A $\sim$32-70 K formation temperature range for the ice grains agglomerated by comet 67P/Churyumov-Gerasimenko

Abstract

Grand Canonical Monte Carlo simulations are used to reproduce the N${}_2$/CO ratio ranging between 1.7 $\times$ 10${}^{-3}$ and 1.6 $\times$ 10${}^{-2}$ observed {\it in situ} in the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA mass spectrometer aboard the Rosetta spacecraft, assuming that this body has been agglomerated from clathrates in the protosolar nebula. Simulations are done using an elaborated interatomic potentials for investigating the temperature dependence of the trapping within a multiple guest clathrate formed from a gas mixture of CO and N${}_2$ in proportions corresponding to those expected for the protosolar nebula. By assuming that 67P/Churyumov-Gerasimenko agglomerated from clathrates, our calculations suggest the cometary grains must have been formed at temperatures ranging between $\sim$31.8 and 69.9 K in the protosolar nebula to match the N${}_2$/CO ratio measured by the ROSINA mass spectrometer. The presence of clathrates in Jupiter family comets could then explain the potential N${}_2$ depletion (factor up to $\sim$87 compared to the protosolar value) measured in 67P/Churyumov-Gerasimenko.

Accepted for publication in The Astrophysical Journal Letters

References in corpus (5)

• Sequestration of ethane in the cryovolcanic subsurface of Titan
• Clathrate hydrates as a sink of noble gases in Titan's atmosphere
• Variability of the methane trapping in martian subsurface clathrate hydrates
• New insights on Saturn's formation from its nitrogen isotopic composition
• Origin of volatiles in the Main Belt

Cited by in corpus (2)

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