Re: Potato Rule doesn't apply
well, yes and no. it all depends on the size distribution of the material being accreted, and whether it happens symmetrically. For instance, if all the material accreting onto a body was the size of dust grains, and was uniformly distributed, you might expect the result to be a spherical body even if it was well under the mass for gravity to do the job, for example if you had a body moving through a large, dense dust cloud (such as in a planetary ring system). On the other hand, if you have a relatively sparsely populated field of material, where the size varied from microscopic upwards, in a Poisson distribution, you might expect accretion to happen as a serious of collisions between bodies of varying sizes, resulting in a much more random shape. The observations suggest that in the outer solar system at least, the mode of formation is much more the latter.