Because of the huge distance between stars in any galaxy, it is highly unlikely that any single pair of stars would actually collide. As galaxies draw close to each other, they become distorted by the changing gravitational forces, sometimes sending billions of stars into entirely new orbits. Depending on the relative sizes of the galaxies, the outcome can be different. The colliding galaxies sometimes combine to from a new, larger galaxy; and other times pass directly through each other, with their new, warped shapes being very different from their original states.