Institute of Astronomy

Rocky bodies in the Oort Cloud

SpeakerTalk DateTalk Series
Andrew Shannon28 July 2014Across HR 2014 Posters


Oort cloud comets are icy bodies with semimajor axes of thousands to tens of thousands of AU. Formation at such large distances from the Sun is believed to be impossible, and Oort cloud comets are generally believed to have formed in the outer solar system. They were then injected into the Oort cloud via scattering by the giant planets, and subsequently had their pericentres raised by the galactic tide and perturbations from passing stars. This dynamical path should not be exclusive to small outer solar system bodies, inner solar system should also sometimes follow a similar path. Consequently, some fraction of the Oort cloud should consist of rocky bodies without significant ice. We explore this pathway for the solar system with N-body simulations augmented with the galactic tide and stellar flybys, and estimate the fraction of Oort cloud comets that should have originated in the inner solar system, and hence contain no ice. The occurrence rate of rocky bodies among Oort cloud comets can provide strong constraints on models of the solar system's history and planet formation.


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