Talk:Io (moon)

There are some issues with the article including over a dozen cn tags, some ^{[better source needed]} 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)

• @Buidhe: Since this notice was placed in 2022, it seems like the "citation needed" and "better source needed" concerns have been mostly resolved. The verification page number concerns still seem to remain. Should this be removed from WP:FARGIVEN, or should this be given another notice to potentially go to WP:FAR? Z1720 (talk) 15:12, 14 June 2025 (UTC)

• I am going to remove this from FARGIVEN: it seems like the citation needed and better source needed tags have been resolved. If the verifiability issues remain, or if there are other issues, this article will need a new notice anyways, so I think it is better to remove it from the list for now. Z1720 (talk) 00:42, 10 August 2025 (UTC)

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)

Any updates on this?

Also, why is it so hard to find a proper, full-disc true color photo of Io? After all, it has been imaged extensively, but for some reason (unlike the other Galilean moons) there only seem to be true color photos of parts of the moon, without a corresponding full-disc composite.

By the way, I apologize if I've been too bold recently with my edits, especially with the Io image. IvarTheBoneless123 (talk) 12:46, 2 November 2025 (UTC)

No idea, but my guess is that the popular impression that the current infobox image is already in true color (or close enough) means few people give it a shot. And the few people who do haven't released their own processings under licenses we can use. We have a few editors who carry out image processing themselves like @Ardenau4:, but they're on hiatus/seldom work with Galileo imagery. ArkHyena (she/they) 18:26, 2 November 2025 (UTC)

I wanted to give my input here since I work/worked with Galileo images in the past (and also gave my input here in the past as well) -

I have tried a processing of this Io mosaic here but there a number of problems with this image which is why I feel like it's not appropriate for use here.

But there is another problem with this current image that is used on Wikipedia: it seems to actually be some weird mapping or projection of the original images, or at least some weird stuff is going on. Because in this official image from NASA, the surface topography is actually cut off (i.e. the disk is actually cut to a circle). I know this because I worked with the original data and I would say this is maybe not a good image because of that.

If we were to find true color images, I would expect it from Voyager and Juno. Both of those spacecrafts have their own problems with imaging filters etc. but I would consider it much better than the crappy Galileo one we have now. Ardenau4 (talk) 15:45, 6 November 2025 (UTC)

Well, we don't have a dedicate mission to Io coming soon (Sad music: Europa Clipper and ESA's JUICE are skipping over poor Io).

I guess it only means that we don't be getting a good image of Io anytime soon. IapetusCallistus (talk) 15:59, 6 November 2025 (UTC)

"I have tried a processing of this Io mosaic here but there a number of problems with this image which is why I feel like it's not appropriate for use here."

How does it compare to supposed true color images like these from JPL/NASA: https://d2pn8kiwq2w21t.cloudfront.net/original_images/1-PIA26484_-_Io_north_polar_region.png ?

Because, amateur as I am, there's a particular 'tinge' to Io in JPL's images that lacks in other 'true color' reconstructions.

I don't know what that's about. IvarTheBoneless123 (talk) 16:18, 6 November 2025 (UTC)

This is not a NASA processing but instead one that was done by Gerald Eichstädt. It's red-tinged probably because the processing incompletely accounted for JunoCam's damaged red-balancing, which has been discussed earlier here.

Ardenau4 (talk) 16:57, 2 December 2025 (UTC)

Fixed the image display. IapetusCallistus (talk) 15:32, 4 November 2025 (UTC)

My attempt to process based on the Planetary Society's rendition. Unfortunately, it looks far from the supposedly true color images captured by Juno. IapetusCallistus (talk) 15:00, 4 November 2025 (UTC)

I'm generally in favour of true-colour images (defined as what a human would see if they were to look out a window at a planet), but I'm taken aback by how "not yellow" the edited images appear to be. It appears that the S-8 sulfur allotrope common on Earth is present on Io, so it is surprising to me that there is very little trace of the bright yellow S-8 in the linked "true colour" images. This image looks subjectively more like what I would expect, without the bright yellow saturation in the current infobox image. TROPtastic (talk) 02:34, 12 November 2025 (UTC)

Should the orbit and rotation section link to Tidal heating of Io instead of the generic Tidal heating page? Belgaers (talk) 16:47, 20 November 2025 (UTC)

Hello. Can I request someone to please process these filtered images of Io? Big thanks.

IapetusCallistus (talk) 13:01, 12 February 2026 (UTC)

maybe you could use GIMP and true color tools and do it? - anonymsiy.user - (talk) 07:48, 27 February 2026 (UTC)

Have you found someone to process these images? Because someone just changed the Io infobox image, and I honestly can't blame them - I really think we ought to put this issue to bed once and for all: what does Io actually look like to a human eye and what image can we use that approximates it well enough? Because I get the feeling that others here are also generally dissatisfied with the long-standing, all-too-vividly colored Galileo image. IvarTheBoneless123 (talk) 13:31, 26 March 2026 (UTC)