Coming The seasons is a concept in astronomy that is particularly difficult to understand (Plummer, 2012). What’s more, it is almost impossible to teach the seasons using direct observations made by students, as the phenomenon changes almost imperceptibly from day to day and takes a whole year to unfold. To overcome this difficulty, we propose to teach the seasons by prompting students to analyse day-to-day data (sunrise and sunset times and azimuth, height of the Sun at noon, length of day, etc.) for their location, and compare it with the same data for a location positioned at the same latitude in the Southern hemisphere. By answering a series of questions about the data analysed for both locations, students are led to realise that seasons are inverted form one hemisphere to the other and that seasonal changes are mainly due to the height of the Sun in the sky and the length of day. By modelling the reasons for seasons using concrete objects (a Styrofoam ball and a lamp), students will connect the apparent motion of the Sun with the inclination of Earth’s axis of rotation to the plane of the ecliptic. We will present the results of an experiment conducted with pre-service high school teachers enrolled in an astronomy teaching course, using a Seasons Concept Inventory as pre- and post-test.
