Sample material grains: (left) cm-sized grains produced from UCF-1 CI Orgueil simulant. Millimeter-sized grains are very similar in shape, surface roughness, and overall aspect of the grains with the only difference being the smaller grain size; (right) grain size distributions of the two populations prepared. The mm grain population is shown with the smaller symbols and peaks at 1 mm, while the cm population is shown with the larger symbols and peaks at about 13 mm. Both distributions were normalized with the total number of grains considered for the measurement (over 1000 for mm-sized grains and over 100 for cm-sized grains).