Here's why:

* Regolith is a layer of broken rock and dust that covers the surface of a celestial body.

* The Moon's regolith is composed of:

* Fine-grained dust: This is the result of billions of years of meteorite impacts and solar wind bombardment.

* Larger rock fragments: These come from the impacts as well.

* Glass beads: Created by the intense heat of impacts, these beads are unique to the Moon.

So, while we might casually call it "moon dust," the scientific term for the lunar surface material is regolith.