  The migration of cohesive regolith on the surface of an otherwise monolithic
or strong asteroid is studied using theoretical and simulation models. The
theory and simulations show that under an increasing spin rate (such as due to
the YORP effect), the regolith covering is preferentially lost across certain
regions of the body. For regolith with little or no cohesive strength, failure
occurs by landsliding from the mid latitudes of the body at high enough spin
rates. As the cohesive strength of the regolith increases, failure occurs by
fission of grains (or coherent chunks of grains) across a greater extent of
latitudes and eventually will first occur at the equator. As the spin rate is
further increased, failure regions migrate from the first failure point to
higher and lower latitudes. Eventually failure will encompass the equatorial
region, however there always remains a region of high latitudes (around the
poles) that will not undergo failure for arbitrarily high spin rates (unless
disturbed by some other phenomenon). With these results a scaling law is
derived that can be used to determine whether observed asteroids could retain
surface regolith grains of a given size. The implications of this for the
interpretation of spectral observations of small asteroids and boulder
migration on large asteroids are discussed.
