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Unmanned Spaceflight.com > Outer Solar System > Saturn > Cassini Huygens > Titan
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ngunn
A fantastic collection of new images of the northern lakes has just arrived: http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=298704
titanicrivers
Very cool raw images indeed !!
Click to view attachment
Phil Stooke
Wow, they are great. This is one with a bit of a stretch and cleanup.

Phil

Click to view attachment
volcanopele
Wow, looks like I'll be busy for a while...

Still sorting through the images myself.... This looks like a great image of Sparrow Lacus

http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=298793
Ian R
Three-frame WAC mosaic of Titan's northern wetlands, with a *tentative* identification of PUNGA MARE labelled as 'PM'.

Click to view attachment
stevesliva
Is any high-contrast spot safely assumed to be a lake?
Ian R
At this latitude, I think that's a fairly safe assumption.
ngunn
Recalling the south polar views from a few years back there is also the possibility of temporary dark patches resulting from recent rain.

(BTW does anybody know if recent lake imaging includes any shots through polarising filters? My sporadic searches have not turned up any.)
Ian R
The same region of Titan's north pole, as seen by radar (cropped from PIA10008):

Click to view attachment

Ian R
Blink GIF version:

Click to view attachment
Ian R
Labelled version:

http://postimg.org/image/3uvjfogdz/
ngunn
Nice mosaic and great overlay. There are some interesting differencences from the SAR view.

Here is an image from a few days earlier that I like because it shows almost the whole of Titan's northern lake province now in daylight. (It's one of many that are ripe for stacking and other clever stuff.) http://saturn.jpl.nasa.gov/multimedia/imag...0/N00216700.jpg
Juramike
QUOTE (Ian R @ Sep 14 2013, 07:31 AM) *
At this latitude, I think that's a fairly safe assumption.


There are no safe assumptions on Titan.
antipode
QUOTE (Juramike @ Sep 15 2013, 08:00 AM) *
There are no safe assumptions on Titan.


Looks like its been raining up there! ph34r.gif

P
Ian R
QUOTE (Juramike @ Sep 14 2013, 10:30 PM) *
There are no safe assumptions on Titan.


True, true: but I still think it's fairly safe to say the dark splodges are more likely to be fluid-related than anything else.
titanicrivers
"Here is an image from a few days earlier that I like because it shows almost the whole of Titan's northern lake province now in daylight. (It's one of many that are ripe for stacking and other clever stuff.)"

Agree the earlier views of the N polar lakes are striking. The September 6th images stand in stark contrast to those of Sept 2009 when plenty of tropospheric clouds appeared over the N polar lakes and seas (figure on left). The apparent lack of clouds raise questions as to 1) whether the clouds are seasonal-atmospheric phenomena and not much influenced by the lakes presence or 2) whether the lake/sea composition and minimal seasonal winds at this time are less conducive for cloud formation.
The color composite images and the upper haze layers (seen in the UV3 filter) are also awesome (figure on the right).
Click to view attachmentClick to view attachment
ngunn
One late arrival - some smallish lakes from fairly close in. Is that MacKay lacus at the bottom left?
http://saturn.jpl.nasa.gov/multimedia/imag...0/N00217222.jpg
ngunn
Another family portrait of Titan's great lakes, clockwise from top: Kraken, Jingpo, Punga, Ligeia.
http://saturn.jpl.nasa.gov/multimedia/imag...0/N00217414.jpg
Ian R
Click to view attachment
ngunn
Beautiful! I was really hoping someone would do that, so my hearty thanks. smile.gif
There's one area in these new views that I'm finding hard to reconcile with the earlier ISS views of the lakes. It's the area on the eastern side of Kraken Mare that in the first images resembled the foot of Italy. Looking at it now Italy appears to have curled up its toe! Here's the older view: http://upload.wikimedia.org/wikipedia/comm...Kraken_mare.jpg
titanicrivers
I've added a Sept 2013 image (bottom of composite figure below) of Kraken. The "toe of Italy" is about the same stage of 'falling off' as best I can tell and there hasn't been major changes from 2007. Perhaps with the ground surrounding the lake and seas saturated with methane and/or ethane http://www.newscientist.com/article/dn2443...s-on-titan.html big changes are not expected.
Click to view attachment
ngunn
My clumsy atempt to highlight what I was referring to on a crop from Ian R's mosaic. 'Toe' is the upper oval. Lower oval is the dark area I don't see on the earlier images.

EDIT: still trying to attach . . aah, there we go:
ngunn
What a bountiful harvest of wonderful views!!! There is unprecedented detail (I think) in the ISS products and the spectacular VIMS release is particularly welcome. We had evidence of a light fringe around Kraken Mare before but now we see the full extent of these possible evaporite deposits. I'm a bit surprised that the greenish background on the VIMS mosaic is described as water ice. I thought exposed water ice was rather rare on Titan.
elakdawalla
I think I had a conversation with somebody about that at DPS -- that there's a new calibration of VIMS data that has changed the apparent relative brightness of the surface in two windows that suddenly make water ice a possibility for that surface. I think. I better go check that with somebody. Is Jason Barnes still hanging around here?
ngunn
Such a reinterpretation would make sense. I think the Huygens team has always maintained that the pebbles on the surface are probably water ice. It would be good to know, one way or the other.
Ian R
Fantastic work Jason! ohmy.gif
Jason W Barnes
QUOTE (elakdawalla @ Oct 23 2013, 02:22 PM) *
I think I had a conversation with somebody about that at DPS -- that there's a new calibration of VIMS data that has changed the apparent relative brightness of the surface in two windows that suddenly make water ice a possibility for that surface. I think. I better go check that with somebody. Is Jason Barnes still hanging around here?

I've been lurking recently, but I show up every once in a while wink.gif The greenish stuff is probably more icy than the evaporites, for sure, but isn't pure water ice, even with the 2.7/2.8 micron correction that I talked about at DPS. But it's got SOME ice, while the evaporites have none. Note that the press release was simplified from what I would have written; I don't get to have them be rigorous enough for this crowd always wink.gif

- VIMS Jason
remcook
There was an interesting talk by Pascal Rannou at EPSC ( http://meetingorganizer.copernicus.org/EPS...PSC2013-459.pdf - although the abstract doesn't mention results yet), showing a very nice fit to the DISR data with a combination of water ice and fractal haze particles. Apparently it shows a water ice feature at 1.5 micron.
Jason W Barnes
QUOTE (Jason W Barnes @ Oct 23 2013, 03:00 PM) *
The greenish stuff is probably more icy than the evaporites, for sure, but isn't pure water ice, even with the 2.7/2.8 micron correction that I talked about at DPS.

Speaking of which, the paper associated with that talk is just now out in ApJ, here's a link to the copy on my website.

- VIMS Jason
ngunn
A joy to read; thanks very much as ever for making your paper availalable to all. What it says about the presence of water ice on the surface of Titan is a tiny part of a paper that has so much more in it, but it's the sort of nugget that is much appreciated here.
rlorenz
QUOTE (remcook @ Oct 24 2013, 02:21 PM) *
There was an interesting talk by Pascal Rannou at EPSC ..... showing a very nice fit to the DISR data with a combination of water ice and fractal haze particles. Apparently it shows a water ice feature at 1.5 micron.


Awesome. 20 years ago we were grappling with disk-integrated groundbased spectroscopy, and the best fit people could come up with was 'dirty ice'. And now, after much debate on Huygens/DISR and Cassini/VIMS, we discover.....dirty ice. This is getting as bad as water on Mars.....
stevesliva
QUOTE (rlorenz @ Oct 26 2013, 12:33 AM) *
Awesome. 20 years ago we were grappling with disk-integrated groundbased spectroscopy, and the best fit people could come up with was 'dirty ice'. And now, after much debate on Huygens/DISR and Cassini/VIMS, we discover.....dirty ice. This is getting as bad as water on Mars.....


For any poorly constrained yet hugely significant question in planetary science, there will be an endless series of releases answering various better-constrained versions of that question.

See also, Voyager, exiting solar system. Or earthlike planet, discovered.
Explorer1
There was controversy about what material Huygens pebbles were made of? Wasn't water ice the obvious explanation right from the start? Obviously confirmation is important news but what other material could they have been?
I remember reading it in the thread in this very sub-forum as the images came down.
Good times...
ngunn
QUOTE (Explorer1 @ Oct 26 2013, 11:48 PM) *
what other material could they have been?


Take your pick from a wide range of waxy or soapy organics (evaporites?). We were staring at them but we just didn't know - and truth to tell we still don't, even if water ice now seems increasingly likely.
Juramike
The effective dielectric constant data over most of Titan, including the Huygens landing site, is not consistent with water ice. (Janssen, 2010)
Spectral measurements only look at the top few microns of paint.
RADAR probes deeper.

+Mike
ngunn
I've been busy with house and family and missed this when it came out. It's a particularly clear view of Titan's lake district:
http://saturn.jpl.nasa.gov/multimedia/imag...4/N00227079.jpg

Apart from enjoying the whole picture I notice there is a bright streak across the middle of Ligeia Mare. Is it a patch of cloud, or something to do with the 'magic island' recently reported off one of Ligeia's headlands?
volcanopele
Those are clouds.
elakdawalla
Forgive me if I'm out of touch, but: Jason, haven't you been looking for clouds for, like, a long time? Is this a big deal?
belleraphon1
Cassini press release

Cassini Tracks Clouds Developing Over a Titan Sea
http://saturn.jpl.nasa.gov/news/newsreleas...elease20140812/

CICLOPS site
http://ciclops.org/view/7929/Clouds-Over-L...e-on-Titan?js=1


volcanopele
Hmm, well, I guess I can talk about this now. Yes, we have been looking for clouds for a while and not seeing them. And yes this is kind of a big deal.
antipode
Is this a 'lake effect'? Is there much of a difference between the liquid and the overlying atmosphere?

P
MahFL
For a weather nut like me, that is awesome smile.gif.
titanicrivers
Yes, awesome observations and imaging! From Rev 207 http://www.ciclops.org/view/7921/Rev207 two CB3 images N00227321 and N00227310 taken on August 13th appear to show clouds in motion over Ligeia Mare and Muggel Lacus. (although spacecraft motion causes whole image shift and my less than ideal image processing may have me fooled!)
Click to view attachment
ngunn
Well we've seen the first clouds for a while and measured their speed, now its time to hunt for the 'magic island', lake altimetry and depth sounding.
http://www.google.co.uk/url?sa=t&rct=j....73231344,d.ZGU

Will the data from this flyby establish the relative surface altitudes of Ligeia nd Kraken? I'm not sure what is meant by Kraken Mare's estuary. Does that term refer to the channels that appear to link it with Ligeia or the ones around Mayda Insula? I note that the first convection clouds appeared over Ligeia, not Kraken. This would be consistent with Ligeia being relatively methane-rich and draining into Kraken; the latter acting as the less volatile ethane sump.
titanicrivers
I presume this is the estuary (E) connecting Ligeia mare (L) and Kraken mare (K).
Click to view attachment
Juramike
Yup.

See: Sotin et al., Icarus 221 (2012) 768–786. "Observations of Titan’s Northern lakes at 5[microns]: Implications for the organic cycle and geology".
doi: 0.1016/j.icarus.2012.08.017.

Freely available here: http://www.barnesos.net/publications/paper...thern.Lakes.pdf
(Thanks to Jason Barnes for making this available on his webpage.)
ngunn
Thanks for that confirmation of what is meant by 'the estuary'. Actually there seem to be quite a lot of estuaries draining into Kraken Mare, mostly at its northern end from what we've seen so far. The paper you refer to explicitly leaves as a significant open question the relative levels of Kraken and Ligeia, hence my interest in whether the current flyby science activities aim to address this.
brellis
When Cassini first arrived at Saturn, the release of Huygens was delayed (to get a better angle for comm relay, IIRC). I wondered why not delay it for many orbits so a landing site could be chosen based on the better info being obtained from numerous Titan flybys. Prudence favored releasing the lander as soon as possible.

A question for our Titan experts: if Cassini were still carrying Huygens today, where (and when) on Titan would you want to have it land?
ngunn
QUOTE (brellis @ Aug 22 2014, 10:23 PM) *
if Cassini were still carrying Huygens today, where (and when) on Titan would you want to have it land?


(No expert, but I do have opinions . smile.gif )
I'm really glad nobody had the chance to choose the site. It landed with exceptional good fortune in a very information-rich location which would never in a month of Sundays have been selected by cautious planners. But yes: now we know what we know, and what we know is we badly need a robotic chemist in one of the lakes. Huygens was designed to cope with a lake landing but it wouldn't have done much chemistry.
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