Santa's Second Moon

[mikeemmert]

Mike Brown's team of astronomers has discovered a second moon for 2003 EL61:<br /><br />http://www.gps.caltech.edu/~mbrown/2003EL61/#moon<br /><br />The second moon is about 0.2% of the mass of Santa. It's orbit is inclined about 40 degrees to the orbit of the first moon.<br /><br />In the article, Mike Brown figures that Santa's moons were formed much like Earth's, via a collision with another object. This makes sense.<br /><br />Santa gets my vote (and Mike Brown's, too) as the strangest object in the outer solar system. It's big, 32% of the mass of Pluto, and spins at a dizzying rate of one revolution in 3.9 hours. This distorts it into the shape of a Jacobian ellipsoid (as best as they can tell) that is somewhere around twice as long as it is wide.<br /><br />Much more bizzarre is it's density, somewhere around 3 times the density of water. It's made out of stone! This itself is evidence of a huge collision.<br /><br />[Disclaimer: I am responsible for the following material. Mike Brown may or may not agree, I don't know.]:<br /><br />Some of you may have read my post, "UB313 is the Lost Moon of Triton". I think the flyby of a binary with the second object being as massive as Triton is the only way Triton could lose enough energy to get into orbit around Neptune.<br /><br />I have done some gravity simulations of flybys of binaries composed of two Triton-sized objects past Neptune. Indeed, the binary often comes apart; one goes into orbit around Neptune and the other gains energy and goes into orbit around the Sun.<br /><br />Sometimes, however, the binaries collide. What seems to make the difference is the orientation of the two objects at closest approach. If they are lined up, so that the centers of the objects and the center of Neptune are in a straight line, then the binary will separate and one will go into orbit (unless they're going too fast or something). But if one follows another,

 

[silylene old]

I still think Rama would be a better name for this cigar-shaped body. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[mikeemmert]

I read Arthur C. Clarke's "Rendezvous With Rama", it was great. There was talk about making a movie:<br /><br />http://www.rendezvouswithrama.com/<br /><br />But apparently this was not done. It would be a big project, massive special effects etc. But "2001: A Space Odessey" was certainly a great movie, even if it missed an Oscar it deserved. (Those weren't apes in the opening scene; they were actors in ape suits. Really convincing, wasn't it? I missed it, until my brother pointed it out.) <br /><br />For those of you who missed it:<br /><br />In the year 2130, astronomers detect an object on a hyperbolic trajectory around the Sun. A mining crew headed for Mercury was prevailed upon to intercept the object when it was determined to be an artifact.<br /><br />One of the crew, a religious fanatic, tried to blow it up with a 1000 megaton bomb. This was not part of an arsenal but a mining tool, the novel was written in the days before Saddam Hussein and WMD (but they did have religious fanatics). Of course, the rest of the crew stopped him. I missed the sequels. The ship was coming to life at the end of the book. Typical of Arthur C. Clarke, it was very well written with colorful descriptions.<br /><br />The name, "Santa" is already taken by an asteroid. He was not a creation diety but was an actual person, although most of his legend is science fiction. He was the bishop of Myrna, Turkey in about 300 A.D. or so. He burned down the temple of Artemis. He is the patron saint of prostitutes; he threw two bags of gold into the house of two young girls so they would have a dowry and get married rather than become prostitutes. Their old man, curious as to who the benefactor was, kept watch when the third girl came of age, so Nicholas threw the bag of gold down the chimney.<br /><br />He participated in the council of Nicaea, where the Jesus legend was hammered out. He put out the notion that God and Jesus we

 

[yevaud]

<i>Turkey demands the return of Santa to this day.</i><br /><br />We'll return it when they return the Hagia Sophia. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[CalliArcale]

This is awesome. <img src="/images/icons/wink.gif" /> Clearly, technology has advanced sufficiently for a real flood of new discoveries in the outer solar system. 2003 EL61 has two moons! And Pluto has three! This is an amazingly good year for this stuff. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[mikeemmert]

<<We'll return it when they return the Hagia Sophia.>><br /><br />Uh...the place was secularized in 1934 by Kemal Ataturk...OK, I'll scan "Phenomenon" to see if I can dig up a tractor beam to pull this off.<br /><br />Probably have to invent one. What kind of power source does Santa's sleigh use?

 

[jmilsom]

Yes I agree. And I suspect we're only seeing the tip of the iceberg (or ice planetoids) so to speak when it comes to discoveries in the Kuiper Belt and beyond. <div class="Discussion_UserSignature"> </div>

 

[silylene old]

Perhaps one of the moons can be named "Santa's Little Helper", after the dog of <i>Simpson's</i> fame. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[mikeemmert]

OK, one moon is named Rudolph, after a reindeer. Dancer and Prancer won't do, they have gay connotations. Blitzen is too warlike.<br /><br />But then again, most solar system objects are named after god who have some kind of morbid story.<br /><br />How about Donner, after the 1846 expedition to California? He was a hero, having saved the expedition by providing a meal <img src="/images/icons/tongue.gif" />

 

[mikeemmert]

I have looked up the Wikipedia article on Santa:<br /><br />http://en.wikipedia.org/wiki/2003_EL61<br /><br />Here, the explanation for Santa's spin in inspiraling by the moons:<br /><br /><font color="yellow">The rotation period of 2003 EL61 is much faster than any other object of its size, less than four hours. The fast rotation has caused the object to become highly oblate: it is twice as long as wide and shorter still in height. Spiralling-in effect of 2003 EL61 and its moon may have caused the speeding up of the rotation.<br /><br /><font color="white">No way! Santa rotates in 3.9 hours and the moons orbit in 34.1 and 49.12 days. (Rudolph has the longer orbit, being farther away.) This fast rotation must have been the result of a collision. <br /><br />Santa's moons must be migrating outward, like our Moon. Santa's Jacobian ellipsoid shape would enhance this effect. This would mean that they formed and initially orbited much closer to Santa.<br /><br />Rudolph's diameter is estimated as being 350 Km, if it has the same composition and albedo as Santa. For perspective, that would make it the fifth largest asteroid in the main belt. It is, however, smaller than Charon. Charon and Pluto have significantly different surface compositions, Pluto being methane and ? and Charon being mostly water ice. It wouldn't be too unreasonable to suppose that Santa and Rudolph also have different compositions. However, Santa is surfaced mostly with water ice, apparently. It has some methane.</font></font>

 

[lankford]

Freud would have a ball with this topic:<br /><br />a semi-phallic solid structure and a probable collision with a large mass.<br /><br />I actually didn't know there was a Santa in space, I need to start keeping up with my Space news.

 

[mikeemmert]

I have found the names of the "eight tiny reindeer" in Clement Clarke Moore's "Twas the Night Before Christmas":<br /><br />Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Donner and Blitzen.<br /><br />This list does not even include Rudolph! Must be some kind of herd mentality, here... Comet's obviously out - too much confusion. <br /><br />Today being the Winter Solstice is the day of celebration for us atheists, Wiccans and Pagans. NORAD is waiting for Santa but has about as much chance as an Iraqi SAM. NASA has a considerably better chance of getting Santa but they're out of money; too much competition from the Dover School Board.<br /><br />Maybe the spacecraft would have a better chance of funding if it was specifically designed to pin down the Pioneer effect. In that case, Donner would be the best name for the new moon. <br />

 

[silylene old]

I still like the name "Santa's Little Helper" better. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>