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:
Click to view attachment

Here a pair of cyclones of opposite sign presumably propelling each other slowly towards the south:
Click to view attachment

And here a storm particularly bright in methane band:
Click to view attachment

Here a prettified version of PJ30, #19, showing FFRs:
Click to view attachment

Those images are post-processed versions of intermediate image products referenced here. This referenced list will be updated occasionally.

Lots of nice detail for Perijove 30 :-)


Jupiter - PJ30-17 - Detail


Jupiter - PJ30-17 - Detail


Jupiter - PJ30-17/19/21 - Cylindrical


Jupiter - PJ30-23 - Detail


Jupiter - PJ30-24 - Detail


Jupiter - PJ30-25 - Detail


Jupiter - PJ30-26 - Detail


Jupiter - PJ30-27 - Detail

"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?

Gerald - Nice catch of the moon on the limb of PJ30_24 you posted at https://www.missionjuno.swri.edu/junocam/processing?id=9501

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.

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.]

Image PJ30_22 in approximately true color/contrast and enhanced versions.

Click to view attachmentClick to view attachmentClick to view attachment

Click to view attachmentClick to view attachmentClick to view attachment

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.

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.

An enhanced north polar projection map from image PJ30_09 showing the area around Jupiter's north pole:

Click to view attachment

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.

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:
Click to view attachment
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.

Observation of the south polar region is getting more challenging, but is still possible:
Click to view attachment

Southern fisheye view using images 39-47.


Jupiter - PJ30 - Composite

I'l just chime in every few dozen posts to say "Wow," but I could be saying it after basically every post.

An orthographic mosaic of images PJ30_22 and PJ30_23 in approximately true color/contrast and enhanced versions:

Click to view attachmentClick to view attachment

The mosaic shows a pair of vortexes that look remarkably different. The darker one is at planetographic latitude ~44 degrees north.

That is a huge smiley face!

It's a nice flavor of a cyclone-anticyclone pair, which tends to self-propell, like in this simulation run:
Click to view attachment