A Predicted Dearth of Majority Hypervolatile Ices in Oort Cloud Comets

C. M. Lisse , G. R. Gladstone , L. A. Young , D. P. Cruikshank , S. A. Sandford , B. Schmitt (1) , S. A. Stern , H. A. Weaver , O. Umurhan , Y. J. Pendleton , J. T. Keane , J. M. Parker , R. P. Binzel , A. M. Earle , M. Horanyi , M. El-Maarry , A. F. Cheng , J. M. Moore , W. B. Mckinnon , W. M. Grundy , J. J. Kavelaars , I. R. Linscott , W. Lyra , B. L. Lewis , D. T. Britt , J. R. Spencer , C. B. Olkin , R. L. Mcnutt , H. A. Elliott , N. Dello-Russo , J. K. Steckloff , M. Neveu , O. Mousis (2)

1 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble
2 LAM - Laboratoire d'Astrophysique de Marseille

We present new, ice species-specific New Horizons/Alice upper gas coma production limits from the 2019 January 1 MU69/Arrokoth flyby of Gladstone et al. and use them to make predictions about the rarity of majority hypervolatile (CO, N₂, CH₄) ices in Kuiper Belt objects and Oort Cloud comets. These predictions have a number of important implications for the study of the Oort Cloud, including the determination of hypervolatile-rich comets as the first objects emplaced into the Oort Cloud, the measurement of CO/N₂/CH₄ abundance ratios in the protoplanetary disk from hypervolatile-rich comets, and population statistical constraints on early (<20 Myr) planetary aggregation driven versus later (>50 Myr) planetary migration driven emplacement of objects into the Oort Cloud. They imply that the phenomenon of ultradistant active comets like C/2017K2 should be rare, and thus not a general characteristic of all comets. They also suggest that interstellar object 2I/Borisov may not have originated in a planetary system that was inordinately CO rich, but rather could have been ejected onto an interstellar trajectory very early in its natal system's history.

Mots clés: Pluto; Trans-Neptunian objects; Oort cloud objects; Long period comets; Comets; Ice destruction; Ice formation; Comae; Neutral coma gases

Domaines: Planète et Univers [physics]; Astrophysique [astro-ph]

C. M. Lisse, G. R. Gladstone, L. A. Young, D. P. Cruikshank, S. A. Sandford, et al.. A Predicted Dearth of Majority Hypervolatile Ices in Oort Cloud Comets. The Planetary Science Journal, 2022, 3, ⟨10.3847/PSJ/ac6097⟩. ⟨insu-03690855⟩