Cometary nuclei are the solid, icy bodies at the center of comets that are thought to be remnants from the formation of the solar system. These nuclei are typically only a few kilometers in diameter and are composed of a mixture of ice, dust, and organic compounds. Scientists study cometary nuclei to better understand the composition, structure, and formation of comets, as well as to learn more about the early solar system. Research on cometary nuclei involves studying their physical properties, surface features, and activity, as well as analyzing the material they release as they approach the Sun. This field of research can provide valuable insights into the origins and evolution of comets and their role in the history of the solar system.