This is the Web Edition of "A Trip Into Space", a Coimbra-based electronic book on space science. Both the texts and the photos are by courtesy of National Aeronautics and Space Administration. |
A Trip Into Space Fact Sheets Uranus Fact Sheet | |
See also: Notes On The Fact Sheets |
Uranus Earth Ratio (Uranus/Earth) Mass (1024 kg) 86.832 5.9736 14.536 Volume (1010 km3) 6,833 108.321 63.08 Radius (1 bar level) (km) Equatorial 25,559 6,378.1 4.007 Polar 24,973 6,356.8 3.929 Volumetric mean radius (km) 25,362 6,371.0 3.981 Ellipticity (Flattening) 0.02293 0.00335 6.84 Mean density (kg/m3) 1,270 5,515 0.230 Gravity (eq., 1 bar) (m/s2) 8.69 9.78 0.889 Escape velocity (km/s) 21.3 11.19 1.903 GM (x 106 km3/s2) 5.794 0.3986 14.536 Bond albedo 0.90 0.385 2.338 Visual geometric albedo 0.51 0.367 1.390 Visual magnitude V(1,0) -7.19 -3.86 - Solar irradiance (W/m2) 3.71 1,367.6 0.0027 Black-body temperature (K) 35.9 247.3 0.145 Moment of inertia (I/MR2) 0.225 0.3308 0.680 J2 (x 10-6) 3343.43 1082.63 3.088
Uranus Earth Ratio (Uranus/Earth) Semimajor axis (106 km) 2,872.46 149.60 19.201 Sidereal orbit period (days) 30,685.4 365.256 84.011 Tropical orbit period (days) 30,588.740 365.242 83.749 Perihelion (106 km) 2,741.30 147.09 18.637 Aphelion (106 km) 3,003.62 152.10 19.748 Synodic period (days) 369.66 - - Mean orbital velocity (km/s) 6.81 29.78 0.229 Max. orbital velocity (km/s) 7.11 30.29 0.235 Min. orbital velocity (km/s) 6.49 29.29 0.222 Orbit inclination (deg) 0.772 0.000 - Orbit eccentricity 0.0457 0.0167 2.737 Sidereal rotation period (hours) -17.24* 23.9345 0.720 Obliquity to orbit (deg) 97.77 23.45 4.169
* Magnetic coordinates (as determined by the Voyager 2 Radio Science experiment)
Discoverer: William Herschel Discovery Date: 13 March 1781 Distance from Earth Minimum (106 km) 2581.9 Maximum (106 km) 3157.3 Apparent diameter from Earth Maximum (seconds of arc) 4.1 Minimum (seconds of arc) 3.3 Mean values at opposition from Earth Distance from Earth (106 km) 2719.99 Apparent diameter (seconds of arc) 3.9 Apparent visual magnitude 5.5
Semimajor axis (AU) 19.19126393 Orbital eccentricity 0.04716771 Orbital inclination (deg) 0.76986 Longitude of ascending node (deg) 74.22988 Longitude of perihelion (deg) 170.96424 Mean Longitude (deg) 313.23218
Dipole field strength: 0.228 gauss-Ru3 Dipole tilt to rotational axis: 58.6 degrees Dipole offset (planet center to dipole center) distance: 0.3 Ru along the rotation axis
Note: Ru denotes Uranian radii, here defined to be 25,600 km
Surface Pressure: >>100 bars Average temperature: ~58 K Temperature at 1 bar: ~76 K Density at 1 bar: ~0.42 kg/m3 Wind speeds: 0-200 m/s Scale height: 27.7 km Mean molecular weight: 2.64 g/mole Atmospheric composition (uncertainty in parentheses) Major: Molecular hydrogen (H2) - 82.5% (3.3%); Helium (He) - 15.2% (3.3%) Methane (CH4) - ~2.3% Minor (ppm): Hydrogen Deuteride (HD) - ~148 Aerosols: Ammonia ice, water ice, ammonia hydrosulfide, methane ice(?)
Last Update: 2004-Nov-27