Very cool preview of Juno's upcoming encounters with Io from Jason Perry https://www.youtube.com/watch?v=5MtYaSteBRY

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5th Io image using two different enlargement methods, both at 5x. Still processing. VERY quick assessment: No obvious changes since NH.

3rd image (5x Again with nearest neighbor and bicubic smoothing):

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1st image (5x Again with nearest neighbor and bicubic smoothing):

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This is my version of Io image PJ41_3, enlarged by a factor of 5 relative to the original data:

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The color balance is very preliminary but hopefully this is not too far from Io's true color. However, Io's color is a notoriously complicated subject and the color balance can definitely be improved. The color correction multipliers I have been using for Jupiter were obviously not correct for Io. The color multipliers I have been using for Europa worked better but probably also resulted in incorrect color so I made a quick-and-dirty, preliminary modification to them.

So looking at the images, some quick assessments:

Not really seeing any major surface changes at this scale, but then again this covering areas that Galileo and New Horizons saw at poor emission angles, so some of the northern high-latitudes can be hard to judge.

Seeing a few mountains along the terminator but nothing that stands out to me as a plume. There might be something near -7/26W in 41C00002, but I can't find it in the subsequent images

The flows in the northern parts of Lei-Kung Fluctus might have some interesting complexity. WAY TOO early to be sure. Can't wait for PJ43!

And finally here is a set of all 5 images, magnified 5x (nearest neighbor)

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PJ40 Jupiter Images, Exaggerated Color/Contrast
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Full resolution 649 Megapixel (20855-by-31159 JPEG) version available at https://www.missionjuno.swri.edu/junocam/processing?id=12954

Jason, so no firm opinion about the spot on the limb in PJ41_02 (which I think is also hinted at in PJ41_01)?

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Hmm- that looks like a moderately convincing plume to me.

John

Not super convinced from this set of images, no. The location of this spot isn't consistent from one image to the next and in cases where it should be there, it isn't. It might be a plume, but I would only consider it a suspected one at this point. If it is real, it might be associated with E Kanehekili (17S/22.3W), a new eruption site that started up in February 2019.

PJ41 Io Images in various styles:
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While I haven't confirmed the geometry, I assume it is Jupiter-shine slightly illuminating the region beyond the terminator in the low-gamma images.

PJ41_01 to PJ41_05 all rendered from the perspective of PJ41_05 (low gamma).
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PJ41 Io Images, EQR Map Projected (animated GIF). Low gamma for dark details.
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As promised in the PJ43 thread, here are the L and M-band images from PJ41. So a few notes about these as I don’t think I’ve really posted them here before.

These are summed images. I reproject each L and M frame to the same geometry (after using limb fits to correct for slight navigational mismatches with SPICE) then average all the frames together. This can slightly improve the apparent resolution of the image as well as improve the signal to noise ratio, making fainter hotspots easier to spot.

Most powerful hotspot (accounting for emission angle) was Loki, but only in the M band. Barely visible in L band, which suggests that its surface was actually relatively cool during this flyby. Brightest single pixel was in Vivasvant. 100 of the ~250 hotspots detected so far by JIRAM are visible in the M band.

L-band
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M-band
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Stretching the M-band image to show details in Loki (can make out the horseshoe shape of Loki)
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Color composite of L and M bands
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