[X] My Assistant

[belleraphon1]

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

[ugordan]

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

[ngunn]

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?

[ugordan]

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.

[ngunn]

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?

[ugordan]

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.

[ngunn]

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.

[belleraphon1]

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

[volcanopele]

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

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

[belleraphon1]

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

[ngunn]

T28 raw images up now.

[remcook]

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?

[JRehling]

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.)

[remcook]

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

[ugordan]

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.

[remcook]

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

[ugordan]

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

[remcook]

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

[Olvegg]

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.

Attached thumbnail(s)

 

[ngunn]

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

[elakdawalla]

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

[stevesliva]

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

[Juramike]

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

[hendric]

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?)

[nprev]

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???

[remcook]

very cool!

[ngunn]

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

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.

[alan]

Any news about the SAR from T28?

[belleraphon1]

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

[volcanopele]

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

[belleraphon1]

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

[Guest_Sunspot_*]

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

[ngunn]

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

[Stu]

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...



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...

[Exploitcorporati...]

I like the colorization, Stu. Keeper!

[belleraphon1]

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

[nprev]

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

[Stu]

Stu...

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

Craig

No problem. As I said, just messing about

[remcook]

Very nice new mosaic:

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

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

[hendric]

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?

[stevesliva]

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

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

[Juramike]

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?

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

[Stu]

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

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

[belleraphon1]

No problem. As I said, just messing about

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

[belleraphon1]

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

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

[Juramike]

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.



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:



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

[Juramike]

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:











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:



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

[edstrick]

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

[Phil Stooke]

That was my thought too. Anyone for pasta?

Phil

[edstrick]

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

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

[ugordan]

Apologies if this was already mentioned somewhere, but the full T28 RADAR swath was released today:
PIA09217

[ngunn]

Thanks ugordan - it's a beauty.

[belleraphon1]

I was just going to post this.....

thanks uugordon.

Hopefully this is a harbinger of more releases to come?!?!.

Craig

[Juramike]

Awesome!

Wher is this located on Titan?

Anybody got an global map with the T28 RADAR swath indicated?

-Mike

[belleraphon1]

Mike..

looks like this starts in Tsegihi and crosses Aztlan and Fensel as it heads north east.

See slides 14 and 16 in this last CHARM presentation

http://saturn.jpl.nasa.gov/multimedia/prod...CHARM_3Year.pdf

Anybody have radar swath maps that are labeled?

Craig

[rlorenz]

Hopefully this is a harbinger of more releases to come?!?!.

Yes.

[belleraphon1]

Yes.

More Please!!!!!!!!!!

[Stu]

the full T28 RADAR swath was released today:

Some highlights of the lakes area... as usual, purely for "wow" reasons, not suggesting any scientific worth, ok?

[belleraphon1]

Calling all image mages.... ALERT ALERT ALERT.....

Can some one line up http://photojournal.jpl.nasa.gov/catalog/PIA09217 from T28
with http://photojournal.jpl.nasa.gov/catalog/PIA09182 from T25?

And very evocative images Stu....

Amazing little world.... I am constantly amazed seeing these swaths.... as lively a place as we could wish for....... I was commenting to a coworker how wonderful these data are and I still have to pinch myself to be sure this is not some science fiction dream. This is for real....

Craig

[Juramike]

Hey Craig,

I think I got the lower part (I stuck it in the Equatorial Sand Seas thread) here:

(T25 was in the Exploitcorporations mosaic, you may may need to enlarge it to see the T25 insertion. It is immediately to the W of the T28 swath, and also has Sotra Facula at its lower section)

-Mike

[belleraphon1]

Thanks Mike... really really nice line up in the other thread. I am plugging in the Batsignal for Exploitcorporations too!!!!!

Doug... what thread should we use? This is no longer just T28 nor strictly the Equatorial Sand Seas?

Craig

[belleraphon1]

Some highlights of the lakes area... as usual, purely for "wow" reasons, not suggesting any scientific worth, ok?

Stu.... please keep wowing us.

WOW

[Juramike]

This is no longer just T28 nor strictly the Equatorial Sand Seas?

Ahhh, yes, all threads weaving together into one....convergence is at hand....

-Mike

[belleraphon1]

AHHHHHHHHHHHHHHHHHHHHHHHHhhh

Singularity....

cannot see the other side of ecstasy.... but it is there....

Craig

[Olvegg]

Can some one line up http://photojournal.jpl.nasa.gov/catalog/PIA09217 from T28
with http://photojournal.jpl.nasa.gov/catalog/PIA09182 from T25?

My attempt (only for lakes, of course, I can't thnink now of something besides ):

Attached thumbnail(s)

 

[marsman]

Extraordinary! Fractal patterns come to mind. High-res pictures of this fantastic landscape from balloons is something I hope to see in my lifetime.

[belleraphon1]

My attempt (only for lakes, of course, I can't thnink now of something besides ):

Thanks Olvegg. What beautiful patterns.

Fractal patterns indeed Marsman. Balloons would be great and hope that happens in my lifetime.

But, right now, I am trying to imagine what it would be like to hike that maze of organic dusted canyons, round some cragged corner, see that dappled shore. Then travel the ruffled plains, amidst mystery and wonder, tapping tuff from every boot step, til my footprints trace the benzene crests of dunes forever more.

So much more to know and we are SO just learning.

Craig

[nprev]

Yeah...imagination runs riot looking at these oddly familiar yet startlingly different vistas...

I keep wondering what the rivers sound like, or if the waves of the seas make a hissing noise on the ice sands of the shore as they recede.

[belleraphon1]

Yes nprev...

I try and think of the sounds as well. To sit on one of those shores....... listening to the liquid gurgle through the smurst and ice sand of the beach. What a wonderful word that is ..beach. Beaches are very rare in Sol system. Until Voyager, I thought Earth unuiqe in that respect .... even now that we know that interior oceans may be common... beaches are still rare.

These lakes are very dark.... rlorenz, any thought on what the wave features might be given how featurless is the radar return?

Craig

[Stu]

My attempt (only for lakes, of course, I can't thnink now of something besides ):

Now THAT's a WOW image! Thanks olvegg!

What a stunning, stunning place... still can't get over the fact that just a handful of years ago Titan was just a big orange ball to us, now we think of it as a world of lakes and seas, rivers and streams, valleys and mountains, beaches and shores... just unbelievable...

[Stu]

WOW

Thanks, I was quite pleased with those myself...

If you look at the area around the "island" and mess about with enhance it there's a heck of a lot of detail hiding in the shadows there... some long, meandering features and several small circular features too...

[nprev]

...Damn, Stu...that's just...just...words fail me. Uh, wow.

Hard to even get your head around this. It looks so bloody terrestrial in most respects, but assigning cause & effect relationships to explain the features is a real crap-shoot. Heck, is it possible that there are rivers of denser fluid carving channels in the substrate underneath a sea of less dense organic fluid?

Alternatively, perhaps we're seeing fossil features from a previous era recently submerged. Either way, the place looks dynamic as hell.

[Juramike]

Heck, is it possible that there are rivers of denser fluid carving channels in the substrate underneath a sea of less dense organic fluid?

That's entirely possible.

There could be different density gradients of things mixed with the organic layers that cause it to set up into differing layers. (Earth analog: the undercurrent that drives Earth's ocean circulations - these cause actual rivers under Earth's oceans. Nightclub analog: The layers in a tequila sunrise.)

The high latitude lakes should be fairly immune from tidal effects and possibly wind as well. Looking at the sharp shoreline above and in other images, it looks like the liquid slowly filled it up. There was no wave action or sloshing that would've rounded sharp headlands and deposited beaches in the valleys. I picture serene, quiet lakes whose levels slowly rise and fall with Not Much Else Happening.

There could be denser materials seeping out of the methanofer and flowing along the bottom of the lakes. This stuff could cause a crosscutting upper-level flow to go right over it.

Here's how to check:
Look for a large river coming in with and "submerged" stream cutting directly across it's path (I think there's an example in there somewhere.) If the "submerged" stream still has sharp boundaries, there are only a few possibilites:

1) There is still material flowing in the submerged steam, keeping it's edges sharp. (laminar flow of upper level stuff over it)
2) There is only material flowing in the submerged stream. We are looking at dried up lakes with residual trickles along the bottom. The "lighter" dark stuff in the lakes may not be fluid after all.

-Mike

[Stu]

Saved the best 'til last...

Looking at this...



... does anyone else think that looks like a part of the landscape has been eroded away? Does that look like a valley of some sort in the middle there? There's a lot of detail visible in there, pretty easy to visualise material flowing from top to bottom (as this image is oriented).

Could just be a result of the messing about enhancement process, but that gives me goosebumps...

[Olvegg]

Here's how to check:
Look for a large river coming in with and "submerged" stream cutting directly across it's path (I think there's an example in there somewhere.) If the "submerged" stream still has sharp boundaries, there are only a few possibilites:

1) There is still material flowing in the submerged steam, keeping it's edges sharp. (laminar flow of upper level stuff over it)
2) There is only material flowing in the submerged stream. We are looking at dried up lakes with residual trickles along the bottom. The "lighter" dark stuff in the lakes may not be fluid after all.

There's another possibility: these submerged channels are carved during dry seasons (in summer and autumn) when the sea level is much lower and rains are not so heavy.

I even suspect that there's a very complicated system of cross-flow between the great lakes. Look at this twisted delta for example. Light blue and green arrows show possible flow direction during dry season. Upper river flows into the lake, while second may either flow into lake or flow south. It depends on flow direction of "red" channel. Most intriguing is "green" part of river, wich turns 90 degree. It means that overall slope of broader channel is southward. During wet season (as today) methane may outflow from the lake and probably inflow into "Caspian Sea" (dark blue arrows).

Attached thumbnail(s)

 

[tty]

There could be different density gradients of things mixed with the organic layers that cause it to set up into differing layers. (Earth analog: the undercurrent that drives Earth's ocean circulations - these cause actual rivers under Earth's oceans. Nightclub analog: The layers in a tequila sunrise.)

There are even better terran analogs. The submarine canyons which cut through the continental shelf and slope are thought to be formed by turbidity currents (=mud). The are found mostly, but not exclusively, offshore outside the mouths of the largest rivers.

[Juramike]

There's another possibility: these submerged channels are carved during dry seasons (in summer and autumn) when the sea level is much lower and rains are not so heavy.

I even suspect that there's a very complicated system of cross-flow between the great lakes. Look at this twisted delta for example.

That's a beautiful example, Olvegg!

I can almost imagine a real subtle topographic break between the two long channels that you indicated with light blue left to right arrows. There might be just another (subtle) topographic break on a left right line parallel and slightly above the higher of the long channels. This might be the natural dam for the lake.

There's a teeny little dark channel that feeds into the upper long channel right at the tip of the blue arrow. I'll bet when the lake is down, that the fluids in the ridge section drain down this teeny channel into the upper long channel and flow to the left.

I think the light blue arrow on the far left might be reversed. This might be the main outflow for the lake (Notice how all the channels on the lake side near the light blue arrow are really, really stubby. They don't extend into the lake. I'm guessing the lake is draining out these channels to the bottom of the image. I'll also guess that when the lake drains, it backs up the green arrow channel so that it almost does a "river capture" of the upper light-blue arrow channel. I'll bet the topography is extremely subtle - like a tidal slough. Check out aerial images of the U.S. east coast intracoastal waterway (anywhere from coastal New Jersey south to N Florida) or aerial images of the Snohomish River in N.W. Washington State.

When the lake is low, I'll bet the upper light blue channel drains into the "left light blue channel" and drains away from the lake. I also suspect that the darker channels in the upper left of the image are draining the natural dam portion down to the bottom of the image also.

Nice catch!

-Mike

[nprev]

Could just be a result of the messing about enhancement process, but that gives me goosebumps...

Island, I dub thee (informally, of course; the discoverers possess the fundamental right to affix a permanent nomenclature) "New Manhattan"! Stu, mind-blowing as always...careful, you're rapidly earning the title of 'Imagesmith' in addition to Poet Laureate!

Only thing that bugs me is that linear sharp cutoff at about 5:00 on NM...looks like a processing artifact, but in Stu's previous image it also looked like there were some similarly aligned features directly to the left of the cutoff (with respect to his current image). Is this possibly a (very recent in appearance!) fault line?

[Juramike]

Nprev,

I think it's a processing artifact. But there do seem to be trends going up-down in Stu's image. The cute little ridge on the far peninsula (about 1 o'clock). And the streams seem to have an up/down trend (check out the river jog at 7 o'clock in the image).


Hmmm. I wonder.....

Which way is North in this image? Where is the island centered?

What is the ratio of inner diameter/outer diameter? (calling the island the inner diameter, and the outer basin the outer diameter)
If it was originally circular, what is it's squish vector and squish ratio?

Could the island be an uplifted and heavily eroded bright center dark halo object? Like the putative diapirs?

-Mike

[Stu]

Which way is North in this image? Where is the island centered?-Mike

This might help to place "New Manhattan" (like that!) in context...

[nprev]

Mike, funny you should ask...I really don't see any prima facie evidence of an impact or "volcanic" origin for NM. It looks to me very much like an outcrop of highly (and I mean highly) erosionally-resistant terrain that has survived the trevails of this environment in a relatively pristine state. Maybe it's mostly water ice, something like an exposed batholith on Earth?

[Juramike]

I'm thinkin' potential diapir. Like the Mitten feature on Europa. A diapir would rise in the center, but a thin ring around the diapir would subside.

So you'd get a central rise (not necessarily erosion resistant, but in this case it might be) with a moat of subsided material. (like the Mitten feature on Europa).

It might not be a huge difference in elevation. The Mitten diapir on Europa had an altitude difference of ca. 200 m above average elevation, with a "moat" of about 50-100 m below average elevation. Similar elevation differences were seen for diapirs in the Conamara Chaos region as well.

-Mike

[nprev]

Sounds reasonable...but look at how rugged the interior sections of this thing are, seems as if the upthrust was rather vigorous, perhaps atypical for a diapir (caveat: this ain't Earth or even a conventional terrestrial planet). Either it's really recent in origin, or it's tough as nails wrt indigeneous erosional forces. What's your read, Mike? I'm honestly puzzled by this island, and think that its very existence has much to tell us. (To say nothing of that little chain of smaller islands right off the lower right corner...I informally dub them "The Keys".)

[Juramike]

It definitely looks rugged and carved up by erosion in the interior.

But it doesn't take much elevation differential to provide a really impressive shoreline.
(A local case in point is Falls Lake just north of Raleigh, North Carolina - really cool-looking fractal shoreline, maximum elevation difference between lake surface and highest surrounding point is about 100 feet. (Check it out on Google Earth, it looks like it would fit in well on Titan). Falls Lake is a man-made lake that flooded river valleys which gave rise to the fractal pattern - similar to what I think is happening here.) [The flooded river valleys part - not the man-made part]

The other thing to consider is that perhaps fluid erosion is a relatively recent thing on Titan?
Maybe the diapir came up a long time ago, then the climate kicked in and has been working on it ever since?

Or maybe there was a recent upthrust that pushed a previously eroded and buried diapir and it's moat back up into the weather?

The surrounding areas look also pretty carved up, so I don't think this island was singled out for uplift. I'd guess that it is above the fluid level as much as the surrounding carved up areas are as well.

I hope they got altimeter data over this feature, that would really help give an idea of just how high and rugged the overall terrain is.

[I think this island is a polar equivalent of Bacab Facula except it is located in the polar shizzle deposition zone, it's been eroded by seasonal rains on a regular basis for a while, and it's moat filled in by a methane lake.

Another possibility is that it is similar to one of the bright islands from the Equatorial Sand Seas - is there a chain or ridge of rugged areas in a line? Maybe they are tectonic in origin.]

-Mike

[nprev]

Yeowzah. Well, all I got to say is that if this was one of my infant daughter's diapirs I probably wouldn't be here to tell the tale...(yeah, cheap one, sorry, couldn't resist!)

Still interested in the apparent compositional differences between NM and the surrounding terrain...although NM does look like a detached segment of the leftmost mainland in Stu's view.

On Earth, such separation of similar landforms is usually the result of plate tectonics, yet most of Titan (as yet examined) shows no compelling evidence of this process on a global scale. Do you suppose that this region is exhibiting localized tectonic activity, presumably facilitated by the long-term presence of a lubricating fluid? (Blue-skying here big time, but what the hell: alien world, alien thoughts...)

[belleraphon1]

Yeowzah. Well, all I got to say is that if this was one of my infant daughter's diapirs I probably wouldn't be here to tell the tale...(yeah, cheap one, sorry, couldn't resist!)

(Blue-skying here big time, but what the hell: alien world, alien thoughts...)

As a new grandfather, I have now gotten quite expert at observing and changing diapirs. However I do not think NM qualifies here.

We have to remember that these are radar images, which may penetrate some of the overlaying materials and make the deciphering even more interesting. It certainly looks like some of the shallower areas have not had much sediment settled into the lakebeds. The underlying terrain looks pristine.

Actually, some of the unflooded areas look like they have sediments or subdued expanses.... has the liquid washed this overburden off in the flooded areas?

What a beautifully complex terrain!

Will be interesting to see what changes come as the seasons advance.

Craig

[nprev]

Actually, some of the unflooded areas look like they have sediments or subdued expanses.... has the liquid washed this overburden off in the flooded areas?

What a beautifully complex terrain!

Will be interesting to see what changes come as the seasons advance.

Craig

Had similar thoughts myself, Craig...wondering if some of these seemingly submerged channels are seasonal features with a periodicity of, say 14.5 years.

Not to belabor a point...but Titan is alien, period. It might look like Earth in some particulars and spectra, but it isn't. We'll fully understand it someday, but not from Cassini, bless her to the nth power...we'll see some of Titan's wonders, but never quite enough.

This is not a criticism, but an expression of awe and surprise. Cassini is versatile enough to provide salient glimpses of Titan, and that's all that could possibly be asked of such an audicious mission to an unknown set of worlds...the designers did well, and in a more just reality they would sweep the Nobels. We have a lot to learn about Titan, but a far better idea of what questions to ask, and thereby what instruments and missions to design. Now, that will be a legacy!!!

[belleraphon1]

Had similar thoughts myself, Craig...wondering if some of these seemingly submerged channels are seasonal features with a periodicity of, say 14.5 years.

Not to belabor a point...but Titan is alien, period. It might look like Earth in some particulars and spectra, but it isn't. We'll fully understand it someday, but not from Cassini, bless her to the nth power...we'll see some of Titan's wonders, but never quite enough.

Agree.... CASSINI will write the text for the NEXT set of questions. This is how we explore. I am old enough to remember PIONEER11's Saturn flyby in 1979 (actually a LOT older than that). Back then the debate was over a thick versus thin atmosphere. Some reserchers felt that the methane gas detected on Titan was buffered by a another gas, nitrogen, to make a thick atmosphere, while others felt that methane was the chief ingredient and that the atmospher was thin. It was hoped that PIONEER11 would be able to take a measurement of the day/night temperature difference in the atmospshere..... a big diff would mean thin air.
Unfortunately, a thunderstorm over the Deep Tracking site caused the loss of this data. So we had to wait for Voyager 1 to make this determination.....

But now... I am amazed and happy to see what CASSINI can do to extend our knowledge of this magnificent world. Back in 1979 I could not have dreamed to be seeing what we now see. And to be able to
play with the data, and perhaps even make our own contributions to this effort.

WOW indeed.

Craig

[ngunn]

Calling all image mages.... ALERT ALERT ALERT.....

Can some one line up http://photojournal.jpl.nasa.gov/catalog/PIA09217 from T28
with http://photojournal.jpl.nasa.gov/catalog/PIA09182 from T25?

Can I add another request? I note that the overlap around 'Manhattan' is to be used to provide relief data for the area. I was wondering if anyone here could produce a stereo pair? It would be nice if we were the first to see the 'skyscrapers', though from rlorenz's very welcome monosyllable we may not have long to wait for an official version.

[ugordan]

Here's an anaglyph showing the region of interest. I'm not sure how pronounced the stereo effect is, the look angle appears to be similar in both T25 and T28 swaths and noise in the data further reduces the stereo feel. T25 was obviously lower resolution (left eye red here) and some detail visible in T28 is harder to make out there. North is to the left.

If anyone would like a cross-eyed stereo pair instead, speak now or forever hold your silence...

[nprev]

I'm speakin' UG...my eyes are pre-crossed, and thank you!

Damn...just looking at your R/G stereo image without glasses is incredible. This topography is virtually indistinguishable from analogous terrestrial terrain; it's been said before on the board that it resembles the Pacific Northwest of the US or the British Columbian coast, and your image reinforces that perception./

This is not a conventional 'UMSF target object surface' as we've become accustomed to (not a single crater in sight, for example). Active, current modification processes are very much at work. Astonishing.

[ugordan]

The left one is the "clean" stereo pair, just as in that anaglyph, the right image was heavily denoised. I don't think it killed much actual detail in the process. In any case, I'm not sure just how much of the apparent parallax is real and how much is an artifact of the processing and map projection. You be the judge.
:::

[nprev]

You Croats are just way too cool...thank you, thank you, thank you!!!!

That sinuous mountain ridge to the right of center is particularly striking, as well as the island right at the outflow point of the main canyon...how incredible this must look from the ground!

[dvandorn]

Yes, it's hard to say how reliable the stereo effect actually is in the images in ugordan's post. However, even without the stereo effect (but very much suggested by it), it sure looks like the bright markings along the left side of "New Manhattan" are tectonic features. Looks like the island pushed into something and its left edge was somewhat crumpled up. Whatever the juncture of the two masses looked like, it's now been completely eroded away into the channel that lies between the left side of the island and the larger "land" mass to its right.

-the other Doug

[Stu]

thank you, thank you, thank you!!!!

Took the words right out of my mouth... I'm in the process of making a Swear Bucket, having thrown my humble Swear Jar away as that image appeared on my screen... just stunning...

[ngunn]

Well! - A big thank you from me too. The relief certainly looks real to me from that anaglyph. The outstanding features seem to be narrow raised ridges surrounded by lower relief with outward drainage, rather than (say) a dissected plateau.

Another thing. I don't know what the vertical resolution might be here, but IF it were good enough to resolve relief on the lake bed (tens of metres?) then we'd suddenly know a lot more about the liquid via its transparency to radar.

[belleraphon1]

uugordon

you bring me to tears......

I never ever would have imagined that Titan was going to be this dynamic... this complex. Who could have guessed what wonder hid under that orange haze.

Since we have stereo radar...... can we truly pin altimetry with these passes?

WOW... the possibilities OUT THERE for the many worlds in the greater universe must be mind boggling.

Thanks to all the scientists, the mission teams, for battling through the process with blood, sweat, and tears, and the YEARS of patient waiting, and you UMSF mages, for bringing this treasure to us .....

Craig

[nprev]

WOW... the possibilities OUT THERE for the many worlds in the greater universe must be mind boggling.


Craig

Oh, yeah...no question at all that we ain't seen nothing yet, and our great exp n grandchildren will probably be able to say the same thing. Good thing I'm a robot; need to hang around a few hundred more years to watch the show unfold...

Just to get back on the tectonics thought: Is it just a coincidence that we see apparently tectonic processes at work in the vicinity of extensive surface fluid deposits? Not sure if/whether there is a cause & effect relationship, and there also seems to be a bit of chicken-and-egg uncertainty here as well...

[Juramike]

Looks like the island pushed into something and its left edge was somewhat crumpled up. Whatever the juncture of the two masses looked like, it's now been completely eroded away into the channel that lies between the left side of the island and the larger "land" mass to its right.

-the other Doug

There is a very cool polar map in Fig 1 of the following abstract: Mitchell et al Ice Oceans and Fire (2007) Abstract 6042. “Titan’s North Polar Lakes as observed by Cassini RADAR: An update.” (Abstract freely available here).

Approximate location of New Manhattan Island: (80N,305W)
"inner" vs "outer" diameter ratio (ratio of island inner diamter vs. outer "moat" diameter): 0.68
squish ratio (short island axis vs. long island axis): 0.54
squish vector: 340 N

[For those of you keeping score with the home game, the island matches really nicely with the putative Generation III diapirs in the Equatorial Sand Seas that were noted in the EXCEL sheet. And the squish vector is very similar to things identified in N Senkyo. Coincedanza?? Downright spooky... ]

I think this is some sort of crustal extrusion (ice pluton? ice batholith? ice diapir?) that extruded out of the marsh and has been subject to tectonic compresson (towards the NNW) and gotten roughed up during the squish. Then the rains came and eroded the heck out of it, carving deep valleys and sharpening the terrain, then washing sediments down into the moat and filling in the surrounding marsh.

The marsh land probably looks like a Titanian version of an alpine meadow (Tuolumne Meadows in Yosemite?) with a massive rain carved ice pluton/diapir sticking rudely out of the marsh. Slow lazy brown streams of organic-laden methane creep slowly through a marshy slurry of deposited atmospheric products.

-Mike

[Juramike]

The T28 swath has an interesting feature in the bland zone between the Equatorial Sand Seas and the North Polar Lakes.



As the swath pulls away from Fensal, the area becomes one of really low contrast. Presumably we are looking at a landscape that has been buried in eons of atmospheric chemistry products brought down by seasonal rains. In the image below, there are alternating bands of dark medium and light medium RADAR reflecting surfaces. These are oriented roughly E-W and could be due to wind deposition of two different types of materials. (Think of huge fields of windblown snow or giant loess deposits). Also visible are bright white specks, these could be RADAR-bright rough ice monadnocks sticking out of the medium contrast schizzle. They are also oriented roughly E-W, which may also correspond to the local tectonic ridge alignment.

Red arrows indicate dunes that have formed alongside one of the partially buried ridges. It would be very interesting to see if these have the same VIMS signature as the dark brown unit of the Equatorial Sand Seas – or could they be dunes of a different material? They seem to have a slightly different aspect than the typical cat scratches, but this could be due to latitude or local meteorology differences.

In the zoomed in view in the middle, the deeply incised ridges are visible (especially in the orange boxes), but have been buried and almost swallowed up by deposited material. The tectonic ridges in this area appear different than those in the Equatorial Sand Seas. The ridges in this areaa appear more deeply carved by erosion instead of the rounder slightly more blobby "pearls on a string" look in the Sand Seas. Compare the aspect of these ridges with those from the T8 Belet-Shangri-La swath. (In the image, the ridge lines have been re-oriented for better comparison)

The entire mid-latitude landscape seems to be low contrast and uniform. Not a lot of exciting features seem to poke up through the schizzle.

Mid-latitudes of Titan: The Big Bland.

Who knows how many interesting features have been buried and hidden under this stuff?

-Mike