  Asteroid 162173 Ryugu is a rubble-pile asteroid, whose top-shape is
compatible with models of deformation by spin up. Rims of major craters on
Ryugu have an east-west asymmetric profile; their western crater rims are sharp
and tall, while their eastern crater rims are rounded and low. Although there
are various possible explanations, we theoretically assess the effect of
asteroid rotation as the possible reason for this east-west asymmetry. It is
known that the trajectories and fates of ejecta are affected by the rotation.
The Coriolis force and the inertial speed of the rotating surface are the
factors altering the ejecta trajectories. Consequently, we found that the
east-west asymmetric crater rims might be formed as a result of rotation, when
the inertial speed of the rotating surface is nearly equal to the first cosmic
velocity of the body. In other words, it is possible that the observed
east-west asymmetric rims of the Urashima, Cendrillon, and Kolobok craters were
formed when Ryugu's rotation period was ~3.6 h.
