Juno perijove 30, November 8, 2020 |
Juno perijove 30, November 8, 2020 |
Nov 11 2020, 02:08 AM
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
A few days ago, Juno performed her Perijove 30 (PJ 30) Jupiter flyby. A first set of JunoCam images was already downlinked to Earth.
From PJ to PJ, closest approach is gradually moving northward. The northern FFRs (folded filamentary regions) are going to be resoved better and better. At the same time, the northern spring time is going to reveal the north pole in visible light. Here a glimpse at the northern circumpolar cyclones with the north polar cyclone just illuminated in the twilight: Here a pair of cyclones of opposite sign presumably propelling each other slowly towards the south: And here a storm particularly bright in methane band: |
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Nov 11 2020, 02:13 AM
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#2
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
Here a prettified version of PJ30, #19, showing FFRs:
Those images are post-processed versions of intermediate image products referenced here. This referenced list will be updated occasionally. |
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Nov 14 2020, 12:33 AM
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Member Group: Members Posts: 146 Joined: 22-July 14 Member No.: 7220 |
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Nov 14 2020, 11:46 PM
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Member Group: Members Posts: 425 Joined: 18-September 17 Member No.: 8250 |
"Pirate Grumpy Cat" Jupiter PJ30_21 Crop, Exaggerated Color/Contrast PJ30_26 Crop, Exaggerated Color/Contrast PJ30_24 Crop, Exaggerated Color/Contrast PJ30_28 Crop, Exaggerated Color/Contrast PJ30_23 Crop, Exaggerated Color/Contrast PJ30_11 Crop, Exaggerated Color/Contrast Mike, is it taking longer to get PJ30 downlinked than usual, or am I just impatient? |
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Nov 15 2020, 12:23 AM
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#5
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Member Group: Members Posts: 425 Joined: 18-September 17 Member No.: 8250 |
Gerald - Nice catch of the moon on the limb of PJ30_24 you posted at https://www.missionjuno.swri.edu/junocam/processing?id=9501
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Nov 15 2020, 01:22 AM
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#6
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
Thanks, Brian! I looked at the hazes along the limb, when I noticed the moon serendipitiously providing us with a second approach to assess the optical thickness of the hazes, especially of a haze layer that appears to be almost detached.
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Nov 15 2020, 02:02 AM
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#7
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Senior Member Group: Members Posts: 2542 Joined: 13-September 05 Member No.: 497 |
Mike, is it taking longer to get PJ30 downlinked than usual, or am I just impatient? I don't have the stats at my fingertips as to what "usual" means, but the DSN schedule does tend to vary a lot. There's nothing wrong that I've heard of. [edit: I would expect the rest of the images tomorrow, 11/16.] -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Nov 15 2020, 09:01 PM
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IMG to PNG GOD Group: Moderator Posts: 2254 Joined: 19-February 04 From: Near fire and ice Member No.: 38 |
Image PJ30_22 in approximately true color/contrast and enhanced versions.
Following a detailed look at many JunoCam images I recently made minor changes to the R/G/B multipliers I use to produce true color images. I also took a look at some Cassini images, groundbased images and two visible light spectra of Jupiter. I suspect the gamma of the JunoCam images differs a bit from the Cassini images. The parameters I use when removing limb darkening from the JunoCam images don't work well for the Cassini images. Limb darkening is apparently slightly more pronounced in the Cassini images; I'm still taking a look at this though. |
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Nov 16 2020, 08:15 PM
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Member Group: Members Posts: 425 Joined: 18-September 17 Member No.: 8250 |
I suspect the gamma of the JunoCam images differs a bit from the Cassini images. Definitely want to hear more about this. I haven't worked with Cassini images, but for JunoCam my pipeline treats decompanded values as linear up through raw value 224. Raw values > 224 I "discard", thinking non-linear well saturation effects are coming into play. I'd assume the Ca$$ini imaging program produced calibrated linear results. |
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Nov 17 2020, 10:00 PM
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IMG to PNG GOD Group: Moderator Posts: 2254 Joined: 19-February 04 From: Near fire and ice Member No.: 38 |
An enhanced north polar projection map from image PJ30_09 showing the area around Jupiter's north pole:
The map was processed to reveal faintly illuminated features near the terminator more clearly. The area near the terminator above and a bit left of the central North Polar Cyclone looks especially interesting in this image. Latitudes are planetographic. |
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Nov 19 2020, 07:22 PM
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#11
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
Gerald - Nice catch of the moon on the limb of PJ30_24 you posted at https://www.missionjuno.swri.edu/junocam/processing?id=9501 After cross-checking with "Eyes on Juno", I think that it's Callosto. In the PJ30 outbound red lightning search sequence, there seems to be a rather faint moon. My first candidate would be Amalthea by its size and redness, but cross-checking by position data is TBD. Here a composite of six images with some of the stars identified: I'd estimate the visual magnitude of the moonlet (marked yellow) to be well fainter than 3m. Besides the small size, the fairly large phase angle will result in a low brightness. |
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Nov 19 2020, 10:37 PM
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#12
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
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Nov 20 2020, 05:02 PM
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Member Group: Members Posts: 146 Joined: 22-July 14 Member No.: 7220 |
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Nov 21 2020, 03:57 AM
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#14
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
I'l just chime in every few dozen posts to say "Wow," but I could be saying it after basically every post.
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Nov 21 2020, 10:22 PM
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IMG to PNG GOD Group: Moderator Posts: 2254 Joined: 19-February 04 From: Near fire and ice Member No.: 38 |
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