David A. Minton^a and Harold F. Levison^b

^aPurdue University Department of Earth, Atmospheric, & Planetary Sciences, 550 Stadium Mall Drive, West Lafayette, IN 47907
^bSouthwest Research Institute and NASA Lunar Science Institute, 1050 Walnut St. Suite 300, Boulder, CO 80302

We develop a model for planetesimal-driven migration (PDM) in the context of rocky planetary embryos in the terrestrial planet region during the runaway and oligarchic growth phases of inner planet formation. We develop this model by first showing that there are five necessary and sufficient criteria that must be simultaneously satisfied in order for a rocky inner solar system embryo to migrate via PDM. To investigate which embryos within a given disk satisfy the five criteria, we have developed a Monte Carlo planetesimal merger code that simulates the growth of embryos from a planetesimal disk with nebular gas. The results of our Monte Carlo planetesimal merger code suggest that, for typical values of the minimum mass solar nebula for the inner solar system, an average of 0.2 embryos capable of PDM emerge over the lifetime of the disk. Many disks in our simulations produce no migration candidates, but some produced as many as 3. The number of embryos that experience PDM in a disk increases with increasing disk mass and decreasing il planetesimal mass, although we were not able to simulate disks where the average initial planetesimal size was smaller than 50 km. For disks 4× more massive than the standard minimum mass solar nebula, we estimate that an average of 1.5 embryos capable of PDM emerge, with some producing as many as 7.

Reference
Minton DA and Levison HF (2014) Planetesimal-driven migration of terrestrial planet embryos. Icarus
[doi:10.1016/j.icarus.2014.01.001]
Copyright Elsevier

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