UNLV researchers add an important computational capability to a widely-used, open source software. Specifically, a summer undergraduate researcher working with Jason Steffen (all Physics and Astronomy), along with a graduate student and an outside collaborator, added the Yarkovsky effect to the REBOUND software. This is a force that affects the orbits of small asteroids due to temperature gradients across their surfaces. The results of this effort will appear in the Astrophysical Journal.