National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
Larissa: Facts & Figures
   Back to Neptune   Overview   Gallery   Facts & Figures   News 
Discovered By
H. Reitsema, W. Hubbard, L. Lebofsky, D. Tholen
Date of Discovery
Orbit Size Around Neptune (semi-major axis)
Metric: 73,548 km
English: 45,701 miles
Periapsis (closest)
Metric: 73,445 km
Apoapsis (farthest)
Metric: 73,651 km
Sidereal Orbit Period (Length of Year)
0.001519507 Earth years
0.555 Earth days
Orbit Circumference
Metric: 462,115.49 km
Average Orbit Velocity
Metric: 34,693.4 km/h
Orbit Eccentricity
Orbit Inclination
0.205 degree
Mean Radius
Metric: 97.0 km
By Comparison: 104 x 89 km, ellipsoidal
Equatorial Circumference
Metric: 609.5 km
Metric: 3,822,996 km3
Metric: 4,945,605,829,220,740,000 kg
Scientific Notation: 4.9456 x 1018 kg
Metric: 1.3 g/cm3
Surface Area
Metric: 118,236.98 km2
Surface Gravity
Metric: 0.035 m/s2
Escape Velocity
Metric: 297 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: 6 Feb 2014