Collision Chains among the Terrestrial Planets. II. An Asymmetry between Earth and Venus

During the late stage of terrestrial planet formation, hit-and-run collisions are about as common accretionary mergers, for expected velocities and angles giant impacts. Average hit-and-runs leave two major remnants plus debris: target impactor, somewhat modified through erosion, escaping at lower relative velocity. Here we continue our study dynamical effects such collisions. We compare fates intact runners that start from with proto-Venus 0.7 AU proto-Earth 1.0 AU. follow orbital evolutions runners, including other planets, Jupiter, Saturn, in an N-body code. find accretion these can take $\gtrsim$10 Myr (depending on egress velocity first collision) involve successive original or planets. treat runner experiences using surrogate models machine learning, previous work, evolve subsequent a similar fashion. identify asymmetries capture, loss, interchange growth Venus Earth. Hit-and-run is more probable outcome proto-Venus, being smaller faster orbiting than proto-Earth. But acts sink, eventually accreting most its assuming typical events, whereas loses half, many those continuing to Venus. This leads disparity style late-stage could have led significant differences geology, composition, satellite formation Earth