Insane detail... again...
How fast is the hex structure actually rotating? It would be nice if you could see it rotate relative to features around it..?
Hi Emil - I'm sure you've looked at some of this type of info but I'll post it here at the bottom of this post with some relevant parts of a couple of emails between myself and Mike Foulkes (BAA Saturn Director) relevant to your post.....We've imaged a distinct bright spot right next to one of the Hex's vertices on 2 occassions this apparition (5th March & 25th March) and thought they might be the same feature.....here's part of my email and Mike's reply although I haven't followed up with any inferences there might need clarifying in his answer.....you'll see by the "potted" summary of the NPZ's hex further down that it might well be this bright feature shifting in longitude relative to the hex - but as said I haven't clarified that as yet with him.....
Me <“In the rgb16393 image (March 25th) I note a bright spot very high in the Northern latitudes right next to one of the NPZ’s hexagonal vertices…..I haven’t measured this feature yet but believe it is very likely the same spot I would’ve drawn your attention to in my March 5th images…..”>
Mike Foulkes <”…..with this in mind the white spots in the hexagon come out at System 3 = 149 and 101 on 5 March and 25 March respectively.”>Here's a bit of material I pulled off the internet on Saturn etc - might be superceded for all I know but thought it worth posting for anyone's interest!
Astronomers using infrared imaging have shown that Saturn has a warm polar vortex, and is the only such planet known in the solar system.
A persisting hexagonal wave pattern around the north polar vortex in the atmosphere at about 78°N was first noted in the Voyager images. Unlike the north pole, HST imaging of the south polar region indicates the presence of a jet stream, but no strong polar vortex nor any hexagonal standing wave. However, NASA reported in November 2006 that the Cassini spacecraft observed a 'hurricane-like' storm locked to the south pole that had a clearly defined eyewall. This observation is particularly notable because eyewall clouds have not been seen on any planet other than Earth (including a failure to observe an eyewall in the Great Red Spot of Jupiter by the Galileo spacecraft).
The straight sides of the northern polar hexagon are each about 13,800 kilometers long. The entire structure rotates with a period of 10h 39m 24s, the same period as that of the planet's radio emissions, which is assumed to be equal to the period of rotation of Saturn's interior. The hexagonal feature does not shift in longitude like the other clouds in the visible atmosphere.
The pattern's origin is a matter of much speculation. Most astronomers seem to favor some sort of standing-wave pattern in the atmosphere; but the hexagon might be a novel sort of aurora. More extreme speculation has Saturn's radio emissions emanating from the hexagon (something we can see and which has the right rotation period) rather than from the planet's interior (something we cannot see). Polygon shapes have been replicated in spinning buckets of fluid on laboratory scales.
Since Saturn does not rotate on its axis at a uniform rate, multiple rotation periods have been assigned to it (as in Jupiter's case): System I has a period of 10 h 14 min 00 s (844.3°/d) and encompasses the Equatorial Zone, which extends from the northern edge of the South Equatorial Belt to the southern edge of the North Equatorial Belt. All other Saturnian latitudes have been assigned a rotation period of 10 h 39 min 24 s (810.76°/d), which is System II. System III, based on radio emissions from the planet, has a period of 10 h 39 min 22.4 s (810.8°/d); because it is very close to System II, it has largely superseded it.
While approaching Saturn in 2004, the Cassini spacecraft found that the radio rotation period of Saturn had increased slightly, to approximately 10 h 45 m 45 s (± 36 s). The cause of the change is unknown — however, it is thought that this is due to a movement of the radio source to a different latitude inside Saturn, with a different rotational period, rather than an actual change in Saturn's rotation.
In March of 2007 it was reported that the variance in measured rotation periods may actually be caused by geyser activity on Saturn's moon Enceladus. The water vapor emitted into Saturnian orbit by this activity becomes charged and "weighs down" Saturn's magnetic field, slowing its rotation slightly relative to the rotation of the planet itself. If true, this means that there is no currently known method of determining the actual rotation rate of Saturn's core.
reference: http://space.wikia.com/wiki/Saturn We have so much data to sift and process atm and we collected more yesterday morning.....