Images from ISS' observation of Saturn's north polar region are in:

NAC: http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=274011
North pole pretty much looks like the south pole of Saturn
WAC: a hexagon http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=273947

That sequence is unbelievably spectacular. The CB2 images of the pole...I swear I'm seeing vertical relief but it could just be an optical illusion. I fiddled with trying to take out the rotation by stretching the pole to a circular shape and then rotating the frames to align some features (you can't align everything because of differential rotation) but I couldn't make it work. Hopefully someone with greater skill here will take up that challenge...

Thats the image of the year - right there (actually - yes, go look at the whole sequence, its amazing).

I remember being gobsmacked by the south polar 'eye' images, but these are clearly at a much higher resolution and at beautiful sun angles.

All that convection! I wonder if someone can figure out the vertical relief of those cloudtops?

However it still looks different to the south pole, the spiral inside the 'eyewall' here seems quite different to the calmer looking area with 'popcorn' convection inside the southern eye. Maybe its just because theyre better images, but I dont think so...

I hope someone does a rotation movie - I'm stuck at work!

P

Simply gorgeous!
And it's very nice sequence indeed.

I tried this with the best tools in post production, but the frames are not enough to create a satisfactory result. Maybe Machi's manual method will work.

Simply amazing ! Theses NAC view are just mesmerezing. I will try to make an animation of it.

I'm pretty sure it's real. In some places you can see shadows of clouds and you can take a stab at the height of some of the clouds from that.

My try to make a reprojected animation, with some smoothing between frames. But yes, there is not enough frame to do something smooth.

http://www.youtube.com/watch?v=dMsGxIkxlUk

Absolutely amazing images.


The CB2 image has a resolution of ~3 km/pixel (maybe a bit better) so seeing vertical relief might be possible. Something like ~30 km vertical relief (that's what I get from very crude 'measurements') does not seem implausible given what's known about Saturn's cloud layers. The sun is also coming from the right at a fairly low angle and the appearance of the clouds seems consistent with that. *But* - what we're seeing might be partially or entirely an optical illusion as noted above - the color/brightness of different clouds is variable and the image is heavily contrast stretched. But it's also interesting to note that vertical relief is visible in Voyager images of Jupiter at significantly lower resolutions (~15 km/pixel) and Saturn's atmosphere isn't as 'compressed' vertically as Jupiter's thanks to Saturn's weaker gravity (the scale height of Saturn's atmosphere is higher and the altitude difference between different cloud layers is bigger at Saturn).

In fact it just might be possible to extract some vertical relief information from these images by using two of them as a stereo pair and by correcting for the zonal (east-west) winds. The interval between the images has to be short though and the shape of the cloud features must be fairly stable over that interval.

I've been experimenting with this using two Voyager 1 images of Jupiter as a stereo pair with mixed results. The resolution of that data is significantly worse than here. The resulting 'DEM' reveals a change in the height of cloud features roughly where expected (lots of noise though) but the change is the opposite of what I was expecting and I think my software is detecting latitudinal variations in the zonal wind speed and not vertical relief. I should probably clean this up a bit and post it in the Jupiter forum.

There are some in colour. As usual, a gorgeous Saturn
Click to view attachment
Click to view attachment

This is a first pass, rough draft done in Gimp (Photoshop's at home).**




**Blame it on my ignorance of the app, but I didn't immediately find a way to perform scaling/perspective/and rotation all at once within Gimp. On top of that, when performing transformations on images, whatever layer you are on immediately overlaps all others, so you can't adjust beneath another layer or within a painted selection. Therefore, the destructive nature of each individual change rendered the overall result a bit on the blurry side and not in perfect sizing. I'll create a cleaner version without as much distortion and blurriness when I have access to Photoshop (which should be later tonight).

AWESOME. That is exactly what I was trying to do. Can't wait for the Photoshop version.

Incredibly beautiful....
how I would love to glide through the cloudscapes of Saturn just as we rove the rockscapes of Mars...

Craig

Here's a cleaned up version of the above.

Wonderful Kemcab !

From my side; I've been playing with a reprojected version of one picture, and use it as a bump map. Here's the anaglyph version. Looks pretty accurate for me (of course, vertical relief is exagerated).

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

Beautiful!

Wow, Ant103, that's gorgeous!

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:

Click to view attachment

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.

I see definitely vertical relief:

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

Thank you all

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

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

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.)

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

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.

These pictures are simply incredible!
Here below an RGB merge of 3 images taken close in time with different filters (N00198382+83+85):
Click to view attachment
Note: colors are arbitrary and do not reflects real coloration!

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.

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

That's an amazing video! Well done!

It's like I'm looking at liquid.

Wow.

I guess there's not that much difference between liquid and dense gas but this is easily one of the most spectacular photos I've ever seen of Saturn. Wow.

I decided to experiment with this (possibly crazy) idea and tried using two of the north polar images as a stereo pair. The results were as I expected: Nothing interesting, i.e. no recognizable features, just noise. I might get better results once I have accurate viewing geometry information after this gets released at the PDS but I'm not expecting it. The interval between the images is probably too long for using them as stereo pairs. The shape of individual cloud features changes in the time that passes between the images and this makes stereo matching difficult and maybe impossible.

The nominal altitude difference between cloud layers on Jupiter is about 60 km. On Saturn, that should be about 2.5x, or 150 km. At some level of magnification that must, obviously, allow stereo imaging, but the edges of the hexagon are almost 100 times that vertical difference, so the relief is likely very muted, maybe a couple of pixels, in any image that shows the whole hexagon.

The best "magnifying glass" we have for subtle relief in these clouds, as with Saturn's rings, and the lunar maria, etc. are the long shadows at very low sun angles. Stereo as seen looking down at a feature is less sensitive. There are stereo images of terrestrial cloud features as seen from orbit that might help define the baselines of what is required to get a nice effect.

I had to go through a few pairs but I think this one shows some stereo effect.

Click to view attachment
Oops, I missed the earlier posts of these same images.

Lots of nice images of Saturn's N Polar hurricane have been posted today in JPL's Photojournal. http://photojournal.jpl.nasa.gov/targetFamily/Saturn