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Venus

Venus Geologic History

Venus has two alternative histories, depending upon how one views the age of the extensive resurfacing volcanic lavas. In the "catastrophic" model of Venus history, there was a huge resurfacing event in Venus' history about 200 to 700 million years ago, probably due to rather sudden solidification of the interior of the planet. Vast volcanic features of about the same age favor this interpretation. In the "gradualistic" model of Venus history, global resurfacing has occurred gradually over the whole of Venus' history and the rate of this activity has been rather high so no older surface areas still exist. The mechanism for this is random and continuous volcanic activity. This model does not explain the lack of magnetic field (explained in the other model by the internal solidification event). Future studies of Venus will hopefully help us understand which of these (or perhaps some other) model is correct about Venus' past.

Resources

Books

Beatty, J. Kelly, Carolyn Collins Petersen, and Andrew L. Chaikin. The New Solar System. Cambridge: Cambridge University Press, 1999.
de Pater, Imke, and Jack J. Lissauer. Planetary Sciences. Cambridge, UK: Cambridge University Press, 2001.

Morrison, D., and Tobias Owen. The Planetary System. 3rd ed. Addison-Wesley Publishing, 2002.

Taylor, F.W. The Cambridge Photographic Guide to the Planets. Cambridge University Press, 2002.

Periodicals

Goldman, Stuart. "Venus Unveiled." Sky and Telescope 83 (March 1992).

Luhmann, Janet, J. Pollack, and C. Lawrence. "The Pioneer Mission to Venus." Scientific American (April 1994). Paul, Jeffrey. "Venus in 3-D." Sky & Telescope 86 (August 1993). Saunders, Stephen. "The Surface of Venus." Scientific American (December 1990).

Other

Arnett, B. SEDS, University of Arizona. "The Nine Planets, A Multimedia Tour of the Solar System." November 6, 2002 [cited February 8, 2003] <http://seds.lpl.arizona.edu/nineplanets/nineplanets/nineplanets.html>.

Martin Beech

David T. King, Jr.

KEY TERMS

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Albedo: —The fraction of sunlight that a surface reflects. An albedo of zero indicates complete absorption, while an albedo of unity indicates total reflection.
Doppler effect: —The apparent change in the wavelength of a signal due to the relative motion of the source and the observer.
Dynamo effect: —A model for the generation of planetary magnetic fields: the circulation of conducting fluids within a planet's hot, liquid inner-core results in the generation of a magnetic field.
Greenhouse effect: —The phenomenon that occurs when gases in a planet's atmosphere capture radiant energy radiated from a planet's surface thereby raising the temperature of the atmosphere and the planet it surrounds.
Lithosphere: —The solid outer layer, or crust, of a planet's mantle.
Mantle: —The major portion of a terrestrial planet's interior, made of plastic rock.
Retrograde rotation: —Axial spin that is directed in the opposite sense to that of the orbital motion.
Tectonic activity: —The theory of crustal motion.

Additional topics

Science EncyclopediaScience & Philosophy: Two-envelope paradox to VenusVenus - Basic Properties, The Rotation Rate Of Venus, Venusian Surface Detail, Venusian Surface Processes, Venusian Internal Structure