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Solar System Exploration
Prospero: Facts & Figures
   Back to Uranus   Overview   Facts & Figures   News 
Discovered By
Matthew J. Holman, John J. Kavelaars, Brett J. Gladman, Jean-Marc Petit, and Hans Scholl
Date of Discovery
18 July 1999
Orbit Size Around Uranus (semi-major axis)
Metric: 16,276,800 km
English: 10,113,935 miles
Periapsis (closest)
Metric: 9,041,762 km
Apoapsis (farthest)
Metric: 23,511,838 km
Sidereal Orbit Period (Length of Year)
5.416481862 Earth years
1978.37 Earth days
By Comparison: Retrograde orbit
Orbit Circumference
Metric: 97,014,053.99 km
Average Orbit Velocity
Metric: 2,043.2 km/h
Orbit Eccentricity
Orbit Inclination
By Comparison: Retrograde orbit
Mean Radius
Metric: 25.0 (assuming an albedo of 0.07) km
Equatorial Circumference
Metric: 157.1 km
Metric: 65,450 km3
Metric: 98,912,116,584,414,800 kg
Scientific Notation: 9.8912 x 1016 kg
Metric: 1.5 g/cm3
Surface Area
Metric: 7,853.98 km2
Surface Gravity
Metric: 0.011 m/s2
Escape Velocity
Metric: 83 km/h

Additional Information:

-USGS Astrogeology: Gazetteer of Planetary Nomenclature:

-JPL Solar System Dynamics:

-Encyclopedia of the Solar System, second edition; edited by Lucy-Ann McFadden, Paul R. Weissman, and Torrence V. Johnson; Academic Press 2007
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Last Updated: 7 Mar 2011