Planetary interiors refer to the composition and structure of the interiors of planets, including their core, mantle, and crust. Synonyms for planetary interiors include planetary geology, planetary science, planetary physics, and planetology. These terms are often used interchangeably to describe the study of the physical and chemical properties of planets and their evolution over time. Planetary interiors are an important area of research for understanding the origin and evolution of our solar system and for exploring the potential habitability of other planets. The study of planetary interiors also has significant implications for understanding Earth's own interior and the forces that affect its surface.