The big idea of "celestial motion", observational astronomy phenomena explained by the relative position and motion of objects in the solar system and beyond, is central to astronomy in primary and secondary education. In this paper, I argue that students' progress in developing productive, scientific explanations for this class of astronomical phenomena can be defined by the increasing sophistication of spatial knowledge and reasoning in the domain. Drawing upon literature on children's ideas about celestial motion, instruction that supports progress in that domain and literature on spatial thinking, I developed a learning progression (LP) framework that integrates cognition, instruction and assessment to understand student learning in this domain. This framework was applied to a study of children learning to explain the daily celestial motion of the Sun, Moon and stars, and the phases of the Moon. The application of the LP framework to analyse teaching sequences in astronomy extends this review by illustrating how progress within these phenomena is shaped by students' ability to visualise the appearance of objects and their motions across moving frames of reference.