Titan T28 mission description is now available. Note grountracks displayed on pp 9-10.
http://saturn.jpl.nasa.gov/multimedia/prod...description.pdf

These groundtrack graphs are awesome, I hope they keep them in the future.

The groundtracks polar plot on page 10 includes the first version I've seen of the ISS Titan Map in polar format. In our lakes discussions here I mentioned that the South polar one in particular would be very useful for comparisons between the two polar regions.

On Ciclops Sector 6 I posted a query about whether such a projection could be made available but received no reply.

Now this appears in the Mission Description, indicating that such a polar version does indeed exist somewhere. Does anybody here have access to it in its original, non-PDS, unannotated form?

The south polar coverage on that ground track map looks the same as Ta south polar coverage to me, with the clouds artificially removed. Then there's this release showing Ontario Lacus and I believe it's a polar view with the red mark marking the south pole. I'm not aware of any other polar views.

Thanks ugordan. Yes I know that view, though I didn't know it was an actual polar projection. However it's nice at last to see the whole hemisphere with the lat and long grid. It gives a clearer idea of the relative positions of Ontario Lacus, Mezzoramia and the other features. They must have a hi-res version somewhere, so why not release it?

As I said, I believe that polar view from the groundtrack plot was just using the updated Titan map which was projected onto a globe and then this was produced. The updated map IIRC uses the Ta data (it's not terribly up-to-date for other regions as well) for the south pole which if memory serves me is a pretty low resolution view (300 000 km C/A) so releasing a separate polar view of it would be of little use.

On the other hand, yes, it would have been nice if that Ontario Lacus mosaic clearly stated it's a polar projection and also a version with a lat/long grid would have been nice.

Sure, I realise that the map uses mostly lower res and not fully up-to-date data and that the images themselves are a better place to go for whatever details are available. I'm not expecting to see any new details in a polar version, I just like having the geographical context made explicit. It helps with formulating questions like why is Ontario Lacus (probably) wet and southern Mezzoramia (probably) dry? It would also be useful for plotting future RADAR noodles - and other planned imagery - on, now that there is heightened interest in the high latitudes.

All...

I feel the pain too and would like to see better projections but there really has not been much south pole coverage in any detail as yet in the mission.

looking at http://cassinicam.com/titanflybys/ by Joe Knapp looks like some better coverage of the south pole (and some of my other faveorite regions) is coming up later this year (In addition to more north polar passes in this quarter).


Jul 19 07 (T34) - Belet

Oct 02 07 (T36) - South Pole

Nov 19 07 (T37) - Xanadu

Dec 05 07 (T38) - South Pole

Dec 20 07 (T39) - South Pole

Jan 05 08 (T40) - Xanadu

According to Emily's site http://planetary.org/explore/topics/saturn/titan_radar.html
T39 will have south pole SAR coverage.

Good stuff is coming .....

Craig

The latest "Looking Ahead" post on the CICLOPS site for Rev42 and T28 is online:

http://ciclops.org/view.php?id=2901

Thanks volcanopele.....

from the latest "Looking Ahead"

"Cassini encounters Titan for the 29th time on April 10, with a closest approach distance of only 990 km (615 mi). Like the last few encounters with Titan, this flyby (known as T28) will allow for imaging of the northern portion of Titan’s trailing hemisphere following closest approach. The Cassini cameras will take two mosaics of this region. These mosaics (and a lower resolution context mosaic) focus on an area centered at 45º North Latitude, 240º West Longitude, north of the dark region named Belet. The T28 observations will allow for a follow-up on discoveries made in T25, T26, and T27 images, such as a set of lineaments north of Belet … features which were also observed by the RADAR instrument during T21 (December 12, 2006). The discovery of northern mid-latitude clouds in late February suggests that these observations may also allow for cloud tracking. During closest approach, the Cassini RADAR instrument will obtain a Synthetic Aperture Radar (SAR) swath covering similar terrain as the swath obtained in February, during the T25 encounter (see PIA09182). This RADAR swath will cover, like the T25 swath, the northern portion of a Caspian Sea-sized dark region discovered by ISS in February. Shortly after closest approach, VIMS will obtain several high-resolution observations of the northern half of the trailing hemisphere, including the dark lineaments mentioned above. "

Very Cool!!!!! RADAR saw the lineaments on T21!

And clouds at mid-northern latitudes.... seasons are a changin!?

Craig

I do not

T28 raw images up now.

This seems much more up close than previously. Lots of weirdness on the surface there (crater? http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=107207 ) of which this is my favourite I think:

http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=107204

You couldn't see this area very well from the last flyby, not these lattitude stripes anyway I think. Dune fields cutting into somthing else??? Very cool anyway

tiger stripes?/rivers?/weirdness:
http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=107189
http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=107185

Anyone got a needle?

The dunes (which have never looked so clear in ISS images that I can recall) should be going east-west, so north is either to the left or to the right. (I know, that sounds like the kind of directions you'd get in New England.)

in the ciclops page VP linked it's the area in the middle I think ( shaped like a ">") so these stripes look to go along lines of latitude.

the needle was a stitching reference, not so much a compass reference

Err, what dunes? Are you referring to precise vertical dark strips? Those are artifacts from the camera, enhanced by binning and histogram stretch. These kinds of artifacts are present in practically all telemetry modes of the cameras and as of the time the calibration volumes were archived in the PDS, their cause was unknown.

no the very broad vague stripes. kinda diagonally. well, probably much wider than 'stripes' on the surface. more like the red sea

and the horizontal pattern interrupting the wite ">" bit. not individual dunes (much too big), but seem pretty straight and parallel

Oh, that... Well, that's too broad and too vague so I figured you didn't mean that when you all said "clear looking" dunes

dunes were reference to the other picture. and I said dune field, because there's no way you can see individual dunes i assume

The mosaic of raw images. Position of top three images (with vertical dark strips) is very uncertain, there are almost no details to locate them properly.

Very nice Olvegg. Curien Station almost squeezes in at lower right. Seeing that shape of eastern Adiri again sure brings back memories.

Really nice work, Olvegg. There is a LOT of interesting-looking territory north of Adiri. All kinds of suggestive round and straight shapes. We don't have any RADAR coverage at all over this area, do we?

--Emily

Fantastic! The difference between the raw and the coallated map is huge. Thanks for sharing.

Thanks for posting this, Olvegg!

That little complex area in the upper right center looks real similar to Shiwanni Virgae near Tsegihi. I wonder if the same formation process was active up here?

-Mike

Arrggh, you scurvy dog Olvegg! Releasing me pirate map of me buried treasure!

(There's a little 'X marks the spot' SE of the hole in the mosaic, I wonder how it got there?)

Terrific, Olvegg...thank you very much!

That 'sliced carrot' feature near the middle of the mosaic is intriguing, to say the least. What the <clink> is happening there???

very cool!

You see 'sliced carrot', I see 'McNaught tail' Maybe in fact dune material drifting through passes in a range of hills???? This is indeed a most interesting area that we see newly revealed.

Any news about the SAR from T28?

On the CASSINI web site is a new video clip that shows the other "side boundary of the black sea".

http://www.jpl.nasa.gov/videos/cassini/cassini20070423/

Can any of you video gurus capture this?

Craig

Actually, they don't. None of the views shown in that movie show the T28 SAR swath.

My apologies.... I see that now ... looking at this link from a previous thread...

http://www.unmannedspaceflight.com/index.p...ost&id=9749

I was misled by the island being cut off in this video release.

Too bad.... assume many of the researchers may have been present at the EGU last week and so the total lack of updates.... or am I getting spoiled? I remember, in the pre web days, having to wait months for formal publication of ANY results beyond the candy pieces released to the t.v. and print press. You younger folk have NO idea.

Craig

Maybe they are waiting for the results from the latest April 26th radar pass before releasing anything from the previous April 11th flyby?

New T28 global view on Ciclops:
http://ciclops.org/view.php?id=2928

Like that... couldn't resist messing about with enhancing it a little...

Click to view attachment

I've been working on something similar with other fly-by images for use in one of my talks, too... gets its premiere today in Keswick... again, not scienifically that accurate (or useful!) in any way, I know, I just like showing people Out There just how amazing Titan is...

Click to view attachment

I like the colorization, Stu. Keeper!

Stu...

love the map and the globes for comparison. May I use this if I credit your work?
Great work indeed....

You folks are incredible. SO glad I found this forum!!!!

Craig

Nice work, Stu...thanks for the new desktop!

No problem. As I said, just messing about

Very nice new mosaic:

http://photojournal.jpl.nasa.gov/jpeg/PIA08945.jpg

including Titan's own tiger stripes (river beds this time I assume)

There's a nice dancing monkey there SE of the rivers. Makes for a good background. Have we seen areas like this before on Titan?

Looks like the stripes is Mars' polar cap to me...

It looks kinda like areas seen in the T-20 Flyby and written up by VP: LPS 2007 abstract here. (Real pretty map on 2nd page).

They were interpreted as "extensional terrain, with bright horsts and grabens filled in with dark material".

Also, Shiwanni Virgae (S of Aztlan) and Percunas Virgae (S of Shangri-La) are also similar. (At low resolution, if you rotate Percunas Virgae 10 degrees clockwise it is almost indistinguishable from Shiwanni Virgae).

I would bet that the local highest sea (lake?) level was just right so that all the details in the fractures in this area were nicely brought out by the bright/dark boundary. I'd also bet that when RADAR images become available of the "dancing monkey" feature that there will be huge areas of Titan that look similar. (Many of these areas are not noticed by ISS imaging due to a thin layer of bright material that obscures the topographical contrast).

More RADAR data will be cool!

-Mike

Show up even better with a bit of messing about enhancing...

Click to view attachment

Thank you Stu....

I want to put together a presentation on planetary research and I would love to use this.
You will be credited!!!!!

Craig

NICE.

Those faux "tiger stripes" are very interesting. And the spaghetti terrain.... almost looks like this area is being compressed to the northeast....

I know this is a REALLY kooky analogy, but for those os us who live in northern climes, ever see ice buildup on a car windshield and then watch how the ice sheets break up and flow when heat is delivered?
Same fractal behaviour..... seeing the lighter terrain reminds me of that.... almost as if sheets of ice are being sculpted and pushed against each by wind and tectonics as some elements melt under a methane drizzle.

I know I am not expressing this very well.... and I am not suggesting we are looking at a cosmic windshield..

Craig

The Dancing Monkey feature located in the bright temperate highland area N of Adiri (approx location [30N, 210W]) looks very much like a cycloid crack pattern as seen on Europa.
Here are is an image of the Dancing Monkey feature (clipped from the CICLOPS website in the Looking Ahead Rev 47 post). And here is an image of a similarly complex patterned area on Europa.

Click to view attachmentClick to view attachment

It is thought that the cycloids are generated by diurnal tides. (Europa orbits Jupiter every 3.55 days). Each arc is generated in one orbit due to changing and rotating tidal forces. The area on Titan and the area imaged on Europa are in almost the same tidal force environments (same longitude, almost exact opposite latitude). [Fun fact: (0N,0W) is the subprimary point for rotationally locked moons.] See this post for diagram showing Titan’s tidal forces and this post showing where the forces in Titan are strongest.


Cycloid cracks are now thought to result from rotating tensile and shear stresses (Marshall and Kattenhorn Icarus 177 (2005) 341-366. “A revised model for cycloid growth mechanics on Europa: Evidence from surface morphologies and geometries” HTML (text-only no pictures - freely available here (A earlier work describing strike-slip faults on Europa is available freely here). A diagram of the cycloid growth model proposed by Marshall and Kattenhorn is shown below:

Click to view attachment

At a certain point, the tensile strength of the crust (ice) breaks and a crack forms and propagates. If the forces rotate faster than the crack propogates, the crack will try to form an arc. But as the forces rotate faster, they set up a shear as the tidal pull yanks the material on one side of the crack. The crack then begins to behave as a slip fault. Eventually the tensile force decreases, the crack stops propogating. But the forces keep rotating and eventually set up a shear in the old crack, and a tensile stress in the terminus. The shear forms a “tailcrack” and the crack propogates again. This makes a line with a series of arcs hopping across the surface.

From the article, I got the impression that faults and cycloid cracks on Europa might be two flavors of the same thing.

Also, cycloid cracks have recently been observed on Enceladus’s south pole: Hurford et al. LPS XXXVIII (2007) Abstract 1844. “A cycloid-like rift near Enceladus’ South Pole: Europa-style Production by Tidal Stress.”. Abstract freely available here.

-Mike

Europa-like cycloid crack propagation may be responsible for the evolution of the Dancing Monkey feature as shown in the following putative formation sequence. This final steps of this sequence are pretty much the same as proposed for the putative formation sequence for the neighboring Sliced Carrot feature (described in this post), save for the atmospheric chemistry product deposition:

Click to view attachment

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Click to view attachmentClick to view attachmentClick to view attachmentClick to view attachment

Click to view attachment

Here are the steps in the putative sequence:
1) Cycloid cracks start
2) Cycloid cracks propagate (1 arc/orbit)
3) Cycloid cracks continue (Tectonic faulting also?)
4) Network widens
5) Erosion from runoff cuts/shapes makes new channels (river capture?): dark blue ice sands deposited
6) Bright material deposited
7) Inundation and flooding by hydrocarbon solvents removes bright material from below flood stage
8) Dune sands invade system
9) Atmospheric chemistry products brought down by seasonal rains: deposition over dune sands and bright highlands: contrast lowered.


(The exact formation sequence of the network will be very tricky to work out. Different cracks may have formed at different times. Shifting and faulting may also have occurred to complicate matters).

Here is a comparsion of the diagram from the sequence above with the observed image:

Click to view attachment

The Dancing Monkey feature is probably an overall shallow area that has cracks just at the right level to be inundated by flood events that removed the bright material and increased contrast. Rather than a series of canyons and hoodoos, the feature most likely resembles a low-lying series of backwater sloughs. (using the “western US” definition of slough. Earth analog: Elkhorn Slough wiki here: http://en.wikipedia.org/wiki/Elkhorn_Slough)

We may expect to see more regions of cycloid cracks on Titan. The area directly to the SE of the Dancing Monkey feature may have formed similarly but lying slightly lower, was subject to more extensive erosion from fluvial and tidal effects of the Equatorial Sand sea basins.

It might be interesting to see if any of the ridges or grabens have a cycloidal or arcuate pattern overprinted on them. (T8 RADAR swath ridges that look like ski tracks? Or the "tiger stripes" river paths waaay up north?)


-Mike

Why do I keep thinking it looks like the Flying Spaghetti Monster....?

That was my thought too. Anyone for pasta?

Phil

It's only a fake flying spaghetti monster....

....so it's an im-pasta!