There are still many mysteries surrounding the moon, which still today leads hundreds of scientists and scholars to examine it in an attempt to find answers, using increasingly cutting-edge equipment. Among the many questions regarding our natural satellite, there is also that relating to its composition, which has often been defined as asymmetric. Why, astronomers have often asked, is there a greater presence of titanium-rich volcanic rocks on the visible side compared to the “face” which remains hidden?
For a long time, scientists have wondered about the thickness and composition of the lunar crust and regolith (i.e. the layer of dusty rock), which appeared irregular. Many have felt that the asymmetries could explain the shift of the Moon's center of mass.
The reversal
An attempt was made by a research group to answer these questions American University of Arizona, in Tucson. In a study published in the journal Nature Geoscience, disconcerting news is given: the Moon would have overturned over 4 million years ago. But in what sense “reversed”?
In essence, the authors of the study explain, when our satellite was still young, it would have had some changes in its composition. The materials that were initially on its surface sank into it, melting and mixing, and then returned to the crust later in the form of lava. That's why the composition is so irregular. This is why there is a greater quantity of rocks rich in titanium on the visible face. Experts do not exclude that a similar reasoning cannot also be applied to the Earth itself, or the planet Mars.
Here's how it went: the studio
What could have happened, then? When it formed, our satellite was most likely immersed in a liquid sphere of magma which then cooled over time, until it solidified and gave rise to minerals such as ilmenite, which contains iron and titanium. The latter, at the moment of the overthrow, sank into the lunar mantle, melting.“Our Moon has literally turned upside down, but until now it has not been possible to shed light on the exact sequence of events during this critical phase of lunar history”said the professor Jeff Andrews-Hannawho collaborated on the study.
The various simulations regarding the behavior of the minerals present in the lunar mantle are fundamental for reconstructing all the steps. Much of the information was obtained thanks to NASA's Grail mission. “Our analyzes show that theoretical models and data tell a remarkably consistent story.
The ilmenite materials first migrated towards the nearer side and then sank inward in a cascade of slabs, leaving behind traces responsible for the detected gravitational anomalies,” explained the doctor Weigang Liangleading the study, as reported by SkyTg24.