Book excerpt: Long before astronauts ventured into space, scientists and philosophers used models to develop theories about Earth and what lies beyond it. This experimentation guide shows students how they too can create models to forge a deep understanding of topics like the scale of the solar system, how eclipses occur, and the cyclic patterns that govern life on our planet. Through the creation of models, readers learn how to develop and test hypotheses and how to represent their findings visually in graphs and charts.