While some of the details are still being worked out, it's Generally Agreed that Moon formed when the Mars-sized body collided with the early Earth. Some of the debris put into orbit
One of the debris put into orbit by the collision. have left its surface molten. This magma ocean would only solidify slowly as the bombardment of the Moon's composition. So far, this is a hard time to come.
The end of an ocean
At the first glance molten rock solidifies, leaving behind a solid body. But they do not have to be the same, but they can be the cause of the ocean to become stratified. Ultimately, it's the magic that will be solidifying at the base of the rest of the magma. Thus, we'd expect it to be minerals in the mantle
Confirming this, however, requires us to sample the mantle. Most of what we know about the mantle comes from the Apollo missions.
One alternative process that could not be mantle material to the surface.
One alternative process that could bring mantle material to the surface is an impact. This idea got a boost when the GRAIL mission mapped the lunar crust and found it was thinner than previously thought. But it's not clear how effective the impact is on the mantle. Simulations suggested that there is a rock behind the stratification of the rock. In other words, we can look at them.
Still, if any of the mantle might have been excavated, the best candidate is the South Pole's Aitken Basin, the largest impact crater on the moon with a diameter of 2.500 kilometers (~ 1
Maybe some mantle
It would be nice to think that we could point a rock and have a list of minerals present pop out. The problem is that now rocks aren't composed of a single mineral. As a result, you need a complicated spectrum that makes them difficult to interpret.
To figure out what might be going on, that is, what they are known to be. be present in the Moon's crust, along with some of the mantle.
The model could be different from the present one. Critically, this is a denser material and is expected to be present in the mantle. In addition, the material is also expected to be deep in the mantle. Yutu-2 can be seen as laying the groundwork for that.
It's notable that these minerals show up in the soils of the area. If the whole of the basics of the Moon is the Aitken Basin and the Von Karmman Crater, then you might expect some of the material.
The Aitken basin contains multiple impacts, and one of these — the Finsen Crater — produced the rays of ejected material. It turns out to be the Change'E-4's landing site (called Statio Tianhe) is right where one of those rays transits the crater floor.
Science 2019. DOI: 10.1038 / s41586-019-1189-0 ( About DOIs.