To a nonastronomer a comet is a fuzzy object in the sky.
Comets can suddenly brighten or fade from view in a matter of hours.
They can lose their tail or develop multiple tails. Sometimes they can even split into two or more pieces, so that, through a telescope, several comets can be seen moving together across the sky. Comets represent some of the oldest, basically untouched objects in the solar system. Their very composition seems to represent the original makeup of the vast nebula that ultimately condensed to form the sun and planets. Recent years have revealed comets have shaped the progress of life as we know it here on Earth.