Useful Notes: The Moons Of Uranus
The biggest ones
Or perhaps we should say, The Moons of Uranus; Or, The Bard in the Heavens.
is a small gas giant, and its moons are small, too. It can boast none so big as Jupiter's Ganymede
or Saturn's Titan
; its largest moons are medium-sized. There are twenty-seven of them known, with only the five biggest being spherical. Very little is generally known about them, since Uranus hasn't received many probes
Unlike the moons of the other planets, whose names are drawn from Classical Mythology
(except for, you know, the obvious
), the names of the moons of Uranus
are drawn from the classics of English Literature
, specifically Alexander Pope's The Rape of the Lock
and the plays of William Shakespeare
was discovered by an Englishman (well, a naturalized German...but so was the King
!), Sir William Herschel; his son John ended up naming the moons when they were discovered a while later. The younger Herschel reasoned that the sky god Uranus would be accompanied by spirits of the air, and took the names of these spirits from the aforementioned works. Later astronomers ignored the "spirit of the air" bit and just gave names from Shakespeare and Pope.
The Little Shepherds
Thirteen moonlets orbit close in; two (Cordelia and Ophelia) serve as shepherds for the rings of Uranus
. These are very small and of irregular shape, made of ice, tholin and some silicate dirt. They are very dark, the entire system is a chaotic jumble prone to changes.
Collision Course - Cupid and Belinda
Scientists predict that sometime between 1000 years and 1,000,000 years from now, inner moons Cupid and Belinda will collide. It's unknown what the result will be. They predict either 1), they'll "bounce" off each other, 2) merge, or 3) make Uranus' whisper-thin ring system a whole lot thicker.
The Broken Ball - Miranda
This moon, barely large enough to be a ball, is unusual in the high variability of its terrain. Miranda's surface has patchwork regions of broken terrain indicating intense geological activity in the moon's past, and is criss-crossed by huge canyons. A discredited theory claims that Miranda was shattered
and then recoalesced into its current clumsy shape; now scientists think it was a tidally-heated ocean moon, like Europa
, in the past, then froze over, causing its ice crust to crack and break. Nowadays it is, in all aspects, a boring iceball in the middle of blackness, dead as a doornail.
White and Black - Ariel and Umbriel
These medium-sized moons (1100-1200 km in diameter) are very similar in all except color. Ariel is a very shiny object, Umbriel is dark, albeit with a bright, shiny crater called Wunda on its equator. It's likely that they have silicate cores, but subsurface oceans are unlikely. In all other aspects, they are boring iceballs in the middle of blackness, dead as a doornail.
The little Fairies - Titania and Oberon
These two are the largest moons of Uranus
, with diameters of almost 1500 km, rivaling Saturn's Rhea
. They are large enough to have tiny traces of atmosphere and be suspected of hiding subsurface oceans deep on the border between ice and rock. That makes these iceballs in the middle of blackness possibly not boring and possibly not dead.