Abstract
As an instructor in courses for prospective teachers, I am interested in my students' ideas and ways in which they reconstruct their ideas in conversations about science. In the case study presented here, I reflect upon (a) ways in which I engaged prospective teachers in thinking together about their observations of a natural phenomenon, the changing phases of the moon, and (b) the ideas that they expressed. The case study examines ways in which prospective teachers developed understandings of the sun–earth–moon system from two perspectives: as viewed from the earth and from outside the solar system.
