Talk:Io (moon)

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    Here are the current list of issues that I feel need fixing before an FAC attempt (or peer review):

    • Clarify technical language, especially in the second half of the article
    • Standardize article citations, using the various Cite templates.
      • Add articles links for each citation
    • Improve description of Tidal Heating
    • Add description of dust streams
    • Improve External Links

    --Volcanopele 21:23, 3 June 2007 (UTC)

    Contents

    [edit] older entries

    it must be very young. an estimate in years would be nice. 10,000 years old? 100,000? Kingturtle 22:53, 24 Oct 2003 (UTC)

    I'd guess that the oldest portions of Io are approximately 10,000 years old. The most volcanically-active regions on the moon change visibly over a course of a couple of months or less.
    10K years seems a bit short when concerning the oldest features on the surface of Io. When considering Earth, which is also considered to have a fairly new surface, there is still some exposed area that is on the order of several billion years old. Closer analysis of Io will likely show the age of the oldest surface areas to be on the order of at least millions of years old. These areas may, however, be covered by some amount of dust, which will surely give debators plenty of arguing space when discussing the true age of the surface. -yalbik 06:15, 14 Oct 2004 (UTC)

    that 10,000 years suggestion stinks of YEC...... there is a reason for io's surface to be so young. io itself is not. Ezkerraldean 12:12, 18 January 2007 (UTC)

    In fiction/film Outland - which was nicknamed High Moon for its' clear Western genre aspect - was nearly called Io. It was changed to avoid confusion with the comedy 10. -Sparky 23:30, 8 Feb 2004 (UTC)

    [edit] Volcanos and Sulfur Dioxide

    The comment: "Unlike volcanoes on Earth, Ionian volcanoes emit sulfur or possibly sulfur dioxide." is odd, because volcanoes on Earth often emit sulfur dioxide. Occasionally they even emit actual sulfur.

    I changed it to: "Similarly to volcanoes on Earth, Ionian volcanoes possibly emit sulfur and sulfur dioxide". Miraceti 17:03, 9 Oct 2004 (UTC)
    I think the volcanos on Io emit significantly more sulfur and sulfur dioxide than those of Earth, however. In fact, I recall that it wasn't until Galileo that there was evidence that there was any silicate lava being erupted at all. If my recollection is correct, the line should be a lot more strongly worded than that. Bryan 18:15, 9 Oct 2004 (UTC)
    I have changed it again :-). This time according to idea written on [1] Miraceti 19:38, 9 Oct 2004 (UTC)
    This issue isn't whether Earth or Io emits more sulfur (or Sulfur dioxide) during volcanic eruptions, it is that on Earth, there is far more variety in volcanic gases than is apparent on Io. Volcanic eruptions on earth tend to spew large amounts of water vapor and carbon dioxide, gases absent on Io. not sure where this puts the statement in this article but I hope this helps. Volcanopele 19:55, Jun 24, 2005 (UTC)

    [edit] Request for references

    Hi, I am working to encourage implementation of the goals of the Wikipedia:Verifiability policy. Part of that is to make sure articles cite their sources. This is particularly important for featured articles, since they are a prominent part of Wikipedia. The Fact and Reference Check Project has more information. Thank you, and please leave me a message when you have added a few references to the article. - Taxman 17:43, Apr 22, 2005 (UTC)

    [edit] EO?

    On Jeopardy today there was a clue where the answer (question) was "What is IO?" but the guy said "What is EO?" and they accepted it. This made me wonder if there was another pronunciation. I looked around and found this PBS webpage that says the 4 moons are "Eo, Europa, Ganameta, and Callisto". Is Eo an alternate spelling? What's the deal? -- 1 July 2005 06:01 (UTC)

    No, but it's an alternate pronunciation. I assume that the Jeopardy answer was spoken, not written? I also notice that the PBS page is a transcript, and transcribers have to write down a lot of stuff they know nothing about; especially with proper names, they often just make a guess at the spelling. Note that 'Ganymede' is also spelled wrong. From the transcription, I'd guess that guy they were interviewing was trying to recreate the Classical Greek pronunciations. (Each of the moons in Wikipedia is listed with its Greek source, if you want to check it out, although a few are missing stress markings.) The Galilean moons would be pronounced [iː.ˈɔː] for Io (Îô), which with an English accent would come out as EE-oh; [ew.ˈrɔː.pɛː] for Europa (Eurôpê); [ga.ny.ˈmɛː.dɛːs] for Ganymede (Ganymêdês); and [kal.li.ˈstɔː] for Callisto (Kallistô). —kwami 2005 July 1 07:11 (UTC)
    P.S. A couple months ago, the various moon names were a hodgepodge of pseudo-Greek and naturalized English pronunciations, with no indication of what was what. They should now all have naturalized pronunciations, but for those who wish to pronounce Titan as tee-TAHN, the Greek (or Latin) is there as well.
    Oops, I take back part of my comment. The 'Classical' pronunciations are sometimes an attempt to recapture the Latin version of the names, not the original Greek. (They were borrowed by the Romans from the Greeks, and we got 'em from the Romans.) In these cases the stress would be the same as in English: Io would be EE-oh rather than ee-OH, and Titan would be TEE-tahn. kwami

    [edit] Ionian vs. Ioan?

    Some anon changed all the adj. forms to 'Ioan', claiming this was the form in the technical lit. I've never seen this, but if there is a ref, we could add it as an alternate. kwami 14:06, 22 November 2005 (UTC)

    Examples of Ionian (yes, I know this is irregular given the Greek, but we're not speaking Greek):
    "The calculated loss cone ranges from ~1.5° to ~2.5° over one Ionian revolution around Jupiter."
    — Electron Beams and Ion Composition Measured at Io and in Its Torus, Science 18 October 1996
    "The UV emissions from the torus will reveal the nature of the Ionian material and Jupiter's energy output."
    —STS-95 Payload: International Extreme Ultraviolet Hitchhiker (IEH-3) (NASA)
    "PIA00709: Massive Resurfacing of the Ionian Volcano Ra Patera"
    —Title of NASA photo release.
    "These lava lakes could be an Ionian version of mid-ocean ridges"
    —quote from Tracy Gregg, assistant professor of geology at State University of New York, Buffalo
    Etc. kwami 18:00, 22 November 2005 (UTC)

    some people use the word ioan for people from ioia USA —The preceding unsigned comment was added by 172.206.77.234 (talk) 20:23, August 20, 2007 (UTC)

    [edit] Translations upcoming

    I added the first big section of information I translated from the Portuguese wiki- more is coming later.--Adam (talk) 03:50, 24 January 2006 (UTC)

    Sorry, I forgot to add that I have translated all the information that was available from the Portuguese version.--Adam (talk) 11:41, 8 April 2006 (UTC)

    [edit] Largest recorded volcanic eruptions?

    "In February 2001, the largest recorded volcanic eruptions in the solar system occurred on Io.[5]" Is that eruption bigger than the recent Tvashtar? What meassurement: plume height, lava distribution, something else? -- Jeandré, 2007-03-09t19:10z

    This statement is based on the amount of energy released by the Surt eruption in 2001. This power measurement is related to the temperature and areal extent of lava generated by a given eruption. As far as I know, no such measurements have been announced for the current Tvashtar eruption, though coordinated Keck AO measurements and measurements with the RALPH instrument on NH might be able to determine if the 2007 Tvashtar eruption was more powerful than Surt 2001. However, prior eruptions by Tvashtar, in 1999 and 2001 were weaker than Surt. --Volcanopele 21:03, 9 March 2007 (UTC)

    [edit] Thoughts on a new image

    image:io_diagram.gif

    NASA just released this image demonstrating Io's tidal flexing, but I thought I'd post it here before releasing it onto the page, because it isn't quite "scientific looking". What do you think? Serendipodous 15:48, 12 March 2007 (UTC)

    It looks like the creature in the Zoloft ads.--Curtis Clark 03:34, 13 March 2007 (UTC)
    I think we could do better than this. It doesn't really explain much and it looks amateurish - the moon inexplicably flips mirror-image halfway through the animation. http://spaceplace.nasa.gov/en/kids/gll_moons1.gif and http://spaceplace.nasa.gov/en/kids/gll_moons2.gif (from the same source, [2]) would be better images to appropriate, IMO; they explain how it is that Io's tidal flexing is driven by the other moons. If Io were in isolation it would soon become tidally locked with Jupiter and circularize its orbit, putting an end to all the flexing. Bryan Derksen 05:07, 13 March 2007 (UTC)
    The apparent mirroring is just a really bad job of switching volcano eruptions from upper-left/lower-right to upper-right/lower-left. I agree about the other images.--Curtis Clark 05:25, 13 March 2007 (UTC)

    OK; we may not put that one up, but we have to post this one. I don't care where, I don't care why. But it must go up somewhere:

    [3]

    Why? Sure it is kinda cool looking but it doesn't illustrate anything about Io that can't be better explained by better images. --Volcanopele 22:04, 2 April 2007 (UTC)

    And it's clearly nonsense!

    [edit] Current Revision

    I am currently working to revise the Io article to bring it on par with the Enceladus article I and others worked on last year. Obviously, this is still a work in progress, but so far I have greatly expanded the "History of Exploration" section. I have also added sections on Io's orbit and interaction with Jupiter's magnetosphere, though those will need a lot of work. I will work on the physical characteristics section tomorrow, plus I will be working to add image to the article, or generally improving the selection we have.

    If others would like to help, that would be great. Particularly, I would like to reevaluate what images are used in this article. I like the Io interior model image and the title image, those I think should stay where they are. The image below the Io interior model should be changed since it shows the same area as the title image, and it might be nice to get a few global image that show different regions on the surface, like this one of the Pillan "black eye", this one of the trailing hemisphere, or this one of the leading hemisphere. I'd also like to include one or two Voyagers image in the History section, like the plume discovery image and a mosaic of the south polar region. —The preceding unsigned comment was added by Volcanopele (talk • contribs) 04:38, 22 April 2007 (UTC).

    Do we really need ALL of those parameters in the infobox? I propose eliminating the following parameters: Rotation velocity at equator, Volume, Surface Area, Periapsis, Apoapsis, Orbital circumference, and Max and Min orbital speed. --Volcanopele 05:10, 22 April 2007 (UTC)
    I'm hoping to start work on the Volcanism section soon, but likely always, life gets in the way of Wiki editing (finals, jury duty, work, moving...). I am currently reading the best source I could find on Ionian volcanoes, my friend Jani's PhD dissertation on Ionian paterae (otherwise known "Everything You Would Ever Want to Know about Io's Volcanoes but Never Thought to Ask). This is a 250-page behemoth, so it will take me a while. --Volcanopele 21:04, 2 May 2007 (UTC)
    I want to thank Yomangani for their very helpful copyedits. There are few things I would like to add first before any peer review or FAC attempt. First, the "Interaction with Magnetosphere" section needs improvement. Second, the various red links in the article need to be dealt with. So all the volcanoes mentioned in the article will need at the very least a stub article. For some, this should be very easy, like Prometheus and Pillan Patera. I'm surprised that these don't have one already. I haven't touched the atmosphere section; I'll have to take a look at that. Finally, I want some Io researcher friends of mine to have a look at it. --Volcanopele 17:11, 25 May 2007 (UTC)
    Redlinks won't stop it getting to FA (it isn't a criterion and claims that they are a bad thing for articles is one of my bugbears). In this case there are probably easy to write articles for most of the redlinks, so it wouldn't be a bad thing to fill some off them, but don't feel it is your duty to make up for the fact that somebody else hasn't written an article that should be in the encyclopedia (I normally take articles to FAC riddled with redlinks, and I haven't had one fail yet). Yomanganitalk 17:58, 25 May 2007 (UTC)
    I'm tempted to remove Io played a significant role in the development of science in the 17th and 18th centuries. as it is a bit of a waffly sentence. Better way of writiing this maybe? cheers, Cas Liber | talk | contribs 01:12, 27 May 2007 (UTC)

    The heading History of observation and exploration is longish but is there a succinct alternative?cheers, Cas Liber | talk | contribs 01:16, 27 May 2007 (UTC)

    OK - the orbit section should have the stuff about the Io Plasma Torus as a subsection - should all the Interaction with Jupiter's magnetosphere go within it?

    thank you for the comments and the edits. WRT your first point, maybe "Io and the other Galilean satellites played a significant role in the development of astronomy in the 17th and 18th Centuries" to make it a bit clearer. WRT your second point, maybe "Observational History"? Finally, I think the two sections, "Orbit" and "Interaction with Jupiter's magnetosphere" should remain separate sections. --Volcanopele 19:59, 27 May 2007 (UTC)
    • It would be good to work all the See Also items into the general text. They seem to frowned upon at FAC these days. cheers, Cas Liber | talk | contribs 08:36, 3 June 2007 (UTC)

    Can we lose the doctored images where the areas which were too hot to be imaged by the camera have been coloured to look like terrestrial lava flows.

    I think the images are entirely appropriate but I have changed the caption of that image to mention that the November 1999 were drawn in to replace areas that were saturated in the original data. However, the graphic is based on knowledge of how the CCD acts when it is saturated. So the height of the fire curtain and the size of the lava flow it produced is accurate. It isn't as if Galileo imaging scientists pulled the size of that lava flow and lava curtain out of thin air. --Volcanopele 18:32, 21 June 2007 (UTC)

    These doctored images just stink of assumption. The Galileo imaging scientists have not pulled this information out of thin air, they are seeing something they do not understand and explaining it by looking at similar things happening on Earth. Very short sighted, for example. If the only thing happening on Io is volcanism why are these plumes not smeared over the surface of the moon by coriolis force?

    [edit] Video of eruption

    There's a spectacular video of an eruption here: [4]. If the rights are available, can this be uploaded? Spikebrennan 15:02, 16 May 2007 (UTC)

    It's a NASA image, so it's public. I'll have a go at swapping it for the still image of Tvashtar. Serendipodous 17:11, 16 May 2007 (UTC)

    [edit] GA pass with suggestions

    This article more than meets the requirements for GA, in my opinion. Here are my suggestions for improvement.

    On clarity:

    • Io is primarily composed of silicate rock surrounding a molten iron (or iron-sulfide) core - Do you really mean "or"? Perhaps you mean "that is"? Right now the sentence sounds like the core is made of molten iron or iron sulfide, we are not sure which.
    • Could you include some dates for Simon in the "Name" section so that we can place him historically? (It is weird to have that information come after you have introduced him - in the "Observational" section.)
    • During the 17th Century, Io and the other Galilean satellites served a number of practical purposes, including helping mariners determine their longitude, validating Kepler's Third Law of planetary motion, and determining the light time between Jupiter and Earth. - do these all really count as "practical"? To me, only the sailing one really does.
      How did Io help mariners determine their longitude?  —Preceding unsigned comment added by 155.246.141.172 (talk) 00:34, August 29, 2007 (UTC)
    • Observations during these encounters revealed the detailed nature of the geologic processes occurring at Io's volcanoes and mountains, excluded the presence of a magnetic field, and demonstrated the extent of volcanic activity - "excluded" phrase doesn't' match the rest - kind of like a non-parallel construction
    • In December 2000, joint observations of Io were made by Galileo and the Cassini spacecraft (making a distant encounter with Jupiter en route to Saturn) - "which was making"? - tenses do not match up
    • new observations of Io's volcanism predominately came from adaptive optics imaging from the Keck telescope in Hawaii - "predominantly"?
    • Some of this material escapes Io's gravitational pull, and goes into orbit around Jupiter. - "goes into orbit" sounds a bit too informal

    This article is a bit too technical at times for the educated, lay reader like myself. I would suggest additional explanations and wikilinking to counter the use of unfamiliar scientific terminology and concepts. I am not advocating that you do away with the scientific terminology - just explain it better. Here are some examples from the first part of the article:

    • Improved telescope technology in the late 19th and 20th centuries allowed Io's disk to be resolved by astronomers. - Does "resolved" mean "seen" here?
    • In the 1890s, Edward E. Barnard was the first to resolve variations Io's brightness between its equatorial and polar regions, correctly determining that this was due to differences in color and albedo between the two regions and not due to Io being egg-shaped, as proposed at the time by fellow astronomer William Pickering, or binary, as initially proposed by Barnard.
    • The authors calculated that Io's interior must experience significant tidal heating caused by its orbital resonance with Europa and Ganymede. - Could you explain this process a bit more?
    • Data from this flyby showed that the surface of Io is dominated by sulfur and sulfur dioxide frosts, compounds that also dominate its thin atmosphere, and the torus of plasma centered on Io's orbit (also discovered by Voyager). - Could you link or explain "torus"?
    • This resonance helps maintain Io's orbital eccentricity (0.0041), which in turn provides the primary heating source for its geologic activity. - Could you explain a tad more?
    • Galileo's magnetometer failed to detected an internal magnetic field at Io, suggesting that the core is not convecting. - might you briefly explain "convecting"? Awadewit | talk 08:57, 3 June 2007 (UTC)
    Thank you for the review. Here are some responses:
    • I really do mean "or". Based on current models of Io's interior, we can't be certain how much sulfur is in Io's core. The amount of sulfur can change the size of the core by an appreciable amount and the addition of "(or iron-sulfide)" is necessary.
    • Ah, I see. Then, I suggest you remove the parenthesis - make the "or" a real "or." Awadewit | talk 19:16, 3 June 2007 (UTC)
    • Added date for Simon Marius' naming of Io in the Name section.
    • Maybe practical isn't the right word here, but I am trying to say that astronomers and mariners used Io for purposes other than actually studying Io. This is a matter of word choice and I am open to suggestions.
    • What about "In the seventeenth century Io served a variety of purposes, everything from helping mariners to determine their longitude to playing a vital role in proving Kepler's third law of planetary motion" (or something like that). Awadewit | talk 19:16, 3 June 2007 (UTC)
    • Rereading that sentence, I think it is the first clause that doesn't fit the pattern. Removed "the detailed nature of".
    • I've reworded the Cassini and Galileo sentence as: In December 2000, the Cassini spacecraft performed a distant encounter with the Jupiter system en route to Saturn. Cassini and Galileo obtained joint observations of Io, which revealed a new plume at Tvashtar Paterae and provided insights into Io's aurorae.
    • "performed a distant encounter with"? Still doesn't sound right to me. How about, "Cassini had a distant and brief encounter with the Jovian system en route to Saturn during which it was able to obtain pictures of Io that revelaed a new plume at Tvashtar Paterae and observations that provided insights into Io's aurorae." (or something like that). Awadewit | talk 19:16, 3 June 2007 (UTC)
    • It kind of sounds repetitive - what makes all of these telescopes different? (Sorry to be so picky.)Awadewit | talk 19:16, 3 June 2007 (UTC)
    • Hmm, not sure how to rephrase that right now..."enters orbit", "starts orbiting"...
    Yeah, I know I've tried to explain as much as possible but let's see what you have to say. I know I need to do more wiki-linking
    • hmm, "resolved" is technical...hmm, how's "Improved telescope technology in the late 19th and 20th centuries allowed astronomers to see large-scale surface features on Io"
    • That's fine. Like I said at the top of my comments, you can keep "resolved," just explain it. "resolved, that is, see" (that way you are teaching the reader! yeah!). Awadewit | talk 19:16, 3 June 2007 (UTC)
    • Replaced "resolved" with "observed" and "binary" with "two separate objects".
    • Oh, I didn't even think about "binary" - good catch. Awadewit | talk 19:16, 3 June 2007 (UTC)
    • I've added a link to the Interior section at the end of the sentence where I did put a more detailed explanation of Io's tidal heating.
    • I didn't understand why the tidal heating happened. I was very curious about that. Later in the article, there is an explanation, but I'm not sure I totally got it. Awadewit | talk 19:16, 3 June 2007 (UTC)
    • I've added links to the relevant sections in the article in that sentence.
    • I've again added a link to the Interior section at the end of the sentence where I did put a more detailed explanation of Io's tidal heating.
    • I can't explain the importance right now, but I will try later today.
    Again, thanks for the review, and I will look for overly technical language in the rest of the article. In the end though, to really clear things up, I need lists like you have provided to point out what is technical, and what is not. I just got my BS in Geosciences and I spent several years working on Io research (I should point out that I am a co-author on several of the papers cited in this article, as well as the main author for a couple of the citations). So, sometimes I am not always sure what is technical and what is not. --Volcanopele 18:03, 3 June 2007 (UTC)
    I totally understand where you are coming from. I am working on my dissertation in English literature and when I write pages on my dissertation topic, sometimes I assume too much knowledge and use words that have a different meaning in literary theory than they do in the "real world." But there are a lot of nice, helpful science reviewers who read my articles and go "what in the world are you talking about there?" I try to ask myself the question, "How would I guide a freshman or sophomore through this page?" I suppose I have an advantage answering that question since I teach freshman composition, but it is still a worthwhile question to think about. Awadewit | talk 19:16, 3 June 2007 (UTC)
    I think I have cleared up a few of these items in the article. The tidal heating paragraph could use some expansion (maybe even made into its own sub-section) so that it is more fully explained. In the interim, I had added the most important point to understand to the lead section: "This extreme geologic activity is the result of tidal heating, friction generated within Io's interior by Jupiter's varying pull on Io". --Volcanopele 20:11, 3 June 2007 (UTC)
    If there is to be a separate "tidal heating" section (which I think is a good idea) then perhaps this JPL illustration could be used to illustrate the concept. Serendipodous 15:34, 4 June 2007 (UTC)

    [edit] Articles for Individual Volcanoes

    As mentioned in the Current Revision post above, one of the issues that I think should be resolved in this article are the red links, particularly some of the individual volcanoes on Io that need articles. To facilitate such article creation, here is a tiered ranking, that IMHO, represent the volcanoes that need articles the most:

    Tier One:

    • Pele - I added a stub article this recently for this persistently active volcano. Pele is responsible for one of the most conspicuous surface deposits on the surface of Io.
    • Prometheus - No article yet. Persistently active and well-studied volcano
    • Loki Patera - Stub article exists, but for being one of the most powerful volcanoes known, that is a pretty small article (only 3 sentences :O )
    • Tvashtar Paterae - Another stub article - definitely could use improvement
    • Amirani - Like Prometheus, a persistently active and well-studied volcano
    • Pillan Patera - No article. A well-studied outburst eruption from mid-1997

    Tier Two:

    • Kanehekili - No article. Persistently active volcano (with plume)
    • Masubi - No article. Persistently active volcano featuring one of the largest active lava flows on Io. Site of two plumes in 2007.
    • Marduk - No article. Persistently active volcano (with plume)
    • Thor - No article. Well-studied outburst eruption from 2001. Still an active volcano.
    • Surt - No article. Site of a well-studied outburst eruption from 2001.
    • Zamama - No article. Persistently active volcano from the 1990s.

    Tier Three:

    • Tupan Patera - Well-studied active volcanic depression. Site of a 2003 outburst.
    • Gish Bar Patera - Well-studied active volcanic depression. Site of a 2001 (and maybe 1999 and 1996 as well) outburst.
    • Culann Patera - Well-studied active volcano.

    --Volcanopele 18:35, 4 June 2007 (UTC)

    [edit] Scientific Peer Review

    As noted at the top, I have submitted this article for Scientific Peer Review. Please feel free to participate in the discussion there. I think I have taken care of most of the issues posed in the Good Article review above and the to do list I created from that. I wikilinked to some of the jargon introduced in the article to help explain them. I standardized the citations used by switching all of them to {{cite}} templates. I know they look ugly in the body of the article when you look at the wiki text, but it is preferable to the alternative. I have added a little more to the Tidal Heating section (also made it a section so people can quickly get to it). I will probably use the Volcanism on Io article to provide a more extended discussion. I've added a paragraph on the dust streams, improved the organization of the external links, and brought the lead section up to the standards of WP:LEAD.

    Thanks for everyone's help! --Volcanopele 00:37, 13 June 2007 (UTC)

    [edit] Observational history

    should include a section on New Horizons. Serendipodous 18:45, 20 June 2007 (UTC)

    There are a few sentences covering the New Horizons encounter. However, at the depth of coverage currently in Observational History, I don't see why a separate section for New Horizons is needed. Maybe after the first round of papers and the significance of any discoveries made by New Horizons is officially out there, maybe. But I think at this point, the level of coverage is appropriate is on par with the Cassini encounter. Now, if you would like a sister article dedicated to Ionian exploration, I would be all for that. And in that article, New Horizons would definitely have a separate section. --Volcanopele 18:51, 20 June 2007 (UTC)
    Would you mind if I split off the final paragraph in "Galileo" and created a section called "Subsequent observations"? Serendipodous 19:02, 20 June 2007 (UTC)
    Okay, that makes sense. --Volcanopele 19:09, 20 June 2007 (UTC)

    [edit] Synchronous?

    This article (as well as tidal locking) says that Io's rotation is synchronous with Jupiter. But the cover story in the August 2007 Astronomy magazine says: "Io has tried to become tidally locked to Jupiter. But the moon's orbit is too eccentric, and its siblings add stresses that prevent it from achieving synchronous rotation." After reading that, I was wondering what other solar system bodies are known to be not tidally locked, but now I'm wondering about Io itself. Is one of the articles incorrect, or am I missing something? --Spiffy sperry 02:47, 14 July 2007 (UTC)

    [edit] Shouldn't this article get an FA review?

    Its scientific review hasn't been active in over a month. I think User:Volcanopele has done more than enough for Io to requalify for an FA nom. Serendipodous 12:13, 23 July 2007 (UTC)

    I agree, I was just coming back to check exactly that. Yomanganitalk 13:26, 23 July 2007 (UTC)
    OK. Just nominated it. Serendipodous 13:32, 23 July 2007 (UTC)

    [edit] Issues

    Some questions came up when I read this article:

    • The following sentence is somewhat unclear to me: "Over a 20-hour period, these particles form a banana-shaped neutral cloud that can reach as far as 6 Jovian radii from Io, either inside Io's orbit and ahead of the satellite or outside Io's orbit and behind the satellite." So is there a cyclical process at work? Otherwise, what is the significance of the 20-hour period? Does the banana-shaped cloud oscillate back and forth?
    • The expression "quadrupole gravitational coefficients" is unexplained jargon. Could this be clarified?
    • In the "Tidal Heating" section, where does the energy comes from to maintain the tidal dissipation? I.e. is it from a net change in the resonant satellite orbital periods? Perhaps from a change in Jovian rotation? It must come from somewhere—I can't imagine it's a perpetual motion machine—but it's not really clear from the article.

    Thanks. — RJH (talk) 17:43, 29 July 2007 (UTC)

    Questions answered in FAC. --Volcanopele 19:34, 29 July 2007 (UTC)
    As to your third point, the energy comes from Jupiter's gravity attempting to circularize Io's orbit through tidal dissipation. Europa and Ganymede's gravity act to maintain Io's orbital eccentricity, so the tidal dissipation adds energy to Io's interior rather than to orbital circularization. Thus energy is added to Io's interior and removed from Jupiter.
    Thanks, but this doesn't really answer my question. If the orbits of Io, Europa and Ganymede are stable (so there is no change in their orbits), then there is no net change in energy. So the energy has to come from some other source, such as Jupiter's rotation or a net contraction in Jupiter's mass. — RJH (talk) 15:56, 1 August 2007 (UTC)
    That assumes that the orbits don't change. [5] has the best explanation I could find online. --Volcanopele 18:37, 1 August 2007 (UTC)
    Yes that's a good article. But this article appears to say that torque exerted by Jupiter provides orbital energy to the satellites, which is then dissipated by tidal friction. So wouldn't that slow Jupiter's rotation rate? — RJH (talk) 19:17, 1 August 2007 (UTC)
    The orbits change of course, and the ultimate source of energy is rotation of Jupiter. The best explanation is here [6].Ruslik 10:02, 2 August 2007 (UTC)
    Thanks. So, for the sake of comprehensiveness, could an explanation of this be incorporated into the text? — RJH (talk) 16:05, 2 August 2007 (UTC)

    [edit] Tvashtar pic

    What happened to the image of Tvashtar Patarae? It's showing up on its own page but it's not showing up on any page it's linked to. Serendipodous 06:55, 29 August 2007 (UTC)

    Not quite sure. Should we try to upload another version? --Volcanopele 17:22, 30 August 2007 (UTC)
    Subbed a new image. Should hold up for a while, I hope :) Serendipodous 17:43, 30 August 2007 (UTC)

    [edit] Most active vs. One of the most Active

    I saw in the boilerplate of the article the following phrase: "Io has one of the most geologically active surfaces in the solar system, " should this not be changed to simply state that it is in fact THE MOST active by far of any object in the solar system. My Astronomy text book says this and so do the following articles: [7] [8] [9] Why be vague? The current wording begs the question, "well what is the most active in the solar system?" --Metal.lunchbox (talk) 23:19, 7 December 2007 (UTC)

    agreed. Added source and rewrote sentence. Serendipodous 18:46, 12 February 2008 (UTC)

    [edit] Io on the main page

    I propose to nominate Io to be the article of the day on January 7 2008—the day of discovery. Ruslik (talk) 15:06, 10 December 2007 (UTC)

    Image of Io taken by the Galileo spacecraft

    Io (pronounced /ˈaɪoʊ/ eye'-oe, or as Greek Ῑώ) is the innermost of the four Galilean moons of Jupiter and, with a diameter of 3,642 kilometers, the fourth largest moon in the Solar System. It was discovered in 1610 by Galileo Galilei, along with the other Galilean satellites. This discovery furthered the adoption of the Copernican model of the Solar System and the development of Kepler's laws of motion. Unlike most satellites in the outer Solar System (which have a thick coating of ice), Io is primarily composed of silicate rock surrounding a molten iron or iron sulfide core. Io has one of the most geologically active surfaces in the solar system, with over 400 active volcanoes. This extreme geologic activity is the result of tidal heating from friction generated within Io's interior by Jupiter's varying pull. Several volcanoes produce plumes of sulfur and sulfur dioxide that climb as high as 500 km (310 mi). Io's surface is also dotted with more than 100 mountains that have been uplifted by extensive compression at the base of the moon's silicate crust. Some of these peaks are taller than Earth's Mount Everest. Most of Io's surface is characterized by extensive plains coated with sulfur and sulfur dioxide frost. (more...)

    [edit] Own magnetic field or not?

    This page currently states:

    Observations during these encounters [Galileo] revealed the geologic processes occurring at Io's volcanoes and mountains, excluded the presence of a magnetic field...

    Does this mean the current view is that Io has no own magnetic field? In this case, could we please be more specific and state when (during which mission) this was established, and reference it?

    This NASA page states Data from the Galileo spacecraft indicates that an iron core may form Io's center, thus giving Io its own magnetic field.

    and

    This NASA/Galileo page (from 1996) states Galileo Finds Giant Iron Core in Jupiter's Moon Io... etc

    so you may understand I am a little confused here... Regards, --Dna-Dennis (talk) 02:57, 30 January 2008 (UTC)

    The sentence gives those details. The Galileo spacecraft, during its encounters with Io earlier this decade and in late 1999, ruled out the presence of a magnetic field, despite the presence of an iron core noted in the press release you linked to. The confusion comes from the fact that there was some evidence for a magnetic field in the 1995 flyby data, and given the result that Io had an iron core, this conclusion made sense. The later encounters showed that the data better supported the signature of an ionosphere (basically a atmospheric layer consisting of charged particles) than it did a magnetic field. Let me look up some more info on this issue. Maybe something can be added to the internal structure section, akin to "Despite having an iron core, Io does not have a magnetic field..." --Volcanopele (talk) 17:29, 30 January 2008 (UTC)
    Nevermind, that's already there: "Galileo's magnetometer failed to detect an internal magnetic field at Io, suggesting that the core is not convecting.". And that's referenced. --Volcanopele (talk) 17:32, 30 January 2008 (UTC)
    Many thanks, very good, all sorted out. It's amazing that I missed that last line, since I was looking for info on Io's (own or not) magnetic field. My regards, --Dna-Dennis (talk) 13:50, 31 January 2008 (UTC)

    [edit] Radiogenic Heating and Tidal Heating

    Heat output due to tidal heating: about 4 x 1013 W
    Heat output due to radioactive decay: about 5 x 1011 W

    So tidal heating is about 100 times as great as radiogenic heating, not "up to 10 times" as the main article says.

    Source: An Inroduction to the Solar System (ISBN-13: 978 0 521 54620)
    Eroica (talk) 14:37, 2 February 2008 (UTC)

    added source and changed figure. Serendipodous 18:31, 12 February 2008 (UTC)

    [edit] Most active, again

    With over 400 active volcanoes, Io is the most geologically active object in the Solar System.

    Two requests:

    1. Because the sentence shouts for it, the sentence needs to say 'by comparison, Earth has xxx active volcanoes.'

    2. Volcanism isn't the complete story of "geologically active" - does Io have plate tectonics? Isn't there other activity that needs to be measured before categorically stating it's the most geologically active object? Tempshill (talk) 15:20, 17 April 2008 (UTC)

    Good points. Perhaps we could say "volcanically active" instead (as we do in the volcano article). One commonly quoted figure for number of active volcanoes on Earth is 1500, but as this source points out, this depends very much on the definition of "active", and their definition almost certainly doesn't match that used for Io. Also the 1500 figure doesn't include active deep sea volcanoes - there may be a million of these. Earth is also much larger. I think a better measure for comparison would be the eruption rate for a given surface area. -- Avenue (talk) 15:52, 17 April 2008 (UTC)
    The title is based on heat flow from the interior, not based on number of active volcanoes. --Volcanopele (talk) 17:27, 12 May 2008 (UTC)
    Fair enough. It's not clear to me from our article that that's the basis of the claim, however, and I don't think readers will naturally equate "geologically active" with "high heat flow". I wonder if there's a relevant quote from one of the sources that we could add to its footnote, at least. -- Avenue (talk) 03:37, 13 May 2008 (UTC)