Dynamical environments of (486958) Arrokoth: prior evolution and present state

Abstract

We consider dynamical environments of (486958) Arrokoth, focusing on both their present state and their long-term evolution, starting from the KBO’s formation. Both analytical (based on an upgraded Kepler-map formalism) and numerical (based on massive simulations and construction of stability diagrams in the 3D setting of the problem) approaches to the problem are used. The debris removal is due to either absorption by the KBO or by leaving the Hill sphere; the interplay of these processes is considered. The clearing mechanisms are explored, and the debris removal timescales are estimated. We assess survival opportunities for any debris orbiting around Arrokoth. The generic chaotization of Arrokoth’s circumbinary debris disk’s inner zone and generic cloudization of the disk’s periphery, which is shown to be essential in the general 3D case, naturally explains the current absence of any debris in its vicinities.