National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
Portia: Facts & Figures
   Back to Uranus   Overview   Gallery   Facts & Figures   News 
Discovered By
S. Synnott, Voyager 2
Date of Discovery
Orbit Size Around Uranus (semi-major axis)
Metric: 66,100 km
English: 41,073 miles
Periapsis (closest)
Metric: 66,093 km
Apoapsis (farthest)
Metric: 66,107 km
Sidereal Orbit Period (Length of Year)
0.001404517 Earth years
0.513 Earth days
Orbit Circumference
Metric: 415,318.55 km
Average Orbit Velocity
Metric: 33,732.8 km/h
Orbit Eccentricity
Orbit Inclination
0.059 degree
Mean Radius
Metric: 67.6 km
Equatorial Circumference
Metric: 424.7 km
Metric: 1,293,983 km3
Metric: 1,681,505,981,935,050,000 kg
Scientific Notation: 1.6815 x 1018 kg
Metric: 1.3 g/cm3
Surface Area
Metric: 57,425.30 km2
Surface Gravity
Metric: 0.025 m/s2
Escape Velocity
Metric: 207 km/h
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writers: Courtney O'Connor and Bill Dunford
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> NASA Advisory Council
> Open Government at NASA
Last Updated: 12 Aug 2013