  The cohesion of particles has a significant effect on the properties of small
bodies. In this study, we measured in open air, the cohesive forces of tens of
micron-sized irregularly shaped meteorite, silica sand, glass powder, and
spherical glass particles, using a centrifugal method. In addition, we
estimated the amount of water vapor adsorbed on the particles under the
measurement conditions. The measured cohesive forces of the meteorite particles
are tens of times smaller than those of an ideally spherical silica particle
and correspond to the submicron-scale effective (or equivalent) curvature
radius of the particle surface. Moreover, based on the estimated amount of
water vapor adsorbed on the particles, we expect the cohesive forces of the
particles in airless bodies to be approximately 10 times larger than those
measured in open air. Based on the measurement results, we estimate that the
cohesive forces of the particles on asteroids are typically in the
sub-micro-Newton range, and that the particles on fast-rotating asteroids are
tens of microns in size.
