T98 flyby description is up http://saturn.jpl.nasa.gov/mission/flybys/titan20140202/ . This occurs during rev 201 http://www.ciclops.org/view/7796/Rev201?js=1 and features radar views of Ontario Lacus.

Pretty excited for this flyby!

I just put together these two views of Titan, from January 26th: Above and Below Titan's Atmosphere #6

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And here's my own rendering of the three CB3 frames:

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Thanks to the wonders of Celestia, I was able to animate the flyby, and point out some of the primary science objectives:

http://www.youtube.com/watch?v=1i1obyesxFs

for any that do not know
there is a celestia SPICE thread for Cassini over here
http://forum.celestialmatters.org/viewtopi...?f=18&t=590


it is an ongoing update , right now it is through feb7
( the default celestia cassini mesh is mis rotated by x=90 deg )

A snapshot during the approach to Titan, Feb 1st 2014. Filters used in this RGB composite: CB3 (red) and MT1 (blue) with synthetic green channel. Second image is in visible light.

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I wonder is the methane spectrum absorbtion (shown as reddish part of the atmosphere) at the pole is due to methane evaporating from the surface lakes?

This is a rather crude, but reasonably effective attempt at coaxing out detail in the northernmost latitudes, especially just south of the bright evaporite deposits:

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Dumb question: does the south have a bright polar cap like this (I dont remember seeing such a clear ISS image of the south) and if so does it have the same relationship to lake basins full or otherwise?

Actually can anyone direct me a a map of putative southern lake basins? I dont mean Ontario, I mean the ones that a currently dry.

P

A quick google search turned up this:
http://www.google.co.uk/url?sa=i&rct=j...391639165393287

The brighter area is closer to the pole than the one big southern lake, Ontario.

EDIT : I think there is a map of putative southern paleolake basins somewhere in the latest 2014 LPSC abstracts. Sorry not to be more help - it's late.

Recent topographic maps of Titan's polar regions highlight the now dry south polar basins. http://www.jhuapl.edu/newscenter/pressrele...0515_image3.asp
The topic was discussed a bit in this forum as well. http://www.unmannedspaceflight.com/index.php?showtopic=6142

It's figure 1 in the first abstract in the 'Titan Lakes' session. The Palaeobasins are coloured purple. Here again is the link that machi posted:
http://www.hou.usra.edu/meetings/lpsc2014/...Abstracts/view/

Thanks everyone - very interesting - the 2014 LPSC abstracts will keep me busy for ages!

Wow - tentative detection of waves on Punga Mare!
http://www.hou.usra.edu/meetings/lpsc2014/pdf/1947.pdf

Double wow - putative tidal races in the 'throat of Kraken'
http://www.hou.usra.edu/meetings/lpsc2014/pdf/1476.pdf

Have there been any southern lakes other than Ontario formally named?

p

Note also this one:

Hofgartner J. D. * Hayes A. G. Lunine J. I. Zebker H. Stiles B. et al.
The Case of Titan’s Mysterious New Island: Analysis of Anomalously Bright Features Observed in the Cassini T92 SAR Pass Over Titan’s Ligeia Mare [#1841]
Anomalous features were detected in Ligeia Mare that were not in any preceding nor subsequent observations. They are unique on Titan or transient in nature.

I note that this feature appeared in SAR with illumination angle 6 degrees off nadir - exactly the same distance from the specular point as for the VIMS putative waves observation. There is no mention that they might have the same explanation, however, even though the two abstracts have authors in common. I couldn't follow the discussion on quasi-specular reflection well enough to know if they ruled out localised 6 degree waves for the SAR observation.

Ok, having now read Dr. Lorenz's paper, and knowing that he contributes here, I'd like to ask a few questions!

Figure 2 of the paper, the blowup of the 'throat' area between the two Kraken basins not only shows the throat, but on the promontory to its west, what looks like multiple islands separated by narrow channels all the way to the 'mainland'. Surely these constrictions have the potential to generate even bigger tidal races?

Also - has the 'mare' on the equatorside of the southern Kraken basin been named?

P

I may be wrong but in general I doubt that authors will be willing to discuss their work here before presenting at the conference. After that though let's hope they do.

Talking about an active area of research is a double-edged sword. On the positive side, it's always fun to openly discuss work and learn ways to improve and collaborate. On the other hand, you are tipping your hand early and opening up to other groups "scooping" your work. (Yes, even in here, that stuff happens.)

That being, said, the story of the "Mystery Island" is going to be very interesting to follow. (full disclosure, I am in the author list). Jason is doing a very careful, thorough, and collaborative analysis on an interesting observation. This will be a good story on not only the results, but also the process of discovery and analysis.

Here is the link to the abstract: Hofgartner et al., LPSC 2014, Abstract 1841: http://www.hou.usra.edu/meetings/lpsc2014/pdf/1841.pdf

Well, you're right in that sometimes people prefer to keep work close until published or presented. Had we observed a whirlpool or something, then we'd have likely submitted to Science or Nature and been very up tight about it. But we just saw a strait (which has the potential to generate whirlpools) and have now submitted a paper to Icarus (note that some of the numbers have been revised since the abstract, which was written over a month ago, and the paper reflects a wider set of contributors). The work has been and is being presented at internal meetings too.
The paper, and the bathymetry 'dataset' are at http://www.lpl.arizona.edu/~rlorenz/titansea.html

No. For small overall conductance across the isthmus, there is a fixed hydraulic head (sea level difference) driving the flow. So small and/or shallow channels will have more friction, and so slower velocities. When the conductance gets big enough, there will be enough volume flow that the driving head is reduced (since the liquid doesnt pile up, just goes through). So in terms of dissipation (flow amount times friction) there is actually an optimum amount of conductance. When the conductance is very large, then lots of liquid goes through, but slowly.
When you have multiple conductances in parallel, the largest one dominates - so the main strait is shorting out the narrow labyrinth.

It may help to think in terms of electrical analogies : the tide overall is like an ideal voltage source (indeed, it's not called a tidal potential for nothing)



As I understand it, a proposal has been made (I'm not sure the basin merits a separate name myself) but nothing official has happened as of yet.

Yeah, not sure any more names are needed, it's all just one big sea according to VIMS and ISS data (some of the HiSAR data suggest far southern Kraken Mare isn't connected to the rest of it, but I don't believe that based on the rest of the RADAR/ISS/VIMS comparisons...

Thanks for sharing that here, it's a great read. It's interesting that you make a comparison with the Baltic Sea. We often see Kraken compared with the Caspian Sea for size, but I've long thought the Baltic a much better comparison. Not only is the total area about right but it also has a sprawling, branching shape with many islands, plus a similar northerly location.

Ian R’s nifty enhanced image from T98 shows a prominent dark albedo near the north pole (NP) of Titan that is not a “full lake” in the HiSAR of the area of 2007 (T25). One wonders if we are seeing an actual change (due to seasonal fluvial mechanisms) vs an artifact due to limitation of resolution and phase angle. The area in question is circled in red in the left image and in white in the right image below. On the left are Ian R's image and the incredible recent VIMS image http://www.ciclops.org/view_media/38696/Ti...kes-Salt-Flats; on the right is the N Polar SAR image provided by Lorenz here. http://www.jhuapl.edu/newscenter/pressrele...0515_image3.asp
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Well, I guess it must be considered a 'full' lake now, having received the official name of 'Müggel Lacus' (as opposed to Lacuna).

The “full lake” designation and location map appeared in the LPSC abstract http://www.hou.usra.edu/meetings/lpsc2014/pdf/2341.pdf but it appears to be misplaced on the polar lake location map? The ISS WAC and VIMS images from 9-12-2013 align better with the radar map location. If fact VIMS shows lots of bright signal (?evaporite) within and around Muggel lacus. This and the possibility that radar is showing the bottom of the lake (from T25) suggests the lake is probably shallow and might be a good place to check for seasonal changes.
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