Research has documented childrens difficulty reconciling observations of the sky (Earth-based perspective) with scientificmodels of the solar system (space-based perspective) (e.g., Vosniadou & Brewer, 1994). We developed a coding rubricto capture childrens explanations before and after instruction that emphasized relational learningmapping the spatial,temporal, and causal relations inherent in the day-night cycle. We focused on several key dimensions including theperspective of the child and their causal attributions, focusing primarily on their mental model (e.g., Sun goes up/down).We coded pre- and post-test videos from 3rd graders from two experiments (N=205) using the rubric. Results suggestthat (a) consistent with prior findings, children who received the instruction demonstrated fewer unscientific conceptionsabout Sun motion at posttest, and (b) these conceptions were more pronounced in modeling than in verbal responses. Weconclude that topics that require integration between Earth- and space-based perspectives are particularly challenging foryoung children.