A PROTOSOLAR NEBULA ORIGIN FOR THE ICES AGGLOMERATED BY COMET 67P/CHURYUMOV–GERASIMENKO

Journal Article · Thu Mar 10 00:00:00 EST 2016 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8205/819/2/L33· OSTI ID:22521441

Mousis, O.; Vernazza, P. ^[1]; Lunine, J. I. ^[2]; Luspay-Kuti, A.; Hässig, M.; Waite, J. H. ^[3]; Guillot, T. ^[4]; Marty, B. ^[5]; Ali-Dib, M. ^[6]; Wurz, P.; Altwegg, K.; Bieler, A.

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1. Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France)
2. Center For Radiophysics And Space Research, Space Sciences Building Cornell University, Ithaca, NY 14853 (United States)
3. Department of Space Research, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228 (United States)
4. Laboratoire J.-L. Lagrange, Université de Nice-Sophia Antipolis, CNRS, Observatoire de la Côte d’Azur, BP 4229, F-06304 Nice (France)
5. CRPG-CNRS, Nancy-Université, 15 rue Notre Dame des Pauvres, F-54501 Vandoeuvre-lès-Nancy (France)
6. Université de Franche-Comté, Institut UTINAM, CNRS/INSU, UMR 6213, Besançon Cedex (France)

The nature of the icy material accreted by comets during their formation in the outer regions of the protosolar nebula (PSN) is a major open question in planetary science. Some scenarios of comet formation predict that these bodies agglomerated from crystalline ices condensed in the PSN. Concurrently, alternative scenarios suggest that comets accreted amorphous ice originating from the interstellar cloud or from the very distant regions of the PSN. On the basis of existing laboratory and modeling data, we find that the N{sub 2}/CO and Ar/CO ratios measured in the coma of the Jupiter-family comet 67P/Churyumov–Gerasimenko by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument on board the European Space Agency’s Rosetta spacecraft match those predicted for gases trapped in clathrates. If these measurements are representative of the bulk N{sub 2}/CO and Ar/CO ratios in 67P/Churyumov–Gerasimenko, it implies that the ices accreted by the comet formed in the nebula and do not originate from the interstellar medium, supporting the idea that the building blocks of outer solar system bodies have been formed from clathrates and possibly from pure crystalline ices. Moreover, because 67P/Churyumov–Gerasimenko is impoverished in Ar and N{sub 2}, the volatile enrichments observed in Jupiter’s atmosphere cannot be explained solely via the accretion of building blocks with similar compositions and require an additional delivery source. A potential source may be the accretion of gas from the nebula that has been progressively enriched in heavy elements due to photoevaporation.

• OSTI ID: 22521441
• Journal Information: Astrophysical Journal Letters, Vol. 819, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ARGON
CARBON MONOXIDE
CLOUDS
COMETS
ICE
JUPITER PLANET
NITROGEN
ORBITS
PLANETARY NEBULAE
SOLAR SYSTEM
SOLAR SYSTEM EVOLUTION
SPACE VEHICLES