Activity Notes For related resources in Spanish, see the Explora Más en Español section below. In this activity, students will learn the basic characteristics of a comet and older students will practice evaluation and improvement of their comet models. The importance of this activity is not the initial model or its exercise, but the fact that it will put students in the position of emulating a process that scientists and engineers follow on all missions. Materials Styrofoam ball or 8.5 x 11 pie