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Data/hora: 08/06/2017 16:46:43
Provedor de dados: 5
País: France
Título: Methane Clathrates in the Solar System
Autores: Mousis, Olivier; Chassefiere, Eric; Holm, Nils G.; Bouquet, Alexis; Waite, Jack Hunter;
Geppert, Wolf Dietrich; Picaud, Sylvain; Aikawa, Yuri; Ali-dib, Mohamad; Charlou,
Jean-luc; Rousselot, Philippe.
Data: 2015-04
Ano: 2015
Resumo: We review the reservoirs of methane clathrates that may exist in the different bodies of
the Solar System. Methane was formed in the interstellar medium prior to having been
embedded in the protosolar nebula gas phase. This molecule was subsequently trapped in
clathrates that formed from crystalline water ice during the cooling of the disk and
incorporated in this form into the building blocks of comets, icy bodies, and giant planets.
Methane clathrates may play an important role in the evolution of planetary atmospheres.
On Earth, the production of methane in clathrates is essentially biological, and these
compounds are mostly found in permafrost regions or in the sediments of continental
shelves. On Mars, methane would more likely derive from hydrothermal reactions with
olivine-rich material. If they do exist, martian methane clathrates would be stable only at
depth in the cryosphere and sporadically release some methane into the atmosphere via
mechanisms that remain to be determined. In the case of Titan, most of its methane
probably originates from the protosolar nebula, where it would have been trapped in the
clathrates agglomerated by the satellite's building blocks. Methane clathrates are still
believed to play an important role in the present state of Titan. Their presence is invoked
in the satellite's subsurface as a means of replenishing its atmosphere with methane via
outgassing episodes. The internal oceans of Enceladus and Europa also provide
appropriate thermodynamic conditions that allow formation of methane clathrates. In
turn, these clathrates might influence the composition of these liquid reservoirs. Finally,
comets and Kuiper Belt Objects might have formed from the agglomeration of clathrates
and pure ices in the nebula. The methane observed in comets would then result from the
destabilization of clathrate layers in the nuclei concurrent with their approach to
perihelion. Thermodynamic equilibrium calculations show that methane-rich clathrate
layers may exist on Pluto as well. Key Words: Methane clathrate-Protosolar
nebula-Terrestrial planets-Outer Solar System.
Tipo: Text
Idioma: Inglês
Identificador: http://archimer.ifremer.fr/doc/00266/37718/41116.pdf
DOI:10.1089/ast.2014.1189
http://archimer.ifremer.fr/doc/00266/37718/
Editor: Mary Ann Liebert, Inc
Formato: application/pdf
Fonte: Astrobiology (1531-1074) (Mary Ann Liebert, Inc), 2015-04 , Vol. 15 , N. 4 , P. 308-326
Fonte: 2012 Mary Ann Liebert, Inc. publishers. All rights reserved, USA and worldwide
info:eu-repo/semantics/openAccess
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