Regolith thickness refers to the layer of loose, fragmented material covering solid rock on the surface of a planet or moon. This layer is formed by the weathering and erosion of the underlying rock, and can vary greatly in thickness depending on factors such as the age of the surface, the level of geological activity, and the presence of water and other erosive agents. Studying regolith thickness can provide valuable insights into the geological history and composition of a planetary body, as well as its potential for supporting life or future human exploration. Researchers use a variety of methods to measure regolith thickness, including remote sensing techniques, geophysical surveys, and direct sampling and analysis of regolith samples. By understanding the thickness and properties of regolith, scientists can better understand the processes that shape planetary surfaces and inform future missions to explore and potentially exploit these bodies.