We present an inquiry-based augmented reality (AR) learning environment (AIBLE) designed for teaching basic astronomical phenomena in elementary classroom (children of 8-11 years old). The novelty of this environment lies in the combination of both Inquiry Based Sciences Education and didactics principles with AR features. This environment was user tested by 69 pupils in order to assess its impact on learning. The main results indicate that AIBLE provides new opportunities for the identification of learners' problem solving strategies.