Talk:Io (moon)

Note

Galileo himself noted that Marius used the Julian calendar while Galileo used the Gregorian one. This is not made clear as it is. Of course, the two calendars and the different parties using them are well known. — Preceding unsigned comment added by 92.26.0.234 (talk) 14:26, 22 September 2014 (UTC)

The date of Galileo's publication, 1610, is not logical proof that he made any observations before Marius. Galileo's direct argumentation should be used. I think his argumentation is indeed proof that he did have priority, not that it is very important. — Preceding unsigned comment added by 92.26.0.234 (talk) 14:34, 22 September 2014 (UTC)

Logical or not, publication was traditionally used to determine priority as it was the first evidence that was available to people in general (and possibly because it encouraged people to publish?)

IceDragon64 (talk) 23:06, 20 January 2019 (UTC)

Water on Io

The introduction states that Io has the least amount of water of any celestial body; that would include the Sun, planet Venus and the tiniest asteroids. A user held a hot debate about that topic on Tbayboy's talk page and this link provided by the user states there might a sub-surface ocean on Io just like on the other Galilean moons. Maybe the introduction should better say Io has the least water out of all moons, that would certainly be true (if the assumption of a sub-surface ocean is wrong), but not every celestial body. Come on! Io can't have less water than the Sun or tiny asteroids, can it? -- 12:34, 6 May 2019 (UTC)

Some more context: There's a statement in Surface Composition saying "Io has the least amount of water of any known body in the Solar System", with a reference to a published textbook. It's also repeated in the lead.

My own comments:

• The German page above doesn't seem reliable: Given Io's constant volcanism, any sub-surface ocean would be coming out with the eruptions and would be spewed across the surface or in the plumes. It would be easily seen. I think the author got confused reading about Io's possible sub-surface magma ocean and its comparison with the water oceans of the other moons.
• Does the source say Io has the least total mass of water, or the least fraction? It's hard to believe that Io, dry as it is, has less water than some little asteroid.
• If it's water fraction, wouldn't the Sun have less? Or was it implicit in the source that the Sun was excluded?
• Most importantly, is there any data on the quantity/fraction of water in all known bodies for this statement to have any meaning? I find it hard to believe they even know how much water Io has at all, if you include possible internal supplies.

It's certainly worth noting how dry Io is, but saying it has the least water seems a stretch. Could somebody with access to the source (Seeds, Michael A.; Backman, Dana E. (2012). The Solar System (8th ed.). Cengage Learning. p. 514. ISBN 9781133713685) please check it? Tbayboy (talk) 15:36, 6 May 2019 (UTC)

Sub-surface MAGMA ocean, not water. Based on spectroscopic measurements going back to the 1970s all the way through Galileo NIMS have found no evidence for water ice on Io beyond some evidence for hydrated minerals north of Gish Bar Mons, though other molecules are possible candidates including SO3 and S2O (or other polysulfoxydes) (Doute et al. 2004). Is it possible there is water locked in Io's interior? Sure, I guess anything is possible, but this is a world that literally spits its interior out into space and back onto its surface. If there was water in its interior, it should have been observed either through spectroscopy of surface frosts and volcanic plume deposits or by observing Io's plumes as they transit a star. At least water vapor has been found at the Sun... Volcanopele (talk) 20:20, 6 May 2019 (UTC)

The source claims there might be a water ocean beneath Io. On the Sun, where does the water vapor come from? -- 06:41, 7 May 2019 (UTC)

I think that source is wrong: they confused magma ocean with water ocean. It's just a pop-sci website, and I couldn't find anybody else making that claim with a quick google. On the Sun, there's lots of hydrogen and a bit of oxygen, and they cool enough to combine for a while in sunspots. Tbayboy (talk) 11:53, 7 May 2019 (UTC)

The source might err, but I still don't believe that Io has less water than 10-feet-long meteoroids. 212.186.0.174 (talk) 13:52, 7 May 2019 (UTC)

10-feet long meteoroids can have a lot of water. Ruslik_Zero 06:20, 8 May 2019 (UTC)

More than Io has? 212.186.0.174 (talk) 08:28, 8 May 2019 (UTC)

If you see my question why don't you respond? If you don't know, say that you aren't sure. 212.186.0.174 (talk) 11:04, 10 May 2019 (UTC)

We (obviously) don't know the hard numbers. There may not even be any numbers. But Wikipedia goes by sources, not what we surmise, and all the reliable sources say Io is about as dry as it gets. Asteroids, generally, aren't that dry (water is bound up in the rock). Without any reliable sources to the contrary, we go with what the one referenced in the article says. I would like to check that the statement here matches the source, but don't have access to the source. Tbayboy (talk) 12:06, 10 May 2019 (UTC)

I think it's anyway unwise to mention the absolute amount of water rather than the amount relative to the size of the body. If one mentioned the latter one I think Io has a higher percentage of water than the Sun or Venus. 212.186.0.174 (talk) 17:07, 10 May 2019 (UTC)

If you can find a reliable source stating the moon Io has water, or any facts about the amount of water on IO, then link it and edit the article, but if we can't find a reliable source , we can't add it. MaximusEditor (talk) 09:25, 24 September 2020 (UTC)

FA sweeps

There are some issues with the article including over a dozen cn tags, some issues (the ones that I found are marked in the article), and some verifiability issues with page ranges of 20 pages or more. (t · c) buidhe 08:31, 13 February 2022 (UTC)

Requested move 17 September 2023

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: Not moved – consensus here seems skeptical of the idea that the moon is the primary topic. ErikHaugen (talk | contribs) 20:43, 26 September 2023 (UTC)

---

• Io (moon) → Io
• Io → Io (disambiguation)

– The moon, which played a pivotal role in our early understanding of the solar system, is clearly the primary topic by long term significance. It also appears to be primary by page views; it received around two thirds of the views of all topics with the name Io in the past year, and around three times as many as the next most common, Io (mythology). Even when we include .io, which is differentiated by the lowercase and by the dot per WP:SMALLDIFFS and thus isn't directly relevant to what the primary topic for Io is, it receives approximately half of the total views for all topics, and about twice as many as .io itself. BilledMammal (talk) 07:09, 17 September 2023 (UTC)

• Oppose per consistency. Except for the planets (and Pluto) that are named after mythological figures, the base name tends to be a disambiguation page: Europa, Callisto, Ganymede, Ceres, Vesta, Pallas, Eris, Sedna, Titan, Rhea, Tethys, Triton... Egsan Bacon (talk) 15:59, 17 September 2023 (UTC)

  WP:CONSISTENT says explicitly that we do not strive for consistency when it comes to requiring disambiguation. Orange (color) doesn't necessitate Red (color). This is literally policy. Red Slash 18:57, 17 September 2023 (UTC)

• Support as proposed. Well said, both criteria of PRIMARYTOPIC lean this way. Red Slash 18:55, 17 September 2023 (UTC)
• Weak support. The film looks like it is really IO (film) (I'll follow up with another RM once this is one is decided), so it's really between the moon and its namesake. Even discounting the film, the page view advantage isn't huge, especially given the number of other topics with this basename, and WikiNav shows the two are nearly equally sought by users reaching the dab page, which is a non-trivial number, ~5k. I think there are long-term signicance arguments on both sides. All in all I think this could go either way, but the page views do weigh slightly in favor of making the moon the primary topic. Probably the disambiguation regarding all major moon articles should be revisited with this sort of analysis. It shouldn't necessarily be that planets win out over deities but moons generally do not as it currently seems; every title should be examined by primary topic criteria individually. Of course the problem is that some titles like Europa have a lot of other uses to consider. Mdewman6 (talk) 23:15, 17 September 2023 (UTC)
• Oppose per Egsan Bacon. Also, there are 62 entries listed upon the Io / IO / iO / I/O / i/o / i.o. disambiguation page — too many for one topic to be presented as primary over the combined notability of the remaining 61 entries. —Roman Spinner (talk • contribs) 00:34, 18 September 2023 (UTC)
• We already place it among the two entries at the top, and https://wikinav.toolforge.org/?language=en&title=Io indicates that these two meanings take the lion's share of outgoing clickstreams, each the same ratio, which certainly doesn't indicate that the moon is primary over the other meanings. The computing concept of IO has at least a comparable amount of long-term significance in its field. This actually indicates that other meanings with significance are effectively being hidden from view by being part of the huge list below. In any case, I think we need a better rationale than this to make a change. (Oppose) --Joy (talk) 08:35, 18 September 2023 (UTC)

  IO is differentiated by WP:SMALLDIFFS; it will, of course, still redirect to Io (disambiguation). BilledMammal (talk) 08:42, 18 September 2023 (UTC)

  But that doesn't matter for the purposes of this discussion - IO redirects to Io already, presumably because we expect the average user to type "io" when they might mean "IO" often enough, which in turn does not seem like an unreasonable expectation. --Joy (talk) 11:27, 18 September 2023 (UTC)

  I assume it's because there is no primary topic for IO; for example, the movie using that stylization. BilledMammal (talk) 11:32, 18 September 2023 (UTC)

  Since there doesn't seem to be primary topic for Io by usage, either, this is moot. --Joy (talk) Joy (talk) 18:22, 19 September 2023 (UTC)

• Support per WP:PRIMARYTOPIC. Rreagan007 (talk) 21:32, 18 September 2023 (UTC)
• Oppose per consistency and views arguments above. There is no primary topic. -- Netoholic @ 01:24, 19 September 2023 (UTC)
• Weak oppose .io isn't really covered by WP:SMALLDETAILS as ".io" is a variant of "Io" not the other way round. Yes the moon comes to mind first but given all the other uses of the 2 letter term I don't see a clear primary topic. Crouch, Swale (talk) 18:32, 19 September 2023 (UTC)
• Oppose this primarytopic takeover. The disambiguation serves well, with two main uses acknowledged. Dicklyon (talk) 20:16, 22 September 2023 (UTC)
• Oppose no primary topic. 217.180.228.138 (talk) 03:31, 24 September 2023 (UTC)
• Oppose per Egsan Bacon where many moon names listed as well as Mercury and Ariel where they each list a lot of entries covered. Mythology and the moon are the most well known for Io.
• Support per nomination. Clearly the WP:PTOPIC long-term significance, much more than any obscure character in Greek mythology. Edward-Woodrow • talk 14:24, 24 September 2023 (UTC)

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.

Infobox image: true color or full disk?

Approximately true-colorEnhanced color image of Io from the Galileo spacecraft, taken in 1999. The dark spot just left of the center is the erupting volcano Prometheus. The whitish plains on either side of it are coated with volcanically deposited sulfur dioxide frost, whereas the yellower regions contain a higher proportion of sulfur.

True-color image of Io from the Juno spacecraft, taken in 2023. The upper-left dark spot is Io's largest volcanic basin Loki Patera. The whitish plains surrounding the dark volcanic spots are coated with volcanically deposited sulfur dioxide frost, whereas the yellower regions contain a higher proportion of sulfur.

Pinging @CactiStaccingCrane and Nosferattus:

I noticed that you two have different agendas when it comes to choosing which image is appropriate for the infoboxes of Solar System objects. CactiStaccingCrane prefers having true-color images, even when they may not show the whole view like in the case for Venus, whereas Nosferattus prefers having whole-disk images that represent the body as much as possible, with the expense of sacrificing color and data accuracy as in the case of Triton, whose colors are enhanced to appear iridescent and images are projected onto a 3D sphere that is being viewed from an angle that was not achievable by Voyager 2.

I need you two to agree on which Io image to use since this article had a minor conflict regarding that: @IapetusCallistus: changed the infobox image to the true-color Juno photo but Norsferattus reverted the image change, citing that full-disk and featured images are preferred. However, I am not aware of any official guideline that explicitly says that, let alone anybody else who vocally supports this set of criteria.

Personally, I prefer using true-color images since these portray the objects the most realistically (duh). I believe using true-color images as the lead image (and explicitly stating which images are true or enhanced color throughout the article) is necessary to avoid misleading the reader--recall the news about Neptune's true color, which led to CactiStaccingCrane and I replacing the deep blue Neptune image everywhere on Wikipedia. As I mentioned earlier, true color images may come with the downside of partial views (crescent or out of frame) since there aren't many of them out there (either due to limited spacecraft imaging, filters, or people who focus on processing true-color). However, if having full-frame and full-disk images is what Nosferattus insists for, then Venus's image would need discussion.

As a proponent for true-color, I suggest that we replace the enhanced-color image of Io with this true-color Juno image. This is true color according to this Planetary Society article by expert image processor Jason Perry. Yes, the previous saturated yellow image of Io by NASA also claims true color, but I assure you this is incorrect considering that: 1) NASA's public communication doesn't have a great track record with being clear about colors. Their deep blue Neptune image that has long misled the public is an example. and 2) The saturated yellow Io image uses near-infrared and violet filters that extends beyond the human visible range. Juno uses red, green, and blue filters that fit more within the human visible range. If that doesn't satisfy you all, then we should try looking for a better true color image that is high resolution and free to use (from Flickr).

Nrco0e (talk) 22:09, 23 January 2024 (UTC)

Hmm I'm fine with either since I am new here so I don't consider myself as a skilled editor. And I am not very interactive because I am busy always and I edit on my free time

But.. but. Remember that Juno will approach Perijove 58 this Feb 3 and will make another pass of Io at the same distance at Perijove 57. Maybe we can get better illuminated photos later.

And Juno will continue passing by Io several times starting at Perijove 59, but more and more distant ones as time progress? Long story short my opinion: let us wait for Juno IapetusCallistus (talk) 22:24, 23 January 2024 (UTC)

I would note that Juno's cameras are already quite degraded due to Jupiter's radiation belts, and are only going to get worse from here; I wouldn't count on future passes to be any better than what we already have, unfortunately. We also do have better-processed images from older missions such as Galileo which are much more accurate in terms of color and appearance. ArkHyena (talk) 22:45, 23 January 2024 (UTC)

In my opinion both of these factors need to be balanced. We should keep the current image since Io's Juno pic seems to not actually be in true color. CactiStaccingCrane (talk) 01:00, 24 January 2024 (UTC)

So far as I can tell, Juno's images of Io -- or at the very least, the one which was processed and shown above -- are decently close to Io's true color, especially when compared to the article which attempts to reprocess Galileo images of Io to be closer to true color. ArkHyena (talk) 01:27, 24 January 2024 (UTC)

@ArkHyena hmm.. yeah Juno's camera is significantly damaged already. However, I would like to assume that the citizen scientists who are processing these images like Gill, Perry, Jónsson et. at. are all proactively taking the damages into consideration. By the way, off topic - your username Ark Hyena reminds me of a hyena character from Arknights IapetusCallistus (talk) 09:43, 24 January 2024 (UTC)

@CactiStaccingCrane@Nrco0e

Look at this nice reprocessing. Can anyone find the full picture of this?

It's a reprocess attempt by the Planetary Society. It's a mostly fully-illuminated true color image of Io. IapetusCallistus (talk) 13:56, 24 January 2024 (UTC)

@CactiStaccingCrane@Nrco0e

Sorry, ignore my message. I didn't see the fact that you already shared the link to the Planetary Society image. I want to delete the message, but it doesn't look like I can delete it here in Wiki. IapetusCallistus (talk) 14:04, 24 January 2024 (UTC)

It may be possible to recruit the help of some people who know much more about image processing to process existing full-disc images from Galileo; if I am not mistaken, Neptune's infobox image was produced that way. However, I personally do not know of anyone who actively contributes to Wikipedia who is also experienced with processing Galileo imagery. ArkHyena (talk) 19:22, 24 January 2024 (UTC)

@Ardenau4 Hello again Ardenau. Can you help us again by processing these [pictures of Io] into true color? IapetusCallistus (talk) 22:39, 24 January 2024 (UTC)

It appears the link you posted isn't working.

Unfortunately, I'm not that experienced with Galileo imagery. Most Galileo images are in IR-G-UV format, and I'm not that experienced with being able to process Galileo imagery in true color from filters that are far removed from the visual spectrum. Voyager imagery might be better, but I'm not super familiar with the Io imaging sequence for either of the Voyager probes. I've actually never processed Io from any spacecraft before so I'm really not sure how to death with such an object.

Io is also just a difficult object to deal with in general Io's color is dissimilar to other sola system objects and also that it's hard to calibrate the color contrast on the surface of an object which has a lot of varying colors. I'm not sure I would be able to process any images better than the ones that are posted online already. Ardenau4 (talk) 15:16, 25 January 2024 (UTC)

I'm sorry @Ardenau4

I don't know why the link is not working when I used "|". Here is the link if you want to check it out properly:

https://www.planetary.org/articles/2629

Also, it's okay if you can't. Thank you for responding. IapetusCallistus (talk) 16:13, 25 January 2024 (UTC)

So I guess... "expert image processor" Jason Perry here.... okay. So let's define the issue here. What is true color? Like your digital camera, it comes down to filter choice. Your digital camera makes the choice with the individual pixels being sensitive to RGB in a Bayer pattern. For spacecraft missions, filters come down to several factors including scientific usage and cost. Before we even get to filters, I should briefly mention why it is relevant for Io. Does this discussion happen over on the Europa page? Ganymede? No, because for Io, differences in the wavelengths your red and blue filters are sensitive to can dramatically change the resulting image. There is a deep absorption band caused by sulfurous materials on Io's surface in the ultraviolet and the wing of that band occurs between 400 and 500 nanometers, in the violet to blue range of the visible spectrum. So if you have a filter closer to 400 nm, then that sulfurous material appears very dark, and if it is closer to 500, then that material has a moderate brightness, and albedo is affected by the presence of certain sulfur allotropes like S4 or by SO2. there is a similar absorption and between 500 and 600 nanometers caused by S4. So areas rich in S4, like some plume deposits or the polar regions can appear reddish in color images and how bright red they are depends on where a red filter is WRT to that absorption band.

So how is this relevant here? Galileo didn't have a blue filter but a violet filter. So to generate color images of Io, that violet filter was used in place of blue. The deep absorption band for S meant that areas rich in S8 appear as a deep yellow. Galileo's red filter largely matched that of RGB. JunoCam has some factors that make it more true color, but there are somethings to watch out for and you should all be wary about saying that it is absolutely true color! JunoCam has a blue filter, but that blue filter has a center wavelength of 465 nm, a bit green-ward of the RGB standard of 465 nm (I think that's what it is anyway...). So blue is higher up on that ramp up from the S absorption band and sulfurous materials don't appear as dark. So features appear less yellow than they should. Green is fine. It's seems very hard for someone to mess up a green filter. But what about red? RGB standard (again I think) is around 645. The RED filter on Galileo SSI is a little long-ward at 663 nm (and the mosaic currently in use has the 756 nm filter in place of red, which wasn't taken at the time). But the RED filter on JunoCam is centered at 698 nm and is a much broader band filter, encompassing the wavelength range of SSI's 756 nm filter. Materials rich in S4 appear much more vividly red in images that use SSI 756 or JunoCam RED.

So what does this all mean? JunoCam isn't quite true color either. Is it closer? Honestly, this is an on going discussion among some of us scientists as we try to wrestle with JunoCam calibration, which hey, just like the arguments you all are having here, calibration is kind of important for Io... I definitely think it is closer as long as you understand the caveat the reddish materials are bit more vivid than what you would see IRL. and it has been a while since I've added to a talk page so hopefully this auto adds a signature... Volcanopele (talk) 22:11, 25 January 2024 (UTC)

@Volcanopele Hey there, nice to meet you. I saw your entries in the Juno website. Nice to finally finding someone IapetusCallistus (talk) 15:10, 28 January 2024 (UTC)

I'm all for whatever image shows more realistic color of the object. However, there are problems with Junocam and most people who process its raw data. Neither of the two images in question are close enough to reality. Galileo's image, and all those lemon yellow images are made with false color, in this case remapping unrelated bands to RGB system which have been sadly advertised by NASA's sensationalistic public relations as true color (true hue might be a better term). Indeed, NASA has a disastrous history of being honest with visual reality of its images which are made with robotic spacecraft. Sadly, that has only fueled nutters' ramblings ever since the great explosion of insanity in 2016. First public example of gross mistake was with Vikings and Martian sky which was presented as blue. Nowdays with MRO, the agency constantly pumps out false colors of Martian surface with blue, dark bluegreen, cyan and light blue features, and never even mentioning what's that all about. Images from rovers are nearly always pushed into wrong white balance to help geologists, but it does not help the laymen. Would it hurt the imagers to release proper images to the public and reserve the others for scientists? It's just this pervasive inability to understand how damaging this is to the trust of society which is increasingly uneducated and paranoid. Keep doing this in a democracy where your funding depends on public popularity and problems will occur.

Juno's latest images, synthesized by "citizen scientists", showed us quite vividly, through examples with Jupiter, how grossly far from reality those can get. But anything for likes on Instagram, am I right? I seriously doubt Io is a brown body without a hint of yellow. After all, it has elemental sulfur deposits on its surface. Some of it is in the typical allotropes which are yellow.

Attempt by the Planetary society is a very good middle ground - more towards dull brownish than lemon yellow. Lajoswinkler (talk) 14:25, 22 February 2024 (UTC)

Unfortunately, the one provided by the Planetary Society only covers a partial mosaic of Io's surface. We'll have to get someone to process a full-disc image of Io on our own, it looks like. I do agree that it does seem like the most color-accurate of the three provided, and it should provide a very helpful reference point to work from should anyone here decide to tackle the issue of processing Galileo imagery. ArkHyena (talk) 19:37, 22 February 2024 (UTC)