In this paper, we present the results from a study of the impact on students involved in a large-scale inquiry-based astronomical high school education intervention in Australia. Students in this intervention were led through an educational design allowing them to undertake an investigative approach to understanding the lifecycle of stars more aligned with the 'ideal' picture of school science. Through the use of two instruments, one focused on content knowledge gains and the other on student views of school science, we explore the impact of this design. Overall, students made moderate content knowledge gains although these gains were heavily dependent on the individual teacher, the number of times a teacher implemented and the depth to which an individual teacher went with the provided materials. In terms of students' views, there were significant global changes in their views of their experience of the science classroom. However, there were some areas where no change or slightly negative changes of which some were expected and some were not. From these results, we comment on the necessity of sustained long-period implementations rather than single interventions, the requirement for similarly sustained professional development and the importance of monitoring the impact of inquiry-based implementations. This is especially important as inquiry-based approaches to science are required by many new curriculum reforms, most notably in this context, the new Australian curriculum currently being rolled out.