Icarus is a little light this month (1 Mar, vol. 428):
N. Le Beca, S.J. Conway, B. Jabaud, G. et al. A new model of crater degradation on Ceres involving ice sublimation and talus formation Article 116353
Ilgmars Eglitis, Darja Svincicka Rotation period estimates for 14 asteroids with the Earth MOID less than 1.1 AU Article 116380
Ceres: giant asteroid, or giant comet? Ceres has formed a ‘crust’ or ‘mantle’ (by the comet definition) when sunlight, micrometeoroid bombardment, and the occasional not-so-micro bombarder bake the surface. Bakes the surface…of its ice content, to some distance (varying) below the exposed regolith. Still, some fraction of the (unexposed) bulk material is volatiles (including ammoniated compounds, light organics, and arguably some sulfur compounds) and still motile given certain conditions. As imaged by the Dawn mission (extensively), craters on Ceres look different from many other asteroids, Earth’s natural satellite, in cases Earth itself, etc. That difference is wasting by volatiles, as on Mars, Callisto, places on Mercury, etc. When combined with traditional mass wasting (rockslides, or talus), we have another point along the scale of crater morphologies.
Eglitis et al. is a bit more cut-and-dried, no pun intended. As part of characterizing asteroids, rotation is one of the parameters. At first, rapid rotators (~2 hours) must be monolithic rock, not rubble piles. This has implications for planetary defense, should any such asteroid come at Earth. The other end of the study scale is that rotation gives the Yarkovsky and YORP effects, also relevant for planetary defense. On longer timescales, the YORP effect can spin up or spin down an asteroid, to the point of disintegrating it like a lawn sprinkler. The Yarkovsky effect (with or without YORP- depends) makes small bodies drift slightly. Given enough time, Yarkovsky drift can turn an Earth impactor into a non-impactor, or vice versa. Predicting near-impacts and non-impacts into the future may come down to Yarkovsky-drifting that last little bit. And in the middle of the study scale, rotation puts other stats into perspective and context- it’s good to know.