Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso


  • Therese EncrenazEmail author
Living reference work entry

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DOI: https://doi.org/10.1007/978-3-642-27833-4_1404-3


Saturn by order of mass, size, and heliocentric distance is, after Jupiter, the second among the solar system’s giant planets. Its mean distance to the Sun is 9.5 AU. Its diameter is 120,530 km or 9.45 times the Earth’s diameter and its mass amounts to 95 terrestrial masses. Its density is 0.69 g/cm3 such that Saturn is the lightest solar system planet. Saturn is best known for its extensive ring system, much larger and more massive than the ones of the other giant planets. Its atmosphere shows a strong dynamical activity and its magnetosphere, perturbed by the ring system, is unique in the solar system.


Saturn as a Giant Planet

Jupiter and Saturn have the same basic chemical composition, dominated by protosolar gas (mostly hydrogen and helium) which accreted on their rock/ice core at the time of their formation; they are called the gas giants. The difference in density between Jupiter (1.3 g/cm3) and Saturn can be explained by Jupiter being more than three times...


Giant planets 
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References and Further Reading

  1. Baines KH et al (2009) Saturn north polar cyclone and hexagon at depth revealed by Cassini/VIMS. Planet Space Sci 57:1671–1681ADSCrossRefGoogle Scholar
  2. Drossart P (2001) Saturn. In: Murdin P (ed) Encyclopedia of astronomy and astrophysics. IoP Publishing, BristolGoogle Scholar
  3. Gehrels T, Matthews MS (1984) Saturn. University of Arizona Press, TucsonGoogle Scholar
  4. Godfrey DA (1988) A hexagonal structure around Saturn’s north pole. Icarus 76:335–356ADSCrossRefGoogle Scholar
  5. Guillot T, Gautier D (2015) Giant planets. In: Spohn T, Schubert G (eds) Treatise on geophysics, vol 10. Elsevier, New York, pp 529–557CrossRefGoogle Scholar
  6. Zarka P, Lamy L, Cecconi B, Prangé R, Rucker HO (2007) Modulation of Saturn’s radio clock by solar wind speed. Nature 450:265–267ADSCrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.LESIAObservatoire de Paris, PSL, CNRS, Sorbonne University, University Paris-DiderotMeudonFrance