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Posted by: ngunn Apr 16 2009, 12:33 PM

Rev 109 'looking ahead':
http://ciclops.org/view/5594/Rev109

Posted by: ngunn Apr 17 2009, 09:40 AM

Mission description:
http://saturn.jpl.nasa.gov/files/20090420_titan_mission_description.pdf

Some imaging may be lost due to downtime at Goldstone apparently. It won't be the highest priority stuff, but it still amazes me that mankind can contrive to have science data collected and beamed back all the way from the far reaches of the solar system and then fail to tune in to it.

Posted by: ngunn Apr 22 2009, 06:55 PM

Spooky! (Titan in eclipse)

http://saturn.jpl.nasa.gov/photos/raw/rawimagedetails/index.cfm?imageID=188803

Posted by: remcook Apr 23 2009, 07:09 AM

Cool From the 'Looking ahead' bits it seemed that these observations are accidental, in the style of 'we will do cloud observations, but Titan turns out to be in eclipse', but I assume they have a purpose...I guess you could look for lightning ..VP?

Posted by: volcanopele Apr 23 2009, 07:21 AM

Are they on purpose? Good question... I am not sure. the filter sets and the exposure times aren't all that different from other cloud monitoring observations. I guess that there wasn't a check to see if Titan was in eclipse at the time. At least Titan is visible in these images.

Posted by: Juramike Apr 23 2009, 07:36 PM

Another of the T53 raw images:
http://saturn.jpl.nasa.gov/multimedia/images/raw/casJPGFullS49/N00133830.jpg

Dark shape down there. (I think this might be in the S Polar region.)
I'll play with this later to see if I can pull out more details.

Posted by: volcanopele Apr 23 2009, 08:15 PM

From the Looking Ahead article:

"VIMS will acquire a high resolution observation of the margin of a bright region with lobate edges. This bright region surrounds a 300-kilometer wide dark region near 40 degree south latitude, 280 degrees west longitude. This dark feature resembles many of the dark lakes seen at Titan’s polar regions. The fact that two features with morphologic characteristics similar to Titan’s polar lakes have been found on Titan’s trailing hemisphere near 40 degrees south Latitude suggests a possible connection with the mid-latitude convective cloud features seen earlier in the Cassini mission. It is not known if surface liquids at these features help increase the methane “humidity” levels at this latitude, or if these features are fed by rainfall from the clouds. ISS and VIMS will observe this feature in the higher altitude mosaic observations."

Posted by: ugordan Apr 23 2009, 09:48 PM

Here's my stab at an enhancement:


I don't know, doesn't look like your typical lake to me.

Oh, and, the doughnut-shaped ring to the left of center is a dust ring artifact.

Posted by: Juramike Apr 24 2009, 03:01 AM

N00133830 and N00133829 combined, noice-reduced, gradient adjusted, and limb brightened, and contrast enhanced.
(And dust rings left in).

It looks like there is a small less dark patch next to the big one (to the right) and that there is a v. slightly brighter "island" in the dark patch.

Posted by: Juramike Apr 24 2009, 05:13 AM

Here is a crude ISS mosaic from the T53 flyby

Comparison with Celestia image (I'm putting the dark thingy right smack at [-40S, 280W] as advertised. It is visible in the recent global mosaics of Titan):

Here is the Cassini raw image assembly for the mosaic (I'm guessing wildly for 21-22):


This is a pretty large chunk of terra incognita that just got imaged.

Here there be Tygers....

-Mike

[EDIT: While trying to put together the full mosaic, I think many of these overlap. Stay tuned...]

Posted by: Juramike Apr 24 2009, 06:09 AM

Interim T53 Mosaic assembly:

Posted by: Juramike Apr 24 2009, 12:39 PM

Corrected T53 mosaic location and approximate footprint on Celestia view from CICLOPS "Looking ahead" image:

Corrected sequence of Cassini Raw images:


(I've convinced myself that image N0013821 is a close-up view of the white streak in the SE corner, then after the field expands to it's largest, the camera swivels around counterclockwise.)

Posted by: Juramike Apr 25 2009, 05:42 AM

Final T53 Mosaic:

[EDIT (4/25/09): graphic removed, corrected version posted http://www.unmannedspaceflight.com/index.php?s=&showtopic=5957&view=findpost&p=139561 (this thread, post#18)]

(This is a sizable chunk of real estate that is no longer "neutral gray" on the big Titan map.)

The full res version of the mosaic can be found at: http://www.flickr.com/photos/31678681@N07/3472772378/

-Mike

Posted by: ngunn Apr 25 2009, 07:39 AM

Very nice! (The US looks a bit on the small side though.)

Posted by: volcanopele Apr 25 2009, 08:30 AM

Probably because the scale bar on that map should be 2000 km instead of 4000 km. Thanks for spotting that...

Posted by: ngunn Apr 25 2009, 09:21 AM

The bright streak at the extreme left looks familiar.

http://www.planetary.org/image/PIA09032_med.jpg

Posted by: volcanopele Apr 25 2009, 09:35 AM

Yep, the bright streak region is visible there. We saw them back in T20 and led to my LPSC talk back in 2007:

http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2219.pdf

Posted by: Juramike Apr 25 2009, 01:11 PM

Thanks for the catching that!

Here is a corrected version:

Posted by: titanicrivers Apr 25 2009, 11:29 PM

Fantastic work Mike. The western portion of the T53 area with its streaks is fascinating as VP’s abstract points out. Is there or is there not a mountain range? I gotta admit I’m hooked on the VIMS notion of a Titan Sierra. The animated image below is my favorite image from T52 on April 4th covering the area of VIMS mountains. Is it just an albedo apparition?

Posted by: volcanopele Apr 26 2009, 12:04 AM

They might be or they might not be. I'm just not as convinced about them being mountains based on the present evidence as others have been. I am definitely not convinced that they drive orogenic clouds at 40 South. Mountain height vs. atmospheric scale height doesn't make as much sense for them to exist as here on Earth. Certainly we do see hill chains on Titan based on the RADAR, so I don't think I would definitely say they are not mountains, they very well could be. But the albedo relationship with topography has been pretty spotty as we have seen bright mountains and dark mountains. And the topographic shading VIMS says they see...well, again, we'll see.

Personally, my bet is that they are fresh fractures akin to the ones you see on Dione.

Posted by: Juramike Apr 26 2009, 09:31 PM

I took my T53 Mosaic and carefully warped it to match features up with the PIA11149 Feb 2009 Titan Global map.
Here is a blink animation with the PIA11149 and an overlay (not a blend!) with the T53 Mosaic.

(click to animate)

This came out pretty good - I'm really happy with this.

Even subtle contrast differences and features seen in the Feb 2009 Map are also observed in the T53 Mosaic.
I've indicated diagnostic features that I used for the coordination:
Blue arrows indicate dark albedo features
Light blue arrows indicate darkish gray albedo features (funky graben thingy in NW)
Red arrow indicates bright blobby "island" in darker region
Yellow arrow indicates bright albedo pattern in light gray region. (near vertical bright albedo feature)

Note how the vertical bright albedo feature at west (mountains?/fracture?/other?) is present in both image sets.

Posted by: ngunn Apr 26 2009, 09:59 PM

That's fantastic Mike - it's great to see what fits where. Funny thing though, there are lots of other parallel streaks on the earlier ISS mosaic that don't appear on the new one. Are they artifacts of the special processing used in 2007 for particular scientific (as opposed to cartographic) purposes? Is it time to reprocess the earlier mosaic to make it more compatible with the rest of the global map?

Posted by: Juramike Apr 26 2009, 10:34 PM

I can only speak for the the T53 mosaic - it has lots of artifacts. There are dust rings everywhere, edge effects, JPEG compression artifacts (now warped in a NW to SE curve), and artifacts due to the warping process.

The dark zone running SW to NE in is right between two images, so it is very suspect.

The W to ENE dark channel in the central W part of the mosaic is real. Two images have this structure in different portions of the image and they matched up perfectly.

Posted by: Juramike Apr 26 2009, 10:37 PM

Here is another blink with the T53 Mosaic vs. PIA09032: Titan's Sierras.

(click to animate)

The vertical streak and the dark albedo patterns match up between VIMS and the T53 Mosaic in the overlap region.
(The T53/ISS mosaic was contrast-enhanced for easier comparison with the VIMS image)

That vertical streak is "real" - whatever it is.

-Mike

Posted by: Vultur Apr 27 2009, 06:00 AM

Could that vertical streak be a row of hills? It kind of looks like one.

Posted by: Juramike Apr 27 2009, 08:38 PM

That was the original explanation. But with the recent elevation data publications, I'm not really sure what's up (!) with Titan.

Posted by: volcanopele Apr 27 2009, 09:52 PM

Well, at this point all we know is that it that they are roughly north-south streaks of bright material with some dark stuff nearby. As I said above, I don't think we can tell. Remember, bright on Titan does not always mean tall! We've seen dark topped mountain terrain as well as bright mountains.

Posted by: Juramike Apr 28 2009, 02:57 AM

T53 Mosaic blended with the February 2009 Titan Global Map (PIA11149):

Links to Flickr page, 2.1 Mb JPEG at full resolution: http://www.flickr.com/photos/31678681@N07/3482176588/

Posted by: titanicrivers Apr 28 2009, 05:17 PM

Image N00135063, cropped and enhanced, taken 4-26-09 (? from non-targeted flyby sequence). Highlights include Hotei arcus (lower center) and Minerva (upper left). Click on image for approximate Celestia grid location.