What is the primary cause of erosion on the Moon?

The primary cause of erosion on the Moon is due to breccia and atomic particles from the Sun. Unlike Earth, the Moon lacks significant atmosphere and weather systems, which means that traditional forms of erosion, such as rain and wind, do not play a role in shaping its surface.

On the Moon, the constant bombardment by micrometeorites and cosmic rays contributes to the erosion process. These atomic particles and the impacts from meteoroids break down the lunar surface material, creating a layer of fine dust and small rock fragments known as regolith. This process is distinct from Earth, where erosion is heavily influenced by water flow and atmospheric conditions.

While other options involve common erosional processes observed on Earth, they can be ruled out in the context of the Moon's unique environment.