A Sublime Opportunity: The Dynamics of Transitioning Cometary Bodies and the Feasibility of $\textit{In Situ}$ Observations of The Evolution of Their Activity

TL;DR

This paper explores the dynamical pathways of Centaurs transitioning into the inner Solar System, highlighting the potential for in situ observations of their activity evolution, exemplified by the upcoming arrival of object P/2019 LD2.

Contribution

It provides N-body simulations of Centaur transfers, analyzes orbital dynamics near Jupiter, and proposes in situ spacecraft observations of transitioning objects like LD2.

Findings

High efficiency transfer of objects with Tisserand parameter ~3 to inner Solar System

Approximately 55% of simulated objects encounter Jupiter before reaching q<4au

Jupiter-proximate spacecraft could observe the onset of cometary activity in situ

Abstract

The compositional and morphological evolution of minor bodies in the Solar System is primarily driven by the evolution of their heliocentric distances, as the level of incident solar radiation regulates cometary activity. We investigate the dynamical transfer of Centaurs into the inner Solar System, facilitated by mean motion resonances with Jupiter and Saturn. The recently discovered object, P/2019 LD2, will transition from the Centaur region to the inner Solar System in 2063. In order to contextualize LD2, we perform N-body simulations of a population of Centaurs and JFCs. Objects between Jupiter and Saturn with Tisserand parameter $T_J\sim$3 are transferred onto orbits with perihelia $q<4$au within the next 1000 years with notably high efficiency. Our simulations show that there may be additional LD2-like objects transitioning into the inner Solar System in the near-term future, all of which have low $\Delta$V with respect to Jupiter. We calculate the distribution of orbital elements resulting from a single Jovian encounter and show that objects with initial perihelia close to Jupiter are efficiently scattered to $q<4$au. Moreover, approximately $55\%$ of the transitioning objects in our simulated population experience at least 1 Jovian encounter prior to reaching $q<4$au. We demonstrate that a spacecraft stationed near Jupiter would be well-positioned to rendezvous, orbit match, and accompany LD2 into the inner Solar System, providing an opportunity to observe the onset of intense activity in a pristine comet $\textit{in situ}$. Finally, we discuss the prospect of identifying additional targets for similar measurements with forthcoming observational facilities.