APOD: Beneath Jupiter (2017 May 29)

[Peter R]

There was some disappointment with the low quality of the first images taken by JunoCam a year ago. I don't know if the calibration of the processing has been modified but some recent images like this one are absolutely stunning.

Would love to see an animation of the vortices evolving (and maybe devolving) at these eternally dim poles. Though perhaps not possible with the planned orbital pattern of Juno. Whilst there are a lot of other tasks keeping Juno busy, these first polar images are quite special, though perhaps not entirely unexpected. I think a large hexagonal vortex (like on Saturn's more tilted poles) would have been more surprising.

I think that the speed of Juno at perijove is too high to be able to take several images in succession so that they could be animated but even an animation of only 2 images would be interesting at this definition. That could be compared to the Hubble OPAL program https://archive.stsci.edu/prepds/opal/ .

Regarding the existence of a possible north pole hexagon like the one on Saturn, most scientists seem to agree that none has been detected on Jupiter.
When assembling the video "A Journey to Jupiter" https://www.youtube.com/watch?v=YZc1Y662jtk (the inflight sequence was an APOD a week ago) I noticed that there is a stationary zones caught between prograding and retrograding flows in the north polar region 2m15s to 2m30s). I would not say that it is an hexagon but it looks very much like a somewhat ill-defined polygon with some straight sides. This has been reinforced when I overlaid our images with the ones from Hubbles OPAL program. As I understand it, the hexagon on Saturn is just one of several possible polygons that could have formed depending on the conditions and in lab simulations everything from triangles to heptagons have been created.

/*Peter R

[neufer]

As I understand it, the hexagon on Saturn is just one of several possible polygons that could have formed depending on the conditions and in lab simulations everything from triangles to heptagons have been created.

https://apod.nasa.gov/apod/ap100928.html
https://apod.nasa.gov/apod/ap070501.html

[Nitpicker]

Actually, I only mentioned Saturn's tilt because it made it easier to observe its relatively well lit poles much earlier than Jupiter's virtually seasonless, dim poles. But I understand that the internal heat flows from Saturn have considerable seasonal variation, too.

Saturn is colder than Jupiter on pretty much all counts. Both emit more energy than they get from the Sun, with the ratio being slightly larger on Saturn. The net heat flux is considerably greater on Jupiter.

[Nitpicker]

Re the polar vortex patterns, one would think there are many more irregular/unstable possibilities than regular/stable ones, like Saturn's.

[ygmarchi]

I think the white ovals band is about 45° of latitude not near the equator.

Or even higher. But the caption says nearer the equator, not near, which seems like an accurate way of putting it.

Yes you're right, I didn't read carefully