Margaret (Uranus moon)
Margaret is the only known prograde irregular moon of Uranus. Discovered in 2003, it orbits far from the planet on an inclined, eccentric path and is named for a character in Shakespeare's Much Ado About Nothing.
Overview
Margaret is an outer, irregular satellite of Uranus notable for being the only known prograde non-spherical moon among that planet's irregular satellites. It was first reported in 2003 and later received a permanent number and the name Margaret, following the convention of naming Uranian moons after characters from the works of William Shakespeare and Alexander Pope.
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Discovery and name
The object was discovered in 2003 by a team including Scott S. Sheppard and colleagues using ground-based telescopes. Initially designated S/2003 U 3, it was subsequently confirmed and numbered Uranus XXIII before being given the name Margaret. The name honors the servant Margaret from William Shakespeare's play Much Ado About Nothing, in keeping with the tradition for Uranian satellites.
Orbit and physical characteristics
Margaret orbits far beyond the regular moons of Uranus on a distant, inclined and notably eccentric path. Unlike the majority of Uranus's irregular moons, which move on retrograde orbits, Margaret travels in a prograde direction relative to the planet's rotation. It is small and irregularly shaped rather than spherical, implying that it lacks the mass needed to pull itself into hydrostatic equilibrium; observations suggest a modest diameter on the order of tens of kilometres.
Origin and dynamical behavior
As an irregular satellite, Margaret is generally interpreted as a captured object rather than having formed in situ with Uranus's large regular moons. Its prograde motion and unusual orbital parameters make it dynamically distinct among Uranian satellites and mean it may be subject to complex gravitational interactions and secular perturbations. These dynamical features are of interest to researchers studying capture processes and long-term orbital stability.
Significance and observations
Margaret provides a valuable counterexample within the population of Uranian irregular satellites, helping astronomers test models of satellite capture and evolution. Because it is small and distant, detailed physical characterization requires large telescopes and careful observation campaigns; photometric and astrometric data remain the primary sources of information about its size, shape, and orbit.
Key facts
- Type: Irregular (non-spherical) satellite — see irregular satellite.
- Discovery: 2003 by Scott S. Sheppard and collaborators.
- Designation: S/2003 U 3; numbered Uranus XXIII.
- Name origin: Margaret, a character from Much Ado About Nothing by William Shakespeare.
Questions and answers
Q: What is Margaret?
A: Margaret is a non-spherical prograde moon of Uranus.
Q: Who discovered Margaret?
A: Margaret was discovered by Scott S. Sheppard, et al. in 2003.
Q: When was Margaret given its designation?
A: Margaret was given the designation S/2003 U 3.
Q: What is the significance of Margaret being confirmed as Uranus XXIII?
A: The confirmation of Margaret as Uranus XXIII means that it is the 23rd discovered moon of Uranus.
Q: Why was Margaret named after the servant of Hero in William Shakespeare's play Much Ado About Nothing?
A: Margaret was named after the servant of Hero in William Shakespeare's play Much Ado About Nothing because Uranus's moons are named after characters in the plays of William Shakespeare and Alexander Pope.
Q: Is Margaret a rare moon of Uranus?
A: Yes, Margaret is a rare moon of Uranus, being the only prograde non-spherical moon of the planet.
Q: What is the significance of a moon being prograde?
A: A prograde moon is one that orbits in the same direction as the planet rotates.
Related articles
Author
AlegsaOnline.com Margaret (Uranus moon) Leandro Alegsa
URL: https://en.alegsaonline.com/art/61748
Sources
- arxiv.org : Preprint
- cfa-www.harvard.edu : 8217
- planetarynames.wr.usgs.gov : USGS
- cfa-www.harvard.edu : Ephemeris: IAU-NSES
- ssd.jpl.nasa.gov : Mean orbital parameters: NASA JPL