Uranus, one of the four giant planets, is the fourth most massive planet in the solar system (Plate 30). Its orbit has a period about the Sun equal to 30 685 Earth days, a semimajor axis of 2.87 billion km, and lies between the orbits of Saturn and Neptune. Uranus' orbit plane is inclined to the Earth's orbit plane by only 0.774°, and thus lies close to the orbit planes of most other planets. Uranus' orbital motion is prograde; i.e. the planet moves counterclockwise in its orbit when viewed from above the north pole of the Sun, in the same sense as other planetary orbits. Uranus' orbital eccentricity e = 0.0472, which is similar to the small values found for the other giant planets.
The one remarkable and unique dynamical characteristic of Uranus is its obliquity, or angle of inclination between the spin axis and the normal to the orbital plane. Uranus spins with an interior rotation period of 17.24 h and an obliquity of 98°, much larger than the obliquity of any other planet. It is...
This is a preview of subscription content, log in via an institution to check access.
Bibliography
Atreya, S. K., Pollack, J. B. and Matthews, M. S. (1989) Origin and Evolution of Planetary and Satellite Atmospheres, part IV, Outer Planets. Tucson: University of Arizona Press.
Bergstrahl, J. T., Miner, E. D. and Matthews, M. S. (1991) Uranus. Tucson: University of Arizona.
Hubbard, W. B. (1984) Planetary Interiors. New York: Van Nostrand Reinhold.
Hubbard, W. B. (1990) Interiors of the giant planets, in The New Solar System, 3rd edn (eds J. K. Beatty and A. Chaikin). New York: Cambridge University Press. pp. 131–8.
J. Geophys. Res. (1987) Voyager 2 at Uranus issue, 92, 14837–5375.
Stevenson, D. J. (1982) Interiors of the giant planets. Ann. Rev. Earth Planet. Sci., 10, 257–95.
Cross references
Rights and permissions
Copyright information
© 1997 Chapman & Hall
About this entry
Cite this entry
Hubbard, W.B. (1997). Uranus . In: Encyclopedia of Planetary Science. Encyclopedia of Earth Science. Springer, Dordrecht. https://doi.org/10.1007/1-4020-4520-4_425
Download citation
DOI: https://doi.org/10.1007/1-4020-4520-4_425
Publisher Name: Springer, Dordrecht
Print ISBN: 978-0-412-06951-2
Online ISBN: 978-1-4020-4520-2
eBook Packages: Springer Book Archive