Focusing on the interplay of context and language, this study examined a group of high school students and their mentors' use of language during a robotics competition. This informal setting allowed us to gain insights into the mediation and manifestation of power within the group. Using critical discourse analysis of competition transcripts and interviews we found that both students and mentors felt a sense of ownership and community leading to symmetry in power amongst them. The shift in power led to greater student ownership and agency and created a space for authentic and meaningful science learning. The context of the robotics competition mediated discourse practices that were different from students' classroom experiences in that they were descriptive, relational, explanatory, and had an authentic evaluative dimension. This engaged the participants to co-construct and critique each other's knowledge claims thereby engaging in scientific practices that approximated the practices of scientists. Our study presents an argument that language and context reflexively influenced one another and reduced the imbalance of power amongst the participants thereby adding a new dimension to what has already been established about the conditions under which authentic science learning is likely to occur.