I know the first close Io flyby is still a couple of months away but I'm going to go ahead and start up the topic now with a few preview images that the global map from PJ55 into the pixel scale, lighting conditions, and orientation of the highest resolution images that JunoCam would take (illuminated by the sun, there's always a chance for Jupiter-shine images), based on the current reference spk and c-kernel:

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This also assumes an image cadence of 1 every other rotation (so 1 per minute).

info about the encounter:

Edited to include the first six instead of the first and third (skipped one) using the global map I generated from PJ55 images.

Will this flyby get an entry on the Gish Bar Times?

at this point, probably not (grumble grumble prior publication). That being said, I've considered doing a follow-up video for Youtube and might do some live events for the flyby and stream my processing work.

Very excited to see any changes at Loki.

Juno is going even closer?

Yes, December 30th and February 3rd, only 1500 km!

The next two flybys will be close enough that Doppler radio science is expected/hoped to provide meaningful science regarding Io's interior. The Galileo Orbiter made several flybys even closer than this; I am unsure what, if any, benefits may be obtained as a result of superior technology or differences between the geometry of these flybys and those made by Galileo.

The combination of PJ55 and the next three close Io flybys will provide something approaching global coverage at about the resolution of PJ55 or better. So all told, it's going to be a pretty nice dataset given that the surface of this world changes over time and the last detailed imagery of many areas is ~20-25 years old.

I've heard that the Juno gravity data will have higher precision than the Galileo data, so a couple of close Juno flybys will provide a considerable improvement in understanding Io's gravity, beyond the half-dozen flybys that Galileo accomplished.

John

We're less than a week out from the Io flyby. The first Junocam image should be taken at 2023-364T08:37:21 +/- 15s and the first four images are at 60s spacing.

Preview images using the latest ephemeris and c-kernel. First image according to that kernel has the green frame centered on Io at 2023-Dec-30 08:37:07.177. Preview images are spaced every 2 rotations.

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I take it that there are not images prior to C/A/ Looked like there might be some decent imaging at ~19 km/pixel of the anti-Jovian hemisphere. A bit disappointed at the lack of Jupiter-shine images but given what happened in PJ56 I totally understand.

Correct. Maybe we should have taken one, but Io starts leaving the FOV illuminated limb first by the time the resolution has gotten decent, so we judged it wasn't worth it.

Would have been cool to test if there was airglow from the volcanoes. Will the SRU be taking pictures of the night side?

They can take one. I'm hoping they can get one showing Tonatiuh, a large lava flow (~500 km long) north of Zal that formed between 2008 and 2018 (between first ground based detection of a hotspot to a 150-km shifting of the flow front in 2018). Kinda difficult given the longitude (~65-85°W) but even something just showing the general morphology of the flow would be useful enough. For example, I'm pretty sure that the eastern end is the source based on ground-based data, but there are no visible edifices at that end in older imagery. There is one toward the western end in Galileo imagery, and maybe the "western expansion" in 2018 was just a fresh, westward flow from that source.

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having a bit too much fun prepping for a preview video...

Wow, okay, so an hour long preview video is processing now on Youtube. Should be available in a few hours.

https://www.youtube.com/watch?v=pLRPS9LZmn0 It finally posted!

Wonderful video, thank you Jason!

I also made an approximate flyby "map" to mark the occasion.

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Just checking on the outbound portion of the flyby with Eyes on the Solar System.

https://eyes.nasa.gov/apps/solar-system/#/s.../distance?to=io

Thanks Jason for your very nice preview video.

First Io image is up on social media, e.g., https://www.facebook.com/NASASolarSystem/

missionjuno data post to follow shortly.

That's a nice sharp image

Yes, and great detail on the night side too.

Phil

Wow. My eyes watered. That first image is already great.

after fretting for a month about these images after seeing the PJ56 images.... Mike, if I ever see you at a conference, I owe you a beverage of your choice.

When I saw the color image on missionjuno, I said, "You're kidding me." Holy smokes, there is surely science value to follow, along with the beauty.

Images are on missionjuno now.

Here's the lat/lon grid for the first image.

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First pass on PJ57-22:


Io - PJ57-22

Yes this is amazing and will be interesting to add to the cylindrical maps. One previously named feature I can note is Vivasvant Patera as per this map.

My take:
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Here's the only thing I've found that vaguely appears to resemble a plume. It's visible in at least four different raw image slices.

I haven't gotten that far yet but my best guess at this point would be Xihe.

My new favorite volcano is visible in Jupiter Shine!!!!!

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this is Tonatiuh, a 500-km long lava flow that wasn't there 15 years ago, at all. This is also the site of that plume that JunoCam saw at the end of 2018.

Full set of six:

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Plus a nice bonus color anaglyph
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Absolutely spectacular stuff, well worth the wait. Congrats to the team for pulling it off.

Couldn't resist brushing off StereoPhotoMaker for a crosseye stereo pair, hope you don't mind borrowing your image (from @volcanopele on twitter before I even got here).

Somewhat tortured view but really puts it in perspective for me.

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Congratulations to the Juno team. The high quality of these images compared to PJ56 is a nice surprise to me. Even the blue images have clear details on the nightside.

Congratulations to Juno team! There seems to be some "visible" changes at Loki compared to Voyager 1 images!

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Wow- there's real stereo information on those big mountains- nice job, Jason!

Has the camera performance actually improved since PJ56? It looks like it.

John

A captivating time in the Juno mission around Jupiter !

Regarding the mountains or volcanoes of Io, there is a remarkable shadow of a mountain or volcano in a high-resolution view of Io during that flyby. I think we can approximate the potential height of the mountain.

I took one of the images presented by Jason to evaluate the size of the topographic structure and to evaluate the potential height of the mountain or volcano.
I assume a diameter of around 1302 pixels for the disk of Io (real diameter of 3643.2 km).
From the peak of the mountain to the limit of the shadow, there is a distance of around 56 pixels (From location A to B, there is a distance of 56 pixels).
That distance of 56 pixels must represent aroud 157 km (56 pixels /1302 pixels * 3643.2 km).
If we have the angle of the Sun above the horizon from location B (location of the limit of the shadow related to the peak of the mountain), we should be in a position to approximate the potential height of that mountain that may be closer, in appearance, to "Mont Cervin" (The Matterhorn) in Switzerland than "Le Piton de la Fournaise" (Peak of the Furnace) in the island of "La Réunion" !

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There is enough information in the image itself to determine the angular height of the sun at that peak, based on the position of the terminator. But the peak is pretty close to the terminator so the angle is quite low and will exagerate the relief considerably.

Yes, certainly.

Buried in the Facebook comments from NASA Solar System Exploration:



Credit to Jamie Carter at Forbes.com for actually finding that comment and reporting it.

Yes, definitely a very large improvement since PJ56. The image quality is now probably comparable to PJ55.

This is a preliminary version of image PJ57_22:

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North is up. The brightness of the nightside has been increased to show details there.

There's some detail around Loki in the color that implies changes, too, although to be absolutely certain we'd have to check against differences in filters.

At the hazard of gushing too much for board rules, this is just amazing stuff, way better than expected. Amazing work by the team and the citizen imagery mavens. I notice that the good stuff came out much sooner after the flyby than with P55; I was ready to chew my fingernails waiting a little longer.

Add this to the long list of tremendous opportunistic science where a mission funded for one purpose wonderfully observed another target. The Ganymede and Europa observations were very nice but this is astonishing. I look forward to learning what the radio science tells us about Io's innards.

A very rough / preliminary idea of how one of volcanopele's images fits in a cylindrical map (before and after)

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Another go using PJ57-23 with decorrelated colors and darkness boosting. I'm so happy the camera performed as well as it did and am loving the results that everyone is coming up with :-)


Io - PJ57-23 - Decorrelated Colors

Cylindrical Map:

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Of course, mine was a quick comparison and it clearly needs a thorough alignment and analysis but both images were compared using the blue bands, so there might be some changes after all!

The color around Loki is certainly fascinating. These are, I think, the highest resolution color images of Loki ever obtained (the nearest competition being the Voyager 1 approach 4-frame color mosaic). Same goes for the terrain further north, of course.

John

Kicked off the processing pipeline this morning, expecting to be greeted by PJ56 quality images that were going to require a lot of TLC, and gasped when this came up...

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A fine ChristMSSS present for us all.

And Exaggerated Color/Contrast version
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