A year ago, China’s Yutu-2 rover found a mysterious, green, gel-like substance on the surface of the moon. Now, scientists know what it is.
Assuming that you hadn’t heard of the gel-like substance until today, though, I’d like to give you some time to think about what it might be, and form a guess. This will be like a better version of Netflix’s reboot of Unsolved Mysteries. In this version, you are clued in on a mystery, given some time to figure out your theory, and then told the answer. (In Unsolved Mysteries, you are not told the answer, as the answer is Unsolved.)
The substance was found last year by the rover in the southern hemisphere of the far side of the moon. Chinese scientists thought it might be melted rock formed after some sort of impact, and they had the rover take two additional passes at the goo in order to collect more data; at first, according to cNet, the area was covered in shadow, making data collection impossible. But upon second and closer inspection, the scientists were able to use the rover’s onboard spectrometer (an instrument used to measure light and identify materials) to examine the material. Do you have your guess about what the material might be yet?
Here are a few of my theories: the “green-apple” flavored sour gel that used to come in a tube and which could be purchased at the register of K·B Toys in the mall; an unmentionable alien secretion; an alien that turns to goo when it is frightened. All pretty good guesses, if you ask me.
Do you have your guess? Okay, I’m going to tell you what it is. It is melted rock formed after some sort of impact. Ah, sometimes the answer is just right in front of your face.
Researchers at the Chinese Academy of Sciences recently published a report about the substance in the journal Earth and Planetary Science Letters. The rock, or to be more specific, the “impact melt breccia,” is described there as “dark greenish and glistening” and is said to be similar to the samples of impact melt breccia collected by astronauts on the Apollo missions.
Breccia, according to the Planetary Science Institute, is a mixture of different types of fragmented rocks, held together by something; with an impact melt breccia, that something is “impact melt,” which occurs when an impact causes rock to melt.
“The dark greenish and shiny features observed from Pancam color image are signs of possible presence of glasses,” the study said. “Glasses in the lunar regolith are usually sourced from impact melts or from volcanic eruptions.”
Because the area hasn’t seen volcanic eruptions in over three billion years, the scientists suspect a meteorite is the likely cause.
Well, mystery solved. And isn’t that satisfying?