The introduction of a planetary science topic into teaching provides an opportunity for teachers to broaden the science base and offer an enrichment activity outside the National Curriculum. It enables students to undertake independent learning by engaging in a scientific investigation relevant to the real world. Here, more able students are given the opportunity to carry out a classroom-based investigation to measure the depth of an impact crater using the length of a shadow and the angle of the source rays of light. This investigation provides the opportunity for teaching staff to extend the traditional impact cratering practical and demonstrate how scientific knowledge expands. Students also learn the importance of evaluating conclusions by comparing data which have been analysed using different techniques.