2024-07-10 23:59:43
We know more or less how the Moon was born. The sequence of subsequent events has been more in doubt, but now there is some very interesting new data.
Unlike other planets like Jupiter, Earth has Moon as its only satellite. We don’t have to divide our knowledge among more celestial bodies of its characteristics. And yet, it still holds many mysteries. One of the most interesting is how it managed to become like a sock in its beginnings, billions of years ago.
The only information available about the Moon comes from two main sources. On the one hand, of the rock samples brought to Earth by astronauts on the Apollo missions more than 50 years ago. On the other hand, the computer simulations based on this data and on data obtained by unmanned missions dedicated to studying the surface and surroundings of the satellite. Possibly, with future Artemis missions we will be able to learn much more. But, for now, that is all there is.
Thanks to that, we have a rough idea of how the Moon was born. It is believed that 4.5 billion years A young planet collided with Earth and the extremely high energy of the impact caused a large amount of molten material to fly out into space. Afterwards, it remained at a point not far from our planet, held by its gravitational attraction, and there it cooled and solidified, giving rise to a sphere that would be condemned to rotate around us for millions and millions of years. So far, so good. What comes next, as the authors of a new study have explained in a statement, is practically a novel of the kind choose your own adventure.
The mysteries behind the birth of the Moon
Thanks to the missions dedicated to studying the surface of the Moon, we know that it is covered by minerals very rich in titanium, but that are not distributed evenly. Most of them are in what is known as the cara visible. That is, the one that always points towards the Earth.
Some information has been gleaned from rocks brought back to Earth by astronauts on the Apollo missions. Image: NASA
Given the way it originated, the Moon must have been initially covered by a magma ocean. This, as it solidified, would give rise to the satellite’s mantle and crust. As on Earth, the crust is the thinnest and outer layer, while the mantle is the one immediately below. In this process, according to computer models, part of the magma would form crystals that would remain just below the crust. Among them would be the formation of manifesta mineral composed primarily of iron and titanium. We already have titanium, but for now it is just under the surface.
The models have also offered a hypothesis about how it could have come out. These minerals are denser than the mantle, so they probably sank into it. Once this happened, as it approached the core, They were heated and melted againemerging to the outside through volcanic chimneys.
You could say, therefore, that the Moon turned inside out like a sock. What was on top sank inwards and then came back out, even further outwards. Now, in what order did it happen? That is the mystery. It is not known whether it happened all over the Moon equally, but only emerged on the visible side of it. Or whether it actually moved first towards the visible side of the Moon and then sank and emerged. Until now, there was no evidence that one hypothesis was more likely than the others. But it seems that we now have some.
The lunar near side with its dark regions, covered by titanium-rich volcanic flows (center) constitutes the familiar view of the moon from Earth (left). The mare region is surrounded by a polygonal pattern of linear gravity anomalies (blue in the image at right) interpreted as the remnants of dense material that sank into the interior. Their presence provides the first physical evidence of the nature of the global mantle that filled more than 4 billion years ago. Credit: Adrien Broquet (University of Arizona)
Two studies that show a more probable order
In 2022, a study was published using computer models that indicated that there could possibly be a large impact on the opposite side. pushed all the titanium toward the near side of the Moon, so the whole process of turning into a sock happened there.
It could be, but more evidence is needed. That’s why another study has just been carried out that analyzes this hypothesis using a new computer model fed with data on linear gravity anomalies detected by the NASA’s GRAIL mission in 2011 and 2012.
Thanks to this new study, now published in Natureit has been found that the gravity signatures measured by the GRAIL mission are consistent with simulations of the ilmenite layer based on the 2022 study. In addition, the gravity field can be used to map the distribution of ilmenite debris remaining after the subsidence of most of the dense layer.
In short, we no longer know just that the Moon turned like a sock. We also have much more evidence about how it happened.
By: HIPERTEXTUAL