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Unmanned Spaceflight.com > Outer Solar System > Saturn > Cassini Huygens > Titan
titanicrivers
Raw images from the T64 Titan encounter are now up on the Cassini web site. This interesting flyby is described in Ciclops looking ahead here: http://ciclops.org/view/6082/Rev123
Some nice ISS images from the outbound montage of the Adiri region are shown below.
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titanicrivers
T64 also included a passage over Titan's North pole and an opportunity to obtain SAR data over two large polar lakes (Ligeia and Punga Mare). Changes in shorelines may be found when comparing T64 SAR with SAR images of several years ago, reflecting an active N polar weather pattern with ethane-methane percipitation and evaporation. I could not quite get the SAR pass of the Spilker map http://www.unmannedspaceflight.com/index.p...st&id=19154 into a polar projection, so the figure below shows the spacecraft ground tract (taken from the mission description http://saturn.jpl.nasa.gov/files/20091228_...description.pdf ) and the position of the lakes to be evaluated.
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Decepticon
As exciting as this is, I don't expect to see the SAR data till maybe this summer.
Sunspot
QUOTE (Decepticon @ Dec 30 2009, 06:58 PM) *
As exciting as this is, I don't expect to see the SAR data till maybe this summer.


Didn't they used to release it more frequently? Still waiting to see the SAR from T58
volcanopele
Yeah, I wouldn't put too much stock in that map, particularly for the later orbits. They changed the look direction for T64 from the looks of it, and that T65 swath, yeah, just looking at Cassini in Celestia, RADAR will definitely not be doing that...
Juramike
There's a hint of structure in the South polar haze in this image (S pole is at top) in the CL1 UV3 filtered image:
http://saturn.jpl.nasa.gov/multimedia/imag...6/N00149282.jpg

(Has S polar structure been seen before by Cassini? unsure.gif )
titanicrivers
An interesting image Mike. Wonder if its the start of a dark polar hood over the south pole. Another interesting image is N00149278. This is a NAC image with CL1 and CB3 filters taken from 1.2 milion Km on the Dec 30 outbound cloud search sequence. Clouds were found! Looks like more of the mid-southern latitude variety seen on the last flyby. Celestia (nice new grid!) locates these between 40 and 50 degrees S latitude.
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titanicrivers
QUOTE (Juramike @ Dec 31 2009, 11:07 AM) *
There's a hint of structure in the South polar haze in this image (S pole is at top) in the CL1 UV3 filtered image:
http://saturn.jpl.nasa.gov/multimedia/imag...6/N00149282.jpg

(Has S polar structure been seen before by Cassini? unsure.gif )

A quick look back at the raw images from 2004 til now seems to show little or no S Pole structure in the haze layer with UV3 CL1 filter photos. The image Juramike has mentioned above is compared with a UV3 CL1 image from Oct 2004 below. The Celestia grids for each image are given and indicate a different (although not too different) spacecraft to Titan angle (the 2004 image is from closer in as well). Is this a real change or no ?! (Cassini images are rotated so N is up)
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Juramike
Here a Methan-o-Vision composite of the T64 flyby image. I rotated it so that N is at top.

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You can see the S polar structure way down as a slightly darker stain.

Here is an enhanced image made by simply subtracting the CL1 UV3 from the CL1 MT1 image. Lots of banded structure is apparent in the N and a little bit in the S. Also interesting how the cloud in the CL1 CB3 seems to correlate to a diffuse brighter zone seen in the CL1 MT1-CL1 UV3 image.

Click to view attachment
Juramike
New images recieved today. Here is a two-frame animation of the CL1 CB3 filtered images that shows high southern latitude cloud movement:

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[animated GIF-click to animate]

The text number shift approximates the rotation displacement at the equator.

The clouds can be seen to be diving for the higher S latitudes and also moving W (in image "1" the E edge lies below the tip of the arrowhead shaped feature in SW Belet, in image "2" it lies well to the W).
ngunn
Interesting - there almost seems to be an elliptical loop forming as the cloud moves south. I know that the Coriolis effect is relatively weak on Titan, but are we seeing a hint of it here?
Juramike
I'm wondering if it's more of a downdraft kicking up the next batch of clouds. So you get kind of a wavefront emanating from the original clouds.

IIRC, this was postulated for some of the big storm clouds moving their energies around Titan in the Brown et al. telescopic observations.
Not sure if this storm system is big enough to do that or not....
Hungry4info
Some Saturnshine observations of Titan.
http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=210736
titanicrivers
Hmm … wouldn’t cloud motion East to West be unexpected given the motion of past mid-southern latitude clouds and the super-rotating atmosphere from W to E. Clouds elongate W to E along latitude lines and tend to dissipate over hours to days. Spacecraft motion, distance and viewing geometry of clouds vs surface features should be factored in as Titan’s rotation rate is relatively slow (I calculated 42.3 km/hr at the equator) compared to Cassini’s velocity. In the image below (using the same CL1 CB3 images as Juramike above), blue arrows point to the edge of the more northerly cloud which may moving a little south but which ends still close to the 280W longitude line and may be dissipating; in contrast a cloud blob (red arrows) closer to 50 latitude appears to have elongated to the east between 12/30 and 12/31.
OWW
Groovy Hills Rising from Titan Surface
ngunn
Fantastic - a new terrain type on the 65th flyby! What a world.
stevesliva
Reminds me of Arches National Park. Erosional fins.
ngunn
Here's the nearest thing I can find:

http://earthobservatory.nasa.gov/IOTD/view.php?id=6465
Juramike
That's neat! Where is it?

Hungry4info
Taking a wild stab here, Salt Dome in the Zagros Mountains... in Iran? wink.gif
ngunn
I've just edited the post to give the full context and annotation rather that just the bare image. Click again Mike. (H4I - not quick enough to catch the first version?)
stevesliva
Arches NP is over a salt formation as well:
Fiery Furnace Area
Windows Area
ngunn
QUOTE (stevesliva @ Jan 25 2010, 10:11 PM) *
Arches NP is over a salt formation as well:


What a coincidence. wink.gif Thanks for those nice pics. (My googling didn't turn up anything that made sense of your original Arches post.)
stevesliva
One thing you don't get from the pretty pictures of arches is that there are lots of areas of parallel sandstone fins that are due to parallel vertical cracks in horizontal strata that formed when the sandstone settled/uplifted on the salt layer.

Incidentally, it appears that the two user-submitted panos in the Arches NP wikipedia article are the two areas I linked to from above with google maps:
Fiery Furnace ground pan
Windows area ground pan
Juramike
That patch of bright ridges in the lower left is regularly spaced, and one in the lower middle has a tuning fork pattern.

"RADAR-Bright stuff" Dunes?
titanicrivers
Approximate location of T64 swath and PIA12496 image using VP's latest RADAR map. Grid added to help in locating swaths and features. T64's position is a guess as it seems further west compared to Spilker's map.
ngunn
I note that this location is pretty close to the source region of one or more of the 'Siberian rivers'. I don't know how close. It would be interesting to see that more clearly. I'm not suggesting a connection but I think it's worth checking out the spatial relationship.
titanicrivers
Using the coordinates and size of PIA12496 I’ve tried to place it more accurately in relationship to the Siberian rivers as seen in T30. At the far southeastern portions of that swath are roughly circular bright areas. I cannot say however these areas are blurred versions of the groovy hills of PIA12496.
Click to view attachment

peter59
T64 swath.
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elakdawalla
Oooh that must mean the Cassini PDS release is out smile.gif I wonder what caused all the data dropouts. Bad downlink? Bad weather at a ground station?

Some really nice fluvial/lacustrine features in that one. Would you be able to post a full-res chunk from near the middle of the swath, where there's that section of beautiful fractal-looking coastline? Which lake is this, I wonder? According to the looking ahead article linked to in the first post, the two lakes covered are Punga Mare and Ligeia Mare...
peter59
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I do not know what is what, except SAR Main swath (previous post)
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ngunn
QUOTE (elakdawalla @ Oct 1 2010, 06:42 PM) *
that section of beautiful fractal-looking coastline


I thought I recognised it. It's at the extreme right of T25:
http://pirlwww.lpl.arizona.edu/~perry/RADA...20_T025_V01.jpg

I remembered it looking sharper than that though, so possibly we've had yet another view of it ??

EDIT Ah yes, here it is again, T29:
http://pirlwww.lpl.arizona.edu/~perry/RADA...T029S01_V02.jpg
And full res:
http://pirlwww.lpl.arizona.edu/~perry/RADA...1_V02_part2.jpg

It will be interesting to look for changes.
sariondil
QUOTE
Would you be able to post a full-res chunk from near the middle of the swath, where there's that section of beautiful fractal-looking coastline? Which lake is this, I wonder?


It´s Ligeia Mare.
titanicrivers
QUOTE (ngunn @ Oct 1 2010, 01:42 PM) *
It will be interesting to look for changes.

Looks like Ligeia Mare is showing some recession in its eastern shoreline. Bright islands appear fuller in the center and northern portions of the images below. Initial image is from T29 (April 2007) and final image is from T64 (Dec 2009).
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ngunn
That is excellent - exactly what I was hoping for. The latest image is certainly brighter overall and of course there are differences due to illumination angle. Without your ovelay I couldn't be sure if anything else was going on. Now, I tentatively agree there could be real changes.
Stu
Looking forward to seeing what our image mages make of the latest Titan raws, like this one...

http://saturn.jpl.nasa.gov/multimedia/imag...4/N00164130.jpg

Amazing detail visible inside the atmosphere... ohmy.gif
Astro0
Hey Stu, I made this! Does that count?! laugh.gif

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Stu
Look out, Rorschach has made it to Titan...!
Juramike
HiPassLRGB using HiPass UV3; L = UV3; RGB[RED,GRN,UV3]:

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Neat detail in the atmospheric layers!
titanicrivers
Beautiful image Mike. Astro0's creation reminds me that I'll have to carve a pumpkin before too long!
I think these posts should be moved however to a new topic, say REV 139 as they are not part of the T64 flyby!
Later this week the WAC's will show the area of the previous storm cloud!
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