[X] My Assistant

[Ant103]

Color mosaic of the Northern hemisphere, with the hexagonal polar vortex.

[machi]

Beautiful!

[kemcab2012]

Wow, Ant103, that's gorgeous!

[Bjorn Jonsson]

I'm finding it increasingly hard to believe that we are not seeing vertical relief - and let's not forget that vertical relief is visible in clouds in images of the Earth, Jupiter and Neptune at comparable (or lower) resolution. Here is a small two image example centered at the pole:



Two cloud features are marked with red. Looking at their motion relative to nearby features strongly suggests to me that they are at a higher altitude than nearby, darker features. I get the impression that they lie roughly 10 pixels above the lower (?) cloud deck. This translates into a ~20-40 km difference in altitude, depending on the exact image resolution at the pole (which I know only crudely at this time).

I can't rule out an optical illusion though and there's another problem that makes interpreting the images more complicated: It's obvious from this image pair that the shape of the bright clouds can change quickly.

[machi]

I see definitely vertical relief:

Attached thumbnail(s)

 

[ngunn]

Ant103: Lovely, but my students will ask- what is the red dot?

[Ant103]

Thank you all

@ngunn : a red dot ? Where ? Maybe you are talking about the cosmic ray visible on the right side of the mosaic ?

[machi]

I think that ngunn meant red dot at top left part of the hexagon

[ngunn]

Yes that's the one. It kind of leaps out at you when you focus in on the hexagon. (I notice also a fainter red streak crossing the terminator nearby.)

[eoincampbell]

The views from this orbit are astounding ! Thanks for sharing.

[Ant103]

Ah yes, I'm seeing it now.

I can explain it after examination of the raw images. In order to produce this high resolution mosaic, I used the 256*256 px RGB frames, overlayed onto the CL 1024*1024px ones. It appears that on the red layer of one of the pictures there is a cosmic ray, not visible on the green, blue and greyscale pictures. And with the upscalling of the color layer, this "red" cosmic ray have grown into a blurrish dot. Here is the explanation.

[dilo]

These pictures are simply incredible!
Here below an RGB merge of 3 images taken close in time with different filters (N00198382+83+85):

Note: colors are arbitrary and do not reflects real coloration!

[Bjorn Jonsson]

This should be about the best I can do with these images:

Saturn north polar movie (tweened)

This is a 'tweened' sequence of all 7 CB2 images obtained over a period of approximately 5 hours (the images are separated in time by ~50 minutes). I reprojected the images after reverse engineering the viewing geometry. This wasn't very accurate so I also warped them to 'stabilize' things a bit (especially the big, dark 'circle' around the pole). The final step was to use Sqirlz morph to 'tween' the sequence. This was fairly easy since everything revolves around the pole. In contrast, a movie I did from PDS data several years ago (see this thread) was difficult to tween since features move into view from one edge of the image and then disappear at the other edge.

The resulting movie reveals lots of interesting stuff. It's obvious that most/all of the big spots rotate clockwise and some of the small ones clearly do so as well.

The CB2 images are the sharpest ones from this sequence of images. The red images are also pretty good but they are 'only' 512x512 pixels so I decided to use CB2 only.

Cassini's distance from Saturn's north pole was ~400,000 km during the imaging sequence (it varies by ~40,000 km). This translates into a resolution of ~2.5 km/pixel. The spacecraft was ~40 degrees above the north pole.

A much better version of this movie should be possible once this stuff hits the PDS 10 months from now.

[dvandorn]

Say, guys? Where'd y'all put that swear jar?

Incredible work, Bjorn! Sort of puts paid to any question that the clouds are casting shadows, doesn't it?

-the other Doug

[toddbronco2]

This is a 'tweened' sequence of all 7 CB2 images obtained over a period of approximately 5 hours

That's an amazing video! Well done!