Comets The first written records of comets date back to nearly 3,000 years ago from China and Europe. The accounts of these comets were believed to be the causes of terrible events that occurred afterwards. In more recent times, however, astronomers have found out what they really are. A comet is basically a mixture of ices, from both water and frozen gases, and dust. They have also been given the names “dirty snowballs” or “icy mudballs.” The typical comet is less that 10 kilometers across. They spend most of their time frozen solid in the outer parts of our solar system. Comets are composed of five parts: the nucleus, coma, hydrogen cloud, dust tail, and ion tail. The nucleus is pretty soli