Good old Icarus; what’s in 1 May (vol. 431)?
Micca Longo, G. Suttle, M. D. Longo, S. A numerical model for the atmospheric entry of hydrated, phyllosilicate-rich micrometeorites Article 116490 .2025.116490
Baker, D. A. McMahon, J. W. Boulder-induced spin variability in the YORP effect Article 116487 .2025.116487
Micrometeorites: not so micro when you run the numbers. Take for example, the tonnage of space material falling to Earth as meteorites- palpable, human-scale meteorites. The total mass falling to Earth as micrometeorites and interplanetary dust particles is not slightly greater, but dozens of times greater than that. It behooves us then to consider all these micrometeorites/IDPs. Micca Longo et al. do just that: consider the survival of these particles as they enter and land. Given that some fraction of the micrometeorites are from carbonaceous chondrites, and full of phyllosilicates (basically, clays), they contain water, and can use this thermal mass to survive entry heating.
Now, to the other end of the scale: both Ryugu and Bennu (as well as Itokawa and Eros) had boulders on them, scattered in the regolith. The YORP effect is the spinup (or spindown) of a body, due to sunlight reradiating differently from one side, versus the other. For a perfect sphere, there is no difference side to side, and no YORP effect. But have we considered non-spheres, with non-perfect surfaces (i. e., regolith)… and higher-order surfaces like boulders? Baker et al. have.