Talk:Solar System/Archive 4

This is an archive of past discussions about Solar System. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

Archive 2

Archive 3

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Outer Solar System

The conventions I see used in the literature I've read still use "outer solar system" for the area outside of the asteroid belt, and use "trans-neptunian" for anything beyond neptune. Here's a source for you [1]. I'm going to need to see some kind of source for this, otherwise I'm assuming it's original research shaggy (talk) 20:52, 30 August 2008 (UTC)

[2], [3], [4], [5], [6], [7], [8]. All these scholarly papers refer to the Kuiper belt as the outer Solar System. Serendi ^pod ous 22:19, 30 August 2008 (UTC)

The nineplanets.org source is questionable at best as a reliable source; clearly, the area beyond Neptune is part of the outer Solar System. However, I don't see the term "mid Solar System" in a cursory look, and it is not in the source that was cited for the term, before my recent edit. Anyway, I think it's pretty clear what the article is talking about as it is, so further discussion of who uses what jargon isn't helpful. —Alex (ASHill | talk | contribs) 22:40, 30 August 2008 (UTC)

I understand things have been hectic around here the last few weeks, and I'm not trying to step on any toes here. I've just never seen any reference to the area from jupiter to neptune being called the "mid solar system" or "middle solar system". I know this isn't conclusive, but if you search on google, you get ~470 results for "middle solar system" and ~2000 (mostly wikipedia and mirrors) for "mid solar system", while you get ~182,000 for "outer solar system". In any case, the trans-neptunian region is a subregion of the outer solar system, so we're both correct here. shaggy (talk) 23:05, 30 August 2008 (UTC)

I think we agree; the article no longer uses the term "mid solar system". (It does use the adjective "middle".) —Alex (ASHill | talk | contribs) 23:12, 30 August 2008 (UTC)

Looks good to me. Thanks for cleaning up the things I missed! shaggy (talk) 23:15, 30 August 2008 (UTC)

Gap in Kuiper Belt objects?

The image of the Kuiper Belt objects seems to show a fairly pronounced gap at the bottom of the image. Does anyone know what causes that? --Doradus (talk) 20:52, 31 August 2008 (UTC)

The Milky Way. I asked that question too. :-) Serendi ^pod ous 20:55, 31 August 2008 (UTC)

Cool! Got a reference? --Doradus (talk) 23:14, 1 September 2008 (UTC)

No. I was told by a scientist online. Serendi ^pod ous 16:58, 3 September 2008 (UTC)

The image description in Commons says In the Kuiper Belt, radial "Spokes" of higher density, or gaps in particular directions are due to observational bias (i.e. where objects were searched for), rather than any real physical structure. Looie496 (talk) 17:29, 3 September 2008 (UTC)

Here's a ref Serendi ^pod ous 17:31, 3 September 2008 (UTC)

Cool; but in a quick scan I didn't see anything there about angular distribution. Also let me point out that the Milky Way story doesn't actually make sense: all these objects are orbiting the Sun, so there is no way a gap could stay aligned with the Milky Way, or even persist longer than 100 years or so at the very most. Looie496 (talk) 21:59, 3 September 2008 (UTC)

It's an observational selection effect (or bias, which the article does mention, from my quick scan). Kuiper belt objects are very hard to pick out in the Milky Way. Extragalactic folks call the Milky Way the zone of avoidance for related reasons. —Alex (ASHill | talk | contribs) 22:15, 3 September 2008 (UTC)

Okay, I get it now, thanks. Milky Way-related bias, not Milky Way-related distribution. Looie496 (talk) 23:15, 3 September 2008 (UTC)

Awww, that's not as cool as I thought it was. --19:07, 6 September 2008 (UTC)

Yeah, I know what you mean. When I asked what caused the hole, I asked whether Galactus had taken a bite out of it. When someone explained the real cause, another poster complained that the Galactus hypothesis didn't get more airtime. :-) Serendi ^pod ous 19:24, 6 September 2008 (UTC)

Is it time to split?

This article is now almost 100 k long. I've been wondering whether or not it's time to break off the "Discovery and Exploration" section into its own article. The Formation and evolution section could also be trimmed, since much of its material is already in its own article. Serendi ^pod ous 08:49, 11 September 2008 (UTC)

I agree. Both the Sun and formation and evolution sections in this article are relatively lengthy, even though they're summarizing featured articles, so I think both of those could probably be trimmed. I also agree that Discovery and Exploration could stand on its own. Another thing that might help is finding a more appropriate place for "Definition of planet" (another summary of a featured article, although this one is appropriately short). Having that up front, I think, makes the article read choppily and perhaps feel even longer than it is.

I'll try to get to work on this later today. —Alex (ASHill | talk | contribs) 15:30, 11 September 2008 (UTC)

I didn't get to it until now, but I considerably shortened the summary of Formation and Evolution. The article is now down to 75 k.

The abundance of isotopes table doesn't quite belong in formation and evolution; I think it may be worth writing a paragraph or so of discussion further up and moving the table near that new paragraph. —Alex (ASHill | talk | contribs) 01:30, 22 September 2008 (UTC)

heliosphere extent reword suggestion

Sorry serendipity, you're right I hadn't read the rest of the article !... The scattered disc didn't sound an official term, reading from start and the grammar confused me: currently: 'known as the heliosphere, which extends out to around the scattered disc', still doesn't; but can't think right now of how to put it aptly, maybe an brief explanation of scattered disc, the actual AU of the heliosphere would help and changing 'out to around' -> 'past' would help? LeeVJ (talk) 22:50, 14 September 2008 (UTC)

I've had a go at rewording it. Serendi ^pod ous 10:03, 15 September 2008 (UTC)

thankyou, serendipodous :) LeeVJ (talk) 22:14, 15 September 2008 (UTC)

dy —Preceding unsigned comment added by 72.219.233.180 (talk) 23:26, 17 September 2008 (UTC)

Haumea

the IAU named a fifth dwarf planet: http://www.iau.org/public_press/news/release/iau0807/ I don't add to wikipedia on principle, but maybe someone else will. —Preceding unsigned comment added by 141.30.227.33 (talk) 19:07, 20 September 2008 (UTC)

It's already been added. And I'm not sure what not adding to Wikipedia accomplishes. Serendi ^pod ous 19:21, 20 September 2008 (UTC)

Terminology section

I do not like the new terminology section that was just added. I don't think defining terms up front is helpful in this article; instead, it's better to explain unclear terms when they appear, in context, as I think was done rather well in this recent version. Wikilinks allow readers to easily get a more full description. A separate terminology section up front disturbs the flow of the narrative for readers reading the article straight through and isn't helpful for readers who are only reading a section of the article at a time.

I won't revert for now, pending discussion. —Alex (ASHill | talk | contribs) 15:54, 21 September 2008 (UTC)

I was assuming that the paragraph would only be the first in a new terminology section. If that paragraph is going to be the only paragraph in that section, then there's not much point in having it, since a terminology section shouldn't just define one thing. Serendi ^pod ous 15:57, 21 September 2008 (UTC)

I don't like it even if there is more coming, for the reasons described above. If it's just defining rock, ice, and gas, it's particularly unnecessary. —Alex (ASHill | talk | contribs) 16:00, 21 September 2008 (UTC)

Furthermore, in creating the terminology section, the discussion of where rocky, gaseous, and icy materials are found was removed from the Layout and Structure section, where it more logically belongs. This is another reason why keeping the explanations of terms in context works better. —Alex (ASHill | talk | contribs) 16:11, 21 September 2008 (UTC)

The changes have been reverted, as it is yet more of Harry's unilateral efforts to rewrite this article in what he perceives as a "simplified" version. While discussion is essential, this is a featured article, and text such as "Here we define those possibly confusing terms used in the rest of the article" does not fit. He has been warned accordingly. --Ckatz^chat _spy 20:52, 21 September 2008 (UTC)

tiny mistake

Under Heliopause it says ... 80 100 AU from the Sun ... but should probably read 80-100 AU? —Preceding unsigned comment added by 90.195.11.161 (talk) 15:25, 29 September 2008 (UTC)

Yeah, you're right; well spotted :-) (probably my own mark-up illiteracy) Serendi ^pod ous 15:31, 29 September 2008 (UTC)

Sun gets hotter to burn more fuel??

"it gets hotter in order to be able to burn the remaining fuel"

I'm sorry, but unless you can show me that the sun is alive in a sense that most people will agree with, I must ask that someone rephrase this, preferably by explaining the real reason for the sun to get hotter, namely the gravitational collapse due to the reduced outward pressure from hydrogen fusion.

--Scott McNay (talk) 05:36, 7 October 2008 (UTC)

I think the recent edits by User:Serendipodous have addressed your concern. —Alex (ASHill | talk | contribs) 16:39, 7 October 2008 (UTC)

NPOV Dispute

The purpose of wikipedia according to the NPOV articles is for the articles to maintain as close as NPOV as possible. "Evolution" is not NPOV as it endorses a biased hypothesis on how the universe was formed and is progressing and has not been concretely proven beyond a reasonable doubt. Even evolutionary biologist disagree on the origins and "evolution" of life and the universe. I am not suggesting to change the terms to Creationist (equally POV), but to put the terms into such terminology that would bring the article into NPOV rather than leave it in POV. --Coviepresb1647 (talk) 01:22, 15 November 2008 (UTC)

You're confusing Stellar evolution with Evolution, kinda like Kent Hovind.* There is a big difference:

Evolution: Theory, advanced by Charles Darwin which creationists dispute and isn't part of this article.
Stellar evolution: The cycles stars evolve through, for example the Sun which will evolve into a red giant as its hydrogen is exhausted and begins fusing helium. From there it's expected to become a white dwarf.

Also in order to actually be a WP:NPOV violation, reliable sources which back your assertion would be necessary.

* Hovind's theory isn't a reliable source for an article about astronomy. Anynobody(?) 02:48, 15 November 2008 (UTC)

"Evolution" simply means "change over time"; it isn't unique to biology. And anyway, Darwin's theory isn't "evolution"; it's "biological evolution via natural selection." The "natural selection" bit is arguably the most important part. Creationists have taken the word "evolution" and applied it to every aspect of science that doesn't agree with a literal reading of the first eleven chapters of Genesis, which basically means all of science. But just because a bunch of morons have decided that science itself is evil doesn't mean we should accommodate them. Serendi ^pod ous 08:07, 15 November 2008 (UTC)

You are confusing what Creationism actually represents and asserts. As serendipitous partially pointed out, Creationists assert that God created the Universe from Genesis 1 and how the Universe will end (Revelation), which not only includes biological life but also the planets and all other things in the Universe whether biological or non-biological. Henry Morris and Hugh Ross (who disagree with Hovind) correctly sums what Creationism believes. Creationist do not necessarily espouse a literal reading or interpretation of the Bible. As the Wikipedia Creationism points out and Serendipitous errs, there are those Creationists that believe in Theistic Evolution, and the Catholic Church in its Catechism and Encyclicals do not believe that Evolution and the Bible are necessarily incompatible. Hence, Creationists do not simply apply "evolution" to those scientific theories that may appear or be incompatible with the Bible. Indeed, those who regard science as sinful are indeed morons since science helps us to understand the Universe (what some Creationists call God's General Revelation as opposed what they call Particular Revelation, the Bible). Thank goodness that not even a significant minority of Creationists think that science is sinful. --Coviepresb1647 (talk) 01:57, 19 November 2008 (UTC)

The NPOV dispute/discussion is not resolved. Per Wiki's NPOV guidelines, the tag indicates questioning NPOV regardless if it is actuall NPOV or not or if an editor is confused (which in this case, he is not). Per the NPOV tag, it is not to be removed until the dispute discussion is resolved. Hence, I replaced the tag. --Coviepresb1647 (talk) 01:48, 19 November 2008 (UTC)

The word progress, that you inserted instead of evolution, is meaningless in this context, because it implies improvement over time, not just change. Do you have any sources that state the Solar System has actually become a better place to live? This assertion is highly subjective and therefore is a violation of WP:NPOV itself. Meanwhile, if Solar System can progress, then it can degrade too. :-) Ruslik (talk) 07:51, 19 November 2008 (UTC)

You can see this book (Evolution of the Airliner), which also has nothing to do with biological evolution. The word evolution is widely used in both scientific and mainstream publications meaning change over time. Ruslik (talk) 08:25, 19 November 2008 (UTC)

Very good points. At the time, I was pressed for time. Indeed, I readily concede that "progress" is not a good word to use since being an engineer, I am well aquainted with the 2nd Law of Thermodynamics, which indicates the Universe going from higher order to lower order. The one reason for initiating this discussion/dispute is to received suggestions for words if there are any suggestions. Indeed, the article should avoid the Evolution POV and the Creationist POV. Thanks for being civil in your response! :)

The use of the terminology is consistent with astronomical and cosmological usage. As noted above "evolution" here is simply referring to the development as based on astronomical evidence. It has nothing to do with biological evolution which seems to be the misunderstanding at the base of your comments. The article doesn't need to be "held hostage" to one person's POV based on their misunderstanding. Provide some sources supporting your view and suggest alternative wording based on those sources - and then we can consider your view. Further your comment concretely proven beyond a reasonable doubt... shows a basic ignorance of science. Vsmith (talk) 02:35, 19 November 2008 (UTC)

"Further your comment concretely proven beyond a reasonable doubt... shows a basic ignorance of science." Your insulting comment is not true.--Coviepresb1647 (talk) 23:37, 19 November 2008 (UTC)

The comments and actions especially by the more experienced editors will not receive a reply apart from this. There is NO misunderstanding, confusion, or ignorance (which remains NOT proven beyond a reasonable doubt) on my part. I do not intend to further contribute to a discussion where editors break NPOV rules by prematurely removing tags BEFORE the dispute/discussion resolves or where editors resort to prejudical or insulting comments on the knowledge or mistaken ignorance/misunderstanding of another editor. The editors that are excepted in this reply are Ruslik0 and JoshuaZ as they have remained civil and sensical and have not resorted to prejudicial replies. You all have my agreement to close this discussion, but I still do not concede on that point (misunderstanding or ignorance) or the point of usage of "evolution". I will return at some point in the future either to continue the discussion by maintain what I have said or changing my position. As I am relatively new, I will be in discussion with a more experienced adminstrator-editor (3rd party to this particular discussion) about general NPOV and other wiki things. --Coviepresb1647 (talk) 23:37, 19 November 2008 (UTC)

However VSmith may have phrased his reply, he was nonetheless right. Nothing can be conclusively proven in science, only disproven. Evolution is a scientific theory precisely because it can be disproven. If one were to, say, find an animal without DNA, or a fossilized dog in pre-Cambrian rock strata, evolution would be disproven overnight. Creationism, on the other hand, cannot be disproven. There is no way to show that God did not create the universe 13 billion years ago, 13 thousand years ago, or even 13 seconds ago, because God, by definition, can do anything, and any evidence you might supply to the contrary can be explained because God put it there. Because creationism cannot be disproven, it cannot be considered science, and so cannot be used within a scientific context. Serendi ^pod ous 09:35, 20 November 2008 (UTC)

::You and VSmith are not right. You both misunderstand and twist Creationism and God and whether Creationism can or cannot be disproven. There is no way to prove that Creationim is myth or that theories in science can only be disproven (hence, your statement in violation of the Scientific Method). --Coviepresb1647 (talk) 14:25, 20 November 2008 (UTC)

Evolution meaning stellar evolution is the accepted term. Any creationist concerns trigger massive undue weight issues. There is another argument that using the term "evolution" in this context might be confusing because it might further the common misunderstanding that stellar evolution and other forms of "evolution" are part of some package. But I don't see that as a compelling reason to not use the proper terminology. JoshuaZ (talk) 00:44, 20 November 2008 (UTC)

I thought I'd also point out that Coviepresb1647 is looking for "concretely proven beyond a reasonable doubt", which is a requirement of criminal law, not a requirement of science. Science strives only to develop falsifiable theories with predictive abilities that agree with available evidence. --Doradus (talk) 13:49, 20 November 2008 (UTC)

No, I am not necessarily looking for that. ~~Another case of prejudicial commenting.~~ --Coviepresb1647 (talk) 14:25, 20 November 2008 (UTC)

Undue weight

Coviepresb1647, I'm an experienced admin and editor; I understand you wanted to talk with somebody like that. Thank you for your interest in this article and other science articles. However, I think you need more information about the WP:NPOV policy than you currently seem to have (understandably, as you're a fairly new user). You are perhaps only aware of an incomplete version of the policy. Please read the "Undue weight" section carefully, as it is highly relevant to your arguments. I quote a few sentences:

We should not attempt to represent a dispute as if a view held by a small minority deserved as much attention as a majority view... To give undue weight to a significant-minority view, or to include a tiny-minority view, might be misleading as to the shape of the dispute. Wikipedia aims to present competing views in proportion to their representation in reliable sources on the subject.

I hope that helps. Please don't remove the word "evolution" from Solar System or other science articles, Coviepresb, and don't add the NPOV tag to articles or sections for containing the term. Such actions amount to giving the creationist view of evolution equal weight with the scientific view. That's a violation of the NPOV policy's undue weight provision, and is not a case for "dispute resolution." In other words, any tags like that should and will be removed. Bishonen | talk 12:28, 20 November 2008 (UTC).

Thanks for letting me know on my talk page, but I strongly disagree with you. I am convinced that it is another prejudicial comment and hence, unjust request. I am already speaking with a more experienced admin-editor and ~~may be~~ ~~am not~~ am not interested in talking with you at this point. ~~I am disregarding your prejudicial request and comment since~~You are making an unsubstantiated equivocation between the "scientific view" and "evolution". I am already aquainted with Undue Weight. Indeed minority views that are a "tiny-minority" should not be represented. However, Creationism is not a "tiny-minority", "small minority", or an "extremely small (or vastly limited) minority" as I have given prominent adherents as does Wikipedia's Creationism article. By the principle of NPOV and Undue Weight, if Creationism was held by a "tiny-minority", it would not be in Wikipedia at all. Hence, Creationism does need to be represented in the science articles although obviously not with as much coverage as the Evolution view. Indeed, Creationist terms are unwarranted, but "life cycle", "progress", "change", and other equivalent terms are not Creationist terms but more neutral terms. Indeed "progress" is more reflective of evolution and slightly disagrees with Creationism. Removing "evolution" and substituting it with a slightly more neutral term does not give undue weight since both the Evolution view and Creationist view are represented with fair and due weight. Therefore, my questioning the use of "evolution", making the initial edits, and placing the NPOV tag is valid per NPOV and Undue Weight. ~~Simply removing a term does not give Undue weight or POV.~~ In a valid NPOV case such as this case, removing a tag before the resolution of a discussion/dispute is also a violation of NPOV since the purpose of a discussion/dispute is to actually determine whether or not it is in NPOV or POV, not that it IS in POV. Hence, the tag should remain until the dispute/discussion is resolved as NPOV (and the tag) says and should not be removed until a consensus is formed and therefore the discussion/dispute resolved. Your comment and request has no basis, and you are mistaken and then proceed to give the request on your own mistaken understanding. Your request is unecessarily redundant and late since for several days now, I have ceased and will keep ceasing related edits and tags. However, I will nevertheless keep ceasing, not to concede your erroneous point but to have time to talk with other admin-editor, until my discussion with the other admin-editor is done. Until you are willing to constructively criticise me and to consider the greater picture before issuing justice unlike your comment and request here, please do not talk to me as I do not desire your help nor am I willing to listen to further prejudicial statements from you. --Coviepresb1647 (talk) 14:25, 20 November 2008 (UTC)

However, Creationism is not a "tiny-minority", "small minority", or an "extremely small (or vastly limited) minority" as I have given prominent adherents as does Wikipedia's Creationism article. The creationism article quote says that one count gives 700 out of 480,000 earth and life sciences who support creationism. Tiny minority. Saros136 (talk) 11:14, 22 November 2008 (UTC)

My further participation

17:20 UTC, 20/11/08 is the end of my participation in this discussion. I will no longer be reading or comment here except to possibly reverse my position (after discussion with the more experienced admin-editor) if I am mistaken. At this point, I do not concede. --Coviepresb1647 (talk) 14:25, 20 November 2008 (UTC)

I do appreciate Serendipodus apologizing for his/her offending me (specifically his "moron" comment). --Coviepresb1647 (talk) 14:38, 20 November 2008 (UTC)

With all due respect the minute you said, "biased hypothesis" and "evolution of life", you made your POV quite clear. The evolution of the Universe is not a biological issue since the only biology we currently know is here on Earth. -- Kheider (talk) 16:43, 20 November 2008 (UTC)

Point taken but not conceded (yet) on my part.--Coviepresb1647 (talk) 17:14, 20 November 2008 (UTC)

I'm a late-comer to the discussion here, but it seems the issue is the use of one word rather than the meaning of that word? As someone pointed out earlier, the word *is* applicable. The solar system *has* evolved (changed). As a believer in Darwinian evolution (which is not the issue here) I'm still happy to use the word "creation" when it is applicable, say for a batch of cookies. And the universe *was* created, whether there was intelligent thought involved or not. Maybe the section heading could be changed from "Formation and evolution" to "Creation and evolution" if you're so worried about NPOV.

Feyrauth (talk) 15:08, 2 December 2008 (UTC)

Oort cloud size

It seems to be a small discrepancy, perhaps just a difference in wording, regarding the size of the Oort cloud. This article, in section Oort_cloud says:

The hypothetical Oort cloud is a great mass of up to a trillion icy objects that is believed to be the source for all long-period comets and to surround the Solar System at roughly 50,000 AU (around 1 light-year (LY)), and possibly to as far as 100,000 AU (1.87 LY).

But a little below, in section Boundaries says:

The outer extent of the Oort cloud, by contrast, may not extend farther than 50,000 AU.[67]

Take into account that the main article on Oort cloud states:

The Oort cloud is thought to occupy a vast space from somewhere between 2000 and 5000 AU[7] to as far as 50 000 AU[1] from the Sun. Some estimates place the outer edge at between 100 000 and 200 000 AU.[7]

And also that the article on Light-year states:

1.6×100 ly The Oort cloud is approximately two light-years in diameter. Its inner boundary is speculated to be at 50,000 AU, with its outer edge at 100,000 AU

Given that I'm just a reader and I don't have enough knowledge on the topic, I didn't modified the article. Could some experienced editor fix this, and unify the point of view in the sections? (and also in the related articles, if necessary) Pmronchi (talk) 14:05, 30 November 2008 (UTC)

The problem is that we're dealing with something that may or may not exist. We're pretty sure it does, because the evidence suggests it's there, but any guesses as to its structure or how big it is have to be based on some pretty secondhand information. I suppose I can reword the boundaries section a bit. Serendi ^pod ous 14:24, 30 November 2008 (UTC)

Haumea on the pic?

hi i'v noticed Haumea isn't included on the pic at the top of the page i don't know how to fix that or change the pic to include it, could someone please help with this thanks. Hawkania (talk) 18:06, 7 December 2008 (UTC)

should exoplanets be included?

i like the article, but i just think exoplanets should be included as many are fans of them, and they are quite interesting, i just want to make this article better. Lizardsarecool (talk) 19:34, 6 January 2009 (UTC)lizardsarecool

Exoplanets are not members of the Solar System. Ruslik (talk) 20:05, 6 January 2009 (UTC)

Sadly, we also know almost nothing about exoplanets. Even the masses (and volumes) are generally assumptions, and the composition is very poorly known. Since we can not yet detect smaller bodies in these systems, these planetary systems are very poorly known. One of the he best ways to expand the solar system article is to work on the moons, asteroids, or even create an article like Gertrude (crater). -- Kheider (talk) 20:58, 6 January 2009 (UTC)

#of planets

there are 200 planets in the solar system —Preceding unsigned comment added by 24.2.222.141 (talk) 19:12, 21 January 2009 (UTC)

Got a source for that? Serendi ^pod ous 00:38, 22 January 2009 (UTC)

citation seems unrelated

It is believed that the Sun's position on the main sequence puts it in the "prime of life" for a star, in that it has not yet exhausted its store of hydrogen for nuclear fusion. The Sun is growing brighter; early in its history it was 75 percent as bright as it is today.^[1]

The above data and following sentence seem to have no correlation. To answer your question Serendipodous, yes I read it. That is why I removed it. I have taken the liberty of placing it below. Kindly explain how that relates to above sentence. Garycompugeek (talk) 20:24, 23 January 2009 (UTC)

The possible consequences of very high carbon dioxide concentrations in the earth's early atmosphere have been investigated with a radiative-convective climate model. The early atmosphere would apparently have been stable against the onset of a runaway greenhouse (that is, the complete evaporation of the oceans) for carbon dioxide pressures up to at least 100 bars. A 10- to 20-bar carbon dioxide atmosphere, such as may have existed during the first several hundred million years of the earth's history, would have had a surface temperature of approximately 85 degrees to 110 degrees C. The early stratosphere should have been dry, thereby precluding the possibility of an oxygenic prebiotic atmosphere caused by photodissociation of water vapor followed by escape of hydrogen to space. Earth's present atmosphere also appears to be stable against a carbon dioxide-induced runaway greenhouse.

I have removed reference pending discussion. Garycompugeek (talk) 14:56, 24 January 2009 (UTC)

I don't have access to the entire document, since Nature is a subscription-only service. When I asked if you had read it, I meant the whole thing, not just the abstract. All the paper has to do is mention the initial brightness of the Sun; it doesn't have to make it its raison d'etre. Since the document involves greenhouse effects early in Earth's history, it seems highly unlikely that it would not mention the level of insolation at the time. Given that I cannot read the article in its entirety, I prefer to assume good faith on the part of its original contributor until such time as I can verify it totally. Serendi ^pod ous 20:57, 24 January 2009 (UTC)

http://en.wikipedia.org/w/index.php?title=Solar_System&diff=66137236&oldid=66136694 and http://en.wikipedia.org/w/index.php?title=Solar_System&diff=59997754&oldid=59994509 —Preceding unsigned comment added by 24.10.70.180 (talk) 21:50, 24 January 2009 (UTC)

Serendipodousous, the IP seems to be implicating you as the original contributor. Plus a source that we cannot verify to its conclusion is no source at all. Garycompugeek (talk) 22:16, 24 January 2009 (UTC)

Hm. Well, if it was me, I must have got the original quote from the Google summation. Still, I can recheck it at the British Library on Monday. Serendi ^pod ous 00:41, 25 January 2009 (UTC)

There. I added a new citation. Serendi ^pod ous 13:18, 26 January 2009 (UTC)

Excellent. I never doubted the data for a minute, just needed a better citation. This article is superb thanks to you and everyone else who contributed attention. Garycompugeek (talk) 15:56, 26 January 2009 (UTC)

Thank you. Sorry I got touchy. I do that occasionally. It happens when you spend enough time around here. Serendi ^pod ous 17:06, 26 January 2009 (UTC)

Hey Serendipodous the new ref is great... You don't have to spend time scanning the ref since it is mentioned right in the introduction. But since they suspect life started on Earth 3.8 Billion years ago, I still want to know if Venus was more biologically active than Earth ~2 Billion years ago. :-) Exogenesis seems to suggest that life could have started on Mars and made it to Earth, but poor Venus never seems to get a mention as a candidate even though it may have been the most habitable planet 2 billion years ago. -- Kheider (talk) 17:33, 26 January 2009 (UTC)

The Solar System

Shouldn't this article really be called "The Solar System", because there isn't any other solar system, is there? --Ediug (talk) 01:18, 7 February 2009 (UTC)

You are correct in that there is only the one "Solar System", namely our star system. However, the "t" is not capitalized (except of course at the start of a sentence), and even if it was, Wikipedia articles generally do not incorporate "the" (with limited exceptions.) Hope this helps. --Ckatz^chat _spy 05:40, 7 February 2009 (UTC)

It is okay for me! :) --Ediug (talk) 09:09, 7 February 2009 (UTC)

Proposing chart

This article needs a chart (like a spreadsheet) of information about the planets, dwarf planets, and moons. Radius, Radius of orbit, mass, gravity, and a few other things should be included. Any objections, offers to make it, or questions? Williamrmck (talk) 16:31, 26 February 2009 (UTC)

There is one: List of Solar System objects in hydrostatic equilibrium Serendi ^pod ous 17:07, 26 February 2009 (UTC)

I added a template link to the page. Serendi ^pod ous 17:21, 26 February 2009 (UTC)

S., sorry, but I've had to remove the template and restore the links. Unfortunately, the layout was affected too much by the template, and I don't see a way around it. Thianks for trying, though. --Ckatz^chat _spy 09:07, 27 February 2009 (UTC)

That chart also has Pluto as a planet, and other smaller objects as dwarf planets, and some have not been defined as dwarf planets yet. Thanks for trying to help. Williamrmck (talk) 10:50, 27 February 2009 (UTC)

It has Pluto as a dwarf planet, not a planet, and a number of objects which are almost certainly dwarf planets but have not yet been formally classified. Serendi ^pod ous 11:16, 27 February 2009 (UTC)

You're right, sorry, I'm a noob. But why was the link removed, more specifically? I can't find it and Ckatz says he removed it, so I'm assuming you put it on, Serendipodous. I couldn't find it in the past histories of the page, but I didn't want to look through every one of them. Williamrmck (talk) 17:27, 27 February 2009 (UTC)

It is at the bottom of the page, under the title, "Physical and orbital data on the Sun, planets, dwarf planets, and moons." Serendi ^pod ous 18:22, 27 February 2009 (UTC)

Hmm, it's a little bit out of the way, not many people will stumble across it, but it's still great that it's in the article. Thanks for helping! Williamrmck (talk) 13:38, 1 March 2009 (UTC)

Solar wind speed

Heliopause Solar wind speed should be 400 km/h not 40,000 km/h --Suslik666 (talk) 21:39, 26 February 2009 (UTC)

Source? Actually, it's 40,000 kilometers per second. Serendi ^pod ous 21:48, 26 February 2009 (UTC)

Sorry about the "km/h". I ment "km/s". I looked many different articles about solar wind. As a result i became very confused. I still am very confused, because you just told me that it is 40000 km/s. Now lets look Reference 56. I dont understand most of that "thing". There is a graph where one can read v(r) [ms^(-1)] 4*10^(-7) ms^(-1) at 100 AU which really is 40000 km/s. Now There is also a sentence in there "Assuming a solar wind proton density of about 5 [cm^(−3)] and a solar wind speed in the order of 4*10^7 [cm*s^(−1)] photoionisation is a 10–15% effect with respect to the charge exchange and the above approximation of a solar-distance-independent, spectral EUV-flux only plays a minor role." [cm] in text, [m] on graph! 4*10^7 [cm s^(−1)]= 400000 m/s = 400 km/s. There is another sentence in that text. "The radially symmetric outflow of the unperturbed solar wind flow is described with a bulk velocity of 400 km/s, a proton temperature of 105 K and a proton density of 5 cm^(−3) at the orbit of the earth." Maybe these things got mixed up and as a result of this 40000 km/s was entered instead of 400 km/s. There is another way of looking at this. My english is weak. I dont understand that reference page, im not that good in physics. Those things there could be 100% correct. After googling "solar wind speed" i found out that the speed of solar wind should be in the range of 300-800 km/s. Average speed would be ~400 km/s. Speed of light is ~300000 km/s. 40000 km/s would seem a bit too high? What part of this i cant understand? I hope someone would explain it to me. Suslik666 (talk) 01:57, 27 February 2009 (UTC)

I think you may be right. I'll swap it. Serendi ^pod ous 10:16, 27 February 2009 (UTC)

Solar_wind#Emission mentions 400 km/s (at the Earth orbit) to 750 km/s Ref: On the sources of fast and slow solar wind -- Kheider (talk) 16:56, 27 February 2009 (UTC)

Aren't There STILL Nine Planets?

There has been lots of "unofficial" talk about whether or not the Moon, supposedly Earth's "satellite", is actually a major planet in its own right. When you read the present definition of planet, recently changed by the International Astronomical Union (IAU), you find that this new definition does NOT exclude our Moon.

So I would like to propose a discussion on this topic. Isaac Asimov, before he died, wrote science books on the Moon, and he came up with several reasons why the Moon ought to be thought of as more than just a satellite of Earth. Asimov proved (well, to me anyway) that the Moon is a full-fledged planet in its own right.

You can read more about this fairly controversial subject at the "official" website of... The Planet Moon. This website is dedicated to Isaac Asimov.

Whether or not you read the above website, your opinion about this topic would be very interesting to hear. So let's us talk about whether or not the "Solar System" still has NINE planets, or just eight.

Paine Ellsworth (talk) 13:22, 1 March 2009 (UTC)

A Wikipedia talk page is NOT a place for discussion, please go to another website if you want to talk about whether the moon is a planet or not. Williamrmck (talk) 13:35, 1 March 2009 (UTC)

A Wikipedia talk page is not a place for a discussion about whether or not the moon is a planet. But it is a place for a discussion of how we should edit Wikipedia's articles for their information about whether or not the moon is a planet. - Shaheenjim (talk) 14:41, 1 March 2009 (UTC)

But it's not Wikipedia's job to advocate alternative hypotheses, especially hypotheses advocated by people pushing their own websites. And anyway, that particular controversy is discussed perfectly adequately over at Definition of planet. Serendi ^pod ous 14:59, 1 March 2009 (UTC)

Advocate hypotheses, no. Educate people about hypotheses, yes. As evidenced by the fact that, as you said, Wikipedia already covers it on another article. - Shaheenjim (talk) 15:25, 1 March 2009 (UTC)

To echo Serendipodous, these pages are not here to debate alternate theories. No disrespect to Paine, but the web site represents his/her personal theories, and has not demonstrated that it meets the requirements of WP:RS, WP:N, or WP:V. We cannot use it as a reference for changes to text based on established verifiable material. (As such, I have had to revert the changes to Moon.) --Ckatz^chat _spy 20:36, 1 March 2009 (UTC)

I do remember saying that the Moon-as-planet issue is controversial. However, I did not ask the question to become embroiled in any kind of debate over validity. I am asking, "Aren't there still nine planets?" because by the new definition, that can be found on the Definition of planet page, the Moon is clearly NOT excluded. So by definition, then, the IAU has included the Moon as a planet. And this fact should be clearly noted in ANY appropriate Wiki article on the Moon. --Paine (talk) 23:13, 1 March 2009 (UTC)

And now I feel responsible for other issues revealed above, to wit...

1) Williamrmck admonishes that a talk page is NOT a place for discussion? A "TALK" page is NOT a place for "DISCUSSION"? Please, someone! What is wrong with this picture? Never mind, because I do get the point. I did not ask this question specifically to discuss whether or not the Moon is a planet. I asked the question because when I read the presently accepted IAU definition of "planet", I see nothing in it that excludes the Moon. And I want to discuss whether or not it is appropriate to include this FACT on any Wikipedia page that is Moon-informative.

A talk page is for discussing how to improve articles, not for discussing issues raised by articles. Serendi ^pod ous 09:10, 2 March 2009 (UTC)

2) Serendi ^pod ous, I'm not asking Wikipedia to advocate or not advocate ANY hypothesis. No encyclopedia should do that. What I am asking is for Wikipedia to bring to attention the obvious fact that the IAU definition of "planet" does NOT exclude the Moon. As for pushing my own website, I am sorry if that's what you think. I did not want to discuss here whether or not the Moon is a planet, so I opened that discussion topic on my talk page, and I included the reference so people would be informed of Asimov's and my reasons for considering the Moon to be a planet. I fully recognize that this talk page is supposed to be about appropriate content only, such as noting that the IAU definition of a planet does not exclude the Moon.

Not true. Resolution 5a section 2d specifically excludes satellites from consideration. And for now, despite the opinions of Dr. Asimov, who is given ample voice over at Definition of planet, the Moon is still a satellite. Serendi ^pod ous 09:10, 2 March 2009 (UTC)

3) Ckatz^chat _spy, in case you hadn't gotten back to my talk page yet, I want you to know that I have altered the links to exclude any bad references. As a Wikinewbie, I will try to get myself up to snuff as quickly as possible. Thank you for your kind post to my talk page explaining what I had done wrong. As for removing my site as a reference on the Moon page, don't give it another thought. At first, I felt rather honored, however it did seem a little unusual. At any rate, thank you for your help and comments. And thank you all! --Paine (talk) 01:47, 2 March 2009 (UTC)

My (Kheider's) observations

It is not really a NPOV since it reads biased (IMHO).
Phobos and Deimos are considered captured asteroids, so the usage of "true satellite" is iffy. Nereid has been heavily perturbed by the capture of Triton.
Does not cover the very important Giant impact hypothesis.
The moon did a bad job of dominating the Earth (So only 8 planets under the current IAU definition; the moon would be at best a dwarf planet).

But I do agree about one thing, if they bring Pluto back as a planet I hope the seven moons larger than Pluto get fair treatment. -- Kheider (talk) 02:13, 2 March 2009 (UTC)

(re: 1) On this point we agree. I intend to improve it over time. ^.`^) Paine ^diss`cuss (^^`. 14:45, 23 April 2009 (UTC)

(re: 2) Actually, Phobos and Deimos both have near-circular orbits almost precisely on Mars' equatorial plane. This pretty much shatters the "captured asteroid" hypothesis. They are far more likely to have been formed along with Mars from the beginning, so they must be "true satellites" under Asimov's definition. ^.`^) Paine ^diss`cuss (^^`. 02:25, 23 April 2009 (UTC)

I am glad your opinion shatters professional opinions. ESA (and others) still think the moons might be a result of capture or a large surface impact on Mars. It is always dangerous to make assumptions. -- Kheider (talk) 04:42, 23 April 2009 (UTC)

Agreed. And while there are astronomers who favor the captured asteroid hypothesis, none of them like the odds of any planet capturing objects that "fall" into near-circular orbits almost precisely on the planet's equatorial plane. It is in fact quite a stretchy assumption to call Phobos and Deimos captured asteroids. Astronomers as a rule will acknowledge that there is much more to the Solar System than we as yet know. ^.`^) Paine ^diss`cuss (^^`. 05:37, 23 April 2009 (UTC)

No one claims that anything fell into a circler orbit. Circler orbits take time to evolve. *If* there was ever a debris field around Mars it would have been easier to make the orbits of Phobos and Deimos less eccentric via mutual collisions among numerous moonlets which tend to dampen out both inclination to the equator and eccentricity. -- Kheider (talk) 20:47, 23 April 2009 (UTC)

(re: 3) I'd like to mention in passing that, while the GIH is "very important" and is the most widely accepted explanation for the origin of the Moon, and while computer models do yield its possibility, those models also show the high odds against due to the near-circular orbit of the Moon and its orbit's very near proximity to the ecliptic. ^.`^) Paine ^diss`cuss (^^`. 14:41, 23 April 2009 (UTC)

(re: 4) This is at best a subjective judgement. The Earth and Moon have dominated each other quite well, actually. And if you'll compare the definitions of planet and dwarf planet, you'll find that the Moon fits the planet definition. ^.`^) Paine ^diss`cuss (^^`. 14:41, 23 April 2009 (UTC)

You are giving the moon too much credit as an object that formed in orbit around the Earth. The moon is currently inclined 6.5° to the invariable plane of the solar system. (The Earth is inclined 1.57°) The moon has a mass of 7E22 and Earth has a mass of 6E24, thus the moon is basically submissive to the Earth. The moon is not yet tidally locked to the Earth, but it has been working towards it for 4 billion years. Triton is likely a captured dwarf planet and it has a circler orbit. The gas giants migrated (Nice model) and they have basically circler orbits. -- Kheider (talk) 20:47, 23 April 2009 (UTC)

You misunderstand – I did not say that the Moon formed in orbit around the Earth. I said that the Earth and Moon are both in a binary-planet orbit around the Sun. The Earth/Moon barycenter orbits the Sun in an elliptical path, while the Earth and Moon orbit the Sun in "scalloped" patterns. This fact leads to the possibility that the Moon formed in its own orbit around the Sun that was very near Earth's orbit. At some point very early in the formation of the Solar System, the slower object is overtaken by the faster object and the Earth and Moon "capture" each other. Then they go into their mutual binary-planet orbit that we see today.

The Moon's inclinations to the ecliptic and to the invariable plane are excellent considerations. If the Moon were truly a satellite of Earth, it would orbit squarely on Earth's equatorial plane. Instead, it orbits only 5 degrees off the ecliptic and, as you say, 6.5 degrees off the IP. And this is how one would expect a planet to orbit rather than a satellite. (Mercury orbits the Sun even farther off the ecliptic than the Moon, about 7 degrees.)

Mercury orbits the Sun's equator, as one might expect since it is the closest planet to the Sun. -- Kheider (talk) 18:55, 24 April 2009 (UTC)

Which leads us to an interesting problem... See if you can explain how, if the Sun's equatorial plane is 7.25 degrees off the ecliptic, and Mercury's orbit is 7.05 degrees off the ecliptic, how does Mercury manage to be 3.38 degrees off the Sun's equatorial plane? ^.`^) Paine ^diss`cuss (^^`. 03:38, 25 April 2009 (UTC)

Not sure what you mean by saying the Moon is not tidal-locked to Earth? It has been so for eons. If you're referring to the librations, then yes, the tidal locking is not "perfect". But the Moon is definitely "locked in" tidally to the Earth, and if the Sun had more than 5-7.5 billion years left to shine, Earth would eventually become tidal-locked to the Moon. ^.`^) Paine ^diss`cuss (^^`. 15:42, 24 April 2009 (UTC)

Ok, so I should have written "the Earth is not yet tidally locked to the moon" ... "If other effects were ignored, tidal acceleration would continue until the rotational period of the Earth matched the orbital period of the Moon." (This has not yet occurred so the system is not perfect.) -- Kheider (talk) 18:55, 24 April 2009 (UTC)

Interesting that you should mention the deeply controversial dwarf-planet Pluto. I lobbied to get this classification change mainly to help the Solar System astronomers who were analyzing the tons of data on TNOs. Speed of collating all that data was tremendously improved by the reclassification of Pluto. The upcoming IAU meetings should prove to be fascinating! full of debate on this issue! ^.`^) Paine ^diss`cuss (^^`. 15:55, 24 April 2009 (UTC)

Reclassifying Pluto as a dwarf planet or even a lollipop should have little outcome on "the speed of collating all that data" since there will always be objects that blur definitions. A centaur today might be a very active comet 100k years from now. The line between an asteroid and a comet gets blurrier every time they look. -- Kheider (talk) 18:55, 24 April 2009 (UTC)

Not sure where your lollipop idea originates, but the fact remains that it was the TNO data collation problem that turned the heads of the decision makers. You might sing a different tune if you were on the collation team! ^.`^) Paine ^diss`cuss (^^`. 03:38, 25 April 2009 (UTC)

(this comment was originally posted in response to Kheider in the "Lead needs to be rewritten" section) For your consideration: The Orbit of the Moon around the Sun ^.`^) Paine ^diss`cuss (^^`. 04:35, 25 April 2009 (UTC)

Again, this doesn't belong here. If it belongs anywhere, it is in definition of planet; and it can't just be used as evidence to back up an argument by an editor. It has to be written only as the thoughts of the individual being sourced. Serendi ^pod ous 06:22, 25 April 2009 (UTC)

My dear Serendipodous, I am compelled to beg for your forgiveness on two counts:

Please forgive me for disagreeing with you that any and all discussion regarding the Moon's reclassification to full-fledged major planet belongs right-ab-dab here, right smack here on a discussion page connected to the Solar System article. I agree that the article you cite is also an agreeable place to discuss it; however, it is also a question of whether or not the Solar System has eight planets or nine. So this talk page is an appropriate venue for the topic's discussion.
The particular comment to which you have responded was placed here in this section by another editor, who for reasons known only to that editor, has decided to reorder my comments so that their meanings have been lost. So I also ask you to be generous with your forgiveness on this count. ^.`^) Paine ^diss`cuss (^^`. 07:05, 25 April 2009 (UTC)

Oh I see. It was originally responding to Kheider's objection, then got moved down. OK then. Still, according to official IAU definitions, satellites are not considered planets. And since the Moon is a satellite, it is not a planet. Any objection to this would have to have been made by a large section of the astronomical community to be notable enough for mention in an article on the Solar System. Serendi ^pod ous 07:12, 25 April 2009 (UTC)

The IAU resolution

The IAU resolution adopting the definition explicitly lists the 8 planets. Peter jackson (talk) 11:03, 30 March 2009 (UTC)

And yet the definition itself is not worded such that it excludes the Moon from being a planet. ^.`^) Paine ^diss`cuss (^^`. 02:25, 23 April 2009 (UTC)

It specifically excludes satellites. And the Moon is a satellite, as its barycentre lies within the Earth. It orbits the Earth as its primary, regardless of its orbit around the Sun. Ergo, it is a satellite and, according to the definition, ineligible for consideration. Serendi ^pod ous 17:16, 25 April 2009 (UTC)

Just a gentle reminder, Mr. S, that "satellite" has no official definition in planetary astronomy as yet. It suffers the same issue that "planet" suffered before the last IAU meeting. This fact just means that the Moon is thus far only vaguely classified as a satellite. As for the placement of the barycenter, the best argument I've heard so far is that, while the Sun-Jupiter barycenter is the only planet barycenter that lies outside the Sun's surface, this does not in and of itself make Jupiter a star. Therefore, just because the Earth-Moon barycenter lies a mere 1/8th of Earth's diameter below the surface, this does not in and of itself make the Moon a satellite. ^.`^) Paine ^diss`cuss (^^`. 02:58, 26 April 2009 (UTC)

This discussion could go on forever. But the point is, however we parse the definition, it manifestly states that the Solar System contains eight planets. Since this is an article about the Solar System, not an article about the ambiguities inherent in the definition of planet, such debate does not belong here. Serendi ^pod ous 10:52, 26 April 2009 (UTC)

Mars' Rotational Momentum Anomaly

Since the Martian satellites were mentioned, I wonder how appropriate (or not) would it be to mention the rotational velocity anomaly? I.e., when the Martian day is compared with Earth's day one finds that they're about the same, right around 24 hours. Now, Earth's day has been lengthened over the eons by the close proximity of an enormous object, the Moon. Since neither Phobos nor Deimos are nearly as large as the Moon, and since the day on Mars has lengthened at about the same rate as the day on Earth, the question arises as to what caused Mars to slow its rotation over the eons? ^.`^) Paine ^diss`cuss (^^`. 02:25, 23 April 2009 (UTC)

Interesting point; not really relevant to this article. Might be a good addition to Tidal acceleration, assuming you could find the right sources to back it up. Serendi ^pod ous 13:06, 23 April 2009 (UTC)

As far as I know, I'm out of luck on the backup sources on this issue. It probably constitutes original research, for I've never seen anything written about it. Astronomers make the logical assumption that the isochronous rotation rates (near the bottom of that page) of the asteroids and the spin rates of the outer planets mean that the inner planets also rotated much faster 4 billion years ago. As you know, the tidal action between Earth and Moon resulted in a transfer of angular momentum from Earth to Moon. And the two main results were the Moon's proximity growing farther away and the Earth's spin rate slowing. Mercury and Venus are probably undergoing a tidal-locking process with the Sun. Astronomers seem to think that Mercury is already locked in a weird 3:2 relationship with the Sun, but I think that if the Mercurial spin is studied more closely, we'll find that it is changing, that Mercury is slowly headed for a 1:1 tidal lock. Venus, which presently rotates in a direction opposite to most other planets, also probably has a changing spin rate, as the locking process causes it to oscillate past the 1:1 lock point a few times. Earth is close enough to the Sun for there to be a possible tidal-locking effect with the Sun, but by far the thing that's slowed Earth's rotation to 24 hours was the proximity of the Moon. I've never seen anything in print about it, but I've always questioned what might have caused Mars to slow its rotation so dramatically. Certainly not the Sun for Mars is too far away for the Sun's tidal effect to have caused that much slowing. Certainly not Phobos and Deimos, for they are way too small to have slowed Mars' rotation that dramatically. And yet, there it is, our mysterious red neighbor Mars. It's spin rate is actually a tad slower than Earth's. So what in the name of "heaven" could have robbed it of its initial angular momentum? Perhaps a series of collisions? I don't know. ^.`^) Paine ^diss`cuss (^^`. 14:17, 23 April 2009 (UTC)

Distances to Planets

Hi there guys,

It seems that the distances from the Sun to the planets represent the main aspect of scale of our star system. Therefore, I think you could say that the "size" of the Solar system is based on these measurements. As such, I think this data is worthy of mention at the start of the article : ) What do you think?

InternetMeme (talk) 11:03, 17 March 2009 (UTC)

After a cursory glance, I've noticed that there is no indication of the size of the Solar system in the opening section. I'd say that the size and shape of an object are two of the most basic aspects that need to be described in the first section of any encyclopedia article.

Also, astronomical units are not much use to any ordinary person. "giga" has become a fairly well known prefix, due largely to computer storage capacity measurements, and "metre" is a worldwide unit used everywhere apart from a couple of third-world countries and the US : )

InternetMeme (talk) 11:22, 17 March 2009 (UTC)

The Solar System has no single, fixed size. It depends on how you define it. If you mean, "the bits we've mapped," then it goes out to about 80 AU. If you mean, "the region of space dominated by the solar wind," then that's about 120 AU, and if you mean, "the region of space dominated by the Sun's gravity", then you're talking about around 200,000 AU. Either way, simply listing the distances to the planets and those arbitrary objects we now call dwarf planets will not give anyone a good idea of the dimensions of the Solar System. As for AU, it is the established unit for interplanetary measurement and it would be unnecessarily confusing for Wikipedia to use anything else, since all credible sources use it. The term is defined at the bottom of the page. Serendi ^pod ous 13:22, 17 March 2009 (UTC)

Since this is a general article for the masses, we would need to stay away from gm and use km... -- Kheider (talk) 14:43, 17 March 2009 (UTC)

I think that although Astronomical Units are a reasonable unit for use in specialised astronomical publications, I think they're not a great unit to use in a general purpose encyclopedia aimed at the masses; the masses view units like that as kind of sci-fi space jargon, and they don't really take it in. And sure you can define the unit at the bottom of the page, but that still won't give people any idea of the scale of planetary distances. For example, the distance from Earth to Venus is roughly 2,000 times the distance from China to the US. That's easy to work out when you use kilometres. InternetMeme (talk) 10:50, 19 March 2009 (UTC)

It gives people a far better idea than battering them over the head with hundreds, thousands, millions and billions. At least AUs are simple; do you think people would prefer to count the zeroes at the end of 5000000000 km? In astronomy, oblique measurements are used all the time. Take light years. Most people probably don't even know what a light year is, let alone its value in km. Telling them that Alpha Centauri is 4.5 light years away has no more or less meaning than saying it's 25 trillion miles away; a number as ponderous as counting the grains of sand on a beach. These numbers are so far out of human experience that there really is no way to express them in ways they will grasp. Not even astronomers can do that. Besides, the AU is used not only in this article but in every Solar System-related article on this site. The change you are advocating would require massive work for little (and dubious) gain. Serendi ^pod ous 13:38, 19 March 2009 (UTC)

I agree that most people view AUs as sci-fi space jargon. But this whole article is like sci-fi space jargon. So it's appropriate. - Shaheenjim (talk) 21:47, 19 March 2009 (UTC)

In regards to the Solar system having no fixed size: Well, I guess that's technically true, there are many different aspects of matter and energy distribution that could be regarded as the size of the Solar system. But I think that when most ordinary people envisage the Solar system, they think of the picture at the start of this article (which presumably represents this article's visual definition of the solar system). Therefore I think it's a good idea to give some scale to the visualisation.

Also, the list of the planets in this article is ordered by their distance from the Sun. It would seem fitting, then, to state what those distances actually are. InternetMeme (talk) 15:36, 17 March 2009 (UTC)

That picture isn't a picture of the Solar System; it's just a picture of the planets and dwarf planets with their sizes to scale. I would love to have a decent image of the Solar System to use, but none are available. Serendi ^pod ous 15:47, 17 March 2009 (UTC)

Yeah, what I'd really like is a picture that indicates the relative orbital distances to scale, which would lessen the need to list the distances in the article. It's worth pointing out that the second paragraph states that the Oort cloud spans a distance of roughly a thousand times that of the main planetary region, without actually saying what the distance span of the main planetary region is. The relative meaninglessness of that statement is a good example of why some kind of scale indication is neccessary. InternetMeme (talk) 16:22, 17 March 2009 (UTC)

There is a picture of the orbits to scale; it's in the structure section. Serendi ^pod ous 18:16, 17 March 2009 (UTC)

Might as well list all of those distances. And I agree that we should use AUs for distance. - Shaheenjim (talk) 22:01, 17 March 2009 (UTC)

Whatever happened to this? InternetMeme, you changed them away from kilometers, which hurts the size comparison by having different units, but also confuses people who use the long scale. That's not the issue, though - why were they not listed in AU to begin with, as per this conversation? ~ Amory 16:07, 20 April 2009 (UTC) —Preceding unsigned comment added by Amorymeltzer (talk • contribs)

I've restored the "km" version. --Ckatz^chat _spy 19:55, 20 April 2009 (UTC)

pls add IW link

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.

[[wuu:太阳系]]

This interlangwiki link now appears.

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Solar system basic

The article Solar system basic, a fork of Solar System with a simplified writing style in line with the Simple Wikipedia, was created yesterday by HarryAlffa. I have nominated it for deletion both as a content fork and as something that is more suited to simple:Solar System. The AfD discussion can be found here if you are interested. --Ckatz^chat _spy 08:29, 21 April 2009 (UTC)

fairly simplistic list-like summary of what's what in the Solar System. In addition, given the size of the article (79 KB), there's definitely room to have a much lengthier and more comprehensive lead. Perhaps we could have a few sentences devoted to the Sun, a few to the Inner Solar System, a few to the Outer Solar System, etc etc. Nishkid64 _{(Make articles, not wikidrama)} 16:59, 23 April 2009 (UTC)

As the re-written lead has many of the same characteristics, I've copied over the lead from {was something like this}[9], which is a good start.HarryAlffa (talk) 14:54, 24 April 2009 (UTC)

See http://en.wikipedia.org/wiki/Wikipedia:Featured_article_review/Solar_System/archive1#Solar_System for discussion on the new, expanded lead. —Preceding unsigned comment added by HarryAlffa (talk • contribs) 17:26, 24 April 2009 (UTC)

Comment First, per the observations of several other editors, we should centralize this discussion at Talk:Solar System. Second, I have restored yesterday's version, and would ask that any changes to the lead be hashed out on a talk page first, and only applied after consensus is reached. Solar System is a core article, one of the most important ones in the "Astronomy" section, and we cannot have the lead going back-and-forth. Fair enough? (I was going to post a copy of the revised version here, but instead thought you could decide which revised version you wanted to start from.) --Ckatz^chat _spy 18:17, 24 April 2009 (UTC)

I'm pretty happy with this version. I find "has commonality with" a bit clunky when "is similar to" is a viable alternative, and the fact that two belts "exist" seems a touch metaphysical. Better to say where they are. But other than that, fine. Serendi ^pod ous 18:23, 24 April 2009 (UTC)

Minor edit, named the ecliptic. Serendi ^pod ous 18:44, 24 April 2009 (UTC)

I simply do not trust the Ckatz Cabal, I have tried in the past to have reasoned discussions with them, they will simply not listen to reason. The lead at present is a terrible piece of writing. HarryAlffa (talk) 20:15, 24 April 2009 (UTC)

Your "cabal" essentially consists of everyone who has this page on their watchlist other than yourself. Because we do not agree with you, you claim we don't listen to reason, as your opinions are, by definition, reasonable and ours are not. I think you'd go a lot further towards getting what you wanted if a) you assumed the rest of of us were capable of rational thought and b) assumed that, as we have literally spent years trying to improve this article for no pay or recognition, we actually care about it and want to make it better. Serendi ^pod ous 20:24, 24 April 2009 (UTC)

You know full well who are the members of Ckatz Cabal; yourself and ASHill. You know this, yet deliberately misconstrue this so as to fire off your accusation. Shame on you. HarryAlffa (talk) 20:23, 26 April 2009 (UTC)

Comment I would say that HarryAlffa's version is inferior to the previous stilted version, because it reads like an introduction to Earth in space, and not the Solar System. 76.66.196.218 (talk) 14:06, 25 April 2009 (UTC)

My version conforms to the Wikipedia:Lead_section, the current one does not. HarryAlffa (talk) 20:23, 26 April 2009 (UTC)

Your version is also not an introduction to the Solar System, so does not conform to WP:LEAD. 76.66.196.218 (talk) 02:06, 27 April 2009 (UTC)

Nonsense. The Earth provides context for the reader. Read the WP:Lead.

Anyway, concentrate on the current lead. It does not conform to WP:Lead. HarryAlffa (talk) 14:06, 28 April 2009 (UTC)

The Earth is not the primary topic, so your context statement is non-contextual, since the subject is not the Earth's relation to space. You should read WP:LEAD. So your version of the lead should not be used, since it does not conform. 76.66.202.139 (talk) 08:45, 29 April 2009 (UTC)

The current lead does not conform. HarryAlffa (talk) 21:45, 29 April 2009 (UTC)

kheider reverted lead comments

"The Solar System (or solar system) is the astronomical name for the Sun, the Earth and the Moon"

Since when did the moon become a major body orbiting the Sun?

When did the lead say it was? See Wikipedia:Lead_section#Opening paragraph; "It should establish the context in which the topic is being considered, by supplying the set of circumstances or facts that surround it."

By selectively quoting only half the sentence, you've changed its meaning as a whole; "The Solar System (or solar system) is the astronomical name for the Sun, the Earth and the Moon, and the other orbiting bodies which make up the rest of the planetary system." HarryAlffa (talk) 20:47, 26 April 2009 (UTC)

IMHO, your lead makes it sound like the solar system starts and ends with the Earth. Your lead makes me think I am reading an ancient text book where the next line will read, "They all go around the Earth." -- Kheider (talk) 21:05, 26 April 2009 (UTC)

See Wikipedia:Lead_section#Opening paragraph; "It should establish the context in which the topic is being considered, by supplying the set of circumstances or facts that surround it." References to Earth were used purely to illustrate the plane of the ecliptic and eliptical orbits, following guidance on using familiar frames of reference.

The SOLar system is largely about the things that orbit the Sun and interact with it:

Interact? HarryAlffa (talk) 22:52, 29 April 2009 (UTC)

The gas giants need to be properly mentioned in the lead. -- Kheider (talk) 20:45, 28 April 2009 (UTC)

The lead should summarize: my lead summarizes the Gas Giants well. HarryAlffa (talk) 22:52, 29 April 2009 (UTC)

In your lead the planets other than the Earth are not really mentioned until the 3rd paragraph. In the 1st paragraph you simply refer to the planets as "other orbiting bodies which make up the rest of the planetary system" as if the other planets were insignificant small bodies. Your opening line could be interrepted to suggest that the solar system consists of 3 major bodies (Sun+Earth+Moon). It is not bad, but I think the current one is better. -- Kheider (talk) 02:43, 30 April 2009 (UTC)

We really should be talking about why the current lead fails. Anyway. Professional presentation means that the readers eye can see the prominent bulleted list of planets. The 1st paragraph: WP:Lead says give a familiar context - the Earth. Planetary system is linked; the name suggests other planets and the list of planets means the readers MUST infer there are other planets, and the link explains. This is how WP:Lead suggests it is done.

The 2nd paragraph. Is about the Sun.

3rd paragraph. The reader can see the solar system "edge on" - plane of the ecliptic. Eliptical orbits.

Then comes the list of planets, in order and in what region they are. The list is prominent and can be seen from ~~space~~ the top of the article. HarryAlffa (talk) 14:38, 30 April 2009 (UTC)

You need to remove the statement "It is most notable for the planet Earth" That is subjective. The solar system could exist without the Earth, life (on Earth as we know it) could not exist without the Sun. -- Kheider (talk) 20:45, 28 April 2009 (UTC)

By selectively quoting only half a sentence again (shame on you), you've changed its meaning as a whole; "It is most notable for the planet Earth as the only place in the Universe known to evolve and harbour life.". Are you thinking that life is NOT notable? HarryAlffa

Shame on me because I do not agree with "your opinion" of how much attention should be given to the Earth and life in an article about the whole solar system? Life is not required for the Solar System to exist. Life would be more notable in the articles "Earth", "Habitable zone" and "Terrestrial planet". There is no need to focus on the Earth/life so much. -- Kheider (talk) 02:43, 30 April 2009 (UTC)

Hmm. If I had said that the solar system is most notable for the planet Earth even if there was no life on it. Then that would be stupid. On reflection I think you made a genuine mistake in misquoting me, which made it sound as if I was saying that. If you had done that deliberately then I think that would be shameful! HarryAlffa

No, I did not misunderstand you. I merely claimed that you put too much emphasis (IMHO) about life currently existing on the planet Earth. Life is remarkable but has no major affect on the Solar System as a whole. (perspective). Should the Milky Way galaxy be most notable for life on planet Earth? That would be a very geocentric assumption. -- Kheider (talk) 18:49, 30 April 2009 (UTC)

In your opening line, instead of "and the other orbiting bodies which make up the rest of the planetary system", you should say, "other planets and small bodies which make up the rest of the planetary system.." -- Kheider (talk) 18:49, 30 April 2009 (UTC)

Deliberately? Quit inferring that people are molesting you or this conversation may be terminated without further notice (You have been warned.) -- Kheider (talk) 18:49, 30 April 2009 (UTC)

What you really object to (I think) is saying the solar system is notable for life. Yet you've pretty much just said Earth is notable for life. Then why not the star system that holds the Earth?

You really need to understand what notable means, from what you are saying I think you don't. Ask yourself why is this star system notable compared to others. HarryAlffa (talk) 15:10, 30 April 2009 (UTC)

You really need to quit putting other people down because they do not agree with you. Frankly, I think you are foolish to suggest that life could not exist in other planetary systems that are just like ours. Just twenty years ago, our "star system" was notable for being the only one with known planets. But now we know that planetary systems are common! I am not sure if the lead should infer something that has a good chance of being disproven. -- Kheider (talk) 18:49, 30 April 2009 (UTC)

Our star system is notable for being the only one that we have explored. (perspective) -- Kheider (talk) 18:49, 30 April 2009 (UTC)

I think I would be better using remarkable instead of notable. This would not confuse the reader. HarryAlffa (talk) 15:10, 30 April 2009 (UTC)

My lead says "The Sun determines the solar system, ...". No need to tell me that the system would exist without the Earth. HarryAlffa (talk) 22:52, 29 April 2009 (UTC)

I would not mention the solar wind before I discussed the far more important (and better known) gas giants. -- Kheider (talk) 20:45, 28 April 2009 (UTC)

You keep banging on about how important the Sun is, and it is, so mentioning the solar wind in the same paragraph as the Sun as a step to introducing the important heliosphere is a very sensible idea. HarryAlffa (talk) 22:52, 29 April 2009 (UTC)

You use 32 words to describe the solar wind? I thought you were trying to be brief. -- Kheider (talk) 02:43, 30 April 2009 (UTC)

False. The 32 word sentence has three subjects: solar wind; heliosphere; interstellar medium. On average that's 10.7 words each. HarryAlffa (talk) 15:23, 30 April 2009 (UTC)

I still think the existing lead is better because I think your lead is oversimplified too much. You also seem to have no support for removing its status as a FA because of the existing lead. -- Kheider (talk) 20:45, 28 April 2009 (UTC)

It took my action for FA Review to get the Ckatz Cabal to change from the previous lead[10] (they wouldn't listen to reason before) to the present lead. Unfortunately they've lost the two welcome characteristics that did have and made a long-winded, even worse version.

"oversimplified too much"? A bit of a tautology? HarryAlffa (talk) 22:52, 29 April 2009 (UTC)

As it happens I've further changed my lead for further brevity, removing references to Earth without altering the meaning of each paragraph. HarryAlffa (talk) 14:28, 28 April 2009 (UTC)

Your lead still mentions the Earth and life too much (IMHO). -- Kheider (talk) 20:45, 28 April 2009 (UTC)

It mentions Earth twice, and one of those was too - mention life once. HarryAlffa (talk) 22:52, 29 April 2009 (UTC)

"It is most notable for the planet Earth as the only place in the Universe known to evolve and harbour life"

Subjective. The Sun is most notable IMHO. What does life have to do with general article about the solar system? Besides Venus and/or Mars may have had life 2 billion years ago. --Kheider (talk) 18:26, 24 April 2009 (UTC)

Your humble opinion is subjective too. The Sun is the biggest structural part, but there are many similar stars, the Sun is pretty run of the mill as a star. Life is the most notable thing about the universe. HarryAlffa (talk) 20:47, 26 April 2009 (UTC)

The Sun is the center of the Solar System by definition. Everything goes around it directly or indirectly. What do other stars (that are not part of the system) have to do with any of it? -- Kheider (talk) 22:08, 26 April 2009 (UTC)

The Sun certainly dominates the rest of the system. There are many star systems. Imagine a collection of star systems, all identical to our own Solar System in every respect, with the exception of life. Is the most notable thing about our system still the Sun? HarryAlffa (talk) 14:28, 28 April 2009 (UTC)

Imagine? I imagine there would be life on one of those rocky inner planets. -- Kheider (talk) 20:45, 28 April 2009 (UTC)

You didn't answer the question. HarryAlffa (talk) 22:52, 29 April 2009 (UTC)

Why would I? I don't agree with your assumption. I could imagine that 2+2=5 and start going around asking everyone if they think their math books could be wrong, but why would I make an assumption that I do not agree with? -- Kheider (talk) 02:43, 30 April 2009 (UTC)

What assumption? I asked you to perform a thought experiment, then answer a question on it. How hard can that be? HarryAlffa (talk) 15:39, 30 April 2009 (UTC)

You basically asked me to assume that life does not exist any where else, and then wanted to know if life on Earth would be special... Duh. But I do not think a general article on the Solar System should spend too much time on assumptions. As I mentioned above, Should the Milky Way galaxy be most notable for life on planet Earth? Life=Earth (being brief) -- Kheider (talk) 18:49, 30 April 2009 (UTC)

Duh yourself. There is no scientific evidence that there is life outside the solar system. Even if it was an unreasonable assumption to make, for the purposes of a thought experiment it would not be unreasonable to make an unreasonable assumption! The encyclopaedic stand point must be to assume that there is no life outside the solar system. So, now can you carry out the thought experiment? HarryAlffa (talk) 16:30, 1 May 2009 (UTC)

You seem to be the only person that has an issue with how the lead is *currently* written. Could it be better? Yes. Is it wrong? No. -- Kheider (talk) 02:43, 30 April 2009 (UTC)

I was the only person who had an issue with how the previous lead was written, but that version has gone. The replacement is no good. Nobody said it was wrong. It fails WP:Lead & WP:Featured article criteria. HarryAlffa (talk) 15:39, 30 April 2009 (UTC)

You appear to have no one supporting your opinion. -- Kheider (talk) 18:49, 30 April 2009 (UTC)

And? HarryAlffa (talk) 16:30, 1 May 2009 (UTC)

Do you have the results of the thought experiment? HarryAlffa (talk) 19:31, 3 May 2009 (UTC)

"The Earth's orbit around the Sun is nearly a perfect circle,"

Perfect, not even close. It is simply a near circle. Venus and Jupiter pull on the Earth regularly. --Kheider (talk) 18:26, 24 April 2009 (UTC)

This is the lead, not the body of the article. Brevity versus precision - it does not mislead. "editors should avoid lengthy paragraphs and over-specific descriptions" HarryAlffa (talk) 20:47, 26 April 2009 (UTC)

The word perfect should not be used. Re-read your reply. -- Kheider (talk) 21:05, 26 April 2009 (UTC)

So a small ambiguity easily refined by your suggestion. HarryAlffa (talk) 14:28, 28 April 2009 (UTC)

"but more small objects are found here every year"

New small bodies are found all the time. --Kheider (talk) 23:10, 24 April 2009 (UTC)

Brevity versus precision - it does not mislead. HarryAlffa (talk) 20:47, 26 April 2009 (UTC)

Your statement is basically inaccurate. -- Kheider (talk) 21:05, 26 April 2009 (UTC)

Small bodies are NOT found every year? HarryAlffa (talk) 14:28, 28 April 2009 (UTC)

Plus, outer space does not begin at the heliopause, but at the edge of the atmosphere. Serendi ^pod ous 18:31, 24 April 2009 (UTC)

I'm fairly content with the current version of the article. As noted above, there are several issues with HarryAlfa's version of the lead – factual inconsistencies and stylistic issues. Nishkid64 _{(Make articles, not wikidrama)} 22:49, 24 April 2009 (UTC)

I've answered all of these above. HarryAlffa (talk) 20:47, 26 April 2009 (UTC)

Per what Serendipodous said, "commonality" is a bit clunky - not sure why I went with that, so should we just change it to "similar"? --Ckatz^chat _spy 00:45, 25 April 2009 (UTC)

(this comment was originally posted in reply to Ckatz) We might keep in mind that while the asteroids share compositional commonality with the inner planets, they also share isochronous spin-rate (bottom of page) commonality with the gas giants. Personally, I like the word "commonality", however the general reader might find shorter, simpler words more helpful, as long as the conveyed meaning is not lost or violated. ^.`^) Paine ^diss`cuss (^^`. 04:35, 25 April 2009 (UTC)

(this comment was originally posted in reply to Kheider's first point) For your consideration: The Orbit of the Moon around the Sun ^.`^) Paine ^diss`cuss (^^`. 04:35, 25 April 2009 (UTC)

(this comment was originally posted in reply to Kheider's second point) Notability can arise out of several parameters. The Sun is most notable for mass, and other parameters; however the rest of the Solar System has the lion's share of angular momentum, for which the Sun would be least notable. Earth, of course is most notable for its ability to sustain the only known life in the Solar System and the Universe. But I agree that applying Earth's notability to the Solar System is subjective at best. ^.`^) Paine ^diss`cuss (^^`. 04:35, 25 April 2009 (UTC)

So life would only be notable if it existed on other planets in the solar system? HarryAlffa (talk) 20:57, 26 April 2009 (UTC)

The moon orbits both the Sun and the Earth, so as a satellite (pending IAU definition) it is not a planet. See BAUT 2004 -- Kheider (talk) 09:21, 26 April 2009 (UTC)

There is one image on that page that depicts the Moon's orbit around the Sun as looped. That seems to be what people expect, but it is not so. There are no loops in the Moon's orbit. So the Moon always falls toward the Sun, just like Earth, just like all planets. When you check out the The Orbit of the Moon around the Sun link, it shows this fact. There are many reasons to think of the Moon as a planet in its own right, and to think of the Earth-Moon system as a binary- or double-planet system. ^.`^) Paine ^diss`cuss (^^`. 14:48, 26 April 2009 (UTC)

Martian moons (Phobos and Deimos) also do not have loops in their orbits. Does it make them planets too? Ruslik (talk) 15:02, 26 April 2009 (UTC)

Hi Paine. I agree that the moon orbits the Earth and the Sun. But IF the Sun magically disappeared the moon would keep orbiting the Earth. The moon is a satellite and Pluto is a dwarf until the IAU says otherwise. Europa is a "dwarf planet" on the verge of exiting the Solar System! But wait, it also orbits Jupiter. -- Kheider (talk) 20:41, 26 April 2009 (UTC)

Hi Kheider. Just as in any two-body problem, if the Earth and Moon were taken together without the Sun's influence, they would both revolve around a common barycenter. So neither revolves around the other, but they both revolve around their common center-of-gravity. Of course, the addition of the Sun and other Solar System denizens makes "real life" quite a bit more complicated. The Moon is only a satellite by tradition. There was a long period when the nebula in Andromeda was a nebula by tradition. Then new facts came to light – it was found that this particular nebula was not a part of our galaxy, but instead was far outside it – and the nebula became the "Andromeda galaxy". ^.`^) Paine ^diss`cuss (^^`. 00:43, 27 April 2009 (UTC)

I have no problem with "The Moon" being a dwarf planet or planet but the IAU would have to define it as such. For that matter I feel basically the same way towards Miranda and even demolished dwarf Vesta. But this really has little to do with the Solar System article and the current definitions as used. -- Kheider (talk) 01:15, 27 April 2009 (UTC)

The Earth-Moon system could be thought of as a double-planet system. The mutual stabilisation of their orbits and other factors lead some people to wonder if they should be classified this way. HarryAlffa (talk) 20:57, 26 April 2009 (UTC)

From your words to astronomy's ear, Harry! And a growing number of astronomers are beginning to agree. ^.`^) Paine ^diss`cuss (^^`. 00:43, 27 April 2009 (UTC)

Ruslik, that's a very interesting statement. I wonder if you can point me to the place in the literature that you've read this. I only ask because the presence (or absence) of loops in a body's Solar orbit is generally governed by the gravitational effect of the Sun vs. that of another body. The main reason that there are no loops in the Moon's Solar orbit is because the Sun's gravitational effect on the Moon is about two times the effect that Earth has on the Moon. It's like a "tug of war" for the Moon between the Sun and the Earth, and the Sun wins. In the case of Phobos and Deimos, however, Mars wins the tug of war for those satellites and the Sun loses. Mars' hold on Deimos is 32 times the influence of the Sun, and Mars wins the tug of war by 195:1 for Phobos. Therefore, from the perspective of, say, you and I standing on the surface of the Sun and watching Phobos and Deimos, they would occasionally turn around and move backward (retrograde), and then proceed to go forward again. And this means they definitely have loops in their Solar orbits. From that same perspective on the Sun's surface, however, the Moon never turns and goes backward. The Moon always goes forward, just like Earth and all the rest of the planets. ^.`^) Paine ^diss`cuss (^^`. 23:57, 26 April 2009 (UTC)

Harry, to apply notability to anything just because it "exists" is rather human-centered, don't you think? Notability implies comparison, so that one thing is notable over another thing or things. So even my saying that "Earth is notable as being the only known safe harbor for life" is really poor usage of the word "notable". Why is this notable? To whom is it notable? In improving an encyclopedia, one must carefully stick to facts as best as one can, and one must avoid anthropomorphisms as much as is humanly possible. ^.`^) Paine ^diss`cuss (^^`. 23:19, 26 April 2009 (UTC)

You used "human centred" to mean anthopomorphic, you've mixed up the meanings there! For anything to be notable there has to be a whom to whom it will be. In comparison to the rest of the Universe. HarryAlffa (talk) 20:33, 28 April 2009 (UTC)

The main reason that there are no loops in the Moon's Solar orbit is because the Sun's gravitational effect on the Moon is about two times the effect that Earth has on the Moon. You are wrong here. The loops appear because the speed of a moon relative to a planet is higher than the orbital speed of the planet around the Sun. For Mars the orbital speed is about 25 km/s, while the orbital speed of Phobos is only ~ 3.5 km/s. So, there is no loops. Of course, the ratio of orbital speeds depends on the ratio of gravitational influence but not only on this value:

{\frac {V_{m}}{V_{p}}}={\sqrt {{\frac {g_{p}}{g_{s}}}{\frac {R_{m}}{R_{p}}}}}

,

where m refers to the moon, p to planet, g is a gravitational acceleration of the moon in the field of either Sun ( $g_{s}$ ) or planet ( $g_{p}$ ), and R an orbital radius. Even if ${\frac {g_{p}}{g_{s}}}>1$ , the ratio of speeds can still be less than unity. Ruslik (talk) 07:19, 27 April 2009 (UTC)

Forgive me, Ruslik, because the math of this escapes my grasp. Can you cite a reference for all this? I've looked all over the internet and can find nothing about the solar orbits of Phobos and Deimos. Everything I read is about their orbits around Mars, but not about their paths as they would be mapped around the Sun. ^.`^) Paine ^diss`cuss (^^`. 21:47, 8 May 2009 (UTC)

^ Kasting, J.F. (1986). "Climatic Consequences of Very High Carbon Dioxide Levels in the Earth's Early Atmosphere". Science. 234: 1383–1385. doi:10.1126/science.11539665. PMID 11539665. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

[Kasting-1] Kasting, J.F. (1986). "Climatic Consequences of Very High Carbon Dioxide Levels in the Earth's Early Atmosphere". Science. 234: 1383–1385. doi:10.1126/science.11539665. PMID 11539665. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

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