  Astronomers have played many roles in their engagement with the larger
astronomy education ecosystem. Their activities have served both the formal and
informal education communities worldwide, with levels of involvement from the
occasional participant to the full-time professional. We discuss these many
diverse roles, giving background, context, and perspective on their value in
encouraging and improving astronomy education. This review covers the large
amounts of new research on best practices for diverse learning environments.
For the formal education learning environment, we cover pre-university roles
and engagement activities. This evidence-based perspective can support
astronomers in contributing to the broad astronomy education ecosystem in more
productive and efficient ways and in identifying new niches and approaches for
developing the science capital necessary for a science literate society and for
greater involvement of underrepresented groups in the science enterprise.
