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Solar System Exploration
Hegemone: Facts & Figures
   Back to Jupiter   Overview   Facts & Figures 
Discovered By
Scott S. Sheppard, David C. Jewitt, Jan T. Kleyna, Yanga R. Fernandez, and Henry H. Hsieh
Date of Discovery
8 February 2003
Orbit Size Around Jupiter (semi-major axis)
Metric: 23,566,000 km
English: 14,643,234 miles
Periapsis (closest)
Metric: 15,461,653 km
Apoapsis (farthest)
Metric: 31,670,347 km
Sidereal Orbit Period (Length of Year)
2.025598905 Earth years
739.85 Earth days
By Comparison: Retrograde orbit
Orbit Circumference
Metric: 143,589,402.13 km
Average Orbit Velocity
Metric: 8,086.6 km/h
Orbit Eccentricity
Orbit Inclination
By Comparison: Retrograde orbit
Mean Radius
Metric: 1.5 (assuming an albedo of 0.04) km
English: 0.9 miles
Equatorial Circumference
Metric: 9.4 km
Metric: 14 km3
Metric: 44,960,052,992,916 kg
Scientific Notation: 4.4960 x 1013 kg
Metric: 2.6 g/cm3
Surface Area
Metric: 28.27 km2
Surface Gravity
Metric: 0.001 m/s2
Escape Velocity
Metric: 7 km/h

Additional Information:

-USGS Astrogeology: Gazetteer of Planetary Nomenclature:

-JPL Solar System Dynamics:

-Solar System Moons: Discovery and Mythology by Jürgen Blunck; Springer-Verlag Berlin Heidelberg 2010

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

-Ellis Miner

-Encyclopædia Britannica Online. 2010:
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Last Updated: 21 Mar 2011