We are excited to welcome Astronomer Aaron M. Geller to STEM Voices. Aaron is jointly appointed at Northwestern University's Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and the Adler Planetarium in Chicago. Dr. Geller studies how stars and planets are born and how they change with time, both through observations and numerical simulations. The focus of his research is the study of gravitational dynamics, and particularly how dynamical encounters between stars influence the evolution of multiple-star systems, planetary systems, and star clusters. He is passionate about sharing research and new discoveries with students and the public.