The term "D-body" refers to a specific type of celestial body that is classified within the Solar System. These bodies are typically small and can include objects like asteroids and comets. D-bodies are often found in the outer regions of the Solar System, particularly in areas such as the Kuiper Belt and the Oort Cloud. D-bodies are significant for scientific research because they can provide insights into the early formation of the Solar System. Studying these objects helps astronomers understand the composition and evolution of planetary systems, as well as the potential for life beyond Earth.