3D contour plots of the DM density in the central (2 kpc) ³ volume of Eris. The outer contour (light blue) corresponds to ρ = 0.45   M _☉ pc ⁻³, the middle contour (light orange) to 0.8   M _☉ pc ⁻³, and the opaque innermost contour (red) to the 99th percentile of the DM density in the volume. The dynamical center is marked with a black dot, and the stellar disk lies in the X– Y plane. The images show the time evolution over 11.5 Myr (Δ t = 1.43 Myr) starting from z = 0.0151. In the last two frames we have plotted the positions of all 78 particles located within 1 _soft of the maximum density at the second-to-last output shown. Only 1.43 Myr later (last frame) they have already dispersed throughout the plotted volume, indicating that the density offset is not a bound structure.