It all started on January 3, 2019, the day China succeeds in bringing the Chang’e 4 lunar module to rest in the Von Kármán crater in the Aitken basin, on the moon’s south pole. It was the first time that a team had achieved the feat of landing on the far side of our satellite. And they would also be pioneers in a discovery that continues to be talked about, almost a year later: the discovery of a strange formation of agglutinated matter, which they have called substance (the word ‘substance’ usually refers in scientific terms to something liquid) because of its slimy appearance. “It has the appearance of a gel” , stressed the crew of the mission, before confirming that “its color is unusual.”
Of all the rarities that we could find in our cosmic neighborhood, we have found a mystery as close as our own garden. But perhaps there is no such mystery, and all this commotion has a much simpler explanation. This Nobbot article has compiled the opinion of several experts, which we will summarize below.
What really is the strange substance on the Moon? What is the opinion of the scientists?
The first thing to keep in mind is that even the Chinese authorities have not yet ruled on the nature of this ‘substance’. For this reason, some scientists, such as José María Madiedo, from the Institute of Astrophysics of Andalusia (IAA-CSIC), think that it is very risky to speak of gels or viscous substances: “No viscosity measurements or any other type that allow affirm these extremes on a scientific basis. What is known so far, or, at least, what the Chinese Space Agency has revealed, are simply two images in which a material with an unusual aspect is seen where some bright spots are appreciated ”.
Madiedo, who is a world expert in the study of interplanetary matter that impacts against the Earth and the Moon, believes that it may be a material related to the impact against the Moon of a rock at high speed.
In addition, Madiedo is responsible for the MIDAS project, a network of telescopes for the detection of meteorite impacts in the unlit, but visible, region of the Moon. It is precisely this project that could explain the impact hypothesis: “The temperatures reached when comet fragments collide with the lunar soil, pulling material from said soil and excavating new craters can reach almost 5,000ºC. Much of the rocky material pulled from the ground or “impact plume” is ejected, melted or even vaporized. As it falls back, the material cools and solidifies again. In this solidification process, this material could become vitrified ”.
It is precisely this vitreous appearance that could explain what is seen in the images taken by the Chinese probe Yutu-2.
This hypothesis is not far-fetched if we consider that we have already found similar-looking material decades ago. As Clive Neal, an astrophysicist at the University of Notre Dame, in Indiana (USA) recalls: “The material highlighted in the center of the crater resembles a sample of impact glass found during the Apollo XVII mission in 1972.”
In other words, the famous and “mysterious” substance of the Moon could simply be a glass formed by an impact event , something very normal in our satellite, and according to all our observations.
For other scientists, like Daniel Moriarty of NASA’s Postdoctoral Program at the Goddard Space Flight Center, it is a mere rock . As Moriarty explained to the astronomical news portal Space.com: “the shape of the fragments seems quite similar to that of other existing materials in the area, relatively dark and with brighter fragments embedded within the larger areas”, which It would indicate that we are not looking at anything extraordinary.
According to these impressions, it seems that the extraordinary and mysterious substance found on the Moon is, in fact, a matter of the most ordinary. But, for the moment, we will have to wait for more detailed analysis from the Chinese Space Agency to be able to issue the final analysis.
