Definition
Planetary differentiation is the separation of different constituents of planetary materials resulting in the formation of distinct compositional layers. Denser material tends to sink into the center and less dense material rises toward the surface. If internal differentiation of a terrestrial planet has run to completion, the interior would be subdivided into an iron-rich metallic core and a silicate mantle, overlain by a chemically distinct crust enriched in basalt.
Overview
The accretion of the terrestrial bodies from planetesimals provides the initial source of energy for subsequent planetary evolution. The amount of kinetic energy converted to heat during accretion is not well known because it is strongly dependent on specific formation timescales and environmental conditions. Heat sources, other than deposition of impact energy during accretion, are the release of energy through gravitational separation of light and dense constituents, the decay of radioactive heat...
This is a preview of subscription content, log in via an institution to check access.
References and Further Reading
Abe Y (1993) Thermal evolution and chemical differentiation of the terrestrial magma ocean. In: Takahashi E, Jeanloz R, Rubie D (eds) Evolution of the earth and planets, geophys, vol 14, Monograph Series 74 and IUGG. American Geophysical Union and International Union of Geodesy and Geophysics, Washington, DC, pp 41–54
Armstrong RL (1981) Radiogenic isotopes. The case for crustal recycling on a near-steady-state no-continental-growth Earth. Roy Soc Lond Philipp Trans A301:433–471
Bougher SW, Hunten DM, Phillips RJ (eds) (1997) Space science series: Venus II – geology, geophysics, atmosphere, and solar wind environment. The University of Arizona Press, Tucson, p 1330
Braginsky SI (1964) Magnetohydrodynamics of the Earth core. Geomagn Aeron 4:698–712
Campbell BA, Campbell DB, DeVries CH (1999) Surface processes in the Venus highlands: results from analysis of Magellan and Arecibo data. J Geophys Res 104:1897–1916
Elkins-Tanton LT, Parmentier EM, Hess PC (2003) Magma ocean fractional crystallization and cumulate overturn in terrestrial planets: implications for Mars, meteoritics and planet. Science 38:1753–1771
Ghosh A, McSween HJ Jr (1998) A thermal model for the differentiation of asteroid 4 Vesta, based on radiogenic heating. Icarus 134:187–206
Joliff BL, Wieczorek MA, Shearer CK, Neal CR (2006) New views of the Moon. Mineralogical Society of America, Reviews in Mineralogy and Geochemistry, vol 60, Washington, DC
Kleine T, Münker C, Mezger K, Palme H (2002) Rapid accretion and early core formation on asteroids and the terrestrial planets from Hf-W chronometry. Nature 418:952–955
MacPherson GJ, Davis AM, Zinner EK (1995) The distribution of aluminium-26 in the early solar system – a reappraisal. Meteoritics 30:365–386
Nimmo F, Tanaka K (2005) Early crustal evolution of Mars. Annu Rev Earth Planet Sci 33:133–161
Schaber GG, Strom RG, Moore HJ et al (1992) Geology and distribution of impact craters on Venus: what are they telling us? J Geophys Res 97:13,257–13,301
Schubert G, Spohn T, Reynolds RT (1986) Thermal histories, compositions and internal structures of the moons of the solar system. In: Burns JA, Shapley MS (eds) Satellites. University Arizona Press, Tucson, pp 224–292
Sohl F, Schubert G (2007) Interior structure, composition, and mineralogy of the terrestrial planets. In: Schubert G (ed-in-chief) Treatise on geophysics. Spohn T (vol ed) Planets and moons, vol 10. Elsevier, Amsterdam, pp 27–68
Solomon SC (1979) Formation, history and energetics of cores in the terrestrial planets. Phys Earth Planet Inter 19:168–182
Stevenson DJ (1990) Fluid dynamics of core formation. In: Newsom HE, Jones JH (eds) Origin of the Earth. Oxford University Press, New York, pp 231–249
Tachibana S, Huss GI (2003) The initial abundance of 60Fe in the solar system. Astrophys J 588:L41–L44
Taylor SR, McLennan SM (1985) The continental crust: its composition and evolution. Blackwell Scientific, Oxford
Veizer J, Jansen SL (1979) Basement and sedimentary recycling and continental evolution. J Geol 87:341–370
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 Springer-Verlag Berlin Heidelberg
About this entry
Cite this entry
Sohl, F., Breuer, D. (2014). Differentiation, Planetary. In: Amils, R., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-27833-4_430-2
Download citation
DOI: https://doi.org/10.1007/978-3-642-27833-4_430-2
Received:
Accepted:
Published:
Publisher Name: Springer, Berlin, Heidelberg
Online ISBN: 978-3-642-27833-4
eBook Packages: Living Reference Physics and AstronomyReference Module Physical and Materials ScienceReference Module Chemistry, Materials and Physics