Depression, anxiety, and stress-related disorders continue to rise globally, with South Africa’s burden intensified by structural inequalities and a 91% mental health treatment gap. Accessible complementary interventions are urgently needed. This exploratory mixed-methods pilot study examined the feasibility, acceptability, and preliminary effectiveness of astronomy-based mental health support grounded in Attention Restoration Theory and awe research. Two retreats combined guided naked-eye and telescope-based stargazing with nature immersion: a proof-of-concept peer camp (n=19, Glencairn) and a family-focused retreat (n=27, Sutherland). Quantitative outcomes using the Depression Anxiety Stress Scale (DASS-21) were collected in the Glencairn cohort, alongside qualitative data from Most Significant Change focus groups and asynchronous text-based interviews. Significant reductions in depression, anxiety, and stress were observed in the Glencairn cohort, while qualitative findings across both settings indicated experiences of calm, perspective shifts, and relational connection. However, increased environmental novelty and family dynamics introduced competing cognitive demands in the Sutherland setting. These findings provide preliminary evidence that astronomy-based interventions may support short-term psychological well-being, while highlighting key design considerations, including cognitive spaciousness, contextual onboarding, and relational facilitation, for implementation in diverse African contexts.