This project at Iowa State University uses computer simulations to study planet formation and to teach the core principles of astronomy and computational science in a way that aligns with educational standards. There are two crucial, yet unresolved, questions regarding how planets form. First, how can parcels of protoplanetary disk material trade angular momentum? Second, how do planetesimals (e.g., asteroids and comets) form? The grant also supports the development of a novel website comprised of simulation movies and interactive widgets, named the “Computational Astrophysics Lab” (CAL). It will result in the teaching of students (ranging from high school students from underrepresented and underserved populations to graduate students) in astronomy and scientific research. <br/><br/>The streaming instability is the current leading model for planetesimal formation, and previous simulations of this process overproduce planetesimals compared with Solar System observations. To solve this issue, the investigators propose a novel mechanism involving gas turbulence that regulates planetesimal formation. This project also focuses on studies of angular momentum transport through numerical simulations and comparisons with observations. Thus, the proposed research would address (1) how angular momentum is transported outward in protoplanetary disks and (2) whether gas turbulence in disks can regulate the formation of planetesimals. The development of the new educational tool will provide a friendly user interface to a sophisticated code. It will be employed at three different levels: (1) The CAL will provide a basic understanding of astronomy and scientific computing to high school students from underrepresented & underserved populations from across Iowa. (2) In introductory astronomy courses, the CAL will produce visualizations of astrophysical processes, which will make complex processes understandable on an intuitive, visually based learning level. (3) Finally, the CAL will provide graduate students with a hands-on approach to learning difficult concepts in computational physics via source code and tutorials.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.