Talk:Enceladus

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Lead section - tagged[edit]

I tagged the lead section for a rewrite because:

  • Water plumes have 3 separate entries just within the introduction.
  • Water is mentioned about 14 times.
  • Lead section should ideally contain no more than four paragraphs and be carefully sourced as appropriate.

Thank you, BatteryIncluded (talk) 16:43, 4 April 2014 (UTC)

Agreed (except sources are optional in material is referenced in the body of the article) and will add that it does a poor job of summarizing anything in the article except for the possible presence of water. --ThaddeusB (talk) 19:37, 4 April 2014 (UTC)

Rewrite[edit]

Hi,

How 'bout this for the intro paragraphs? I tried to get rid of stuff thats old scientific opinion and integrate todays new announcements better. Please add your input and what else should be changed. Thanks Reedman72 20:57, 4 April 2014 (UTC)

Enceladus is the sixth-largest moon of Saturn.[1] It was discovered in 1789 by William Herschel.[2]Until the two Voyager spacecraft passed near it in the early 1980s very little was known about this small moon besides the identification of water ice on its surface. The Voyagers showed that the diameter of Enceladus is only 500 kilometers (310 mi), about a tenth of that of Saturn's largest moon, Titan, and that it reflects almost all of the sunlight that strikes it. Voyager 1 found that Enceladus orbited in the densest part of Saturn's diffuse E ring, indicating a possible association between the two, while Voyager 2 revealed that despite the moon's small size, it had a wide range of terrains ranging from old, heavily cratered surfaces to young, tectonically deformed terrain, with some regions with surface ages as young as 100 million years old.

In 2005 the Cassini spacecraft performed several close flybys of Enceladus, revealing the moon's surface and environment in greater detail. In particular, the probe discovered a water-rich plume venting from the moon's south polar region. This discovery, along with the presence of escaping internal heat and very few (if any) impact craters in the south polar region, shows that Enceladus is geologically active today. Moons in the extensive satellite systems of gas giants often become trapped in orbital resonances that lead to forced libration or orbital eccentricity; proximity to Saturn can then lead to tidal heating of Enceladus's interior, offering a possible explanation for the activity.

On April 3 2014, NASA reported that evidence for a large underground ocean of liquid water on Enceladus had been found by the Cassini spacecraft. Cryovolcanoes at the south pole shoot large jets of water vapor, other volatiles, and some solid particles like [[NaCl] crystals and ice particles into space, totaling approximately 200 kg per second.[3][4][5] Some of this water falls back onto the moon as "snow", some of it adds to Saturn's rings, and some of it reaches Saturn. The discovery of the plume has added further weight to the argument that material released from Enceladus is the source of the E ring.

Because of the presence water at or near the surface, Enceladus may be one of the best places to look for extraterrestrial life. By contrast, the water thought to be on Jupiter's moon Europa is locked under a very thick layer of surface ice, though recent evidence may show that Europa also experiences water plumes.[6]Analysis of the outgassing suggests that it originates from a body of subsurface liquid water, which along with the unique chemistry found in the plume, has fueled speculations that Enceladus may be important in the study of astrobiology.[7] According to the scientists at Nasa, evidence of an underground ocean suggests that Enceladus is one of the most likely places in the Solar System to "host microbial life".[8][9]

--— Preceding unsigned comment added by Reedman72 (talkcontribs)

Looks good. I say go for it - it is certainly better than what we have now. I would drop the last sentence as it is largely redundant in some should be a brief summary (it can and should be included in the body). There are a few other tweaks I might make, but for copyright reasons it would be cleaner if you paste your text into the article and then I edit it rather than making the tweaks here. --ThaddeusB (talk) 22:52, 4 April 2014 (UTC)
Ok, thanks man. It has been a featured article for a long time ('06 I think) and it has kinda lost some of its "featuredness" and I hope to help it out. Reedman72 23:08, 4 April 2014 (UTC) — Preceding unsigned comment added by Reedman72 (talkcontribs)
Glad to hear it. I was actually going to nominate it to be improved or delisted as it is definitely not up to current FA standards. The lead was the worst problem - I will have a list of a few other later. --ThaddeusB (talk) 23:59, 4 April 2014 (UTC)
Yes a list would help very much. I'd rather improve it than have to delist it but I think the sectioning is kinda messy. Reedman72 00:07, 5 April 2014 (UTC) — Preceding unsigned comment added by Reedman72 (talkcontribs)
Holy smokes! You guys are busy! The intro looks very good now. And also thanks to user 79.67.241.229 for his relentless energy fixing the references throughout Wikipedia. Thank you all. Cheers, BatteryIncluded (talk) 13:42, 5 April 2014 (UTC)

Major reorganization needed[edit]

I can't do this myself as I am not intimately familiar with the article; however, right now the "Characteristics" section is largely written in chronological order, and needs to be regrouped into topical order. You can't have two sections on a subsurface ocean, for instance. Serendipodous 05:54, 5 April 2014 (UTC)

I have not read the whole article yet but I did notice, and agree, that the subsurface ocean entries should be coalesced to eliminate repetition. Same with its habitability potential. Cheers, BatteryIncluded (talk) 21:07, 5 April 2014 (UTC)
The first thing i'm doing is taking orbit out of characteristics, im just gonna go ahead with this one. Im taking a cue from Europa it has it that way. Thanks Reedman72 02:15, 6 April 2014 (UTC) — Preceding unsigned comment added by Reedman72 (talkcontribs)

"Tidal heating" section[edit]

This is one of many article adjustments coming: Other article sections dismiss tidal heating AND a subsurface ocean at equilibrium, but this section ends with "tidal heating on Enceladus may account entirely for a subsurface ocean at equilibrium". If tidal heating is an old displaced hypothesis, it must be deleted, or presented with a reduced importance weight, or mentioned briefly only for historical context. Need to read the research in a chronological context, determine the present model of 1) hydrostatic (dis)equilibrium; 2) the most likely heat source, and adjust this section/article accordingly. Cheers, BatteryIncluded (talk) 17:47, 6 April 2014 (UTC)

Pre-FA review comments[edit]

This article is currently not up to current feature article standards. If not improved, I intended to send it to WP:FAR for review. Here is a list of some things which need fixed:

  • There are a number of old comments on this talk page that say such-and-such is confusing or inaccurate that were never answered. These need reviewed and addressed where appropriate.
  • BatteryIncluded has just tagged several sentences/sections that need attention.
  • As noted above, the article is repetitive and/or poorly organized in the "physical characteristics" subsections.
  • Eyeballing it, about 20% of the article is unreferenced. All but the most obvious facts should be cited in a FA.
  • The list of Cassini flybys is out of date.
  • The date formatting (in particular in references) in inconsistent. The original authors appear to have used "January 1, 1900" type dates, so all dates should be converted to that format (no 1900-01-01 or 1 January 1900 dates).
  • Don't agree - dates should be 1900-01-01 format, since at least 95% of them already are - at this stage, it doesn't matter what the original authors did, that is ancient history. hamiltonstone (talk) 02:10, 30 April 2014 (UTC)
  • Reference formatting is inconsistent, including some refs with bare URLs. The easiest way to fix is to convert all refs to cite news/cite journal/cite book/etc. templates.
  • The number of external links is excessive and should be trimmed.

That is all for now, ThaddeusB (talk) 18:46, 6 April 2014 (UTC)

My biggest problems with it are how the subsurface ocean, now being official, is referred to as possible. Also i have reed that its discovery has something to do with its high albedo making it possible to see something a few hundred km wide millions of miles a way in the 18th century. Reedman72 (talk) 21:40, 6 April 2014 (UTC)
I agree with Reedman; That is one typical example of the kind of overhaul it needs. My impression so far of this article is that new discoveries were entered as they happened, but the article was not updated as a whole. There is a chronological structure to it rather than currently known facts, and almost every entry claims to be the latest. From the scientific perspective, it needs a thorough review to update the whole article, not just enter new data. I seems to me some important sentences need to be referenced and -unfortunately- most entries may need to be verified against the cited reference AND, further, find out if they are still current hypotheses. Not a quick fix for a single editor, as this requires of commitment to read the references and use them in the correct context. Cheers, BatteryIncluded (talk) 22:48, 6 April 2014 (UTC)

So, the article saw significant improvements during the first half of April, but there are definitely still some problems. It is now well organized, but there still seems to be significant chunks of unreferenced text. I realize that it isn't a quick fix to verify the info is still current and reference it, but there haven't been any edits in 10 days or so. As such, I am wondering if there is still interest in improving the article? --ThaddeusB (talk) 04:34, 26 April 2014 (UTC)

@ ThaddeusB, can you please mark the statements or sections you think need more references? I will make the time to look them up. Thank you. --BatteryIncluded (talk) 15:51, 26 April 2014 (UTC)
I have added cn tags to some places that I think need references. Some statements may be OR or editorializing, and some may just need the previous reference use extended. I will also complain about some references. The Herschel, W. (1790) reference almost certainly will have online readable text and so should be linked. Many other web references should state the date and publisher. A question: should journal names be linked? Or does this just cause confusion for where to click to read the reference? Graeme Bartlett (talk) 08:56, 27 April 2014 (UTC)
I added the best [missing] references I was able to find and read. I still have to go over the whole text and verify the older references support the inline citation. Also, I will let someone else cleanup all the references' format. Cheers, - BatteryIncluded (talk) 02:24, 28 April 2014 (UTC)

Is it 5th or 6th largest.[edit]

According to our article on the moons of saturn its both sixth most massive and most voluminous. The order is Titan, Rhea, Iapetus, Dione, Tethys, Enceladus. An IP changed it from sixth to fith (sic). If its an error lets fix it quick.

Reedman72 (talk) 22:14, 6 April 2014 (UTC)

Heat source[edit]

I spent most of 12 hours reading papers on the likely heat sources. Measurements and interpretations varied with time and techniques, which caused confusion not just in this article, but in the planetary science circles. Basically, tidal heating could not produce more than 1.1 gigawatts power, but the observed infrared signals are much greater than that. One estimate went as high as 15.9 GW, and the latest (2013) brought it down to 4.7 GW. Scientists are still not able to justify the "excess" heat observed emanating from the south pole (tiger stripes). I may have done mistakes in the review, but the punchline is that the heat source must be actually combination of sources; tidal heating is one, but the rest remain a mystery. CHeers, BatteryIncluded (talk) 05:05, 7 April 2014 (UTC)

Does the maximum figure of 1.1 GW include the effect of excitation by the other Saturnian moons? --JorisvS (talk) 09:30, 8 April 2014 (UTC)
It should. The model seems well accepted, so it should include all nearby planetary bodies capable of contributing to the tidal heat. BatteryIncluded (talk) 12:17, 8 April 2014 (UTC)
All right. What about a local decrease of thermal insulation? --JorisvS (talk) 13:12, 8 April 2014 (UTC)
It seems the hot spots in the south pole are not because a thinner crust or decreased insulation, but because of the fissures (tiger stripes). BatteryIncluded (talk) 13:28, 8 April 2014 (UTC)
Well, if there is warm material flowing out of the fissures, that would effectively decrease the thermal insulation in those areas. --JorisvS (talk) 14:28, 8 April 2014 (UTC)

The image for the cryovolcanism shows the surface ice temperature as "-77K". It is probably 77K and someone just tossed in the negative sign. I dont know the real temp so i figured i would just mention it and leave it to someone who knows to fix it. — Preceding unsigned comment added by 50.79.188.77 (talk) 14:42, 9 April 2014 (UTC)

Good question. Actually, the image displays not -77K but a tilde, squiggly line (~) which means "approximately" 77K. Thank you. BatteryIncluded (talk) 18:01, 15 April 2014 (UTC)

Ice[edit]

It may be obvious but it needs to be made clearer that Enceladus is an icy moon. It isn't mentioned in the intro and it isn't mentioned in the surface features section. Ice and water are a fairly important part of its identity. Serendipodous 08:51, 28 April 2014 (UTC)

Reliability of source[edit]

Does anyone have a view on why this webpage prepared by someone called Alexander Clarke should be considered a reliable source? (currently used in footnote 45). hamiltonstone (talk) 02:12, 30 April 2014 (UTC)

The cleanup is a work in progress. Thank you. --BatteryIncluded (talk) 07:34, 30 April 2014 (UTC)


Flattening of Enceladus's rotation axis...[edit]

Regarding:

... have led to a flattening of Enceladus's rotation axis ...

How can a rotation axis be flattened? Isn't it the moon itself that is being flattened? --Mortense (talk) 21:18, 8 June 2014 (UTC)

Yes it sounds weird. I'll read the references and context. --BatteryIncluded (talk) 01:57, 9 June 2014 (UTC)
The source (Porco et alii) actually says "more oblate" and "less oblate". I've restored the sentence and fixed the wording. Tbayboy (talk) 03:32, 9 June 2014 (UTC)

Stop it![edit]

People, quit moving this page back and forth without getting a consensus. Double sharp: saying "we should discuss this" in an edit summary while moving a page over a move over a move... what gives?? hamiltonstone (talk) 03:14, 20 June 2014 (UTC)

I've moved it back for the discussion. (I still think that it looks odd if it's the only moon not needing dismabiguation, and that some other moons in the Solar System may well also be way more well known than their mythological counterparts. (I also note that we have situations Chaldene redirecting to Chaldene (moon), with no article on the mythological character: granted that's not exactly a major moon, but shouldn't we also have the article without disambiguation?) Double sharp (talk) 03:28, 20 June 2014 (UTC)
Similar arguments have been brought up elsewhere on Wikipedia, for example here and here. Consistency is important, but as those discussions show, consistently following WP:PRECISE outweighs consistency with using the same parenthetical disambiguations, especially when those parenthetical disambiguations are unnecessary. Precision shouldn't be ignored just because other articles are at their appropriate levels of precision. If other articles have unnecessary parenthetical disambiguations, the solution would be to fix those articles and bring them in line with Wikipedia guidelines rather than to add unnecessary parenthetical disambiguations to article titles just to have them "match". (Also, thank you for moving it back and discussing it) - Aoidh (talk) 03:40, 20 June 2014 (UTC)
OK, I see. I think I'll go through some of the other moons and remove the disambiguation where it's not necessary. I'm sorry about the repeated moves. Double sharp (talk) 10:03, 20 June 2014 (UTC)