Presentation #322.18 in the session Comets (Poster + Lightning Talk)
We present preliminary findings of the full orbital near-surface temperature solutions of Comet 67P using the time-asymptotic Fast Fourier Transform method (“TAFFT”) recently employed for the cold-classical Kuiper Belt object Arrokoth. We will present a mathematical sketch of how the TAFFT method has been expanded to include near surface sublimation of volatiles. The solutions are a function of volatile species, and the thermal inertia of the sublimating ice layer and that of the refractory cover of depth h. A refractory cover generally reduces the amount of sublimation taking place at the location of the volatile ice layer.
On the assumption that the near surface sublimating ice is H2O, we report several findings: (1) Solutions with no refractory dust cover overestimate the total amount of H2O production by almost a factor of 10 compared to estimates made from direct observations of 67P made by ROSETTA. (2) The onset of regional activity across the body as identified by recently published geomorphological analysis of 67P coincides with the sublimation-driven gas production predicted by the thermal solutions produced using the TAFFT method. We will present a selected survey of these and various other findings, as well as a detailing of the TAFFT method and its extension to include sublimation, and finally a discussion of its superior computational efficiency over and above traditional finite-differencing methods typically employed in such problems. We will also present a survey of some of the method’s limitations. We will wax on its expanded applications to other small body objects including those of the JFC and Centaur populations.