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TheThorn
2004-Mar-14, 02:39 AM
Nasa Schedules News Conference About Unusual Solar Object (http://www.nasa.gov/home/hqnews/2004/mar/HQ_n04040_solar_object.html)

Well, they've got my attention. They say they're going to present the discovery of the most distant object ever seen in the solar system, on Monday at 1 PM EST.

I wonder what it is. From the hype, it doesn't sound like just another KBO.

damienpaul
2004-Mar-14, 02:44 AM
a new planet perhaps??? I will keep my eye on the broadcasts, or perhaps Fraser could report on it.

TheThorn
2004-Mar-14, 02:52 AM
I'll admit it. The first thing I thougt of was that guy who was in here a couple of months back claiming he had evidence that there was a brown dwarf out there beyond the Kuiper Belt. What was his handle? I can't seem to find the threads he was involved in.

antoniseb
2004-Mar-14, 03:07 AM
The announcement implies it was discovered in some Spitzer images. So the object is something that must be fairly easily found in the mid-infrared. A planet or brown dwarf might qualify.

I had thought it was interesting that the kuiper belt had such a hard apparent outer boundry. That sort of suggests a planet. A brown dwarf seems too extraordinary. I'm guessing planet.

Either way, I can hardly wait!

damienpaul
2004-Mar-14, 03:39 AM
So what are the bets? Who wants to wager on Brown Dwarf? Who wants to wager on Planet? who wants to suggest another wager?

TheThorn
2004-Mar-14, 04:39 AM
There was some speculation in YahooGroups MPML (Minor Plante Mailing List) that it might be 2004 DW - a very distant KBO that was discovered recently apparently by the same people making this announcement. Then this post came in from Jim Scotti who apparently is in the know:

"Actually, the object that is to be announced is most decidedly not 2004 DW,
but another object on a very different orbit. Dr. Brown gave a talk here at
LPL a couple weeks ago where he showed us images of this new object (as well
as telling us about the discovery of 2004 DW) and described briefly what he
knew of it at the time and of some of the implications of its existance.
Trust me, it is a unique object in our inventory, nothing like any other
object we've ever seen, but probably not the only one of its kind."

Let's speculate. We'll find out soon enough.

"On a very different orbit" would imply not a KBO, or at least on an orbit that is different in some way than the other KBO's and scattered disk objects.

"Unique in our inventory" is another hint, which would make one think of a brown dwarf, or something other than just a gas giant or big, distant KBO or whatever.

Maybe out that far a gas giant" would actually be an "ice giant". That would be unique.

"The importance of it's existence" kind of implies that its very existence explains some other things (like the hard outer edge of the Kuiper Belt that antoniseb mentioned, or the apparent clustering of the aphelia of long period comets.

But then "probably not the only one of its kind" raises all sorts of other questions. If they'd found a brown dwarf or gas giant in the zone between the Kuiper Belt and the Oort cloud, what would make them speculate that more would "probably" exist?

The only thing I'm willing to bet on at this point is that whatever the announcement is, it's in The Universe Today on Tuesday ;)

DippyHippy
2004-Mar-14, 05:09 AM
I was wondering if this might make it onto UT before Monday...

A few of us are on the emailing list for press releases and this one came through to me on Friday night, at about 5:20pm GMT. Basically, the email read exactly the same as the release linked to above.

In the three years I've been on the list, I've never seen anything announced in this way...

I don't think it's a KBO because when the largest KBO was recently announced, they did so in the normal fashion. No big fuss over that.

I don't think it's anything to do with the Oort cloud either, for the same reason - they wouldn't make this much fuss over it.

As discussed in emails with others, although I'd put my money on a brown dwarf or massive gas giant, a brown dwarf should have been detected already and a gas giant that far out would defy current planetary formation theories. *But* when they found gas giants close to other stars, that defied planetary formation theories too.

I don't think it's anything extra-terrestrial because Bush would make the announcement, I think. (Not that he has any right to, but that's just the way it would happen, I believe)

Whatever it is, I'll bet good money it's gonna be on the evening news...

DippyHippy
2004-Mar-14, 05:32 AM
BTW I'm just moving this to the Other Stories section since I think it'll get more attention there :)

Planetwatcher
2004-Mar-14, 06:31 AM
I'm thinking that this will be a KBO which is larger and/or farther then Pluto.
While other large KBO's were reported in the normal fashion, none were nearly as large as Pluto, and not many of them are significantly farther.
By significantly farther, I'm speaking in terms of either Bode's Law, or a body more then twice the distance of Pluto from the Sun.


As discussed in emails with others, although I'd put my money on a brown dwarf or massive gas giant, Other then this one point, I tend to aggree with Dippy Hippy.

Faulkner
2004-Mar-14, 06:40 AM
Maybe it's a black hole on a collision course with Earth!?

antoniseb
2004-Mar-14, 12:26 PM
Originally posted by DippyHippy@Mar 14 2004, 05:09 AM
a brown dwarf should have been detected already and a gas giant that far out would defy current planetary formation theories.
If the object is a brown dwarf [roughly 10-85 jupiter masses] it could have remained un-noticed if it:
- formed billions of years ago [and so has cooled]
- it has no large moons reheating it's atmosphere with tides
- is located thousands of AU away from the sun [and so does not detectably affect the orbits of Neptune and other planets]
- was going through part of its orbit that is against the Milky Way as we see it.

I am speculating that it is a captured object. That is, something that did not form with the sun, but was in a more elliptical galactic orbit, and got accelerated by the sun's gravity into co-orbiting with us.

GOURDHEAD
2004-Mar-14, 12:54 PM
:unsure: Maybe a binary binary or even larger grouping of near Pluto sized objects.

Unless its in or beyond the Oort cloud, anythning equal to or greater than Jupiter should affect the orbits of some of the outer planets in a manner subject to current observational technology. But then Pluto has only been observed over less than a third of its period. :unsure:

TheThorn
2004-Mar-14, 04:42 PM
Here's something that I'm betting is related, from Spaceref.com's Daily Hubble Status Report. (http://www.spaceref.com/news/viewsr.html?pid=12187) for Mar. 11 (at the bottom of the page)

"SIGNIFICANT EVENTS:

Loads for SA075O02_F1 were signed off @ 072/0800z. SA075O02 supercedes SA075O01, and includes the additional "Director's Discretionary Target" for proposal # 10041 "Characterization of a Planetary-sized Body in the Inner Oort Cloud".

They retargeted the Hubble at the last minute to take pictures of it.

OK, Damienpaul, I'm ready to bet now. ;) I'm betting on a planetary sized body in the Inner Oort Cloud.

I'll also bet that after this is announced, there will be another debate on the status of Pluto - Planet or Kuiper Belt Object. ;)

DippyHippy
2004-Mar-14, 04:47 PM
Just a quick point... Faulkner, if it were a black hole, I think you'd be feeling the effects by now, even at this distance.

I think the TheThorn's right... that HST report sounds connected... but how do you define "planetary sized"? As big as / bigger than Pluto?

antoniseb
2004-Mar-14, 04:59 PM
Some more thoughts on the Brown dwarf idea:

Visual Brightness
Lets assume that there is a brown dwarf at some distance from the sun. Assume that it has the surface area of Jupiter [a conservative guess, brown dwarfs are probably a little larger than that]. Also assume that it reflects light with about the same reflectivity Jupiter has. Planet brightness goes down according to the 4th power of distance. If the Brown dwarf were 1000 times as far away as Jupiter, it would be 1e12 times dimmer than Jupiter, making it 30 magnitudes dimmer, that is magnitude 28. Note that it it were 10,000 AU, it would just barely have appeared as a gray streak on the Hubble Ultra Deep Field survey [if by incredible luck it were in the field]. Of course the Oort cloud probably goes out ten times that far. Who knows where this thing could be?

Note that in the Infrared, Jupiter gives off more light than it reflects because it is slowly collapsing, and radiating away the heat that holds it up. A Brown Dwarf would be doing the same thing.

Gravitational Influence on Inner Planets
The acceleration it would have on Neptune would be (M*G / R*R)
If we assume [for example] R= 7,000 AU = 1e14 meters, and M[bd] = 1e30 Kg [upper end of the range], a[max] = 100G which is about 1e-8 meters per second per second.

At most, this would affect Neptune's orbital position by about 1000 kilometers over the course of a year. If it were a light-weight brown dwarf at four times that distance, the displacement would be 10 Km over a year.

[b]Conclusion
A brown dwarf could be out there and have remained undetected.

Manchurian Taikonaut
2004-Mar-14, 09:43 PM
10th Planet for the SOL system
:huh:
...some news

http://www.theaustralian.news.com.au/commo...5E29098,00.html (http://www.theaustralian.news.com.au/common/story_page/0,5744,8968352%255E29098,00.html)

planet SEDNA orbits at 67 AU from the Sun

DippyHippy
2004-Mar-14, 09:52 PM
Woohoo!!! Thanks for the link :D

And the winner for the first correct guess is.... *drum roll* Antoniseb!

burmese
2004-Mar-14, 10:23 PM
See:
http://www.theaustralian.news.com.au/print...8968352,00.html (http://www.theaustralian.news.com.au/printpage/0,5942,8968352,00.html)

and

http://www.nasa.gov/home/hqnews/2004/mar/H...lar_object.html (http://www.nasa.gov/home/hqnews/2004/mar/HQ_n04040_solar_object.html)

antoniseb
2004-Mar-14, 10:44 PM
This is cool. Somehow, I am happy that it isn't some distant Brown Dwarf. I don't know why, but somehow I don't seem to like big surprises in our own solar system.

It will be interesting to know the orbital inclination and eccentrity.

It will not be interesting to hear the symantic debate about whether it's a planet or not.

DippyHippy
2004-Mar-14, 10:49 PM
I'm going to merge this with the topic in Other Stories because someone has already posted the link and the subject is being discussed there.

DippyHippy
2004-Mar-15, 12:59 AM
Oh boy... I wish I could post what I've just heard but I gave my word... but trust me, this is fascinating... it's a lot more mysterious than the Aussie article makes out... this is the sort of discovery that re-opens a lot of debates about KBO's, the Oort Cloud, Pluto and all the planetary-formation theories....

DippyHippy
2004-Mar-15, 02:12 AM
The BBC have now broken the story too... (about an hour ago)

http://news.bbc.co.uk/1/hi/sci/tech/3511678.stm

jonfr
2004-Mar-15, 03:36 AM
it's going to be interesting.... :)

TheThorn
2004-Mar-15, 05:47 AM
I guess we'll find out tomorrow. But a 2000 km body 60+ AU from the sun hardly qualifies as a "planetary-sized object in the inner Oort cloud", as described in that Hubble task. Iffy on the planetary-sized part, not even close on the Oort cloud part.

So, either they mis-described it in that Hubble report, or our friends in the press have got it wrong.

If that's what it turns out to be, just a rather large, rather distant KBO, in a relatively circular orbit, well, that's cool, but the press conference hype was unnecessary.

DippyHippy
2004-Mar-15, 07:17 AM
It's just been on the BBC television news, at 7:10am this morning... they're already calling it a new planet, which seems a bit premature, but they haven't stated anything that hasn't already been published online, either here or elsewhere.

jonfr
2004-Mar-15, 07:23 AM
Originally posted by DippyHippy@Mar 15 2004, 07:17 AM
It's just been on the BBC television news, at 7:10am this morning... they're already calling it a new planet, which seems a bit premature, but they haven't stated anything that hasn't already been published online, either here or elsewhere.

The discovery of a mysterious object in our solar system is the topic of a listen-and-log-on news briefing on Monday, March 15, at 1 p.m. EST.


That doesn't sounds like an other small ice planet to me... :huh: :unsure: But we will see...

Faulkner
2004-Mar-15, 09:26 AM
Sedna? My aunty's name is Sedna! :P

NasaBoy
2004-Mar-15, 10:15 AM
I hope its a planet.......oh well i'll just tune into Nasa Tv today at 1:00 pm EST...... :)

Dave Mitsky
2004-Mar-15, 01:08 PM
Here are two more links concerning Sedna:


http://www.cnn.com/2004/TECH/space/03/14/p...very/index.html (http://www.cnn.com/2004/TECH/space/03/14/planet.discovery/index.html)

http://www.msnbc.msn.com/id/3217961/


Dave Mitsky

TheThorn
2004-Mar-15, 01:20 PM
And here's a really good link http://www.gps.caltech.edu/~chad/sedna/ to a page by Chad Trujillo, one of the discoverers, with all the details, including the discovery photos.

Smaller than Pluto, farther perihelion than anything else known, but with an aphelion of 850 AU or so, it's hard to call it an Oort cloud object (isn't the Oort cloud 10,000 - 50,000 AU out?).

It's not a planet. There are several similar sized KBO's.

I hate hype.

DippyHippy
2004-Mar-15, 03:21 PM
Oh I agree, I hate hype too... but look at who started it: NASA Headquarters in Washington DC. I grant you, it is special, it is unique, it is fascinating but at the end of the day, this didn't warrant the kind of hush-hush "call the number and give the password" approach... it's a small icy body. There's no reason why they couldn't have announced it in exactly the same way as the others.

Like I said, in the three years I've been on the list, I'd never seen a press release like this before...

TheThorn
2004-Mar-15, 03:46 PM
Don't get me wrong, it's a very interesting small icy body. Its orbit is different than anything previously discovered, in that it never comes closer to the sun than 75 AU or so. It looks like that hard outer edge of the Kuiper Belt isn't so hard after all.

But there are lots of comets with aphelia much larger than Sedna's 850 AU, so it is NOT the farthest known solar system object, as it was billed.

And it's not likely still in the original orbit that it was formed in, like the news articles said. Trujillo gives two possible explanations for its orbit and they both involve it being scattered by a larger object at some point.

And as far as being a planet is concerned, even the discoverers say they think it's about the same size as Quaoar (1250 km diameter, the largest KBO other than Pluto).

A very interesting small distant icy body. And a very interesting way of bringing it to the public's attention.

jonfr
2004-Mar-15, 04:46 PM
Originally posted by NasaBoy@Mar 15 2004, 10:15 AM
I hope its a planet.......oh well i'll just tune into Nasa Tv today at 1:00 pm EST...... :)
What's that in GMT ?

TheThorn
2004-Mar-15, 04:55 PM
18:00 GMT.

Interestingly, Trujillo's page that I linked to above has been taken down. I'd guess that it wasn't intended to be available until after the press conference, and will probably reappear in a couple of hours.

jonfr
2004-Mar-15, 05:03 PM
The News that i have been reading tells that this is something like puto. The queastion that i'm asking me self, why all the hype over just an other ice planet. Even if it was on the edge of the Oorb belt, it isn't that big. Unless they are meaning something else. :unsure:

jonfr
2004-Mar-15, 06:09 PM
March, 15 Monday
3 p.m. - 7 p.m. - Live Interviews - NASA Discovers Mysterious Object In Space - JPL (One-way Satellite Interviews with Television and Radio Media Clients)


Was the time changed ? Becose on NASA Tv, on the internet don't see any news confrance going on.

TheThorn
2004-Mar-15, 06:21 PM
Try here. (http://www.spitzer.caltech.edu/Media/releases/ssc2004-05/index.shtml)

The news conference was for reporters only. Mysterious.

Faulkner
2004-Mar-15, 07:42 PM
I hate hype.

Don't we all. I think NASA need to come back down to Earth.

New Kuipler Belt Object? BIG DEAL!!!

DippyHippy
2004-Mar-15, 08:29 PM
LOL The Thorn, yeah, it was *supposed* to be for reporters... but thanks to NASA posting all the telephone contact details online, you had the usual muppets as well... (apparently - I didn't bother to call)

What's the point in having a secret telephone number and password if you're going to tell everyone what the telephone number and password is anyway??

NasaBoy
2004-Mar-15, 08:53 PM
Im watching it right now. You know Nasa Tv on channel 376(I have satellite tv). They are calling it a Planetoid, meaning its not big enough to be classified as a Planet, yet its not small enough to be classified as a Comet or an Asteroid.

tomcurda
2004-Mar-16, 12:19 AM
[FONT=Courier][SIZE=1]Concerning the discovery of this new planetoid "Sedna"; will someone kindly tell me what a Highly "Ecliptic" orbit is? I was under the impression that the ecliptic was the plane defined by earth's orbit about the sun. Did someone perhaps mean to say Highly "eccentic" orbit?

Fraser
2004-Mar-16, 12:46 AM
I've got to say, I'm pretty disappointed at how NASA handled this announcement. By being obscure about what they were going to announce today, it created a rampant rumour mill. It was pretty hard to get the details right.

An object large enough to rival Pluto is an important discovery, but why all the hype? There's a standard way to embargo science news so that journalists get an advance notice of a breaking news story, but this wasn't an embargo. I found out the story at the same time you all did.

jonfr
2004-Mar-16, 01:22 AM
Well, i got dissaponted in NASA now, i find this not that big of discovery. Since they are finding bigger things out there. However this extend the outer edge of this solar system by few million km :)

TheThorn
2004-Mar-16, 01:24 AM
Another bothersome (although minor) detail about this discovery. They announced a name for it at the same time they announced its discovery. That ain't the way it's supposed to work, and that ain't the standard that other people are held to.

There is a really detailed protocol involved in naming minor plantets, the details of which can be found here. (http://cfa-www.harvard.edu/iau/info/HowNamed.html) The first sentence of that page goes: "The assignment of a particular name to a particular minor planet is the end of a long process that can take many decades."

First the orbit has to be well determined, usually by observations over a period of at least 4 oppositions (in the case of Sedna, that would be 4 years). Then the discoverers have the privilege of suggesting a name to the Committee for Small Body Nomenclature of the International Astronomical Union. If they approve (and they don't always approve), the name is assigned, by the committee.

Brown and company have short-circuited the process by just up and naming it right at the start. Oh, sure, they're careful to refer to it as a "provisional" name, but the IAU strongly discourages discoverers from pre-announcing names.

This is at least the second time Brown and company have just ignored the naming protocols. They did it with Quaoar too, and the IAU quickly circumvented their own rules to make it official.

There are a number of amateurs out there who are a bit miffed right now. Guys who have waited years for the right to name their discoveries, and then had their suggested names rejected.

I just read a note from one guy, for instance (probably a professional at that) who discovered a small moon of Jupiter recently, and was given exactly one option for naming it. Apparently the Committee had a "rule" that small moons of Jupiter in retrgrade orbits will be given names of lovers of Jupiter that start with "e". There was only one left. Today, he's thinking he should have just ignored the IAU, called a press conference, and bestowed a "provisional" name of his choice. (I wonder what the next small retrograde Jovian moon will be named?)

It's minor, but it's in the pattern of self-aggrandizement and arrogance that seems to permeate this whole affair. Calling it a "planet" is simply silly, but it's all over the news.

Faulkner
2004-Mar-16, 03:19 AM
Now I could be mistaken, but I think I read somewhere that "Sedna" was discovered back in November last year...? Correct me if I'm wrong!

Also I don't understand the NASA comment "the largest solar-system object discovered since Pluto's discovery in 1930"...(or something like that)? This simply doesn't make sense.


I found out the story at the same time you all did.

That's not too cool. I would like to think forums like this (via their administrators) should at least get the lowdown on news before the wider mainstream press does. I think NASA's PR department needs a revamp.

Are they creating this "hype" to attract wider public interest? Mate, sounds like that "reality TV" crap I'm bombarded with day & night. Forget the "glitter", NASA, we "the public" want the hard cold facts AS THEY EMERGE!!!!!

Golly, what happens when they detect an object with an obviously "powered" trajectory heading towards Earth...??? :lol:

zephyr46
2004-Mar-16, 03:39 AM
Space Today (http://www.spacetoday.org/SolSys/KuiperBelt/Quaoar.html)
Minor Planet and Comet News (http://www.hohmanntransfer.com/news.htm)

JPL Orbit Applet for 2003 VB12 Sedna (http://neo.jpl.nasa.gov/cgi-bin/db?sstr=2003+VB12)
Check it OUT !! Mad, that is, in a 60s vernacular FAR OUT MAN ! :D
I wish these Applets showed more details like the image below. Anywho whinge whinge.


Thorn:

I'll admit it. The first thing I thougt of was that guy who was in here a couple of months back claiming he had evidence that there was a brown dwarf out there beyond the Kuiper Belt. What was his handle? I can't seem to find the threads he was involved in.

Rajasun.
And he was baseing his theory on 2mass data at three wavelengths. I wondered where he got to?? Chased away by cold science, New Ideas Not Welcome crowd. Probably got fed up with being accused of looking for Nemisis. Can't say I blame Him.

http://images.spaceref.com/news/2004/ssc2004-05d_medium.jpg

From SpaceRef, I posted in the story Discussion. Caltec are settling on Inner Oort Cloud Object. If KBOs and IOCOs don't amuse you maybe you should av a yarn about Quasars or Time.

I think the First Light year is a great area of Astronomy, esp from here to Proxima.

Any chance of putting Pluto express in orbit around Sedna? Or is PE still on the Drawing board? We really need micro satelites carried out to the edge of the solar system that can be deployed as these type of discoveries are made. Voyager Pioneers where great, future missions should be better.

Faulkner
2004-Mar-16, 03:59 AM
Last I heard the "Pluto Express" was axed. Typical. But then, NASA is just another government department, when you get down to it, right?

And yeah, Zephyr46, Sedna's "ecliptic" or "eccentric" or whatever-you-call-it orbit is indeed "MAD"!

Also, why is it being called the "furthest object in the solar system" when it doesn't even come close to the Oort Cloud?

Ah, too many questions that will forever remain unanswered... How irritating...

zephyr46
2004-Mar-16, 04:16 AM
Too far out to be a Kuiper, not far enough to be an Oort. Talk about the black sheep of the family!

Check the JPL orbit applet (if you have Java), and set it to annimate by months, Sedna is going to be around for a while, but no where near Pluto, but in about jun 16 2060 looks like there is a great Gravitational shot at Juipiter, Saturn, Neptune then Sedna. Maybe we will be on Mars and Lauches like that will be a regular occurance. Hmm. :rolleyes:

Faulkner
2004-Mar-16, 04:31 AM
I see what you mean, Zephyr46! Unfortunately I don't think many of us will be around in 2060...!? Pity that.

TheThorn
2004-Mar-16, 04:56 AM
Thanks, zephyr, I just couldn't pull that name out of the recesses of my feeble mind.

Maybe the hype was Nasa's attempt to get public interest stirred up in Pluto Express, which was supposed to take a shot at visiting a KBO or two as well. Who knows, maybe it will work - if so, I'm in favour of it.

Inner Oort Cloud? Before this object, the Oort cloud was supposed to be 10,000 to 50,000 AU away. Sedna goes out less than 1/10th that far max. So this week we've redefined what the Oort cloud is, and what a planet is ;)

I don't think it's too far out to be called a Kuiper Belt Object. There are a number of KBO's that are referred to as Scattered Disk Objects that are in orbits similar to Sedna's - perihelion totally decoupled from the major planets, aphelion several hundred AU out. For example, 2000 CR105 has aphelion at 44.3 AU and perihelion at 410 AU. 2001 FP185 is similar. 2000 OO67 actually has aphelion of over 1000 AU, larger than Sedna's, but it crosses Neptune's orbit at perihelion. Sedna is bigger and has a higher perihelion, but that's a difference in degree, not kind.

A quote from the KBO Home Page (http://www.ifa.hawaii.edu/faculty/jewitt/kb.html): "1999 CF119 has an aphelion distance near 200 AU, showing that the SKBO doughnut extends to at least this distance. Eventually, much larger orbits will be found." Looks prophetic, eh? And there are probably a lot more of them out there. With orbits that eccentric, they spend the vast majority of their time near aphelion, where they're undetectable, so we tend to discover the ones with more circular orbits.

Maybe "Inner Oort Cloud object" is a new synonym for Scattered Disk Object. Another redefinition? ;)

zephyr46
2004-Mar-16, 05:12 AM
Untill we see an Oort cloud object, I think calling anything inside it's Orbit an Inner Oort Object is fine with me. But we are naming objects that we have no definition for. Move with it Thorn :)

Planetwatcher
2004-Mar-16, 09:36 AM
Can I gloat now? :D

I'm thinking that this will be a KBO which is larger and/or farther then Pluto. While other large KBO's were reported in the normal fashion, none were nearly as large as Pluto, and not many of them are significantly farther. By significantly farther, I'm speaking in terms of either Bode's Law, or a body more then twice the distance of Pluto from the Sun.

Boy it's scary when I'm right. Had I instead said nearly as large or larger, I would have been exactly on the money. Am I good, or is my head just swelling? :lol:

DippyHippy
2004-Mar-16, 10:30 AM
The whole thing was a shambles. I won't be so interested in any mysterious hush-hush press release emails anymore...

TheThorn
2004-Mar-16, 05:16 PM
You're right, zephyr. Sorry if I came across as harping. I'll move on.

Sedna is an interesting object in its own right, so let's move on to what makes it interesting. The most intriguing thing is its perihelion.

Its perihelion at 76 AU is unique. Prior to Monday, the largest perihelion belonged to 1999 CL119 at 46.5 AU. Interestingly, there are 26 known KBOs with perihelion in the 43 to 46 range, (and dozens more that are potentially in that range but who’s orbits are not well enough determined to say for sure) but none over 47. There are a number of hypotheses why there is a hard outer edge to the Kuiper Belt, but it certainly wasn’t predicted in advance, and there is currently no widely accepted explanation.

Then along comes Sedna, which has a very eccentric orbit, indicating that it was scattered (objects are thought to originally form in nearly circular orbits). But what scattered it?

When a small object is scattered by a larger object, it is left in an orbit that either intersect, or comes very close to the large object’s orbit (unless it’s ejected from the system completely). So Neptune couldn’t have scattered Sedna, like it appears to have scattered most of the Scattered Disk Objects and Centaurs. It doesn’t come anywhere near close enough. Something else scattered Sedna.

Sedna’s orbit is a hint that there’s a larger object out there, somewhere between say 75 and 1000 AU. If it’s at the inner end of that range, it might explain the outer edge of the Kuiper Belt too.

Speculation is so much fun. And so cheap too. ;) So let’s get real wild. Bode’s “law” seems to be just so much numerology and hocus pocus, but it puts the next planet at 78 AU from the sun. Right at Sedna’s perihelion. Co-incidence?

GOURDHEAD
2004-Mar-16, 07:45 PM
If a passing star, say 65 million years ago, perturbed this new object at its (previous) aphelion, what are the constraints on the set of masses and relative closeness of the star to cause this object to assume its current orbit from one more circular and of smaller semi-major axis? Would the set of orbital parameters of such a star, assuming the passby occurred in the last 65 million years, help us in identifying it now if its a red dwarf or brighter? :unsure:

Spacemad
2004-Mar-16, 08:34 PM
Apparently it was first discovered on November 14th last year. So why has NASA waited 4 months to announce the discovery to the general public? Were they afraid there was a mistake in the finding? Were 4 months investigation really necessary before making the announcement? Was it to refine the measurements of its orbit?

Nevertheless, itīs still an important find! Itīs the first major discovery in our Solar System since the discovery of Pluto! It seems that it is too close to the Sun to really be counted as a Oort Cloud Object (OCO) but too far away to be classed as a Kuiper Belt Object (KBO) - so they called it an "Inner Oort Cloud Object!"


Will they find a still bigger object out there? Is it possible that there is a gas giant undected until now - or a brown dwarf? What about Nemesis - the companion red dwarf star of the Sun - is there any real indication that such a star might exist? :unsure:

Spacemad
2004-Mar-16, 08:46 PM
While I was reading about Nemesis it brought to mind the story of the same name by Isaac Asimov. I was given the book by my children some years ago (it was his newest novel at that time) for my birthday & it impressed me quite a bit. What I didnīt realise at that time - or until today for that matter! - was that his "story" of a companion red dwarf star to our Sun might have some true scientific base!

I would like to read the story again but unfortunately it is still in Spain - with the rest of Isaac Asimovīs books I had collected - or had been given as presents by my family. I hope to return to Spain this summer & bring back all his books with me. What a feast that will be - to be able to reread all his books after 4 years! :D

zephyr46
2004-Mar-16, 11:56 PM
Speculation is so much fun. And so cheap too. So let’s get real wild. Bode’s “law” seems to be just so much numerology and hocus pocus, but it puts the next planet at 78 AU from the sun. Right at Sedna’s perihelion. Co-incidence?


Doesn't bode give us a hint about the Heliopause as well? At 75 to 90 Au (http://antwrp.gsfc.nasa.gov/apod/ap020624.html) Sedna cruises right through the heliopause.

TheThorn
2004-Mar-17, 12:39 AM
Originally posted by zephyr46@Mar 16 2004, 11:56 PM
At 75 to 90 Au (http://antwrp.gsfc.nasa.gov/apod/ap020624.html) Sedna cruises right through the heliopause.
Now that's an interesting thought. I wonder if there's something about the interstellar medium that has caused (after billions of years of exposure) Sedna's peculiar red colour.

zephyr46
2004-Mar-17, 12:46 AM
Like interstelar cosmic Rays breaching the heliosphere and combining with hydrogen from the sun, giving you a shiny red surface?

Now theres an interesting core sample if ever there was one !

jonfr
2004-Mar-17, 03:45 PM
What can give an star that far out the read surfice then? But as someone said, the orbit is scatterd. I also want to know why NASA did kill the Pluto mission, they at least can forward the satelite from pluto to Sedna in the end, but getting there takes long time.

TheThorn
2004-Mar-18, 01:05 AM
A humorous add-on to my rant about the discoverers not waiting to name Sedna until they had the right according to the naming protocols of the IAU:

A suggestion has gone out on a mailing list of minor planet observers that someone who DOES currently have the right to name a minor planet (asteroid or KBO) should request that the IAU that name their object "Sedna".

Since the name has not been assigned to any object by the IAU, it is available. If they give it to some tiny asteroid, that would open a whole can of worms. If they reject it when recommended by someone who does have the right to name an object, so they can reserve it for someone who doesn't have that right (at the moment), that would open a whole different can of worms.

That would certainly be fun to watch. ;)

zephyr46
2004-Mar-18, 01:29 AM
jonf, check this applet out JPL Orbit Applet (http://neo.jpl.nasa.gov/cgi-bin/db?sstr=2003+VB12)

If you fast foward to 2200 (the limit) you will see when pluto and sedna start getting closer. about 2060 saturn and Neptune have a sort of allignment, I guess, but pluto is far away.

:(

It's better if pluto express and any mission to sedna go there separate ways.

Hey Thorn! Whats wrong with sedna ? I like it! it's better than these date based names. They are so bland!

I think it's great that we are recording they mythology of our cultures in the stars.

TheThorn
2004-Mar-19, 01:01 AM
I also prefer names to numbers. Easier to remember when you're getting old. And there's nothing wrong with the name Sedna - it seems appropriate. It's just that no object has been given that name. Yet.

Those bland date based names are just temporary designations that identify a body only until it's orbit is well defined. At that point, the IAU (which is the only body that has the right to assign names) gives it a number, and then (and only then) the discoverers have the right to suggest a name which the IAU (actually the Comittee for Small Body Naming of the IAU) normally accepts, but sometimes rejects for certain reasons (eg. don't try to name an asteroid "Hitler", at least not until 2045). So 2002 LM60 became 50000, and then Quoaor.

That's the protocol. It's intended to keep some order in the naming of bodies, so that two objects don't wind up with the same name, or one body gets named twice, or so that a body that gets a name doesn't wind up lost (like Hermes, which was named before the protocol was established). Some times a body that is given a temporary 2004 BHxx type name winds up identified as the return of a previously observed object. The point is that these things get straightened out at that stage, before a final name is given.

At the moment, the body we're all referring to as Sedna should really be referred to as 2003 VB12, until they nail its orbit better. It's orbit is so undertain (last I read) that its perihelion could range from 69 to 83 AU, and it's aphelion could be as little as 500 or as much as 1500 AU. It will take observations from a period of about 3 more years to get it numbered (and then named). Those observations could come from archived images, in which case it might be numbered next week (that's what happened with Quoaor, which these same guys discovered, and named before it was numbered). Otherwise it will take a couple of years.

Now imagine for a minute you're an Inuit amateur astronomer interested in this stuff, and you've spent countless hours observing and actually discovered an asteroid a couple of years back, and you've been patiently observing and reporting and building up the data required to get it numbered, abiding by the protocol and planning to name it Sedna in honour of your culture when the time comes. Now they number your asteroid, and you have the right to name it, but someone else has jumped the queue and given your name "provisionally, of course" to an object they had no right to name. Would that feel good?

Especially if they are repeat offenders who were quietly given a "private rebuke" last time they pulled the same stunt?

Damn, you got me going again. After I said I'd move on, too. So I will. In the next post.

TheThorn
2004-Mar-19, 01:11 AM
As to the very red colour of Sedna, This Paper (http://www.physics.nau.edu/~tegler/apjl.pdf) probably gives a clue.

The authors have done a careful study of the color of undisturbed KBOs (the ones in relatively circular orbits of low inclination, as opposed to the scattered KBOs), and found that the larger their semi-major axis (i.e. the farther out they are), the redder they are. Given those results, published last December, Sedna's redness implies it was formed on the outside edge of the Kuiper Belt (not in the Oort Cloud) and scattered into it's current orbit. By what remains a mystery.

TheThorn
2004-Mar-20, 01:02 AM
This just in from Andrea Pellorini:

"My friends, I've the pleasure to inform you that the RHP SpaceGuard Team,
composed by Roberto Haver and Andrea Pelloni, with the precious help of
Prof. Giuseppe Forti of Arcetri Observatory, has found on DSS-2 images two
new precovery positions for the KBO 2003 VB12, so that its orbit is now 11
years longer, spanning from 2004 to 1990, for a total of almost 13.5 years."

That should be enough to get it's orbit pretty well defined. I expect they'll be numbering and officially naming it "Sedna" very soon.

DippyHippy
2004-Mar-20, 03:36 AM
Oh, I'd laugh if the IAU said "no" to Sedna and named it something else LOL :lol:

damienpaul
2004-Mar-20, 05:25 AM
Perhaps name it DippyHippy?

DippyHippy
2004-Mar-20, 06:10 AM
Nahhhhhhhhh... don't be silly... HippyWorld sounds much better...

damienpaul
2004-Mar-20, 09:44 AM
The big question is - will HippyWorld be incorporated as a state of the Fraser Federation?

DippyHippy
2004-Mar-20, 10:49 PM
No, we'd fight invasion with smelly joss sticks and incense while singing "We Shall Overcome" and "The Fish Song" :P

Okay, let's get back on topic... :)

Planetwatcher
2004-Mar-21, 12:58 AM
Okay, we're back on topic like Dippy suggested. I want to look at a couple questions posed on the last page.

Is it possible that there is a gas giant undected until now - or a brown dwarf? What about Nemesis - the companion red dwarf star of the Sun - is there any real indication that such a star might exist?
I believe it's possible but not likely that there is something else out there which has not been detected yet.
But I highly doubt that there is a red dwarf out there, or Nemesis, - actually is supposed to be a companion brown dwarf, or a gas giant of super size perportion.

There is no real indication of such a body. It's speculation was based on the deflection of a number of comets, and one news report even gave it a position, although I don't remember it just now and lack the time to look it up.

But during the last Nemesis scare, I consulted with Christine Lafon,
Public Affairs Harvard-Smithsonian Center for Astrophysics
who said there is no real evidence of Nemesis.

One more thing to think about, if we can detect an object less then a quarter of the size of our Moon, at a distance of over 7 billion miles, which gives off no light or heat of it's own, just the very small fraction it gets from the Sun, how likely is it that a brown dwarf which which would be at least 13 times the size of Jupiter, provide much more heat then it recieves, and would give out millions of times more light then Sedna, can go undetected? Much less a red star?

antoniseb
2004-Mar-21, 01:33 AM
Originally posted by Planetwatcher@Mar 21 2004, 12:58 AM
One more thing to think about, if we can detect an object less then a quarter of the size of our Moon, at a distance of over 7 billion miles, which gives off no light or heat of it's own, just the very small fraction it gets from the Sun, how likely is it that a brown dwarf which which would be at least 13 times the size of Jupiter, provide much more heat then it recieves, and would give out millions of times more light then Sedna, can go undetected? Much less a red star?
I agree that it is unlikely that there is a brown dwarf out there, but there are a few things I'd like to update in the section I've quoted from you.

- a brown dwarf would not be substantially larger in diameter than Jupiter [perhaps 1.5 times]... just much denser.
- a brown dwarf could have been captured from a more elliptical galactic orbit, and have a perihelion of from a tenth to a half of a light year. Such an object would be distant enough to have gone undetected even with a substantial mid-IR output. This would NOT be something created as part of our solar system. At visual wavelengths, it would only be detectable if it occults something.
- a minimal red dwarf [class M9] could also be in a similar captured orbit, and have gone undetected if it is currently between us and the denser parts of the milky way.

Planetwatcher
2004-Mar-21, 02:52 AM
Even a brown dwarf that is only 50% larger then Jupiter would be difficult to escape detection. For it would still create it's own light, even if very little.
And the size difference between a brown dwarf and Sedna would be like comparing Mars's moon Phobos to the planet Saturn. So you see, if we can pick up something so small, how could we miss something so big?

As for a minimal M9 red dwarf, just how big would such a star be?
I would think certainly larger then a brown dwarf, but smaller then an orange K9 dwarf star.
And even if obscured by the Milky Way, a minimal red dwarf would be detectable.
However I do aggree that such a body, if it did exist would not be native to our Solar System.

I haven't had the time to go through all the Sedna news releases as I'd like to.
Did anyone get a position or constellation where Sedna lies?

What would be interesting is if it is in the vincity of Delphus the Dolphen at RA/DEC
20:44:51 +09:04:11 because that is where the last claim of an unseen gas giant planet or Nemesis was, and that would explain the deflection of the comets behind the Nemesis theory.

I have taken the liberty of tracking down the news release from the last major tenth planet or Nemesis claim.
10th planet? (http://news.bbc.co.uk/1/hi/sci/tech/467572.stm)

I am also pasting here the origional question I posed and the reply I recieved.

---------- Original Message ----------------------------------
From: Christine Lafon <clafon@cfa.harvard.edu>
Date: Tue, 21 Jan 2003 13:48:20 -0500

>Dear Byron,
>
>This sounds like the "Nemesis" myth that crops up every so often.
>Some have proposed that such a mystery object could cause periodic
>mass extinctions by sending swarms of comets into the inner solar
>system.
>
>Extensive and thorough searches have turned up no evidence of any
>unseen companion to the Sun. Anything large enough to cause the
>effects you describe would have been seen by now. So, that&#39;s why you
>haven&#39;t heard any updates&#33;
>
>Sincerely,
>Christine Lafon
>
>
>>I remember reading a couple years ago of a very large object on the
>>fringes of our solar system. This object was deflecting orbits of
>>comets.
>>At the time of it&#39;s press, there was speculation of whether this object
>>was a new gas giant planet too far and too faint to be seen before, a
>>brown dwarf companion to our Sun, or perhaps even a small black hole.
>>
>>But I&#39;ve heard nothing more about this object since then. Are there any
>>updates, or has there been further study of this object?
>
>--
>Christine Lafon
>Public Affairs
>Harvard-Smithsonian Center for Astrophysics
>60 Garden Street, MS 28
>Cambridge, MA 02138
>617-495-7463 TEL
>617-495-7016 FAX

antoniseb
2004-Mar-21, 12:13 PM
Originally posted by Planetwatcher@Mar 21 2004, 02:52 AM
Even a brown dwarf that is only 50% larger then Jupiter would be difficult to escape detection.
My point was that distance makes a big difference in visibility. Also, an old enough brown dwarf [> 1 Gyear] would not be emitting substantial amount of visible light. If the BD was 10 times as far away as Sedna , and was 100 times the diameter, it would reflect the same amount of sunlight back to us as Sedna. However, I am saying a captured BD could be 100 times or more further away from us. That would make it dim [in the visible spectrum] beyond detection with our present equipment. Note: I am also not claiming such an object is likely [I don&#39;t think it is], merely that it would be undetectable.

BTW, Sedna is currently in Cetus. This is not far from your Nemesis location, but realistically it is too small and close in to be disturbing many comets. Nemesis was supposed to have a 37 million year orbit. Also, I thought Nemesis was supposed to be way out of the plane of the ecliptic. Sedna is only inclined 11 degrees.

TheThorn
2004-Mar-21, 01:14 PM
Planetwatcher, Sedna is no where near the location you mentioned:

Ephemeris:
2003 VB12 a,e,i =531.66, 0.86, 12 q = 75.796
Date TT R. A. (2000) Decl. Delta r Elong. Phase V
2004 03 06 03 13.58 +05 43.4 89.952 89.498 62.5 0.6 21.3
2004 03 16 03 13.85 +05 45.6 90.086 89.489 52.9 0.5 21.3
2004 03 26 03 14.17 +05 48.0 90.202 89.480 43.4 0.4 21.3
2004 04 05 03 14.54 +05 50.4 90.296 89.470 34.2 0.4 21.3

Now about a big object out there: Sedna&#39;s orbit is clearly the result of scattering. A scattered object is left in an orbit that crosses the orbit of the body that did the scattereing. This implies that at the time that Sedna was scattered, there was someting significantly more massive than Sedna in an orbit that brought it into the 70-1000 AU range. Neptune could never have been that far out, so it&#39;s something else. Some people are suggesting the theory that a star passed by early in the life of the sun, which has three advantages: a) it could do the job, B) it doesn&#39;t require changes to any current theories, and c) it&#39;s absolutely unfalsifiable. Oh, c) means it&#39;s not a scientific theory. Shucks.

If it&#39;s still there, how big an object could we miss? It depends on how far out it is, and how big it is. For us to find it, it would have to be bright enough to see, and moving fast enough to notice that it wasn&#39;t just another dim star. Many KBOs are bright enough to be in the range of amateur telescopes, but no one noticed them because they move so slowly. Once they put together observing programs aimed at finding things that were about as bright as a small asteroid, but moved at 1/20th the speed, they started finding lots of them. Now when someone finds one, they go back into archived images and find earlier observations of it that no one noticed at the time. Quoaor was captured on film in 1951. Sedna in 1990. No one noticed either one - they just looked like stars.

Something the size of Jupiter, in a circular orbit the size of Sedna&#39;s (550 AU) would be magnitude 19 or so which is bright enough to see in a good amateur telescope. However, it would move at 1/50th the speed that a typical KBO moves, so our current KBO search projects wouldn&#39;t notice it. Even worse if it were smaller or farther out. At 5000 AU (half way between the Kuiper Belt and the Oort Cloud) it would be magnitude 28 or 29, and moving at less than 1/1000th of the speed of a KBO. Theoretically, the Hubble could see it in a long enough exposure, but it would just look like a background star unless they took a spectrum on it, because its motion would be undetectable - one orbit per 300,000 years.

Since a brown dwarf is only 1.5 times the size of Jupiter, it would only be about 1 magnitude brighter at the same distance. Brown dwarfs don&#39;t emit light of their own, but they do emit infra red, which would make it much brighter to an IR telescope, but the same thing applies wrt its motion. If there is a brown dwarf this side of the Oort Cloud, we&#39;ve probably mapped it as an infra red object, but failed to notice it&#39;s motion.

Same thing for a small star just outside the Oort cloud. With all respect to Ms. Lafon, I believe she overstates her case.

One comment about "capturing" a passing object - be it a star or brown dwarf or whatever. This is much less likely than most people seem to think. If an object enters the gravitational influence of another object (whether it&#39;s a small star entering the solar system, or an asteroid approaching Jupiter) it has enough energy to escape, by definition. It starts off outside the gravitational well, with an amount of potential energy that is defined by its location. Since its location is outside the gravitational influence of the sun, it obviously has enough potential energy to get back outside the influence of the sun. The only way it can be "captured" is if some sort of event happens to it while it is in the sun&#39;s gravitational field that causes it to loose energy. Usually, that would mean an encounter of some sort with another body. For a "capture" to take place, the other body would have to pick up energy from the body being captured. If the other body is less massive, it would be ejected itself - if it were more massive, it might just have its orbit raised a bit.

Now consider what that means wrt capturing a very massive object into an orbit way out from the sun - to do it there would have had to be a large amount of mass already out there which would be ejected (or raised) in the capture process. We&#39;re assuming something out there formed in situ, and then was used to capture something that didn&#39;t form there - Ockham&#39;s Razor would suggest that we just assume that whatever might be out there formed there in the first place. Current theories of stellar formation would have to be adjusted in either case.

Planetwatcher
2004-Mar-21, 10:34 PM
Good replies gentlemen.
antoniseb did a good job of explaining the distance, size, brightness relationship and the thorn brought up the point of movement, which I hadn&#39;t considered before.

However, one of you said Sedna isn&#39;t far from the suspected Nemesis position, but likely too small to have deflected comets; and the other said it is no where near.
Either case the presence of Sedna doesn&#39;t explain the comet deflection which is sort of too bad in itself.

Nemesis was thought to be between quarter L.Y., to as much as half a L.Y. out from us. Given that kind of distance, and the size difference would not likely to be easily seen. But then albedo comes into play and can make a big difference either way.

The captured object conciept is interesting indeed.
It causes me to wonder if at one time all the Kupier objects were in fact one planet like the asteroid belt has been suspected to have been.
And some catastrophical event caused it&#39;s break up, but before it did such a planet could have captured Sedna as it was passing through from somewhere farther out.

Such an event may even help explain why Uranus axles is perpendicular to all the other planets, and/or why Triton orbits Neptune in retrograde.

since it is not likely we will ever know, the speculation can be fun.

antoniseb
2004-Mar-21, 10:54 PM
Originally posted by Planetwatcher@Mar 21 2004, 10:34 PM
However, one of you said Sedna isn&#39;t far from the suspected Nemesis position, but likely too small to have deflected comets; and the other said it is no where near.
It was me who said it was close to the position. By close I meant within the same quadrant of the sky, whereas TheThorn probably meant that it was not within ten degrees.

Concerning a captured object TheThorn is right about it requiring a third object. At the extremities of the solar system, it wouldn&#39;t have to be a very large object if the two galactic orbits were similar enough. Under those conditions, an Oort cloud collision could potentially be enough. [This is very unlikely unless huge numbers of brown dwarfs sail through our system on a regular basis.] This is why I have said that it was possible but unlikely.

Concerning the Kuiper belt objects coming from a single broken up planet... This doesn&#39;t seem too likely. The Kuiper belt objects were ejected from the inner solar system during the planet formation process. It is hard to picture an event that would have blown a planet apart without leaving a very large remnant behind.

The issues of Neptune-Triton and Uranus are inetersting. I suspect we will eventually have a model of the early history of our solar system that explains these things. On this subject speculation is not only fun, but for the moment, its all we&#39;ve got.

Planetwatcher
2004-Mar-21, 11:01 PM
I can&#39;t imagine too many brown dwarfs sailing through our outer Solar System, but like you said, it&#39;s not impossible either.

mystars
2004-Mar-21, 11:52 PM
Some links:

Interactive Sedna ephemeris: http://www.ephemeris.com/ephemeris.php

Sedna webpage of one of Sedna&#39;s discoverers (Mike Brown): http://www.gps.caltech.edu/%7Embrown/sedna/

JPL Sedna website: http://www.jpl.nasa.gov/releases/2004/85.cfm

TheThorn
2004-Mar-22, 05:14 AM
Originally posted by antoniseb@Mar 21 2004, 10:54 PM
It was me who said it was close to the position. By close I meant within the same quadrant of the sky, whereas TheThorn probably meant that it was not within ten degrees.

Planetwatcher said:

What would be interesting is if it is in the vincity of Delphus the Dolphen at RA/DEC
20:44:51 +09:04:11 because that is where the last claim of an unseen gas giant planet or Nemesis was, and that would explain the deflection of the comets behind the Nemesis theory.

Brown&#39;s Sedna page (which mystars provided a link to just above) gave the ephemeris I quoted, which puts Sedna currently at 03:14.17 +05:48.0.

Now I&#39;ll admit my educational deficiencies. Is that in the same quadrant of the sky? The declinations look similar enough, but the RA&#39;s are quite different.

As to the KBOs being ejected from the inner system during the planet formation process, I think you&#39;ve mixed the Kuiper Belt with the Oort Cloud. If I understand correctly, the Oort Cloud objects are thought to have been ejected from the region that the gas giants currently inhabit. The scattered disk objects, Centaurs, and Plutinos are thought to have been influenced by Neptune. The classical KBOs are thought to have formed where they are now, but since they are beyond Neptune&#39;s gravitational influence, they are still in relatively circular orbits. Which is why Sedna&#39;s orbit is a mystery - it&#39;s very eccentric, but no where near a body large enough to scatter it.

antoniseb
2004-Mar-22, 12:38 PM
Concerning RA, the closer boundry of Delphinus is about 6 hours from Sedna. I&#39;m not claiming this is very close, and perhaps it was a mistake to say it was close. I felt that for something completely unknown before that there was some proximity.

Concerning the KBOs, vs. Oort cloud, articles and papers I&#39;ve read recently propose that the KBOs were moved out to where they are [except for a few such as Sedna or DW2004 that were moved deeper by other events] from roughly zone of the orbits of Uranus and Neptune to the KB during the process that brought Neptune and Uranus from further out into their present orbits. The Oort cloud objects were kicked out by Jupiter and Saturn.

Planetwatcher
2004-Mar-22, 07:51 PM
I am not confusing the Orrt Cloud with the Kupier Belt, I was simply thinking with my keyboard and speculating.

It is not impossible, although not very likely, that some kind of large body or even more then one, shattered a giant planet on the fringes or the Solar System to create the Kupier Belt, knocked Uranus on it&#39;s side, and/or had a piece break off to be captured by Neptune, except it orbited opposite of all the other moons.

It is also not impossible, and a little more likely that the intrusive body came from farther inside our Solar System, such as a body ejected by Jupiter, and Saturn, knocked Uranus on it&#39;s side, and on it&#39;s way out either shattered a giant planet, leaving behind a lot of debris which became the Kuiper Belt, or perterved an already present Kupier body to be captured by Neptune in an opposite direction orbit to become Titan.

It is even not out of the question that Triton has always been a moon of Neptune, and that Pluto and Charon were as well, but whatever knocked Uranus on it&#39;s side, could have caused Pluto and Charon to escape Neptune&#39;s influence.

In any event Sedna may have been the object, or part of such an object, or had nothing to do with the other events.

For all we know, Sedna may be an escaped, or distant satelite of Nemesis.

There is just no way to know, but boy the sceneros one with some imagination could conjur up.