Tiny green glass beads collected by China's Chang'e-5 lunar mission are providing scientists with unprecedented insights into the moon's hidden interior, according to Chinese and Australian researchers on Monday.

Unlike typical lunar glass formed by surface impacts, these beads contain unusually high levels of magnesium, which indicates a potentially deeper origin, said a press release from Australia's Curtin University.

"These high-magnesium glass beads may have formed when an asteroid smashed into rocks that originated from the mantle deep within the moon," said Alexander Nemchin of Curtin's School of Earth and Planetary Sciences.

"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," said Nemchin, the co-author of the joint study published in Science Advances.

Co-author Tim Johnson, a colleague of Nemchin, noted that the composition of the beads is significantly different from previously studied lunar materials, suggesting they may have emerged during the formation of the Imbrium Basin – a massive impact crater formed over 3 billion years ago.

"Remote sensing has shown the area around the basin's edge contains the kind of minerals that match the glass bead chemistry," Johnson said, adding if these samples are indeed from the mantle, it confirms that giant impacts can bring deep, otherwise inaccessible material to the surface – a major breakthrough in understanding the moon's geological evolution.

Lead author Wang Xiaolei from China's Nanjing University said the discovery could shape future moon missions.

Uncovering the moon's interior structure helps us compare it with Earth and other planets, and better plan robotic or crewed exploration, Wang said.