Translucent spherical and dumbbell-shaped glassy globules on top of the lunar soil have been revealed in images from the Yutu-2 rover. This is the industrious rover's latest peculiar find on the Moon – and this time it's not an “alien” "house"!
The discovery, reported in the journal Science Bulletin, comes from the far side of the Moon – but it aligns with darker spherules discovered by Apollo astronauts decades ago, plus the Chinese sample return mission Chang’e-5. However, unlike what has been found on the near side of the Moon, these are translucent.
“The globules simply blow our mind, since they are so unique on the Moon,” lead author Dr Zhiyong Xiao, from Sun Yat-sen University, said in a statement.
The beads were spotted along the surface during the 700 meters (2,296 feet) traveled by the rover as it moved away from the Chang’e-4 lander. This trek took 12 lunar days – each 14 Earth days in length, followed by equally long nights.
The globules are most likely impact glass. An asteroid collision could have easily formed them, and the team has identified several possible craters around the area that could have been responsible for them.
Given their color and shape, the team believes that the beads were formed from iron-poor materials such as anorthosites. If this is confirmed, it could be a valuable material for permanent lunar settlements.
“The first discovery of macro-sized translucent glass globules on the Moon confirms that lunar anorthosites are excellent raw materials to manufacture glasses with good light-admitting quality. Their existence on the Moon indicate that impact events on the other planetary bodies could also form tektite-like impact glasses," Xiao says.
"Such glass globules should be commonly produced by ancient impact basins on the Moon, so their compositions and isotopic ages will be highly valuable to understand the early impact history. Also, at the dawn of constructing human-bases to the Moon, lunar anorthosites are a promising and widespread resources to produce glasses in-situ.”
Unfortunately, Yutu-2 did not have a chance to analyze these objects, but they should be valuable targets in future exploration.
“It is a bit unfortunate that when we first found these glasses, the rover has just passed by them, and no compositional data were obtained, but such globules might be pretty common at the lunar farside” Xiao says.