Talk:Uranus/Archive 3

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Talk archives for Uranus (current talk page)
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Contents

Peer reviewed sources

I found only three of them and they are not formated propely. I think it's important not to forget that they are the most reliable. They are also primary sources in a sense that all other references are ultimately based on them. Ruslik 08:31, 20 June 2007 (UTC)

Well, I've got my hands full with Kuiper belt at the moment. Could you do it? Serendipodous 13:38, 20 June 2007 (UTC)
I'm going to add ~20 of them in a few days. Ruslik 13:52, 20 June 2007 (UTC)

Direct vs. Retrograde

Should the article contain some discussion about whether the rotation of Uranus is direct/prograde with a tilt of ~98 degrees or retrograde with a ~82 degree tilt, and perhaps how that would relate to the ambiguity about which pole is North? Contrast with Venus, which everyone agrees has retrograde rotation, not a 180 degree tilt. 76.5.27.25 21:08, 20 June 2007 (UTC) Fwiffo

It does, right below the solstice table. Serendipodous 05:15, 21 June 2007 (UTC)

Recognition of Uranus as a planet

The article says:

"Although ... Uranus is visible to the naked eye ...its small angular diameter (between 3.4 and 3.7 arcseconds, compared with between roughly 16-20 arcseconds for Saturn and 32 and 45 arcseconds for Jupiter[1]) and slow motion across the sky meant that it was never recognised as a planet by ancient observers."

This implies that the five classical planets were recognised as planets at least partly because a visible disk was noticed. Is this really true? I would have thought brightness and motion relative to the stars were the only necessary criteria. Putting it another way, if Uranus were somehow much brighter and moved much faster, while retaining the same apparent size, then it would have been recognised as a planet in ancient times along with the others, wouldn't it? Matt 19:39, 8 July 2007 (UTC).

I seem to recall reading somewhere that the planets twinkle less than the stars because they have a disk, rather than being essentially a point source. In terms of resolving a disk, however, the classical test of excellent vision was to resolve the Mizar/Alcor pair. These are separated by 12 arc-minutes.[1] By comparison, Jupiter has a maximum disk of about 47 arc-seconds. — RJH (talk) 15:03, 25 July 2007 (UTC)

This entire paragraph is uncited

Lalande's proposed name of Herschel was readily adopted by French astronomers. Prosperin, of Uppsala, proposed the names Astraea, Cybele, (now the names of asteroids) and Neptune (which would become the name of the next planet to be discovered). Lexell, of St. Petersburg, compromised with George III's Neptune and Great-Britain's Neptune. Bernoulli, from Berlin, suggested Hypercronius and Transaturnis. Lichtenberg, from Göttingen, chimed in with Austräa, a goddess mentioned by Ovid (but who is traditionally associated with Virgo). The name Minerva was also proposed.

This sentence too is uncited:

Examination of earliest issues of Monthly Notices of the Royal Astronomical Society from 1827 shows that the name Uranus was already the most common name used even by British astronomers by then, and probably earlier.

and the Indian comment still has no source:

while in India it is named Aruna (Devanāgarī अरुण), the charioteer of the sun god Surya in Hindu mythology

A lot of interesting material, but where did it come from? If anyone can come up with proper citations for this info, I'd appreciate it. Serendipodous 15:40, 30 July 2007 (UTC)

Fixlmillner

This info is partially cited, but its source [2] doesn't back up its claims:

The name Uranus was in use in Germany at least as far back as 1791, however.

Maximilian Hell followed suit by using it in the first ephemeris, published in Vienna and computed by the Benedictine priest Placidus Fixlmillner.

About the only concrete information in that page is that Placidus Fixliliner was the first to calculate an ephemeris for Uranus, though it doesn't say when.

EDIT: OK. Found this page in Google translation that sets a date of 1787. Will replace the 1792 date unless someone can show that Fixliliner was wrong. [3] Serendipodous 17:55, 6 August 2007 (UTC)

alchemy

OK, I may need to backtrack a bit from my comment in the history. Uranus's astronomical symbol does appear to be an alchemical symbol for platinum, but in 70 Google hits I have found only two references to it as such, and both place it next to its more common symbol. Neither was particularly illuminating, and neither said where their sources came from (they could have got their info from here, after all) so I think it's best for now to leave it out until a definitive source can be located. Serendipodous 11:55, 4 August 2007 (UTC)

Core temp

One proposed explanation for this dearth of cloud features is that Uranus's internal heat is lower than that of Jupiter and Saturn; in astronomical terms, it has a low thermal flux. Both Jupiter and Saturn radiate more energy than they receive from the Sun. This causes many powerful convection currents to form in the atmosphere. On Uranus that heat source is much lower; roughly 7000 K[2] compared to 24 000 K at Jupiter's core[3] and 12000 K at Saturn.[4] The convection currents formed in the Uranian atmosphere are not as strong and hence it lacks the atmosphere banding of the other gas giants.

This paragraph seems to contradict the rest of the section. If no one is entirely sure why Uranus's heat emissions are so low (whether it be due to a genuinely cold core or to some form of insulation), I'm not sure how one could arrive at a single authoritative figure for Uranus's core temperature. Serendipodous 16:32, 5 August 2007 (UTC)

Keck images

As I know Keck observatory is strictly speeking not a part of NASA, therefore the copyright tag claiming otherwise is wrong and should changed to smth more appropriate. Ruslik 09:43, 7 August 2007 (UTC)

If they aren't NASA, then they aren't public, so they'd have to be taken down. If there's another option, I'd take it. Serendipodous 09:50, 7 August 2007 (UTC)
They are public. Please, visit [4]. However credits are different. Ruslik 10:03, 7 August 2007 (UTC)
I probably erred here so I replaced the image. Ruslik 12:42, 31 August 2007 (UTC)

Core mass

Ruslik, are you sure that Uranus's core is only 0.55 Earth masses? That seems remarkably low. Serendipodous 11:26, 7 August 2007 (UTC)

Radius of the core is less than 1/5 of the planet, therefore volume is less than 1/125. Density of the core is 6 times higher than the average density. So the mass is normal and both refs 41 and 43 agree on this model. Ruslik 12:12, 7 August 2007 (UTC)

bar/bars

We need to make sure which is the standard plural to use for that unit. Serendipodous 11:50, 7 August 2007 (UTC)

I think 'bar' is correct form. Ruslik 07:03, 8 August 2007 (UTC)

"Fourth of July fireworks"

Serendipodous, I think the apropriate place for this paragraph is a climate section, and I did not delete it yesterday but moved. Today I noticed that you reinstated it in the 'Seasonal variation' subsection. So I deleted its duplicate from the climate section. However I continue to think that it should be moved to climate section. Ruslik 07:12, 8 August 2007 (UTC)

Sorry, didn't notice it there. But I think it belongs in seasonal variation, first because the picture in "seasonal variation" relates to it directly and second, because it is about climactic change with the seasons, whereas the "climate" section is more general. Serendipodous 08:31, 8 August 2007 (UTC)

Which two spectral bands?

What compound do they represent? Serendipodous 11:27, 8 August 2007 (UTC)

They don't correspond to exactly any compound. They simply chose two filters: one centered at 550 nm (y or yellow) and the second centered at 470 nm (b or blue). Both have width around 30 nm. However the yellow filter includes a part of the methane absorption band at 543 nm. Ruslik 12:57, 8 August 2007 (UTC)

End of major expansion

I have just finished expanding the article. So now the main problem is copy-edit and figures. I will probably add a couple of graphs. In addition some images can be removed. For example, one of two HST images showing rings and bands. Ruslik 10:03, 16 August 2007 (UTC)

moons orbits

do uranus's moons orbit uranus the way uranus rotates or not? —The preceding unsigned comment was added by 172.206.77.234 (talk) 20:32, August 20, 2007 (UTC)

All the large moons in the Solar System rotate prograde, except Triton. Serendipodous 08:10, 21 August 2007 (UTC)
This question is answered in the infoboxes: if orbital inclinations are less than 90° (actually close to zero for inner moons), the satellites orbits are prograde. Ruslik 13:57, 21 August 2007 (UTC)

I just want to remind everyone

that this page was semi-protected to stop the jokes, and now that the protection has been removed, the jokes have come back. So we need to come to some sort of agreement as to whether we want to spend the rest of eternity reverting the jokes, or whether we should re-instate semi-protection. Serendipodous 10:12, 22 August 2007 (UTC)

Why was it removed? Looks like asking for trouble. Didn't take them long to start up the, let's call them "jokes", again. It should be re-semi-protected. Deuar 22:43, 25 August 2007 (UTC)

About one paragraph

I think the first paragraph in 'Physical characteristics' section should be deleted or moved into 'Exploration' section. It actually provides a short summary of exploration. Ruslik 13:19, 23 August 2007 (UTC)

I deleted it. It just repeats the info in the exploration section. I also deleted the added paragraphs to exploration; they don't actually refer to exploration, and simply repeats information found elsewhere in the article. Serendipodous 18:31, 23 August 2007 (UTC)

Infobox parameters format

I have restored, with some distaste, the arguably spurious quantities like semiminor axis, spurious conversions to imperial units, and pecuiliar spacing of digits to the orbital quantities in the infobox. If this were an isolated article I would gleefully agree with their removal, but removing them and changing the formatting breaks consistency with the infoboxes for the rest of the planets. Imho, keeping consistency and easy comparability between them is a more important issue. If we want to let's bring it up on Wikipedia talk:WikiProject Astronomical objects, and/or do it for all the planets in one fell swoop. Deuar 22:12, 26 August 2007 (UTC)

Proper Pronunciation is no Joke

The pronunciation is given as "your anus".

Ask any astronomer, and they will tell you the planet's name is "YOOR-e-nes". Hell, even the Discovery Channel gets it right!

Promoting the "your anus" joke in no way discourages further jokes.

August 27, 2007 —Preceding unsigned comment added by 167.197.117.47 (talk) 16:37, August 27, 2007 (UTC)

I agree that that is how it should be pronounced, but the alternate pronunciation has become so common that it can't really be discounted anymore. Besides, "YOOR-uh-nus" sounds like "urine-ous", which isn't much better. Serendipodous 16:49, 27 August 2007 (UTC)
Both pronunciations have been in use for a long time. Both are listed in the OED, which was published in, what, 1910? So it isn't even a matter of it being discounted 'any more'. kwami 05:49, 9 October 2007 (UTC)

Clarification needed

  • In orbit and rotation we had:
Its orbital elements were calculated in 1783 by Pierre-Simon Laplace and its orbit was calculated in 1787 by Placidus Fixlmillner.
However, calculating the orbital elements is exactly the same as calculating "the orbit". What's special about the work of Fixlmillner in comparison to the umpteen other orbit calculations since Laplace? The references are of no immediate help, since the first has only the preface online (which doesn't reach the 1700's), while the second is in german. Deuar 17:15, 27 August 2007 (UTC)
Fixlmillner doesn't really need to be there, I suppose; the only thing special about him was that he calculated the orbit used in Uranus's first ephemeris, published by Maximillian Hell. Unfortunately, I can't find any citable info that describes Maximillian Hell as the man who came up with Uranus's first ephemeris, so it's better if he's left out. I'll try and rework the link to Forbes's History so that it links to the right chapter. EDIT: OK, it links directly to it now. Serendipodous 17:29, 27 August 2007 (UTC)
  • Next question in "Structure and composition": in the standard model of the interior, is the core solid or liquid? Liquid seems to be implied by the "no solid surface" statement, but this is never spelled out explicitly.

Deuar 11:51, 28 August 2007 (UTC)

It is not known. However I can observe that under the pressure of 8 million bar it is difficult to speek about any solid surface. Ruslik 13:04, 28 August 2007 (UTC)
  • The mixing ratio is much lower in the upper atmosphere due to its extremely low temperature.
Presumably because the saturation point is lowered and the excess freezes out and falls as snow? Is this right? Deuar 12:04, 28 August 2007 (UTC)
Yes, it is right. This explanaition is given in 'Atmosphere/Structure' subsection.Ruslik 13:04, 28 August 2007 (UTC)
  • An inconsistency (Atmosphere - Structure): First we have Ethane and acetylene tend to condense ... forming haze layers, which may be partly responsible for the bland appearance of Uranus. Then, later, it turns out that the haze is actually weaker than on the other planets, which should bring out the detail rather than obscure it: The concentration of hydrocarbons in the Uranian stratosphere is significantly lower than in the stratospheres of the other giant planets. This, ... makes it less opaque .... I'm guessing that the "which may be partly responsible for the bland appearance of Uranus." should go? Deuar 17:24, 1 September 2007 (UTC)
    I don't see any contradiction. The mixing rations of hydrocarbons are lower, but haze is thicker, which means that more hydrocarbons are in solid phase and less in gaseous. In addition haze particles on Uranus seem to be have higher absorption than, for instance, on Neptune. Ruslik 18:54, 1 September 2007 (UTC)
    So, stratosphere is transparent, and haze layers are in the lowest part of stratosphere and in the tropopause, below the layer, where gaseous hydrocarbons are concentrated. Ruslik 19:33, 1 September 2007 (UTC)
    thinking... ah, yes I probably get it. Will clarify the passage to prevent others getting the same confusion as me. Deuar 19:28, 2 September 2007 (UTC)

can someone please semi-protect this article again?

Seeing the reverted anus jokes is getting tedious. Serendipodous 18:18, 29 August 2007 (UTC)

Atmosphere of Uranus

I think the Atmosphere section is detailed enough to become its own article. I'm not sure an article on Uranus needs to go into so much detail. Serendipodous 17:43, 1 September 2007 (UTC)

Sounds right. Most of the other major sections have their own articles, and the page is getting kind-of long. Deuar 18:50, 1 September 2007 (UTC)
In fact, it is not so long as it could be. I omitted lots of details. I think it is better to keep it in the main article for now. Ruslik 19:15, 1 September 2007 (UTC)
However a separate article can be created with possible future expansion in mind. Ruslik 19:18, 1 September 2007 (UTC)
Personally, I don't think anything below "composition" is really needed for the atmosphere in this article. The rest could easily form a separate article that could link here. But I'm not entirely sure what the conventions are for dealing with planets. All I know is thatno other planetary article has as much information as this, and, besides Neptune, they're all featured. Serendipodous 20:26, 1 September 2007 (UTC)
I'm not sure there is any convention. Other article lack this information, because it is harder to find. I, personally, was dissatisfied by the lack of information regarding the structure of atmospheres, which made me eventually write about it myself. However, I want to note, the article about Earth contains structural information in the main text, and by writing about Uranus I wanted to extend this standard to all planetary articles.Ruslik 15:19, 2 September 2007 (UTC)
Created subarticle. Also had an attempt at a shorter atmosphere subsection. Let me know what you think: Talk:Uranus/atmosphere Serendipodous 14:14, 2 September 2007 (UTC)
I will read it. Ruslik 15:19, 2 September 2007 (UTC)
I have read it. You do like composition more than structure. However the last paragraph hangs in the air. It mentions tropopause and stratosphere without explaining their meaning in the case of Uranus. It also mentions acetylene and ethane without providing information about their origin and mixing ratios. In addition the first paragraph mentions 'coronal gases' without defining corona. Besides some content further in the article is anchored to the atmospheric section.Ruslik 15:52, 2 September 2007 (UTC)
I modelled it on the other featured articles. (see Saturn#Cloud layers, Venus#Atmosphere, Mars#Atmosphere). I don't think we need to go into such detail on the finer structure of the atmosphere in an introductory article. Such information is better off in a separate article on the atmosphere. Serendipodous 16:49, 2 September 2007 (UTC)
I actually made some changes in the atmospheric section and removed one figure, because it was too technical. This figure is now in the Atmosphere of Uranus. As to the text you wrote I think it can (with some corrections) serve as a leading section in this article. Ruslik 16:18, 2 September 2007 (UTC)

mixing ratio

A question probably for Ruslik, who looks to be well versed in this: in the abstract of Lindal 1987 one has the following statement: "... also to contain small amounts of CH4 at ... below-cloud mixing ratio 2.3 percent by number density." Does mixing ratio always compare to hydrogen, or could it be in proportion to the rest of the atmosphere? The journal is not online :( Deuar 23:53, 6 September 2007 (UTC)

The value for helium (0.15) is a molar fraction in pure H-He mixture. In other words, assuming that only H and He are present every 100 moleculars of gas contain 85 hydrogen moleculars and 15 helium. The mixing ration for helium relative to hydrogen is 15/85≈0.18. As I noticed molar fraction is usually used for helium and mixing rations relative to hydrogen for other gases. I can't remember what Lindal et.al meant for methane, but I can look into a hard copy of this article tomorrow. Assuming that 2.3 is mixing ratio and adding this ammount to the mixture leads to an adjustment of molar fractions of H and He. Roughly they should be decreased by 2 %. So for hydrogen we have 83.3≈83 and for helium 14.7≈15. Ruslik 06:48, 7 September 2007 (UTC)
I looked into Lindal et.al and found that 2.3 % is actually a molar fraction, not mixing ratio relative to hydrogen. The phrase in the abstract is inaccurate. Ruslik 19:13, 8 September 2007 (UTC)
Thank you for looking it up. I'll fix the values in the infobox and text. Deuar 22:18, 8 September 2007 (UTC)

Atmosphere and Climate

The Climate section appears to contain much material that looks like it could just as well be in the "Atmosphere" section - discussion of global clouds, temperatures, energy balance even (this should go in the "internal structure" section, perhaps). It seems a bit messy at first glance, especially considering Rings and Magnetosphere intervenes between the two sections. Was there a rationale according to which one sort of information made it into Atmosphere and others into Climate? Deuar 21:02, 13 September 2007 (UTC)

Well the atmosphere section discusses its composition and structure, the "Climate" section deals with dynamics, heat transfer, and movement. They could possibly be merged, but then the atmosphere section would balloon again. I think maybe a single paragraph on the blandness of the atmosphere and a single paragraph on the seasonal variation might be sufficient, with the rest going into the atmosphere article. However, I think that if it is included, the atmosphere section should be trimmed even more, since it is already three sections long. I still think that cloud features/seasonal variation are more important than structure, and that if we do merge the two sections, then the structure should go. I'll do a revision, and you tell me what you think.

Talk:Uranus/climate subpage

(I've also copied the Climate section into the atmosphere article)

I really don't think that detailed discussion of the structure is necessary with the Atmosphere of Uranus article now dealing with that. This article mentions that Uranus's atmosphere consists of a troposphere, a stratosphere and a thermosphere and where they are, and that's all it needs to do. The atmosphere article can do the rest. Serendipodous 05:35, 14 September 2007 (UTC)

Be cautious with references. Ruslik 12:24, 14 September 2007 (UTC)
Well, actually I don't really see the need to trim the atmosphere section any more in comparison to what is in the main article. For instance we have the article going on and on for pages about all the minor details of discovery and naming, and that isn't seen as a problem. After all the atmosphere and clouds account for most of what can be seen on Uranus, and for all the changes that can be seen during a human lifetime. Maybe they deserve a fair amount of treatment. Moving the old "climate" into "atmosphere" and shortening of that section is good, though. For the present length of that section we should, however, mention the South polar hood somewhere. The heat transfer discussion doesn't really seem to fit here either - maybe it should go into "Structure and composition"? Deuar 22:31, 16 September 2007 (UTC)
I don't really know what to do. I don't like the current format, which was mandated by GA reviewers because it matched the format of other featured planet articles. I don't see why "atmosphere", "magnetic field," and "structure and composition" have to all be subsections, especially when the atmosphere section is so huge. That's why I split off the climate section; to avoid the Characteristics section becoming an atmosphere section with bits dangling off it. Serendipodous 07:37, 17 September 2007 (UTC)
I think the best solution is to finish copy-edit and go to FAC. If somebody opposes on the basis of the length of a section or because there is a separate climate section, it is always possible to trim and to merge. Triming is much easier than lengthening. However, as I noticed opposition is more likely to be based on commas, dashes etc. Ruslik 17:27, 17 September 2007 (UTC)