National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
Margaret: Overview
   Back to Uranus   Overview   Facts & Figures 
No Image Available Tag
Contact us if you have an image of this moon.

Margaret is considered an irregular moon of Uranus because of the eccentricity and inclination of its orbit, but it is the only such moon that travels in a prograde direction -- that is, in the same direction as the regular moons and the planet's rotation about its axis. Only about 20 km in diameter and very dark, it is likely an object that was captured by Uranus' gravity.

Margaret was discovered on 29 August 2003 by Scott S. Sheppard and David C. Jewitt with the Subaru 8.2-m reflector at the Mauna Kea Observatory on the island of Hawaii.

How Margaret Got its Name:
Originally called S/2003 U3, Margaret was named after a woman who serves Hero in William Shakespeare's play, "Much Ado About Nothing." Margaret is the lady-in-waiting for Hero and is mistaken for Hero when she entertains Borachio at Hero's window, something that causes Hero much embarrassment at her wedding to Claudio.

Moons of Uranus are named for characters in Shakespeare's plays and from Alexander Pope's "Rape of the Lock."

Just the Facts
Orbit Size (semi-major axis):  14,146,700 km
Mean Radius:  10.0 (assuming an albedo of 0.04) km
Volume:  4,189 km3
Mass:  6,294,407,419,008,210 kg
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: 7 Mar 2011