Impact-driven ice loss in outer Solar System satellites: Consequences for the Late Heavy Bombardment

Abstract

We use recent hydrodynamical results (Kraus, R.G., Senft, L.G., Stewart, S.S. [2011]. Icarus, 214, 724–738) for the production of water vapor by hypervelocity impacts on ice targets to assess which present-day major satellites of Jupiter, Saturn, and Uranus would have lost mass due to impact vaporization during an era of massive bombardment similar to the Late Heavy Bombardment in the inner Solar System. Using impactor populations suggested by recent work (Charnoz, S., Morbidelli, A., Dones, L., Salmon, J. [2009]. Icarus, 199, 413–428; Barr, A.C., Canup, R.M. [2010]. Nat. Geosci., 3, 164–167), we find that several satellites would have lost all their H2O; we suggest that the most likely resolution of this paradox is that either the LHB delivered ≈10times less mass to the outer Solar System than predicted by the standard Nice Model, or that the inner satellites formed after the LHB.