Part one of term paper
The first written records of date back to nearly 3,000 years ago from China and Europe. The accounts of these 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, an ...

Part two of term paper
... solid and stable, composed mostly of ice and gas with a small amount of dust and other solids. The surface of the nucleus is best described as a black crust. Comet nuclei can range from 1 kilometer to about 50 kilometers across. The black crust on the surface of the nuclei helps the comet to absorb heat, which causes some of the ices under the crust to turn to a gas. Pressure builds up underneath the crust and causes the surface to bubble up in some places. Eventually, the weak spots of the cr ...