School of Earth and Planetary Sciences, said the chemistry of the beads was unlike that of lunar surface rocks sampled previously.
Professor Johnson said the rocks may have been brought up from the Moon's mantle by a massive impact.
"One such event could be the formation of the Imbrium Basin, which is a huge crater formed more than 3 billion years ago," Professor Johnson said.
"Remote sensing has shown the area around the basin's edge contains the kind of minerals that match the glass bead chemistry.
"This is a big step forward in understanding how the Moon evolved internally; if these samples really are pieces of the mantle, it tells us that impacts can excavate otherwise inaccessible mantle material to the surface"
Study lead Professor Xiaolei Wang from Nanjing University said the discovery could have wider implications and influence future missions to the Moon and other planets.
"Understanding how the Moon's interior is made helps us compare it to Earth and other planets," Professor Wang said.
"It could even guide future missions, whether robotic or human, that aim to explore the Moon's deep geology."
'A potential mantle origin for precursor rocks of high-Mg impact glass beads in Chang'e-5 soil' was published in Science Advances.
