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Planets

Characteristics of Uranus

Uranus, the seventh planet from the Sun, is one of the two giant ice planets in the Solar System. Its distance from the Sun and its relatively small size compared to Jupiter and Saturn ensure that the planet is below the freezing point of its main constituents. The radius of the planet is defined as the point in the atmosphere where the pressure equals 1 bar (the pressure at sea level on Earth). Two rotation periods are defined for the planet: the rotation period of its magnetic field, and the rotation implied by its flattening.

In the table that follows, the observed values are taken from Yoder (1995).[1] Go to table of characteristics.

Characteristics of Uranus

GM

5.7939(47±23)×1021 cm3 s−2

Mass

8.681×1028 g

Mean Radius

2.53(62±12)×109 cm

Equatorial Radius

2.555(9±4)×109 cm

Flattening

0.00229(3±8)

Surface Gravity

900.8 cm s−2

Escape Velocity

4.244×106 cm s−1

Average Density

1.270 g cm−3

Sidereal Rotation Period
(Magnetic)

17h 14m

62064±36 s

Sidereal Rotation Period
(Hydrostatic)

17h

61704±3240 s

Obliquity to Orbit

97° 51

Sidereal Orbital Period

30588.740 d

Semimajor Axis

19.19126393 AU

Eccentricity

0.04716771

Solar Constant

3.71×103 ergs cm−2 s−1

[1] Yoder, Charles F. “Astrometric and Geodetic Properties of Earth and the Solar System.” In Global Earth Physics: A Handbook of Physical Constants edited by T.J. Ahrens, 1–31. AGU Reference Shelf, No. 1. Washington: American Geophysical Union, 1995.

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