Rev 120-121 - Oct 23-Nov 30, 2009 - Enceladus E7, E8 Options

[elakdawalla]

This was as wide a shot on the plumes as I could come up with. Mosaic of N00146851 and N00146855. I cannot get over how cool it is that we can see those plumes issuing from the darkness. Even after the sun has set on the south pole for the winter, for quite a while we'll be able to see the tiger stripes outlined by the sunlit plumes wherever they reach high enough elevation to see the Sun.

There appears to be a ring feature on the terminator, made of concentric circles of low ridges. I think. I wonder if this is an impact feature, or just a trick alignment of ridges and shadows? Does it line up with anything on the maps? I see something roundish in Steve's blink gif. Someone on the imaging team, I forget who, was doing some tectonic reconstruction on the Enceladan south pole -- I wonder what they thought of that feature? It's certainly dramatic in the oblique views.

--Emily

[scalbers]

Looks as Emily and I are looking at the same roundish feature - have yet to see a name for it, being between Alexandria and Cairo in this map. In her wide shot from left to right we can trace Alexandria, Cairo, Baghdad, and a bit of Damascus Sulci, though the latter two are outside of my comparison map (post #135).

Steve

[nprev]

Was wondering if I was the only one wondering about that 'ring feature'. Amazing how pronounced it is at a low illumination angle; it's hard to even recognize from the overhead images.

Sure looks like a highly modified impact crater to me, though agree that it's hard to be sure given the chaotic nature of this terrain. If it is in fact a crater, could provide some interesting insight re the age of the surface.

[antipode]

Ring feature = diapir?

This thing needs a name! Are there more of them?

As boggled as the rest of you by these images. They should be on front pages everywhere, but of course they wont be.

P

[ugordan]

Approaching the plumes:

[volcanopele]

There have been some arguments made that the feature is a very heavily modified impact crater, a ghost crater if you will. I'm not quite sure I subscribe to that, but I guess something had to happen to the craters after the region got chewed up and spat out.

Another reasonable argument, antipode.

[ngunn]

I too was wondering about the apparent ring feature, but after locating it on the map concluded that it was probably nothing in particular, perhaps a patch of surface that has rotated somewhat due to activity on surrounding fractures. Of course that's not inconsistent with an impact having set up the fracture pattern in the first place.

Emily the first image in your post provides exactly what I've been waiting for since first seeing Stu's version - thanks! That's the one for my wall.

[Gladstoner]

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[nprev]

Ooo...GREAT animation, Gordan!

Cassini did in fact blast right through the biggest plume, right? Looks like she went through a little curtain of lesser emissions immediately prior to that.

[ugordan]

I don't know which part of the plume it went through, but tracking a certain feature like above can be deceptive. Cassini might have been going more sideways than towards that particular "hotspot".

[ngunn]

Would anybody like to guess which sulci the main plumes on the horizon belong to?

[ngunn]

Any ideas regarding the smooth area

My guess is that smooth means old around here, so one side of that fracture is older than the other. What is the sharpest feature we can find in these images and how recent might it be? This must be a question the Cassini scientists are addressing.

[scalbers]

Would anybody like to guess which sulci the main plumes on the horizon belong to?

My guess for the brightest three spots on the limb in Emily's wide angle image is (left to right) Cairo, Baghdad, Damascus.

Approach was from 195 west longitude, passing closest approach at 80S 120W. So it looks to have flown mostly along the Cairo plume passing most directly over it just on the sunward side of the terminator.

To help piece the puzzle together I have a coordinate grid on the image used for the map comparison. Longitude lines are every 20 degrees with the green longitude line at 180. Latitude lines are every 15 degrees. It may have passed just left of the brightest plume (slight slant of path over Cairo Sulcus) on the horizon in this image. Closest approach would be on the visible side midway between the terminator and the limb/horizon.



Hopefully I've got this straightened out. It might be interesting to overlay the ground track on the above image.

[Vultur]

These pictures are absolutely, completely incredible! What an amazing moon...

[ustrax]

One leaves for the weekend and in the meanwhile we fly straight through the freaking plumes of Enceladus?! Someone please slap me in the face, I have a facial paralysis...