Two independent and primitive envelopes of the bilobate nucleus of comet 67P

Massironi, Matteo and Simioni, Emanuele and Marzari, Francesco and Cremonese, Gabriele and Giacomini, Lorenza and Pajola, Maurizio and Jorda, Laurent and Naletto, Giampiero and Lowry, S.C. and El-Maarry, Mohammad Ramy and Preusker, Frank and Scholten, Frank and Sierks, Holger and Barbieri, Cesare and Lamy, Philippe and Rodrigo, Rafael and Koschny, Detlef and Rickman, Hans and Keller, Horst Uwe and A'Hearn, Michael F. and Agarwal, Jessica and Auger, Anne Thérese and Barucci, M. Antonietta and Bertaux, Jean-Loup and Bertini, Ivano and Besse, Sébastien and Bodewits, Dennis and Capanna, Claire and Da Deppo, Vania and Davidsson, Björn and Debei, Stefano and De Cecco, Mariolino and Ferri, Francesca and Fornasier, Sonia and Fulle, Marco and Gaskell, Robert and Groussin, Olivier and Gutiérrez, Pedro J. and Güttler, Carsten and Hviid, Stubbe F. and Ip, Wing-Huen and Knollenberg, Jörg and Kovacs, Gabor and Kramm, Rainer and Kührt, Ekkehard and Küppers, Michael and La Forgia, Fiona and Lara, Luisa M. and Lazzarin, Monica and Lin, Zhong-Yi and Moreno, Josè J. Lopez and Magrin, Sara and Michalik, Harald and Mottola, Stefano and Oklay, Nilda and Pommerol, Antoine and Thomas, Nicolas and Tubiana, Cecilia and Vincent, Jean-Baptiste (2015) Two independent and primitive envelopes of the bilobate nucleus of comet 67P. Nature, 526 . pp. 402-405. ISSN 0028-0836. (doi:https://doi.org/10.1038/nature15511) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://dx.doi.org/10.1038/nature15511

Abstract

The factors shaping cometary nuclei are still largely unknown, but could be the result of concurrent effects of evolutionary and primordial processes. The peculiar bilobed shape of comet 67P/Churyumov–Gerasimenko may be the result of the fusion of two objects that were once separate or the result of a localized excavation by outgassing at the interface between the two lobes. Here we report that the comet’s major lobe is enveloped by a nearly continuous set of strata, up to 650 metres thick, which are independent of an analogous stratified envelope on the minor lobe. Gravity vectors computed for the two lobes separately are closer to perpendicular to the strata than those calculated for the entire nucleus and adjacent to the neck separating the two lobes. Therefore comet 67P/Churyumov–Gerasimenko is an accreted body of two distinct objects with ‘onion-like’ stratification, which formed before they merged. We conclude that gentle, low-velocity collisions occurred between two fully formed kilometre-sized cometesimals in the early stages of the Solar System. The notable structural similarities between the two lobes of comet 67P/Churyumov–Gerasimenko indicate that the early-forming cometesimals experienced similar primordial stratified accretion, even though they formed independently.

Item Type: Article
Subjects: Q Science > QB Astronomy > QB651 Planets, Minor
Divisions: Faculties > Sciences > School of Physical Sciences > Centre for Astrophysics and Planetary Sciences
Depositing User: Stephen Lowry
Date Deposited: 15 Dec 2015 13:30 UTC
Last Modified: 17 Dec 2015 09:22 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/53449 (The current URI for this page, for reference purposes)
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