according to <a href="http://www.nasa.gov/home/hqnews/2004/apr/HQ_04125_sedna_mystery.html">this</a> NASA report Sedna's rotation speed around it's axis is the 3rd slowest in our star system after Mercury and Venus and yet... it has no moon!
I explain. Small asteroids usually rotate a full circle around their axis in a matter of hours. Senda is just 3/4 the size of Pluto, so it can be labeled a big asteroid, a chunk of ice. In theory it should spin around itself in a matter of hours, but it isn't doing that. so ok, astronomers came up with an idea that it must therefore have a companion object somewhere near for it's gravity to slow Sedna down. All looked good in theory until recently Hubble showed that there is no near object.
--
Has anyone of you an idea why it rotates so slow? I'm puzzled. A miniature, small black hole not really particulary far? something to do with it's inner structure? (don't think so. mass is known, so we strike this out I think).
what else? :confused:

Puny people. Sedna is actually the Death star Mk III, made by space hamsters to come and take over earth. I have been preparing the way.
***thinks about what he has just said***
Damn I've just given myself away!

Oh! I thougt that was "Hercobulous" or something like that.... :confused:
I guess I was mistaken... :D

I am asking a purely scientifical question and spacehamsters are not accepted, so is jesus love baloon or smthing simmilar. this is still sciforums, right? or am I wrong...

Chill out Avatar! :D

I guess we don't have all the answers yet... :eek:

If Venus can have a retrograde rotation compared to others, why can't Sedna be slowly rotating without a moon? Who knows when it's spinning fast enough it's hit by something on the side and thus slow down....
Uh, wait, by the way, has Sedna been 'officially' or at least 'publicly acclaimed' as the lost son of our system? Who knows she's a visitor who just passes by...... I missed that info I guess....

Has anyone of you an idea why it rotates so slow? I'm puzzled. A miniature, small black hole not really particulary far? something to do with it's inner structure? (don't think so. mass is known, so we strike this out I think).
what else? :confused:

Perhaps it hit something that slowed the rotation.

"Weird object beyond Pluto gets stranger" (http://www.msnbc.msn.com/id/4740224/)

"There remain some possibilities for a rational explanation.

There's a small chance that during the Hubble observations, the suspected satellite of Sedna was hidden, lurking either directly behind or directly in front of Sedna. Or a satellite might have throttled Sedna's rotation long ago, then been destroyed in a collision or lost in a gravitational interaction with a planet.

Or, Sedna might rotate every 25 hours instead of 24 days, a setup that could fool astronomers into drawing their present conclusion. This latter possibility can be confirmed or ruled out with more observations.

All these scenarios are seen as unlikely. More likely, Brown figures, is that the satellite is darker than expected and simply didn't show up. "

Where's the law that says small things rotate faster? The rotation is caused by a force applied to the object, rather than slowing it down, what if it was never that fast in the first place?

The rotation was determined after only one months worth of observation. And it seems that only a <b>five</b> percent increase in the brightness lead to this conclusion. (hum, that`s a very precise observation needed there).
And given the fact that the planet is very red (or dark as well)...

The latest Hubble photos of sedna are at the limit of the telescopes resolving powers and the `moon` may actually be closer to the planet, or on the `darkside` ...

[that is no moon]

It is early days to say either way...

Who is to say that the shaky correlation between rotation rate and tidal effects observed in the familiar Solar System objects is valid out among the distant members of the Kuiper Belt?

Objects as remote as Sedna may have formed well beyond Neptune (never mind being flung further out by interactions with other bodies!) As such, the primeaval material they accreted from would have been orbiting the Sun very slowly, and imparted relatively little rotational velocity.

(I'm hesitant to use the term "angular momentum," since it's been so ubiquitous in my posts recently!)

Is there any data on comet nucleii rotation rates?

This site (http://www.ifa.hawaii.edu/~meech/rot.html) lists a dozen comets, all with short rotation periods. Relevant? Who knows?

Well Avatar,
I can not give affirmation that this is the reason for the dicrepeancy with Sednas rotation, but what i can say is that all of the new bodies found past neptune , deemed minor planets are actually long distance lunar satilites of the planets within our solar system. in other words those bodies including Sedna are the creation as a result of the planets, and not of the Sun.
This this preliminary but it appears that their orbits are actually following the planets and not the sun, over time they obit the sun but following the path set out by the planets.
Sednas rotation may be hindered by the strong interaction with its parent planet.

DwayneD.L.Rabon

It should be said that there is no discrepancy with Sednas rotation; newer follow-up measurements by Scott Gaudi, Krzysztof Stanek at the Harvard-Smithsonian Centre for Astrophysics using the MMT telescope indicate a 10 hour rotation period which means there is no need to invent a moon or strange impact dynamics...

Read more (http://arxiv.org/abs/astro-ph/0503673)

Not all asteroids rotate fast -- asteroid Mathilde takes 17 days to rotate once:

http://en.wikipedia.org/wiki/253_Mathilde

Thanks for the update, blobrana!

p.s. This is a 4 year old thread I had already all forgotten about.

Hopefully that has killed this thread

Well Blobrana
why would you hope for the end of this topic, Sedna and other bodies are currently the formost discoveries in human science on earth.
it is very interesting, for example it appears that astronomers have finally reached a end to viewing the bodies of the inner solar system, by finding Sedna comes one of the best closers of mystery about our solar system, and so now science will become familuar and leaned about these bodies which do have a effect on earth and other planets of the solar system.
For years astronomers thoguht that mercury,venus had no moon, that earth only had one moon, now it is seen that these bodies also have long distance lunar satilites. something unconceivable even 5 years ago. and so the old view of the solar system by people overtuned and there is a new begining. it couldn't get any better lots to learn.

The complete of this area of the solar system had lent that there may be larger planets, as many as 264 to 360 planets in motion around our solar system, we only know of 8 plantes and their satilites.

DwayneD.L.Rabon

Puny people. Sedna is actually the Death star Mk III, made by space hamsters to come and take over earth. I have been preparing the way.
***thinks about what he has just said***
Damn I've just given myself away!

Wow, 14 year old me was annoying to read.

Hopefully that has killed this thread

Yes!

Well Avatar really why would you like this topic closed.

DwayneD.L.Rabon

My new masters command.

Point two: mistery solved.

I know that there is another thread on this exact subject, but the fastest rotating planet in the solar system has the most moons. I don't think that the last word is in on the subject, and I doubt that a primary can be tidally locked to its satellite.

Sedna has a strange orbit. With 1 AU being the distance between Earth and the Sun, it ranges from 76 to 1,000 AU from the Sun. This suggests that it was captured or may have been formed in a collision, which may have something to do with it's apparent lack of rotation. Or it may just have a very dark moon as some say.