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:
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.
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.
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.
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.
Just checking on the outbound portion of the flyby with Eyes on the Solar System.
https://eyes.nasa.gov/apps/solar-system/#/sc_juno/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.
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.
First pass on PJ57-22:
https://flic.kr/p/2ppCrZL
https://flic.kr/p/2ppCrZL
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 https://stevealbers.net/albers/sos/features/combined_io_lon_zero_center.png.
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!!!!!
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.
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!
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" !
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.
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)
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 :-)
https://flic.kr/p/2ppMscT
https://flic.kr/p/2ppMscT
Cylindrical Map:
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...
There are at least three (apparent) calderas in the imagery that show a diffuse, reddish coloration that trails off to the west (from this view, clockwise). Is this…
• Evidence of a Coriolis effect on plumes?
• Evidence of something of a faint exospheric wind, or something to do with the jovian EM environment?
• Purely coincidence? (n=3, not much to write home about… and perhaps there are also contrary cases to be pointed out)
Here are a some 4K maps using one image from volcanopele and one from Kevin Gill, first before:
https://stevealbers.net/albers/sos/jupiter/io/io_rgb_cyl_in_4k.png
now with the new images added:
https://stevealbers.net/albers/sos/jupiter/io/io_rgb_cyl_2023_4k.png
I wonder if the changes at Loki represent a switch in the location of active plumes or simply deposits? Happy New Year to you all!
Preliminary versions of maps. No photometric correction, and I won't want to average the final product, but the Jupiter shine product is probably final:
A blinking animation between the second map I posted above with Jason's nighttime map (some filtering applied):
https://stevealbers.net/albers/sos/jupiter/io/io_4k_day_night_roll.png
The Jupitershine area really improves coverage on almost the entire area of that large northern hemisphere low resolution area. I really hope we can get further processing of that.
The ideal processing of the Jupitershine areas might benefit from applying an asymmetrical filter to the pixels. Low signal to noise produces a speckling effect which is clearly an artifact and brings out some hot pixels that over-respond, and this makes the colors garish on a very small scale. Smoothing out the values in each filter to bring the hot ones down to the local median might improve this greatly.
Fyi I had applied the https://docs.gimp.org/en/gimp-filter-noise-reduction.html with a setting of 12. This may be related to what StargazeinWonder mentions, and would work better if applied to the original image prior to reprojecting onto the cylindrical projection.
Slightly off topic, but since this is the current active Juno forum: I understand that the Juno extended mission is expected to end by September 2025. Is this driven by a decision to dispose of the orbiter (presumably into Jupiter)? Or is this a current funding deadline with another extension possible?
To zoom in on the problem, here are magnified patches of one of Jason's images, blue filter only, from the dayside and Jupitershine side, normalized to about the same overall brightness.
Obviously, the difference isn't due to Io itself, but the higher share of noise compared to signal in the darker imagery.
Median over a local window (3x3?) is one solution, which of course loses some spatial resolution.
We might beat this by combining information from the three color filters, presuming that the peaks and valleys of the speckles will vary from one filter to another and there is usually not sharp color contrast on the same spatial scale as edges in general albedo. So, maybe average the three filters to produce a grayscale image, apply median (2x2?) to that, and then color it with images that apply a larger median (eg, 4x4) to each of the color filters.
I've gone down a similar road with some astrophotography images, and there may be more wisdom out there in the community that processes images of deep sky objects (galaxies and nebulae). It's almost an entirely different paradigm than the imagery of planets (dayside), where you can always get all the luminance you want.
Yes this may take some doing to set things up in an optimal way. Another example is in the IDL environnment with an FFT related filter. This is more of a random noise situation as I know FFT's can also work with periodic noise.
https://www.nv5geospatialsoftware.com/docs/RemovingNoise.html
Is there really useful color information in the Jupitershine part of the image? A quick look at pj57-031 (the only image with TDI of 6) suggests to me that the green channel by itself is telling you most of what there is to know. Certainly the blue channel is pretty noisy.
We will almost certainly take more nightside images on PJ58, but my inclination is to go with longer TDI and only one channel (green, or perhaps red.)
Will there be an SRU image for PJ58 as well?
Taking one of Jason's images and applying a 3x3 median to the Jupiter shine side, I noted first that the blue was much brighter than it was on the dayside, no doubt due to greater noise. So, I turned the blue down about 40%.
This was the result. There is real color information at some resolution, but that is binning at a greater level than 3x3.
I guess that reducing the blue in a linear way was incorrect, and it would have been better to reduce it more in the areas where blue was darkest and kept it higher where blue was brighter (the terrain is a more neutral white/gray). As mentioned earlier, the noise is not symmetric because in either dark areas or bright it can push the output brighter, but in dark areas, it can't push the output into negative.
Jupiter shine map, with and without 3x3 median smoothing
Hello UMSF members,
I follow everyday all your exchanges about lunar and planetary missions.
I'm one of the co-authors of the "Virtual Moon Atlas" (VMA) and "Virtual Planets Atlas" (VPA) freewares.
https://ap-i.net/avl/en/start
https://ap-i.net/avp/en/start
Our goal is to provide for general public and scientists, easy to use basic tools for improving lunar and planetary knowledge.
As you will see if you download and try it, VPA presents telluric planets and Galileo satellites real time maps. For that, we use with permission equirectangular "textures" in the 2:1 ratio buit from various planets maps found on the Internet and publically available.
I would like to add in VPA Juno's maps of the Galileo satellites since presently, there are only Voyagers and Galileo maps used in the freeware.
Using the VPA "double window" functionnality, it will certainly be useful to look for planetary surface evolutions between these various missions for VPA users.
Does anyone could help us and provide such best resolution equirectangular Juno maps for Io (Sure !) but also for Europa and Ganymede that can be used in VPA with permission and thanks ? (Natural or enhanced colors / B&W / 2:1 ratio / jpg format / 4000x2000 pixels minimum or more)
Thank you in advance for your support to our action if you agree.
Ch. Legrand
PS : Sorry for my rather poor english
The nightside image is a wonderful bonus!
The Jupiter images have been posted to missionjuno. I think we're still waiting on some partials for the approach images, some which are pretty neat (GRS with a distance Io).
Does the next flyby cover the same region?
Hello UMSF members,
Here are my first attempts for introducing Volcanopele work in VPA freeware.
Screen captures are :
PJ 57 et PJ 55 comparison showing resolution increase
PJ57 & Voyager-Galileo texture
PJ57 & Voyager-Galileo texture annotated
PJ57 & Voyager-Galileo texture close-up
Hope that this will be helpful to everyone
Sincerely yours
Ch. Legrand
Fortunately, the next flyby covers almost exactly the opposite side of Io. If that is successful, with comparable jupitershine imagery, we could come away with about as close as possible to global coverage with just two flybys.
Mike, I am definitely coming around to the idea that if you can get well exposed Jupiter-shine images in the green filter, being able to stack them to improve SNR and getting more of them would be fine. While RED has the best SNR, GREEN has the best balance of SNR and albedo information.
maybe they meant the area covered in Jupiter-shine? Because it would be fairly complimentary to the PJ57 coverage, getting more of the southern hemisphere coverage compared to the northern hemisphere coverage of PJ57. I'm looking forward to seeing East Kanehekili (-18/24) at visible wavelengths, as an example.
I'll defer fully on the question of which flybys offer which coverage since my visual interpretation of Jason's map was my only source, and leave that topic both to better informed people and the new threads.
ImagePJ57_23:
For my images, I did have to set jigsaw to correct for spacecraft position to get the limb in the right spot. Plus I had to add many tie points near the limb of 57_22 to avoid color fringing. But given that we only have the predict SPK available, yeah this makes sense.
A couple attempts at the Jupiter images, all processed with my Rust pipeline (I did my Io stuff with my ISIS+Blender method).
https://flic.kr/p/2pqGDVd
https://flic.kr/p/2pqGDVd
https://flic.kr/p/2pqK3rv
https://flic.kr/p/2pqK3rv
https://flic.kr/p/2pqKHmD
https://flic.kr/p/2pqKHmD
So the closest images... were they lost or just degraded to they point they cannot be used? Or was imaging at closest approach not feasible?
Phil
That answers my question - imaging at closest approach was not feasible, it was over the night side.
Phil
Here's a try with the GIMP-GEGL noise filter on one of volcanopele's images, brightened to show the night side. Noise setting is 10 and brightness is +6 f/stops.
Present version of 4K map with both daytime and nighttime regions from the post #90 Juno images. These were additionally processed and added to a prior map.
Family Portrait: Ganymede, Io, Europa, Callisto, and Jupiter. The right three moons and Jupiter are from PJ57-21, however Ganymede was just out of frame to the left. Ganymede last appeared in PJ57-12, so I grabbed it from that and composited it into the approximate location as it would have appeared. The moons have been brightened for visibility.
On a side note, that GRS is looking pretty small...
https://flic.kr/p/2prk2eM
https://flic.kr/p/2prk2eM
Any update on the jupitershine SRU image?
An approximately true color/contrast version (left) of image PJ57_50 and an enhanced version (right):
Can you do a plot where the SRU image is one rotation later for PJ57? The one you have plotted would be too far west and right on the terminator for Jupiter-shine. I would think that the SRU image is either the rotation after that one or two rotations, though I personally really hope that it is one rotation to get all of Tonatiuh.
Seeing the pictures of Io from Voyager, Galileo and now Juno, the colour of the surface seems to differ, the Voyager ones seem to picture Io as being very orange, Galileo less orangy and Juno pinkish ? Which colour is the most accurate?
Some prior discussion of that here:
http://www.unmannedspaceflight.com/index.php?showtopic=4059
PDS release for PJs 57 and 58 was officially yesterday. Pretty much everything is available now except for SRU oddly. Not sure if there was an issue with the instrument or issue with the release. EDIT: the PDS Imaging site has this to say: "SRU data is temporarily delayed" So it looks like they will be released just not yet.
But yeah, the data for all the other instruments is now available. I've been working with the JIRAM data for a few days now and it is going pretty well. They got quite a few postage stamps across the surface and they are of pretty good quality.
Of ALL things, it was the instrument I needed to be released!
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