Chang’e 4 probe reveals what’s underneath the far side of the moon

The Changa 4 mission successfully landed on the Moon's South Pole, deploying the U22 rover to explore the surface. Using lunar penetrating radar, the rover sent signals to a depth of 40 meters, three times deeper than previous missions. The subsurface was found to be composed of porous granular material with embedded boulders, likely due to meteor impacts. This research provides insights into the Moon's geological history.

What materials were found in the lunar subsurface according to the researchers?

What caused the highly porous granular material found beneath the lunar surface?