Portia (moon)

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Portia

Discovery
align="center" Voyager 2 image of the Uranian moons Portia, Cressida, and Ophelia
Discovered by	Stephen P. Synnott / Voyager 2
Discovered in	January 3, 1986
Orbital characteristics
Mean radius	66,097 km
Eccentricity	0.0001
Orbital period	0.513196 d
Inclination	0.087° (to Uranus' equator)
Is a satellite of	Uranus
Physical characteristics
Mean diameter	~135 km (estimate)
Surface area	~57,000 km2 (estimate)
Volume	~1,300,000 km3 (estimate)
Mass	kg (estimate)
Mean density	~1.3 g/cm3 (estimate)
Surface gravity	~0.023 m/s2 (estimate)
Escape velocity	~0.058 km/s (estimate)
Rotation period	synchronous (assumed)
Axial tilt	zero (assumed)
Albedo	0.07 (assumed)
Surface temp.	min mean max ~64 K (estimate)
Atmospheric pressure	0 kPa

Portia (por'-shə, IPA /ˈpɔrʃə/) is a moon of Uranus. Very little is known about it. It is named after Portia, the heroine of William Shakespeare's play The Merchant of Venice. Since the Portian orbit lies below Uranus' synchronous orbital radius, it is slowly decaying due to tidal forces and will one day either break up into a planetary ring or impact on Uranus' surface.

Portia was discovered from the images taken by Voyager 2 on 1986-01-03, and was given the temporary designation S/1986 U 1. It is also designated Uranus XII.

Uranus (satellites) [http://encycl.opentopia.com/ edit]
Cordelia | Ophelia | Bianca | Cressida | Desdemona | Juliet | Portia | Rosalind | Cupid
Belinda | Perdita | Puck | Mab | Miranda | Ariel | Umbriel | Titania | Oberon | Francisco
Caliban | Stephano | Trinculo | Sycorax | Margaret | Prospero | Setebos | Ferdinand
See also: | Rings of Uranus

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