Interpretation of the carbon abundance in Saturn measured by Cassini
HERSANT, F.
Laboratoire d'études spatiales et d'instrumentation en astrophysique [LESIA]
Département d'Astrophysique (ex SAP) [DAP]
Laboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB]
Observatoire aquitain des sciences de l'univers [OASU]
Laboratoire d'études spatiales et d'instrumentation en astrophysique [LESIA]
Département d'Astrophysique (ex SAP) [DAP]
Laboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB]
Observatoire aquitain des sciences de l'univers [OASU]
GAUTIER, Daniel
Institut de Recherche Agricole pour le Développement [Yaoundé] [IRAD]
Ressources forestières et politiques publiques [UPR Ressources forestières]
See more >
Institut de Recherche Agricole pour le Développement [Yaoundé] [IRAD]
Ressources forestières et politiques publiques [UPR Ressources forestières]
HERSANT, F.
Laboratoire d'études spatiales et d'instrumentation en astrophysique [LESIA]
Département d'Astrophysique (ex SAP) [DAP]
Laboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB]
Observatoire aquitain des sciences de l'univers [OASU]
Laboratoire d'études spatiales et d'instrumentation en astrophysique [LESIA]
Département d'Astrophysique (ex SAP) [DAP]
Laboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB]
Observatoire aquitain des sciences de l'univers [OASU]
GAUTIER, Daniel
Institut de Recherche Agricole pour le Développement [Yaoundé] [IRAD]
Ressources forestières et politiques publiques [UPR Ressources forestières]
Institut de Recherche Agricole pour le Développement [Yaoundé] [IRAD]
Ressources forestières et politiques publiques [UPR Ressources forestières]
LUNINE, Jonathan I.
Istituto di Fisica dello Spazio Interplanetario [IFSI]
Jet Propulsion Laboratory [JPL]
Lunar and Planetary Laboratory [Tucson] [LPL]
< Reduce
Istituto di Fisica dello Spazio Interplanetario [IFSI]
Jet Propulsion Laboratory [JPL]
Lunar and Planetary Laboratory [Tucson] [LPL]
Language
en
Article de revue
This item was published in
Planetary and Space Science. 2008, vol. 56, p. 1103-1111
Elsevier
English Abstract
Spectral observations of Saturn from the far infrared spectrometer aboard the Cassini spacecraft [Flasar, F.M., et al., 2005. Temperatures, winds, and composition in the Saturnian system. Science 307, 1247?1251] have ...Read more >
Spectral observations of Saturn from the far infrared spectrometer aboard the Cassini spacecraft [Flasar, F.M., et al., 2005. Temperatures, winds, and composition in the Saturnian system. Science 307, 1247?1251] have revealed that the C/H ratio in the planet is in fact about twice higher than previously derived from ground based observations and in agreement with the C/H value derived from Voyager IRIS by Courtin et al. [1984. The composition of Saturn's atmosphere at northern temperate latitudes from Voyager IRIS spectra - NH3, PH3, C2H2, C2H6, CH3D, CH4, and the Saturnian D/H isotopic ratio. Astrophys. J. 287, 899?916]. The implications of this measurement are reanalyzed in the present report on the basis that volatiles observed in cometary atmospheres, namely CO2, CH4, NH3 and H2S may have been trapped as solids in the feeding zone of the planet. CH4 and H2S may have been in the form of clathrate hydrates while CO2 presumably condensed in the cooling solar nebula. Carbon may also have been incorporated in organics. Conditions of temperature and pressure ease the hydratation of NH3. Such icy grains were included in planetesimals which subsequently collapsed into the hydrogen envelope of the planet, then resulting in C, N and S enrichments with respect to the solar abundance. Our calculations are consistent, within error bars, with observed elemental abundances on Saturn provided that the carbon trapped in planetesimals was mainly in the form of CH4 clathrate and CO2 ice (and maybe as organics) while nitrogen was in the form of NH3 hydrate. Our approach has implications on the possible pattern of noble gases in Saturn, since we predict that contrary to what is observed in Jupiter, Ar and Kr should be in solar abundance while Xe might be strongly oversolar. The only way to verify this scenario is to send a probe making in situ mass spectrometer measurements. Our scenario also predicts that the 14N/15N ratio should be somewhat smaller in Saturn than measured in Jupiter by Galileo.Read less <
Origin
Hal imported