Beginning of Essay
Have you ever looked up in the sky and seen a little ball creeping by? If so, did you wonder what it was? That little ball is called a comet. are small, fragile, and irregularly shaped. Most are composed of frozen gas. However, some are composed of frozen gas ....

Middle of Essay
.... the gases they are composed of glow in the sunlight. All comets are regular family members of the solar system family. They are bound by gravity to a strict path around the solar system. Scientists believe that all comets were formed of material, originally in the outer part of the solar system, which did not become incorporated into planets. This material is from when the planets just started forming. This makes comets an extremely interesting topic to scientists who are studying the history of the solar system. In comparison to planets, comets are very small. They can be anywhere from 750 meters (or less) to 20 kilometers in diameter. ....