Space · Moons
Portia
A moon of Uranus — An inner Uranian moon, namesake of the Portia group of closely-spaced moons.
Quick facts
Parent planet
Diameter (mean)
135 km
Mass
1.7 × 10¹⁸ kg
2.31e-05 Moon masses
Mean orbital radius
66,100 km
Orbital period
0.513 Earth days
Discovery year
1986
Discoverer
Stephen P. Synnott (Voyager 2)
Naming origin
Heroine in The Merchant of Venice
Surface conditions
Portia is the namesake of the Portia group, a cluster of small inner Uranian moons with similar orbits. The Portia group is notable for its dynamical instability — N-body simulations suggest the moons may collide on timescales of millions of years.
Missions and observations
Every Uranus-system mission has had an opportunity to image or characterize Portia. The list below is the Uranus-system mission catalog; specific Portia encounters are documented in mission archives.
| Mission | Year at Uranus | Status |
|---|---|---|
|
Voyager 2 NASA |
1986 | Completed |
Naming etymology
Portia was the heroine of Shakespeare's The Merchant of Venice — the wealthy heiress who, disguised as a young lawyer, saves Antonio's life. Adopted by the IAU in 1988.
Methodology & sources
Diameter, mass, and orbital parameters from JPL Solar System Dynamics — Physical Parameters. Discovery year and discoverer from the JPL Satellite Discovery Circumstances. Naming etymology from the IAU Working Group for Planetary System Nomenclature. Stylized SVG hero composed from NASA / JPL imagery as visual reference; no photographs are reproduced.