Effects of Clumpy Disks on Late-Stage Planet Assembly and Mars Analogs

Current models of late-stage planet assembly in the solar system struggle to reproduce Mars. In particular, Mars analogues are more massive than Mars itself, often by a factor of 10. We attempt to produce better Mars analogues by introducing depletion zones into the model. In current models, mass is distributed in the solid disk along a smooth curve. Depletion zones create valleys in the smooth curve making the distribution clumpy. We have run N-body integrations for solid disks containing 2400 to 3600 planetesimals and 40 to 80 embryos over 200 million years. Planets that form between 1.46-1.52AU are classified as Mars analogues. We compare 200 smooth disks to 200 clumpy disks. The number of Mars analogues remains the same, and we don't see any statistically significant differences between Mars analogues. The mass of a Mars analogue clearly depends on the number of collisions. Deeper and wider depletion zones may be necessary to reduce the masses of the Mars analogues.