In the second December issue (Dec. 10, vol. 977, issue #1) of Astrophysical Journal:
Morton, E. M. Pickard, H. Wombacher, F. et al. Volatile Element Depletion of Carbonaceous Chondrites – Insights from Mass-dependent Zinc, Cadmium and Tellurium Isotopes Art. 53 ad87ed
Quan, R. Song, Z. Liu, Z. Dynamic 3D Simulation of Surface Charging on Rotating Asteroids Art. 127 ad8e37
Tracing the history of the Solar System involves tracing the history of chondrites- the meteorites that are samples of unaltered and poorly-altered asteroids. These preserve the signs of the young Solar system, without having been excessively heated, which would destroy crucial lines of evidence. Zinc, having a low melting point for a metal, is used as a tracer; other elements have telltale isotopes, which we can use as gauges of various processes. Morton et al. used those isotopes, for those processes.
And now we go from geochemistry/cosmochemistry to cosmophysics. The surfaces of airless bodies are bombarded continuously, by the solar wind, micrometeorites, cosmic rays, the occasional macroscopic meteor, etc. This has to have some effect, but what? The NEAR Shoemaker probe at Eros detected dust signatures- collections of dust shed from bombardments, and gathering in low spots (“ponds”). There were some signs that finer dust particles could float about, from such processes. If a particle is light enough, static electricity might actually levitate it off the surface. Having the asteroid rotate helps the process, by both contributing centrifugal force, and by causing day/night cycles that generate static.