Densities resulting from the HD simulations of G292.0+1.8 at 1000, 1500, 2000, and 2500 yr. The input parameters for the simulation correspond to Run 3 in Tables 1 and 2. The pulsar is moving in the direction indicated by the black arrows, so the reverse shock initially impacts the PWN from this direction after 1500 yr. By 2500 yr, the reverse shock has interacted with the entire surface of the PWN. The pulsar remains in the center of the PWN until the reverse shock interaction begins, at which point it becomes displaced toward the southeast (the direction of its motion), as observed in the radio image in Figure 2.