A picture of the crater in which the “gel-like” substance was found.
CNSA / CLEP
When China’s Yutu-2 rover discovered a strange greenish gel-like substance There was an understandable feeling of excitement in a crater on the other side of the moon last year. What was it? Aliens? Space snot? Melted stone?
A team led by researchers from the Chinese Academy of Sciences published an analysis of the substance in the journal Earth and Planetary Science Letters.
It’s rock, more precisely “Impact Melt Breccia”. Breccia is a rock that consists of rock fragments or minerals stuck together, like a geological version of one of these Jell-O salads filled with fruit pieces. Melt it and it can look glassy.
Yutu-2, part of China’s Chang’e 4 Lunar Mission to investigate the mysterious other side of the moon took a closer look at the strange find in late 2019. The maneuver gave scientists a lot of data to work with to get the result of the molten rock.
The researchers described the substance as “dark green and shiny” and measured it at a width of about 52 centimeters. “It was formed by impact welding, cementing, and agglutinating lunar regolith and breccia,” the team said.
A meteorite impact is a likely suspect. “Glasses in the regolith of the moon usually come from impact melts or volcanic eruptions,” the study says.
The study also found that the molten rock resembles breccia samples returned by NASA’s Apollo lunar missions.
One of the big questions about the “gel-like” substance seems to have been answered. They weren’t extraterrestrials, but it was a fun moon secret with a satisfactory ending.