Regolith is a term used to describe the layer of loose, fragmented material covering solid rock on the surface of a planet or moon. This material can include soil, dust, gravel, and other particles that have been weathered and eroded over time. Regolith plays a crucial role in the study of planetary geology, as it can provide valuable information about the geological history and processes of a celestial body. Researchers study regolith to understand the composition, structure, and dynamics of planetary surfaces, as well as the potential for supporting future exploration missions.