Solving problems in a visuospatial domain, such as astronomy, may require not only knowledge about the phenomena within the domain but an ability to instantiate knowledge spatially to generate solutions, as well. Spatial ability assessments and interviews of undergraduates show that problem-solving ability can be limited regardless of the scientific accuracy of an individual's causal beliefs about astronomy. Spatial ability was found to be somewhat positively correlated with problem solving performance, regardless of the causal beliefs an individual holds. Providing external aides (colored balls) for help with spatial reasoning improves performance, a further sign of the influence of spatial ability on problem solving. The specific causal explanation for a phenomenon an individual believes may itself be related to spatial ability. For learners to better understand and apply scientific explanations of astronomy, it may be necessary to provide spatial skills training as a component in instruction. (Contains 16 references.) (Author/MM)