Talk:Scattered disc/archive 1

Capitalisation

In its article Quaoar zet Pluto op zijn plaats (Quaoar puts Pluto in its place) Eos, a Belgian scientific magazine, mentions Scattered Disk Objects, with capitalization. It also mentions the abbreviation SDO. I'd like to know the reason(s) why the capitalization is supposed to be wrong -- if it is, shouldn't the abbreviation be sdo? Of course, a Belgian magazine (even if it is scientific and cooperates with Scientific American) is hardly an authority on language and spelling :-) D.D. 19:37 Apr 24, 2003 (UTC)

I think the capitalization of the phrase in that magazine probably was simply a matter of conforming to that magazine's style conventions. Wikipedia also has style conventions, which eschew capitalization in titles except for the first letter and for proper names or other generally capitalized words. It is commonplace to capitalize letters in abbreviations of this kind when the words are not capitalized when they are not abbreviated. Michael Hardy 21:08 Apr 24, 2003 (UTC)

---

AFAIK there is nothing wrong with excentric. According to my dictionary it is accepted as a variation of eccentric in technical senses. D.D. 19:48 Apr 24, 2003 (UTC)

Diagrams

The diagrams added here (and cubewanos) are modest first drafts. Initially, I used a Java program and saved the graphics as jpeg but the resulting quality was poor. Switched to generating svg. Should have used different colours for Kuiper belt and SDO. Eurocommuter 01:16, 10 February 2006 (UTC)

Extremes

Check out this list of damocloid asteroids. 2005 SB₂₂₃, with an inclination of 91.4 degrees orbits very nearly vertically. 2002 XU₉₃ is inclined at 78 degrees, which means that it is not, in fact, the most inclined object in the solar system. Several of these Damocloids have inclinations close to 180 degrees, which gives them retrograde orbits very close to the plane of the solar system. shaggy 20:11, 2 March 2006 (UTC)

Region of space?

I'm not too sure about describing the scattered disc as a region of space. To me, it refers rather to a type of object: specifically, an object whose perihelion is in the classical Kuiper-belt region, at distances of around 30 to 50 AU, but whose aphelion is much more distant. If an object were discovered in a circular orbit with radius 80 AU, I don't think it would be called a scattered-disc object. If anyone has references that address this terminological issue, I would be interested in looking at them. Kevin Nelson 06:57, 21 August 2007 (UTC)

This is a good point. For example, the Minor Planet Centre [lists SDOs along with centaurs, having in mind that it si a classification of orbits. The description in the intro should be amended. Deuar 11:08, 24 August 2007 (UTC)

Is it right to call Sedna an SDO?

I thought it was an inner Oort Cloud object. Serendi^podous 08:50, 6 September 2007 (UTC)

Can it not be both? Ben Hocking ^{(talk|contribs)} 12:55, 6 September 2007 (UTC)

No it can't; Senda is too far away to have been scattered by Neptune's outward migration, so it can't rightly be called a scattered object. Serendi^podous 12:19, 7 December 2007 (UTC)

I would not call Sedna a SDO (too close) or an Oort cloud object (too far). This is why they came up with the terms Extended SDO's (detached objects) to explain the region in between the two. The primary Oort cloud is very far away. When referencing the Oort cloud, I would call Sedna an inner Oort cloud interloper myself. (Just my 2 cents on the subject.) -- Kheider (talk) 19:27, 29 February 2008 (UTC)

AAA

Absurd Astronomers' Abbreviation. Said: Rursus ☻ 07:50, 10 October 2007 (UTC)

FA Push

Serendipodous, Samuel Sol, and me have decided to start wroking on this article for an FA push, since we found Oort cloud to be a difficult topic. I do not know exactly when we will start FAC, but you can ask Serendipodous since he seems to know the most about this topic. Thanks, Meldshal42_{Comments and Suggestions}^{My Contributions} 19:52, 26 March 2008 (UTC)

P.S. Below I have created a list of all the things this article needs for FA. Please regard them and take them into effect.

The FA preparation process has been restarted. ~~Meldshal42 (talk) 01:32, 19 June 2008 (UTC)

Excellent. Are there any major tasks, other than sourcing, that need to be addressed? I'll start in later today. UltraExactZZ ^Claims ~ Evidence 13:31, 19 June 2008 (UTC)

Should this image be added? [1] ~~Meldshal42 (talk) 18:13, 19 June 2008 (UTC)

If it's from the MPC, then there's copyright issues involved, but yes I think that image is pretty important. Serendi^podous 18:51, 19 June 2008 (UTC)

Alright, I've uploaded it. Could you provide a description of it? You could make it much more sophisticated than I could. It's here-Image:Tnossdosandcentaurs.jpg. Thanks again, ~~Meldshal42 (talk) 22:30, 21 June 2008 (UTC)

OK; I've had a go. Serendi^podous 06:40, 22 June 2008 (UTC)

Things that we need to focus on:

• The "geography" illustrated by that graph.

• The history of its discovery. Harder to plot since there aren't any pop science books on the subject.

• The distinction between the Kuiper belt and the scattered disc, and the unsettled issue regarding the name. The debate is really complex. Getting to the bottom of it will require unravelling Mike Brown's brain-cracking discussion of the topic here.

• The fact that it is the scattered disc, not the Kuiper belt proper, that is the point of origin for short period comets.

That's the start. I'm sure there's a lot more. The Kuiper belt article could serve as a guide. Serendi^podous 19:15, 19 June 2008 (UTC)

New FA Push

I think i noticed an inconsistency between saying SDO and scattered disc object, as well as TNO, etc. ~~Meldshal42 (talk) 01:40, 19 June 2008 (UTC)

I wonder. Should we change SDO to scattered disc object as well as the rest? It certainly would be more encyclopedic. ~~Meldshal42 (talk) 01:42, 19 June 2008 (UTC)

Alright, I have replaced a great number of the SDOs. i will continue later. ~~Meldshal42 (talk) 17:48, 19 June 2008 (UTC)

Sorry I haven't got very far with this; I'm suffering a bit from information overload trying to figure out how to go further. Serendi^podous 15:58, 22 June 2008 (UTC)

Expansion

I'm looking at the article, and trying to view it through the objections I would expect at FAC review. Two of the main ones are converting lists to prose and comprehensiveness. For example, I'd like to have a section that exclusively goes through the various SDOs and describes them. The section would also, ideally, compare and contrast the objects. See, for example, Saturn#Natural satellites. Is the table in this article exhaustive? It is listed as "Noteworthy" objects, but under what criteria? We mention three other objects earlier in the article and talk about how their orbits are unusual enough to merit a notation on the map; why aren't they on the table? We might want to compile a list of all of the SDOs mentioned in the article, and then discuss the objects. Some of them surely have their own articles, and there might be sources there that can be used here. Thoughts? UltraExactZZ ^Claims ~ Evidence 18:13, 7 July 2008 (UTC)

The table would probably have to be taken down in any FA push. The total number of SDOs reaches the hundreds, and including them all would be impossible. Serendi^podous 19:25, 7 July 2008 (UTC)

Agreed - but it's a starting point for any discussion on what to include and why. A certain diameter or mass might be a reasonable limit, for example. UltraExactZZ ^Claims ~ Evidence 19:28, 7 July 2008 (UTC)

It is wise to include a table of the brightest SDOs, for instance, brighter than 4 absolute magnitude. Currently there are only four or five of them. Ruslik (talk) 10:46, 11 July 2008 (UTC)

Go to JPL Small-Body Database Search Engine.
Limit by object characteristics: (1st pulldown) H (mag) < 7. (~100+ km)
Limit by object characteristics: (2nd pulldown) a>48. (Kuiper cliff)
Pre-defined field sets: asteroid basic (append selected).
Selected Fields (optional) highlight "orbit fit quality" through "#obs used" and hit remove. This cleans up the table.
Format Options: 50 rows per page max (my personal preference)
Click Generate Table.
Then click on H to sort be absolute magnitude.
Eris and Senda are the top dogs.
2007 UK126 appears to be a dwarf planet candidate with an absmag of 3.5. This would give it a size of 530 to 1190km.
-- Kheider (talk) 14:58, 11 July 2008 (UTC)

notes and references, page numbers

• Separating the notes and references has always seemed much more clear to me. First, you can arrange the references in alphabetical order, all in one spot. Second, you can place page numbers on the notes, which is always a good thing. In my opinion, it would be preferable to change the format of the notes and references in this article...but until anyone agrees to do so, any info I may find/add will be referenced in the existing style... Ling.Nut ^(WP:3IAR)

Ahhhh where do I put this? You guys figure it out; it's your organizational method for the references. I put in a not about Cis-Neptunian bodies, here's the source: Remo, John L. (2007). Classifying Solid Planetary Bodies. New trends in astrodynamics and applications III. AIP Conference Proceedings, Volume 886, pp. 284-302. Ling.Nut ^(WP:3IAR) 05:44, 12 July 2008 (UTC)

Too messy. I prefer notes to be comprehensively and independently referenced. Serendi^podous 08:05, 13 July 2008 (UTC)

(undent) If I find anything that seems worth adding, I'll add it; you arrange the notes any way that you like.. :-) Ling.Nut ^(WP:3IAR) 08:56, 13 July 2008 (UTC)

note

I wanted to help with the article, but it is simply too much out of my reach. Nevertheless, I did notice the lack of a historic section. I think putting a section before formation with preliminary theories of its existence, initial observations, milestone observations, theories about future observations would help a lot. Nergaal (talk) 20:28, 12 July 2008 (UTC)

Tracking down the history of the Scattered disc's discovery will be extremely difficult, because there hasn't been a comprehensive history of its discovery published (unlike the Kuiper belt) and also, many people, including several involved with its discovery, don't consider the scattered disc to be an independent region at all, but rather part of the Kuiper belt. Serendi^podous 07:32, 13 July 2008 (UTC)

Images and commented text

Temporarily commented out a section at the end of "detached objects" which begins with the words "The diagram illustrates..." The diagram is no longer close to the text; please consider simply deleting this text, or at least moving it nearer the relevant diagram.

This article may have too many images (?).

I'm worried about the licensing of Image:TheKuiperBelt Projections 100AU Classical SDO.svg. I saw it in a book... will look for it... Ling.Nut ^(WP:3IAR) 03:12, 14 July 2008 (UTC)

• found it: Solar System: A beginner's guide Ling.Nut ^(WP:3IAR) 07:25, 14 July 2008 (UTC)

That book is a print version of Wikipedia. Serendi^podous 07:36, 14 July 2008 (UTC)

I'm concerned about Image:Tnossdosandcentaurs.jpg as well... all the images need to be checked carefully and their relationship to the text explained clearly. Ling.Nut ^(WP:3IAR) 06:25, 14 July 2008 (UTC)

The fair use rationale is probably invalid, because this graph is based on the publicly available data, and as such should recreated, not copied. Ruslik (talk) 08:21, 14 July 2008 (UTC)

I agree with Ling.Nut, i think the article has too many images, but the question is, which ones do we remove? I vote for the one I uploaded per Serendi's partial request, tnossdosandcentaurs.jpg. Although Serendi said it was somewhat helpful, I think it is quite the opposite. I see no need for this image as of now. --Meldshal42 (talk to me) 02:15, 16 July 2008 (UTC)

(undent) if several people are closely attached to this article, you can discuss, but it may be best to {{sofixit}}. I didn't do so solely 'cause I have no idea which ones are more useful :-) Ling.Nut ^(WP:3IAR) 02:23, 16 July 2008 (UTC)

1999 TD₁₀ status unsure

This text seems more than a little uncertain:

• 1999 TD₁₀ has an orbit with extreme eccentricity (~0.9), bringing its perihelion near Saturn's orbit. This qualifies it as a Centaur.[2]

Serendipodous and I have been discussing the whole 1999 TD10 issue and trying to figure out where to come down. I have quite literally found contradicting sources: some say centaur, some say SDO... so perhaps the best thing would be to remove it for now, but actively pursue this question on the talk page. Since Kheider weighed in as well, I think it's best to remove the text from the article and research this question more thouroughly. So that's what I did. :-) Ling.Nut ^(WP:3IAR) 04:28, 18 July 2008 (UTC)

DES (Buie) is one of the most respected orbital data sites. I would trust it more than an astronomer potentially assuming with older data. (29981) 1999 TD10 was last observed on 2007/03/05. -- Kheider (talk) 04:54, 18 July 2008 (UTC)

Excellent! I'm glad I removed it from the article... there were originally three bullet points in the article at that particular section; now there's only one. Should the following be deleted as well...?:

"The scattered disc is the place where extreme eccentricity and high inclination appears to be the norm and circular orbits are exceptional. Some exceptional orbits are plotted in yellow:

• 2004 XR190 has the atypical, near circular (the short yellow segment) orbit, but it is highly inclined.

• Ling.Nut ^(WP:3IAR) 05:01, 18 July 2008 (UTC)

04XR190 2007/09/17 (last obs) seems to be showing as a SCATNEAR object now. :-) -- Kheider (talk) 05:34, 18 July 2008 (UTC)

This article [3] may be of interest. Ruslik (talk) 07:41, 18 July 2008 (UTC)

FA-Team Mission 5: Solar solicitude/solidarity

The FA-Team would like to help this article and Solar energy reach FA status: the mission page is linked above. Help with both articles would be much appreciated. Geometry guy 16:19, 26 July 2008 (UTC)

Trimming

I I've just completed a savage trim of this article, removing all the "out of caption" image discussion, which is not appropriate for an FAC. It's now much shorter, but at least it's finally beginning to look like a proper article. Serendi^podous 06:43, 31 July 2008 (UTC)

Discovery

Is there anything we can use to expand this section? We currently discuss the objects themselves, and when they were found, but is there discussion about the discovery of the scattered disc itself? I mean, shouldn't we discuss the discovery that the scattered disc exists as a separate set of objects, distinct from other TNOs? Again, not real sure where we would come up with this, but I can easily see the Discovery section being tagged with a {{Expand-section}}, which wouldn't go well at FAC. Thoughts? UltraExactZZ ^Claims ~ Evidence 14:02, 11 August 2008 (UTC)

It's kinda difficult, because not everyone sees the scattered disc as a separate region. Certainly David Jewitt doesn't, and he co-discovered the first scattered object. Serendi^podous 14:10, 11 August 2008 (UTC)

Well, that's awkward. If we come across something, I'll try to add it in. UltraExactZZ ^Claims ~ Evidence 14:38, 11 August 2008 (UTC)

Calling all NASA gurus

I'm over from the other half of the FA-solar project. You guys are certainly more familiar with this than I so maybe somebody here has a clue.

I'm trying to find a high-resolution version of the picture found here and here.

I'm also trying to determine if this picture is open source because certain NASA projects have copyrighted image? Any help appreciated. Mrshaba (talk) 21:09, 14 August 2008 (UTC)

No, NASA images are in the public domain. Read the {{PD-USGov-NASA}} template to find out whether those meet the cut. --LordSunday 15:09, 24 August 2008 (UTC)

Review

Just some thoughts and questions. Sagan is as close to this subject as I've gotten so forgive me my myopia.

"Specifically, SDOs were expected to have large amounts of surface methane, chemically altered into complex organic molecules by energy from the Sun." - So these objects receive more sunshine than starshine?

The short answer to that question is yes. Kuiper belt objects are warmed enough by the Sun for their surfaces to evaporate into atmospheres. Farther out, and the warming significantly drops. Serendi^podous 18:15, 17 August 2008 (UTC)

Is there an estimate for how many scattered disc objects there are or did I miss that?

I'm looking for a total number of SDOs found to date, but the total number believed to exist is about the same as the Kuiper belt, as is said in the lead. Serendi^podous 18:15, 17 August 2008 (UTC)

There's a lot of detail regarding classification of SDOs vs. Kuipers vs. comets etc. and this overlaps confusingly between the sections. The idea of a Venn diagram popped into my mind as a means of working out the overlaps but I don't know if that could work here. The index at the top of the page lays out the names of TNOs and similar bodies and it indicates that SDO are separate from detached objects but then DOs are covered on the page. My impression is that the classification boundaries need more clarity.

I've rejigged the sections a bit; let me know if it reads more clearly now. Serendi^podous 18:15, 17 August 2008 (UTC)

I think the diagrams in general need a little work. Can a simplified polar view of the Scattered disc area be added? Something similar to the asteroid belt lead image.

There is such an image, here, but it's fairly useless, because it's very difficult to discern the SDOs from the KBOs. Since most of the SDO's we've found so far have been near their closest approaches, they mesh seamlessly into the Kuiper belt. It's their orbits, rather than their current positions, that explain what they are. Serendi^podous 18:15, 17 August 2008 (UTC)

The image helps me to see that the scattered disc objects are all over the place as opposed the the regular orbits of KBOs. It won't be too hard to remove the green KBO objects. The caption could mention your caveat about orbit vs. position. 24.85.246.143 (talk) 16:33, 18 August 2008 (UTC)

Could the Kuiper Belt Projections 100AU Classical SDO images be laid out horizontally side by side?

I'm not sure what you mean. Serendi^podous 18:15, 17 August 2008 (UTC)

It looks as though there are two stacked images in the current version. What if they were side by side? 24.85.246.143 (talk) 16:33, 18 August 2008 (UTC)

The 2003 UB313 near-infrared spectrum can be stretched a little and labeled with larger print - Even the enlarged picture has sub-par labeling. Cheers Mrshaba (talk) 17:06, 15 August 2008 (UTC)

Can't help you there. Images aren't my forte. Serendi^podous 18:15, 17 August 2008 (UTC)

done. --LordSunday 15:12, 24 August 2008 (UTC)