Science Alert reported that the strange gel-like substance discovered by the Chinese Yutu-2 rover in a small impact crater on the Moon's far side has now been identified.
Weird Glistening 'Gel-Like' Substance Found By Chinese Rover Has Now Been Identified
Scientists have analyzed the images and compared them with the samples that the Apollo mission brought back here on Earth and found that this weird substance is exactly what anyone would expect to be - a rock.
Glistening Gel-Like Substance on the Moon Was a Rock
Specifically speaking, the rock melted together more likely because of a meteorite impact and formed into a dark green, glossy, glassy mass.
The researchers wrote in their paper that the Chinese rover, Chang'e, discovered a dark greenish and glistening impact melt breccia in a crater when it was traversing on the surface of Vin Kármán crater within the South Pole Aitken (SPA) basin on the far side of the MoonMoon.
"It was formed by impact-generated welding, cementing, and agglutinating of lunar regolith and breccia," the researchers said.
In late July 2019, Yutu-2 captured an image of the glistening substance, and by July, the Chinese government-sanctioned science outreach blog dubbed Our Space published the image on the Yutu-2 drive diary.
They used an unusual description - "gel-like" - to describe the substance found on the MoonMoon, given the surface is very dry and dusty sort of a place. The images that were released later confirmed that it was indeed glossy, but contrary to its description, it is not moist-consistent that it can be described as gelatinous.
Using Yutu-2's Panoramic Camera, the researchers were able to get a more detailed analysis of the image. Both the Visible and Near-Infrared Imaging Spectrometer (VNIS) and hazard avoidance camera back this hypothesis.
The VNIS allowed Sheng Gou of the Chinese Academy of Sciences and his colleagues to break down the refracted light from the substance and determine the composition and the surrounding regolith.
Their analysis revealed that the regolith is 45% plagioclase, 7% pyroxene, and 6% olivine or the standard Moon stuff. However, the glistening substance was challenging to identify as they can only make out 38% plagioclase.
The substance is very similar to the two samples retrieved by the Apollo 15 and 17 missions, namely the Lunar Sample 15466 and Lunar Sample 70019. Both of these samples are classified as breccia, or rock made up of chunks of rock cemented together by finer material.
Read also: Human Urine Can Help Make Lunar Concrete in an Attempt to Create Colonies on the Moon
Created Likely With a Huge Impact
After their analysis, the researchers concluded that the substance was likely created during a meteorite impact. They think that it melted when a meteorite struck the MoonMoon, and it mixed with unmelted regolith to form a breccia.
However, they noted that the event does not necessarily happen in the crater where the substance was found because the regolith could be a mixture of material from two different craters.
Moreover, the estimated diameter of an impactor that would create a crater in that size could only be 2 centimeters, which is too small to create an impact melt of 52 by 16 centimeters.
But their study is still limited because they do not have an actual sample of the substance. Nonetheless, the results suggest that it was nothing to fear about.