The Yarkovsky thermal force on small asteroids and their fragments - Choosing the right albedo

Thermal (Yarkovsky) forces acting on small bodies in the solar system have been shown to play an important role in the the delivery of meteoroids and km-sized asteroids to Earth. So far, several aspects of the Yarkovsky force have been studied in some detail, including non-linear effects of the heat diffusion problem, non-sphericity and the layered-structure of the objects . In this paper, we address the concept of optical absorptivity. We find th at the best formulation of the Yarkovsky effect uses the first two moment-i ntegrals of an object's hemispheric albedo. A useful approximation of these albedo parameters is an object's Bond albedo.