New Uranus Moons and Rings Discovered

Patrick Furlong writes "CNN reports that the Hubble Space Telescope has discovered two new moons and two new rings around Uranus. The moons had been imaged by Voyager 2 in 1986 but were not recognized as moons at the time." More from MSNBC, and the official Hubble Site. From the CNN article: "The Hubble images also confirmed the existence of another moon, Perdita, which was first identified in the Voyager 2 pictures but had eluded telescopes ever since. Many moons of Uranus are named after characters in Shakespeare, and these new moons follow suit. Mab is named for Queen Mab, who is the subject of a famous speech by the character Mercutio in 'Romeo and Juliet.'"

Comments

Re:Gas giants and rings

[jd]

The rings are unstable and constantly evaporating, so only relatively young gas giants OR gas giants in relatively crowded solar systems should have rings. Uranus' inner moons, which are likely shepharding moons, are in unstable orbits and will likely collide in the next million years. If the rings were to survive that long, I doubt they could survive much longer without the inner moons being there.

Jupiter has thin rings, despite being bombarded a great deal more than Uranus or Saturn, though you'd need to talk to an expert in planetary physics if you have much of a hope of finding out why.

Of the rocky planets, Earth is the only one I know of that has a (natural) ring. It is extremely thin and usually ignored, but does exist. My guess, based on the theory that the moon is a result of a collision between an original Earth and some planet of comparable size, is that the ring is debris that was launched by the collision but did not congeal into the moon as it now is.

The multitude of rings of space junk launched by humans is stupid. That which cannot be retrieved for space museum purposes should be swept up and removed, before it becomes impossible to get into space at all.

Going back to the discoveries - I think it less of a surprise that the discoveries have occured (just think of how many new rings and moons have been discovered around Jupiter and Saturn) than it is a surprise that people haven't found anything before now for Uranus. Its rotation is so strange and its properties so bizare that I would have thought that planetary astronomers would have concentrated extra effort onto it. Discoveries do not come from studying the mundane, they come from studying the exceptions and understanding why and how they have become such.

That famous speech

[AndroidCat]

William Shakespeare, Romeo and Juliet, Act I, Scene iv, lines 49-103 (Sparknote analysis)

Moons

[echostorm]

Im pretty sure this brings the list to 23?

* Cordelia - 1986
* Ophelia - 1986
* Bianca - 1986
* Cressida - 1986
* Desdemona - 1986
* Juliet - 1986
* Portia - 1986
* Rosalind - 1986
* Belinda - 1986
* Puck - 1986
* Titania - 1787
* Oberon - 1787
* Ariel - 1851
* Miranda - 1948
* Umbriel - ?
* Caliban
* Sycorax
* Prospero
* Setebos
* Stephano
* Perditta - 1986
* Mab - 2005
* Cupid - 2005

Thats a heck of alot of moons!

Re:Moons

[Kusunose]

27, according to Wikipedia.
You missed Francisco, Trinculo, Margaret and Ferdinand. They are found in 2001 and 2003.

Re:Who made that name up?

[EnronHaliburton2004]

Nope! Uranus was discovered by William Herschel.

Uranus was an early Greek God of the Sky, Son of Gaia. The word predates the english use of "Your Anus" by a couple thousand years.

It's in postscript, so be warned!

[jd]

The reference discusses systems in general, but does include a brief section on the Earth's rings. The text of interest is at the start of page 4. Ignoring the stuff about the IRAS and COBE satellites, which imaged it, we have the following comment:

The Earth's ring corresponds to Case I in Figure 1, a circular ring with a gap at the location of the planet. However, the Earth's low mass means that it traps relatively few particles; the ring represents a density enhancement of only a few percent. This effect would scarcely appear in an image of the solar system seen from afar.