<p>Participation in citizen science enables students to gain authentic research experience through collaboration with expert scientists. The purpose of this exploratory study was to investigate how the interactions between expert scientists and student citizen scientists were mediated through the collaborative investigation and co-creation of knowledge artifacts within a computer supported collaborative learning environment. Approximately 38 elementary students participated in a public citizen science project at the end of a school year. Their data (posts, comments, and photos) were downloaded for a post-hoc analysis. A mixed methods design, which merged quantitative SNA analyses and contextualized qualitative descriptions, provided an understanding of the interactions on the site. This analysis found that discussions related to knowledge artifacts that were novel or unexpected engaged a higher number of participants, but that the quality of scientific discussion was not related to the level of engagement. Expert scientists fulfilled a crucial role in generating scientific discussions about the artifacts. Students appeared to play moderating roles by asking questions and making assertions. However, they also were sometimes sidetracked by non-scientific interactions. The use of citizen science projects shows promise in engaging students in authentic research and providing a platform for expert scientists to demonstrate science practices for students. Recommendations for future research are offered to further enhance scientific discussions between all participants.</p>