Lunar Rover Finds Translucent Glass Globes On The Moon, Where Did They Come From?

yutu globule
China's Yutu-2 lunar rover detected two distinct glass globules on the far side of the Moon. Discoveries like this could hold information about the Moon's history.

The spherules were spotted by the lunar rover's panoramic camera as they twinkled like stars on the dry, dusty surface of the Moon. While the rover was unable to obtain any compositional data, spherules like those found by the Yutu-2 rover could hold information detailing the Moon's mantle composition and impact events. The material that made up the spherules forms when silicate material is exposed to extreme temperatures, and both are readily available on the Moon.

The Moon has an extensive volcanic past that lead to the formation of volcanic glass. Impacts, such as a meteor, also generate intensive heat and could result in the formulation of glass. It is the latter that a team with Yutu-2 believes to be the cause of the globules found recently. The team of scientists is led by planetary geologist Zhiyong Xiao of Sun Yat-sen University and the Chinese Academy of Sciences.

Spherules found recently by Yutu-2 differ from the others found on the Moon. Most of the spherules discovered have been less than a millimeter in size. Those found by the Chinese rover are much larger, coming in at 15 to 25 millimeters across. This is not unique, being ones that were up to 40 millimeters across were recovered during the Apollo 16 mission. Those were believed to come from a nearby crater and formed after a lunar impact.

globule yutu
Xiao and his colleagues explain that there are differences between the Yutu-2 discovery and those found from the Apollo 16 mission, though. Those found on the far side of the Moon seem to translucent or semi-transparent. Four other spherules (seen above) were also found, but they seemed to lack the same translucency.

The team of scientists believe it is possible that the globules formed from volcanic glass called anorthosite that melted again on impact, reforming into translucent round globs. Researchers wrote, "Collectively, the peculiar morphology, geometry, and local context of the glass globules are consistent with being anorthositic impact glasses."

"As the first discovery of macroscopic and translucent glass globules on the Moon, this study predicts that such globules should be abundant across the lunar highland, providing promising sampling targets to reveal the early impact history of the Moon," researchers wrote in their paper.