Mariner 9 spacecraft images showing evidence of variable surface features and surface erosion resulting from atmospheric wind on Mars have caused a renewed interest in the colian mechanics of saltating grains. To study this phenomenon, both experimental investigation in an atmospheric wind tunnel and numerical solutions of the equations of motion of a single grain under Martian surface conditions were conducted. The numerical solutions for earth were used and empirically adjusted to correlate with existing experimental data for Mars. These modified equations were then solved to estimate grain motion for Mars. These calculations show the importance of a lifting force on the grain to initiate motion in both earth and Mars calculations. Major findings include a comparison of earth and Mars grain trajectories that show Mars length scales to be longer and to fall with a higher terminal grain velocity. The grains in the Mars calculation also made a smaller collision angle with the surface on rebound. In simulation of flow around a raised rim crater it was found that unusually large terminal grain velocities and smaller than normal collision angles existed in the wake of the crater which therefore would have a greater scouring effect on the surface than there would be were there no crater present. This represents a higher erosional rate in the wake of the crater than on the surrounding terrain. Smaller grains exhibit greater normalized terminal velocities than larger grains. This enhanced erosive capability of saltating grains in crater wakes, may well explain the streaks associated with craters that occur in certain regions on the surface of Mars.