Talk:Kuiper belt/Archive 2

Introduction

In the introduction's second paragraph, the first line reads a bit weird: "Since the belt was discovered in 1992,[6] the number of known Kuiper belt objects (KBOs) has increased to over a thousand, and more than 100,000 KBOs over 100 km (62 mi) in diameter are believed to exist.[7]" If the number of large objects are over 100,000, then of course the total number of objects are over 1,000: that seems uninformative. I have no idea what the correct numbers are though, just wanted to point it out. — Preceding unsigned comment added by CBoeckle (talk • contribs) 15:54, 16 December 2013 (UTC)[reply]

1000 is the number of known objects (it's about 1500), 100 000 is someone or another's guess at the number of large objects. Wily D 16:04, 16 December 2013 (UTC)[reply]

We need to update our Kuiper belt graphs

There's a collection of them over at the Commons. Most haven't been updated since 2008. In particular the main image needs redoing with new info. Unfortunately I don't have the skills to do this. Serendi ^pod ous 13:25, 10 December 2014 (UTC)[reply]

Just the same plots, more or less, with newer data? Wily D 14:21, 10 December 2014 (UTC)[reply]

File:Afileforthepurposeofdiscussiononthekuiperbeltpage.png

Actually, the total number of discoveries since that plot was made ain't many (though it says 2012?) Wily D 14:56, 10 December 2014 (UTC)[reply]

Really? As far as I know the main image hasn't been updated since 2007, and there have been some pretty extensive surveys done since then. But hey, you know better than me, and if you think the graphs don't need updating, I'll take your word for it. Serendi ^pod ous 16:27, 10 December 2014 (UTC)[reply]

Well, this is a vs i with symbol-size corresponding to H today. Wily D 16:58, 10 December 2014 (UTC)[reply]

Hm. Doesn't seem that different, though it's hard to tell because the original is so squashed. Your image probably deserves to replace it on aesthetic grounds alone. Serendi ^pod ous 17:37, 10 December 2014 (UTC)[reply]

There are lots of problems with that image (axis labels too small, colors too washed out, etc.) I could play around with it if you're keen (tomorrow, perhaps). Some idea of what you're looking for might help. Wily D 17:47, 10 December 2014 (UTC)[reply]

[outdent]Well, I like the wider spread that makes things clearer; perhaps labels on the largest objects? A black background would be best, maybe? Serendi ^pod ous 18:59, 10 December 2014 (UTC)[reply]

Well, i dunno how I feel about the labels.

Well, I'll leave that up to you. :) Looks nice though! :)Serendi ^pod ous 11:52, 11 December 2014 (UTC)[reply]

Well, Pluto and Eris work okay? I suppose. But the other two are too small? Personally, I find it a bit confusing to have the labels hanging loose outside the symbols, but perhaps people think I'm nuts? Wily D 11:56, 11 December 2014 (UTC)[reply]

Makemake kinda works too. I think you could get away with just moving 2Haumea" above the circle. Serendi ^pod ous 12:02, 11 December 2014 (UTC)[reply]

Well, if you'd rather, I can leave the labels, but inconsistent placement ain't good. Wily D 12:31, 11 December 2014 (UTC)[reply]

Fair enough. Serendi ^pod ous 16:24, 11 December 2014 (UTC)[reply]

Well, if you don't want any changes to those, I'll think about the main image (but that'll take longer). Wily D 18:04, 11 December 2014 (UTC)[reply]

File:Randomplotofwhichicanspeakonlyill.png

A plot

Not as hard as I'd thought; I used to be a lot shittier at this sort of thing, I guess. Anyways, the minor planet centre no longer separates out centaurs and scattered disk objects (which is good in that separating the scattered disk from the hot classicals is dumb, but is bad in that including centaurs here is not good). Also, I plotted all the planets (including Pluto!), so everyone less than two earth masses should probably be cut. Orange is probably the wrong colour for planets (looks too much like the solar yellow?) Doesn't stand out that well against grey (also a bad choice?) What to do about centaurs? plot everyone with a < 30 in a different colour? Other points? Wily D 14:44, 12 December 2014 (UTC)[reply]

Pluto shouldn't be presented as a planet, for it is not one. It is simply the largest Kuiper belt object. --JorisvS (talk) 15:23, 12 December 2014 (UTC)[reply]

Well, unless you don't count resonant objects as Kuiper belt objects (which you shouldn't!). But it's just because I used the default MERCURY planet input. Wily D 15:29, 12 December 2014 (UTC)[reply]

Okay, better colours (I thought - brightness looks a lot lousier as a thumb), cut extraneous planets, cut centaurs (though Scattered Disk Objects are still included, as the Minor Planet Centre no longer pretends you can meaningfully distinguish between SDOs and Hot Classical objects). Probably, at least, the colour of the KBOs needs to be brighter? Previous plot had Neptune Trojans, Centaurs, and Jupiter Trojans; are those still desirable? Were they ever? Wily D 15:52, 12 December 2014 (UTC)[reply]

Nevermind the colour complaint, I think it's good now. Wily D 15:55, 12 December 2014 (UTC)[reply]

Looks good now. If we want a plot without centaurs, we could also have a separate one; I think the one with them is also informative. Depending on which resonance (and therefore semi-major axis), resonant objects are either considered KBOs or SDOs, though never classicals. --JorisvS (talk) 16:29, 12 December 2014 (UTC)[reply]

Well, I can make a second with centaurs on ... Tuesday, maybe. Not before. Perhaps with and without trojans (though main belt/near Earth asteroids are certainly out - not resolvable). If there's any authoritative source of resonant objects (or at least a citable one), they can be marked out, but I don't think there is. Classicals aren't really a thing to intelligently use, though, since Hot Classicals and Cold Classicals don't form a clade. But since the literature is a hopeless mess, we're hosed here. Wily D 17:07, 12 December 2014 (UTC)[reply]

You could pick the cut-off inclination (which seems 12° per classical Kuiper belt object) and maybe give them different colors or something. I can't think of an easy way to weed out the resonant KBOs, though. --JorisvS (talk) 17:38, 12 December 2014 (UTC)[reply]

Well, different people use different standards, and for obvious reasons - the hot and cold populations of the Kuiper belt overlap. Since there's ~0 agreement in the literature as to how to subdivide TNOs, we're not particularly obliged to reproduce something we know to be wrong. Doing some resonant objects ain't hard; but the published lists are woefully incomplete. But I'll think about highlighting objects named as 3:2 (and perhaps others?) in the literature. Wily D 09:56, 15 December 2014 (UTC)[reply]

True. It'll probably take relatively in-depth study of a KBO to know whether it is really part of the hot or the cold population and even then it could be difficult to decide in some cases. --JorisvS (talk) 11:59, 15 December 2014 (UTC)[reply]

+= Centaurs (Green), Neptune Trojans (Fuchsia?), and Uranian Trojan (Yellow-y).

Are Jupiter Trojans a good idea? They were on the old one, though I can't recall why I'd do that. Wily D 10:56, 15 December 2014 (UTC)[reply]

Wouldn't that just create blobs in the plot in front of and behind Jupiter? I'd have to see it to be able to properly judge that. --JorisvS (talk) 11:59, 15 December 2014 (UTC)[reply]

File:Jeeztwistaguysarmwhydontyou.png

Yes, orange-y blobs

Well, one starts to run out of colours, especially if they're colour-blind. Jupiter Trojans are much more akin to asteroids to my mind than to TNOs. Wily D 12:13, 15 December 2014 (UTC)[reply]

Like KBOs, Jupiter trojans are often icy, and they may well have originated in the proto–Kuiper belt. During planetary migration (when Jupiter and Saturn went into 1:2 resonance, which would have destabilized any pre-existing Jupiter trojans) the ice giants plunged into the proto–Kuiper belt, sending many PKBOs inwards, some of which were then captured in Jupiter's Lagrangian points. I don't mind the orange blobs and they do make it clear that that area of space contains many known objects. --JorisvS (talk) 12:54, 15 December 2014 (UTC)[reply]

Well, asteroids are often icy too. While there's obviously some mixing, it's clear that all "small bodies in the outer solar system will all come from the same parent population" predictions of the Nice Model were wrong (although differing percentages of a few parent populations is still allowed) - I don't think . Frankly, it was always kinda silly, given that Hal was like the first guy to realise the high inclination and low inclination bodies have different size distributions. Although for the purposes of the plot, I suppose it hardly matters; we're stuck with the current imperfection state of information + a confused literature and being a secondary source. Wily D 13:43, 15 December 2014 (UTC)[reply]

There has indeed been a lot of mixing, e.g. Ceres has been hypothesized to have originated in the Kuiper belt. Moreover, it is silly to pretend that the entire proto–Kuiper belt was compositionally homogenous in the first place. Because of the extreme difficulty in determining origins, current characteristics are often preferred in classifications. --JorisvS (talk) 13:50, 15 December 2014 (UTC)[reply]

Well, with sufficient mixing, the resulting populations would've been homogenous. Origins are difficult to determine, but other classification schemes run into the problem that if you don't do it by origin, you either can't deal with the overlap, or use hard cuts that look artificial for our purposes. In any event, most objects aren't well enough characterised to hope to much meaningful anyways, though I could highlight objects that have been identified as resonant objects (which're overrepresented anyways, since they're overrepresented among low q objects). Wily D 18:28, 15 December 2014 (UTC)[reply]

I'm surprised; there are a lot more blue dots interior to the Kuiper belt than I expected. Serendi ^pod ous 13:33, 15 December 2014 (UTC)[reply]

Previously SDOs were binned with Centaurs; but the MPC stopped distinguishing, so now they're binned with KBOs. Wily D 13:47, 15 December 2014 (UTC)[reply]

To check, the blue ones are TNOs with perihelia inside Neptune's orbit, right? --JorisvS (talk) 13:50, 15 December 2014 (UTC)[reply]

Blue ones are "distant objects" from the Minor Planet Centres list of distant objects, less objects with a < 30.05, which the Minor Planet Centre defines to be Centaurs. I'll have to dig around for what they mean by distant objects, but I think it's q > 5.2 au; So yes, the ones Serendipodous is talking about are a mix of Resonant and Scatted objects with q < 30.05 au). Wily D 18:28, 15 December 2014 (UTC)[reply]

Ah bugger! Does this mean that the MPC has changed its trans-Neptunian definition? That means we have to too! Serendi ^pod ous 18:50, 15 December 2014 (UTC)[reply]

Perhaps not - I was using their list here, although they do still seem to maintain separate centaurs + SDOs list and resonant + hot classicals + cold classicals but not any 5:2 or longer period resonants list. Like everything, jumbled mess. Wily D 22:35, 15 December 2014 (UTC)[reply]

Now with separate SDOs and Centaurs (@a=30.05)

Right, so I re-did it, separating Centaurs, SDOs, and "Kuiper Belt Objects", where "Kuiper belt objects" means a > 30.05, a < 50, and whatever eccentricity cut the MPC randomly chose. Note that this means resonant objects with a > 50 (such as 2000 FE8) are plotted as "Scattered Disk Objects", while those with a < 50 (Such as 1995 HM5) are plotted as Kuiper belt objects. Which ain't great. Wily D 10:42, 16 December 2014 (UTC)[reply]

Maybe we could also have the two sednoids in a distinct color? --JorisvS (talk) 10:46, 16 December 2014 (UTC)[reply]

I'm not sure we really want to encourage that kind of silliness (especially since everyone will have their own definition for "extended-detached" or whatnot). Since this is about the Kuiper belt, presumably that's the structure we want to show. I plotted the objects I could find sources called resonant as resonant (Which is Gladman et al. 2008, Petit et al. 2011, plus one from Sheppard et al. 2012 - if anyone's aware of recent sources, please do), and dialled down the brightness of everything but Classicals and Resonants. Drives me batty treating Hot Classicals and SDOs differently, but what can you do? Some way of separating Cold Classicals might be a good idea; I'll dig for someone I can blame for the choice. Wily D 14:36, 16 December 2014 (UTC)[reply]

Oh, and Alexandersen et al. 2014 Wily D 15:33, 16 December 2014 (UTC)[reply]

Alright, unless there's anything else, I suppose File:Plotoftheoutersolarsystemwithresonantobjectsandwhaticanonlyassumeareturtles.png and File:Iwouldhavegiventhisfileamoreappropriatenameifihadknownitwasgoingintothearticle.gif are what's wanted/needed. Since the plot's also used at Centaur (minor planet), I suppose I should make another version in which centaurs are brighter and classicals/kbos dimmer. Which I'll do unless anyone wants more changes? Wily D 09:50, 17 December 2014 (UTC)[reply]

Thanks! I was actually going to suggest that Centaur idea. Serendi ^pod ous 12:01, 17 December 2014 (UTC)[reply]

Yeah, no worries. Since it's all scripted now, making new plots is not terribly hard, if other variations are needed/wanted. Wily D 13:42, 17 December 2014 (UTC)[reply]

There may be only two known sednoids, they orbital parameters are distinctly different from those of the normal detached objects. It may be over the top for a plot focused on the Kuiper belt, but it may be interesting for a general plot of trans-Neptunian objects. --JorisvS (talk) 13:18, 17 December 2014 (UTC)[reply]

That's not remotely true. For instance, the de la Fuente Marcos paper shows how smoothly they blend into other extended objects (which themselves blend smoothly into hot classical and regular scattered). We could highlight every arbitrary division people have thrown around over the years, but the plot would be way too busy (which it already is). Even the articles here (which get a bit of press release hype into them) call Sednoids Detached objects (and detached notes everyone makes a different definition, because they joint smoothly with regular scattered). Wily D

Not quite. That paper discusses that the argument of perihelion is close to 0° for all minor planets with a>150 AU and q>30 AU, which is not only the detached objects and sednoids. It does mention Sedna and 2007 TG422 (the latter is just a scattered-disc object) as outliers in semi-major axis. But the sednoids are outliers, too: the perihelia of Sedna and 2012 VP113 are far larger than those of any of the detached ones (the next one is 2010 GB174 at 48.6 AU), and yet that article does not mention this as such. --JorisvS (talk) 16:40, 17 December 2014 (UTC)[reply]

Nominally different, but we're restricted in total number of colours that're legible (and already pushing that limit, I think; though again, being colourblind may influence that). The dynamical difference between a pericentre of 50 and 75 au in the solar system is neglible - (and heck, even the name appears to be just the title of Scott Sheppard's page on it - doesn't appear in the literature, and I've never heard it in the field. There are several more important divisions we're glossing over here. Wily D 18:16, 17 December 2014 (UTC)[reply]

The red part of the spectrum looks underused. Even using the red of the planets would be unproblematic. The difference is that normal detached objects could have been produced during an eccentric-Neptune phase during planetary migration, whereas this is impossible for the sednoids, which, for that reason, have also been called inner Oort cloud objects. I don't care too much about it, though. --JorisvS (talk) 18:55, 17 December 2014 (UTC)[reply]

I'm really not okay with re-using the planetary red, but a dark red or an orange-y red might be okay. Though, again, if we're going to add colour, we should use important, common divisions with the Kuiper belt (Cold Classical vs. Hot Classical, or Inner-Main-Outer, or Plutinos/Twotinos/Other Res), not push an unused classification. When the lit figures out if they're Hill Cloud objects (assuming such a thing exists), or if their pericentres were raised by a Lykawka-Mukai object, or whatever (Did Levison ever publish his work on collisional inject to make detached objects?), we might revisit it, but we shouldn't be using a relatively main article to push a somewhat fringe-y theory (especially using a term that basically exists only in the minds of Wikipedians). Wily D 10:50, 18 December 2014 (UTC)[reply]

I added resonant identifications from a few places. I'm strongly tempted to add updated orbital elements for the objects listed here: http://www.boulder.swri.edu/~buie/kbo/desclass.html if the MPC data doesn't have 2+ Oppositions, because a lot of those are scary-bad. Wily D 16:28, 17 December 2014 (UTC)[reply]

Upon investigation, so are a lot of the CFEPS ones, but I think they're less misleadingly bad, and more just plain bad. Anyways, I do plan to upload a new one once I've poached all the CFEPS values & resonant identifications, as well as one where the centaurs/scattered objects are bright and the classical/resonant objects dim. Anything else, is mostly easy, so feel free to ask (though, uh, the movie is still a little manual, so it's a smidge of work. Everything else is pretty trivial.) Wily D 10:38, 22 December 2014 (UTC)[reply]

Anyways, I notice Serendipodous (talk · contribs) put the movie file into the article, but given that it doesn't give any indication it's a movie, shouldn't the static one be used? Or an indication you can watch it be added?

Static one's fine by me, if you'd prefer it. Serendi ^pod ous 11:53, 22 December 2014 (UTC)[reply]

If there's some reason you used the movie file by all means do, but I couldn't guess why you did that. I suppose it doesn't really matter, but doing so shows the first frame of the movie (which is January 1st, 2000 positions) rather than the static (which uses December 1, 2014 positions). Wily D 12:04, 22 December 2014 (UTC)[reply]

I mostly automated the movie-makery, so I can easily fudge those around or make other variants, if people ask. Wily D 14:38, 24 December 2014 (UTC)[reply]

Resonant and Classical Objects highlighted
Scattered disk and Centaurs highlighted
Trojans of Neptune and Uranus highlighted
Resonant and Classical Objects highlighted - animated Jan 2000 - Dec 2020
Scattered Disk Objects and Centaurs highlighted - animated Jan 2000 - Dec 2020

Scattered Disk Objects and Centaurs highlighted - animated Jan 2000 - Dec 2020

About the lead image - suggestions

Plotoftheoutersolarsystemwithresonantobjectsandwhaticanonlyassumeareturtles.png

Known objects in the Kuiper belt beyond the orbit of Neptune (data from the Minor Planet Center).

  Sun
  Kuiper belt
  Scattered disc

  Jupiter Trojans
  Giant planets
  Neptune trojan

Known objects in the Kuiper belt, derived from data from the Minor Planet Center. Objects in the main belt are colored blue, whereas scattered objects are dark green. The four outer planets are red. Neptune's few known trojans are purple, whereas Jupiter's are grey. The scattered objects between Jupiter's orbit and the Kuiper belt are known as centaurs. The scale is in astronomical units. The pronounced gap at the bottom is due to difficulties in detection against the background of the plane of the Milky Way.

Known objects in the Kuiper belt beyond the orbit of Neptune

  Sun
  Kuiper belt
  Scattered disc (outer region)

  Jupiter Trojans
  Giant planets
  Centaurs (inner region)

(data from the Minor Planet Center)

There has been a lot of talk about the lead image recently.

Comparison

Here are two alternative versions (left) compared to the current version (right).

Suggestion

With all due respect to the effort previously invested, but the current lead image seems not very instructive to the general reader. I'd rather see it replaced by one of the alternatives. Since I don't want to complicate things too much I post them here and leave the article unchanged. Cheers, -- Rfassbind -talk 18:18, 25 January 2015 (UTC)[reply]

If I read this right, this is just the same plot but with the outermost objects cropped off. Wily D 11:11, 26 January 2015 (UTC)[reply]

The image on the top left is only slightly better Tetra quark ^(talk) 11:58, 26 January 2015 (UTC)[reply]

In any event "this is better" without any indication of why one thinks it's better is not very helpful. Wily D 12:34, 26 January 2015 (UTC)[reply]

Hi WilyD, what's your opinion? As you surely have noticed the differences are not just limited to cropping your image. BR, -- Rfassbind -talk 15:07, 26 January 2015 (UTC)[reply]

As far as I see, they're just crops. Are the brightnesses fiddled with or something? Since there are no KBOs beyond 60 au, I suppose plotting all the scattered disk objects ain't necessary, since we treated SDOs as not KBOs for weird historical reasons that I won't rant much about. Normally I wouldn't be caught dead making a plot without axes. Wily D 15:26, 26 January 2015 (UTC)[reply]

My first suggestion uses the same image currently used in the article, i.e. the version you uploaded on Dec 23, 2014 to wikipedia. Yes, scales and units are understandably a must-have for a professional, but since it is a WP:LEADIMAGE that accompanies the lead and also features a text in the caption, the lack of any plotted axis might be generously overlooked, I hope. BR, -- Rfassbind -talk 15:51, 26 January 2015 (UTC)[reply]

Yes, I see that it's the same image (and the other one is a crop o' the image I made a'for). I mean, I'll make whatever image, but if it's just a crop that's wanted, or a brightness complaint, or that making it big enough to include the Scattered Disk is unnecessary (but keep the axes), or ? is necessary to understand to do it. I try not to care, because I get irritated with all the errors that come out of the literature into the article, so I'm happy enough to do whatever. Wily D 16:03, 26 January 2015 (UTC)[reply]

It's because it is more zoomed in, showing only what interests. The legend is not a plus because it could be on the current image as well Tetra quark ^(talk) 16:09, 26 January 2015 (UTC)[reply]

Yes, exactly (if I may reply without being addressed) the image is not only cropped, it is also enlarged as if the original were 500px wide. As for the legend, there are certainly many other possible alternatives. However, the current version doesn't have a legend, my suggestion does, so I consider that an improvement. Don't you? Cheers, -- Rfassbind -talk 16:51, 26 January 2015 (UTC)[reply]

WilyD, it would be fabulous, if you can prepare a different version, that doesn't need the cropping. That would make things simpler and therefore better. Here's my suggestion (I'm trying to be as specific as possible and not to be regarded as being demanding)

Image: cutoff at 55 AU as in the cropped version
No AU scale
No legend in the image, as a concentric circle in a square does not give a lot of options
Slightly enlarge size of objects. Even if it's only +1 pixel it should be notable.
Lighten up color: KBOs from currently #0088CC (RBG 0.136.204) to #1AB3FF (RGB 26.179.255)
Planets: instead of labels "Jupiter", "Saturn", "Uranus" and "Neptune" → only J, S, U and N in twice as large, bold letters.
No label for the Sun, as the yellow dot in the middle needs no explanation other than in the caption's legend.
Lighten up the Neptune trojans (if mentioned in the legend). Currently RGB 102.0.102 or #660066. Change to RGB 255.51.255 or #FF33FF.
Upload the final version to wikicommons instead locally on wikipedia and add legend to description page in French, German, Spanish and Portuguese, so that the image can be used in these articles (I could take care of that topic, although Tetra Quark probably knows better most of these languages).
Displayed image width in the article would be 330px. The caption will feature a legend. The caption's text could be expanded and linking to "Classical KBOs", "Resonant KBOs" and "Plutinos", I think.

That's it. It would be an honor to participate in your efforts. Cheers, -- Rfassbind -talk 18:02, 26 January 2015 (UTC)[reply]

I lightened everything, but kept the Neptune trojans pretty dark, in line with the Uranian Trojan, Jupiter Trojans, Centaurs, and SDOs, which are also not KBOs (per Wikipediar, anyhew)
I kept the au scale, because removing it gave me the heebee-jeebees, but moved it so it wasn't wasting space
The cutoff is at 60 au, because the most distant thing being called a KBO is at 58.something au
I had nothing to do with the caption, which ain't part o' the image anyhow.
Si nous serons en d'accord d'une image finale, on peut uploader l'image au Wikimedia Commons, mais pour example images il faut les uploader ici, parce que c'est pas vaut the hassle, non? Aussi, je ne peut pas écrice des captions in German, Espagne, Portugeuse or des autre langues. So we'll just stick with the horse for le moment, eh? Wily D 10:33, 27 January 2015 (UTC)[reply]

Wow, that was fast and well done! I also think you did the right thing by keeping and amended scale and cutoff at 60 AU. I added a revised legend to your new image and reposted the original lead-image (left) again for comparison. Yes, let's do the wikicommon upload and international articles later, after we finished here. Also good to know that French won't be an issue ;)

Now, if anyone has additional suggestions, pls do so. Otherwise I'd like to address the caption, which I consider a vital part of the lead image. By using a legend some text in the original caption has become obsolete (strikethrough text). Good captions are short captions and mentioning (one of several) artifacts like in the end of the original caption is distracting to the general reader (especially when presenting a link to the Milky Way). Also the Minor Planet Center is best mentioned as a source after the legend. Questions:

Should the Centaurs be included into the legend?
Legend: what about the single Uranian Trojan?
Should the caption mention "Classical KBOs", "Resonant KBOs" and "Plutinos"?

Last thought: Maybe this is corny, but most general readers will come into contact with the Kuiper Belt article because of dwarf planet Pluto. What about indicating the position of Pluto by drawing a circle around it? I think it would be very intuitive for the general reader as he or she can easily relate to.

Once again, well done image. Cheers, -- Rfassbind -talk 16:12, 27 January 2015 (UTC)[reply]

Well, I have a script, so if it's just re-plotting the same data in a slightly different fashion, it ain't hard. Note that the orbital elements are from MPC for multi-opposition objects, but CFEPS for single opposition objects, plus CFEPS & a bunch of other sources (listed in the desc.) are used to identify resonant objects. Wily D 17:48, 27 January 2015 (UTC)[reply]

OK, very well Wily. I'll post this provisional version on the article's lead and hope to get some feedback to the open questions. Would it be correct to use a date in the caption, for example, "Known objects in the Kuiper belt [...] as of 2015"? -- Rfassbind -talk 02:50, 28 January 2015 (UTC)[reply]

Yeah, something like "Known Kuiper belt objects (or object positions?) as of 1st January 2015" would be correct, and gloss over unnecessary details, I think (which're on the image desc. page, for the truly curious). Wily D 09:27, 28 January 2015 (UTC)[reply]

I just uploaded the most recent image to wikimedia commons under your authorship and given license. See: w:File:Kuiper belt plot objects of outer solar system.png. Did I get most of it right? Cheers, Rfassbind -talk 13:54, 29 January 2015 (UTC)[reply]

Caption there should probably include colours for resonance objects, Uranian Trojan, Centaurs, even if it's not necessarily necessary here. Wily D 14:16, 29 January 2015 (UTC)[reply]

Name origin

The History section refers to an article from 1951 by Kuiper, to Fernández's 1980 article, and to a later source suggesting that the name was formed since Fernández (more or less incidently) had both the name "Kuiper" and the word "belt" in the opening paragraph. However, the Fernández article is open sourced, and the impression it gives - rightly or wrongly - is different, giving a more prominent rôle to Kuiper. In the opening paragraph, Fernándes start by mentioning the 1951 article as giving an "earlier version", but mainly refers to an article from 1974 by Kuiper. In the next paragraph, he discusses attempts for observational verification of the existence of "such a belt" - and the reader at that point would get the impression that the observation attemts were concerned with the belt suggested by Kuiper. However, the observations were made in 1968, before Kuipers new article on the subject.

Fernández may have been wrong; or may have expressed himself much too unclear, making readers misunderstand him. However, he describes the suggested belt as one proposed object, where some features were suggested ("pointed out") already in the 1951 Kuiper article, and others determined by observation and further analysis. Accepting that introduction ass correct, it would be most reasonable to name the object "the Kuiper belt". There is no hint that the 1951 suggestion concerned a no longer existing object collection; and that therefore the 1974 article would be the first one by Kuiper about a still existng belt, loosing his priority to others. The mistake, if there was one, thus was not so much in misreading Fernández article, as in trusting its content.

I think that we at least should add a reference to the article

Kuiper, G. P., 1974, Celest. Mech. 9, 321,

since this is quoted by Fernández in his introduction as if it were a principal source about the belt. Moreover, it would be nice to know whether or not that article just discusses an old and dissolved collection of objects, or a still existing one. JoergenB (talk) 20:47, 12 May 2015 (UTC)[reply]

I found a more precise reference:

G. Kuiper, On the origin of the solar system, I, Celestial Mechanics, May 1974, 9(3):321-348; DOI: 10.1007/BF01228575. JoergenB (talk) 16:17, 13 May 2015 (UTC)[reply]

I don't really understand what your point is; at the very least, this sounds like WP:SYNTH. Fernandez didn't name the Kuiper belt; Scott Tremaine did. The source I quoted was by an individual who had actually interviewed Scott Tremaine, and while he didn't directly quote Tremaine (which is why I added the word "reportedly") it does suggest that that was why Termaine chose that name. Serendi ^pod ous 16:23, 13 May 2015 (UTC)[reply]

Just call it the Belt of Comets or Comet Belt . — Preceding unsigned comment added by 85.76.16.192 (talk) 05:47, 19 June 2015 (UTC)[reply]

clumps in KBO graph?

You'll notice that in the graph of KBOs, in the lead section of the article, that the objects in it are not uniformly spread out. about 90 degrees ahead of(above) Neptune is a clump of bodies, and a smaller clump at neptune's location, followed by a sparsity of asteroids, and then another radial clump. At the approximate opposite side of the Sun from Neptune, there is also a slight decline in the amount of asteroids there. What is the cause of these observed values? exoplanetaryscience (talk) 02:40, 21 October 2015 (UTC)[reply]

Plutinos reach pericentre at +- 90 degrees (on average) from Neptune. Objects are more likely to be discovered at pericentre (as they're R^{-4} brighter). This could be what you're seeing. Of course, known KBOs are irregularly distributed because of deeper surveys that only cover portions of the sky. (And they'll sometimes choose to survey the best spots - e.g., where they're likely to find plutinos at pericentre). So that might be what you're seeing too. Wily D 09:41, 21 October 2015 (UTC)[reply]