[X] My Assistant

[Guest_AlexBlackwell_*]

The T25 flyby page is now online; however, so far as I can tell, the mission description document isn't available publicly yet.

[remcook]

from the brief description of the SAR observation on the website, it seems like a very useful observation that will give different incidence angles to already observed terrain. Some useful science will come from that hopefully!

[Juramike]

How much of an elevation difference will the different viewing angle be able to detect?

(Will we get an idea if the ring around the lakes is flat or a 10 meter cliff?)

-Mike

[Olvegg]

According to abstract "First stereoscopic radar images of Titan" the heights of scarps around some lakes are up to 600 m!

ftp://ftp.lpi.usra.edu/pub/outgoing/lpsc2007/full303.pdf
http://www.lpi.usra.edu/meetings/lpsc2007/....download.shtml

[Juramike]

600 m! Wow! Not much of a beach for surfing Titan.

If this is a general trend, this will make it difficult to spot seasonal differences as lake levels change.

[edstrick]

I would expect to mostly see visibility of features around lake margins change, rather than any obvious relief changes due to the possible fluid height variations. If we're seeing stuff "under the water" near the lake margins, they'll get more visible as the methane-ethane level drops.

[Guest_AlexBlackwell_*]

The T25 flyby page is now online; however, so far as I can tell, the mission description document isn't available publicly yet.

The mission description is now online (900 Kb PDF).

[alan]

ISS: New Territory! The area north of Belet, Adiri, and Dilmun will be observed over the next several flybys with some of the highest resolution observations coming in T26. Nevertheless, the medium resolution global map observations at +5 hours from T25 will be very exciting.

[ugordan]

Cool! So we can expect an updated Titan map around 2010, right VP?

[MarcF]

They will try to extend the SAR observations to have a look at Hotei Arcus.
Could be quite interesting.
I heard about several high altitude SAR observations (especially over Tortola) but never found any picture or other informations.
What about it ?
Marc.

[ugordan]

IIRC, someone recently mentioned the last attempt to do high altitude SAR didn't pan out.

[volcanopele]

The T12 HiSAR pass didn't pan out, that's correct, but several others have, such as a passes over the Huygens landing site, Tortola Facula, and western Xanadu. Since the RADAR team seems to be releasing products 5 months after they were taken, I would imagine that the Tortola Facula stuff is due sometime late next month, if they plan on also releasing HiSAR products (yes, I rolled my eyes too when I heard that they called their high altitude SAR products HiSAR ). But that's only because I am innundated with HiNames all day, every day.

[volcanopele]

For more information on this flyby and other events during Rev39, check out the new Upcoming Events section of the CICLOPS website:

http://ciclops.org/news/looking_ahead.php

Here is the link to the Rev39 page:

http://ciclops.org/view.php?id=2592

[Decepticon]

Nice!

[alan]

first images are up
http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=103890

[JRehling]

Hey, there's Belet!

The first thing I see -- or don't see -- is any detail at all in the higher northern latitudes, in what has to be by definition our best look yet at them.

The "shorelines" here seem to have at least as much dune-wispy blurring as we've seen anywhere else.

[remcook]

some structure in the northern haze/cloud(?):
http://saturn.jpl.nasa.gov/multimedia/imag...8/W00025814.jpg

some pretty bright patches here:
http://saturn.jpl.nasa.gov/multimedia/imag...8/W00025800.jpg

almost reminds me of specular reflections, only the geometry seems slightly off. In any case, it reminded me of the Rosetta image of Earth:
http://news.bbc.co.uk/1/hi/sci/tech/6375717.stm

[nprev]

some structure in the northern haze/cloud(?):
http://saturn.jpl.nasa.gov/multimedia/imag...8/W00025814.jpg

Yeah, I see it too...looks like banding. Amazing how much it looks like a little version of Saturn in this view. Maybe Titan is the one and only "gas midget" in the Solar System!

[Stu]

Maybe Titan is the one and only "gas midget" in the Solar System!

Oh god, don't give the IAU naming committee ideas...!!!!

[nprev]

...curses! Stu has discovered my evil plan!!!

It is kind of interesting, though, that of all the moons & planets only Titan & Saturn bear even a vague visual similarity to each other. Of course, that's an entirely subjective and superficial impression that quickly breaks down upon any deeper examination. It'll be interesting to see how much Pluto & Charon resemble each other, given that they're likely to be much more similar in most ways.

[ugordan]

Of all the moons and planets, only Titan has a dense atmosphere so both it and Saturn are bound to look more similar to one another especially due to haze layers both bodies exhibit.
Pluto and Charon might actually turn out quite different to each other, they have a different color and atmospheric properties.

[JRehling]

Titan, Venus, and Uranus are all in the "Go home, folks, there's nothing to see here" category in visible light. For some of my rank-amateur space art, I used a brightness map of a gibbous Titan as a mask to overlay on projections of other worlds to make a gibbous version of them.

I think it's a noteworthy point in the history of science that these blank worlds can so come to life in other spectral bands -- none of them is blank if you pick the right filter. Fortunately. In principle, the solar system could have handed us a major world that was blank in every band.

Saturn and Neptune are relatively bland themselves. Maybe with a Great Dark Spot on hiatus, Neptune is blander yet.

[alan]

A quick stitch of the new territory

[Phil Stooke]

Here's my version of the Titan clouds.

Phil

[nprev]

Nice, Phil! All it's missing are a couple of cyclonic storms and the rings, of course... ...still amazed by the banding & consequent resemblance to its primary in this view.

EDIT: Okay, here's my very first foray into imagery manipulation. It isn't very good, so please be kind..
http://www.flickr.com/photos/26478279@N00/402230475

BTW, how do you make thumbnails on the board?

[Exploitcorporati...]

First attempts at playing with Titan jpegs. Ouch:

[dilo]

Nice work, Orion!

[belleraphon1]

All...

note this CASSINI raw image....... there are dark features up at the northern terminator line. These look like new terrain features coming into view.......

http://saturn.jpl.nasa.gov/multimedia/imag...8/N00078895.jpg

Craig

[Exploitcorporati...]

Wow. Anyone more skilled at cartography might be able to tell if these polar features have any longitudinal correlation with the big lakes visible in the T19 swath:

[Phil Stooke]

A first look at this problem suggests there is a possible correlation.

This map is a composite of the ISS map released at the end of 2006 - northern hemisphere reprojected into a polar azimuthal equidistant projection - and the latest picture just posted above - very approximate alignment only. Zero long. is at the top - the straight line. When the north pole map posted in a previous thread is overlaid on it - not shown here - the big lakes with fjord-like coasts align roughly with the dark shape seen in ISS. I'm surprised to see details so close to the terminator, but it's a good sign.

Phil

[JRehling]

Wow. Anyone more skilled at cartography might be able to tell if these polar features have any longitudinal correlation with the big lakes visible in the T19 swath:

According to:

http://cassinicam.com/titanflybys/titantracks.html

... the RADAR tracks north of Belet will be T28 and T31, both still pending.

The ISS "lake" features in this image would be at about 280W, 60N. And they're very exciting. They are only now coming into spring daylight, and look like they might be some pretty big lakes fed by a long winter's rain.

[Exploitcorporati...]

I finished this composite just before I read your post JRehling, so my guesstimates are off. Thanks for the coordinates. This must be a pretty massive "lake". Thrilling news about the potential for RADAR coverage!




EDIT: Jeez, Phil, I totally missed yours too! Thanks!

[Exploitcorporati...]

Using Phil Stooke's rough polar projection(and suggestion) and the equally rough 70N+ radar composite, this is my unSWAG as to the correlation, assuming one exists. The positions of objects in this map may actually only be accurate in another solar system.

[Decepticon]

WOW!

[MarcF]

Really interesting !
This could be a good candidate for the biggest lake "identified" yet on Titan.
Even if the resolution is yery low, they are also numerous smaller candidates.
Will VIMS try a high resolution observation of this region ?
Marc.

[edstrick]

Looking at Exploit's views of the pole and associated map......

.....I'm wondering where giant polar ring cloud is. I see one little (relatively speaking) linear left-right cloud or something that looks like a cloud just to the right of a down-pointing finger of the possible giant lake... (down being toward 6:00 clock angle on the image), but no trace of circum-polar features.

[Exploitcorporati...]

I have the impression that the filter at this wavelength "sees through" the polar ring clouds, and the linear cloud (deeper? denser?) visible in the image is opaque at this window of the spectrum. Not sure of the how and why. Anybody know what Cassini's filter sensitivities do in regards to cloud composition and/or density?

[ugordan]

The image belleraphon1 originally linked to was taken using the CB3 filter that's a filter covering part of the spectrum where methane is not absorbing. In the MT2 filter which is the methane absorption filter the linear cloud is not visible suggesting it's a low altitude feature. For info on various filters and scientific reasonings I suggest the definitive writeup on the ISS subsytem by Porco et. al. Page 86 in particular has a nice graph showing each filter transmissivity and a sample of Titan's spectrum.

As for the huge polar cloud, it's very likely the 12->8 bit conversion along with jpeg artifacts drown out the weak S/N ratio needed to make out the cloud. Alternatively, that linear cloud might in fact be the same huge cloud made visible only because it's an incredibly dense segment of the cloud and so made visible even in the see-thru-methane filter.

[remcook]

ed - you mean the polar cloud vims imaged?
( http://www.unmannedspaceflight.com/index.php?showtopic=3849 )
although there is lots of ring-like structure, I was under the impression it covered the entire north polar region above 60N.
If so I think it is quite high and so the ISS windows may not be very sensitive to it.

edit - i forgot to say good work to everyone. very cool stuff! this place rules :-)

[belleraphon1]

All...

I posted the original notice regarding the near polar terrain features right before I hit the sack here in Ohio
USA.... glad to see all the wonderful work you folks have done with this since.

Very exciting!!!! Are these lakes?

I too was also wondering about the polar cloud seen by VIMS but not evidenced in this ISS raw. It "looked" so opaque in the VIMS release. Any one see a sign of this feature in the other raws, or are the circumpolar features seen with ISS the link to this VIMS cloud?

Again, you folks do great work.

Craig

[remcook]

my guess is that you see it in images like these:

http://saturn.jpl.nasa.gov/multimedia/imag...8/W00025814.jpg
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00078880.jpg

but can't be sure

[ugordan]

I'm not sure that's the cloud VIMS detected. That's just the complex haze structure over the north pole with several detached layers. It being readily visible in violet and ultraviolet frames is a tell-tale sign that its a very high, stratospheric phenomenon.

See here and here.

[remcook]

exactly!

edit - that would explain why it isn't visible in the iss windows. Just wonder why it shows up in the VIMS image (if these are all window region that are plotted), but the cloud may just be strongly affecting some of the NIR window regions (5 um mostly by the reddish color of the plot).

[remcook]

had another quick browse: does anyone else find this line around a latitude slightly unusual??
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00078894.jpg
or is this an artifact?

[ugordan]

Titan is has a darker band that shifts as the seasons change and goes from the equator to one of the poles. Without knowing which filter this was (it would be more helpful to post a link to the overview page, not the full image itself) I'd say this is real and a combination of that band boundary and limb effects. Polarizing filters can also do weird things to limb appearances.

[remcook]

sorry about that

http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=104045

it does like a polar collar, but it doesn't show up much in other images.

[Guest_AlexBlackwell_*]

PIA09180: Titan: Larger and Larger Lakes

[MarcF]

Great !
I have the feeling hat the resolution of the SAR observation gets better with time !
Is the dark region south of the "island" really filled with liquid ? If its the case, it should not be really deep.

[remcook]

and look at the beautiful rivers! Rivers on a place outside Earth still boggles the mind. Especially if they're made out of methane

[ugordan]

Looking at the new RADAR image and then coming back to the wide-angle image with dark shapes located very high up north, I'm starting to believe that's really a huge system of lakes coming into sunlight and that we're actually starting to see them in visible wavelengths as well. Interesting times!

[Exploitcorporati...]

That's a staggering image, and fortuitously framed as well. The T19 pass seemed to catch only the edges of a much bigger feature. Betcha this swath will require a trip to the bank for rolls of quarters when we see it in its entirety (not to mention the cross-cutting of the other six tracks!)

Pseudoperspective colorized:

[dvandorn]

What we need to know to be able to properly interpret this latest lake image is whether or not the SAR mode can actually penetrate the surface of the liquid we're looking at. If it does penetrate, how deeply does it penetrate?

I'm frankly having a hard time believing that the lower portion of this lake is actually filled with liquid. Look at the upper portion, which is obviously liquid-filled -- there is a spit of linked islands near the center of the image, very near the top. You can see absolutely nothing of the formation which, logically, must connect this spit of islands beneath the lake surface. They completely disappear at what appears to be the surface level of the liquid. It's certainly the horizon at which the radar ceases to "see" through the liquid. There is no darkening, no "bathtub ring" around the bases of these spit islands, to indicate that we're looking through the surface of the liquid (as you would expect if the lower portion of the image is seeing submerged terrain). The break in visibility between the "seeing horizon" and the spit islands is sharp and well-defined.

Also, in the lower portion of the image, there are several locations which reflect just as darkly as the liquid surface above, and they tend to be arrayed in arroyo-like formations. These *could* just be drainage formations that are, indeed, currently submerged, but again, it's really hard to say when you don't know how deeply the radar may be penetrating the liquid's surface.

Without any convincing data about how far the radar can penetrate this liquid, I'm pretty certain that the lower portion of the image is not currently flooded, but that the radar-dark material that seems to complete the lake shore is actually sedimentation from recent flooding. (Also, some ripple-like formations in this darkened terrain look as much like dunes as they look like liquid-flow ripples. Brings to question how much of the time this terrain really spends submerged.)

In addition to the question of whether the entire region is submerged, I'm fascinated by the flecks in the liquid surface in the upper portion of the image. They seem to be more concentrated closer to the shorelines. Are these blocks of ice floating on the liquid? Would the local ices even float in this liquid? Or could these flecks actually represent wave action on the surface of the liquid?

Think of it -- waves on the lakes of Titan...

-the other Doug

[ugordan]

Does anyone know if the SAR swath crossed the sunlit northern latitudes seen in that conspicuous CB3 WAC image?

[hendric]

PIA09180: Titan: Larger and Larger Lakes

Wow, Titan looks more and more like it's covered in fjords. Maybe that's a result of the constant drying&flooding of the valleys.

[Olvegg]

Something like this? Not sure, however.

Attached thumbnail(s)

 

[Phil Stooke]

Messing around with the new radar image...

Phil

[remcook]

also some fun (my imagination is running away with me today - must be because I'm ill):

ice anyone?

Attached thumbnail(s)

 

[Olvegg]

Ethane Claciers? Why not?

[volcanopele]

Giant Lake on Titan:

http://ciclops.org/view.php?id=2607

This view of Titan taken on February 25, 2007 reveals a giant lake-like feature in Titan's North Polar Region. It is approximately 1,100 km (680 miles) long and has a surface area slightly smaller than that of Earth's largest lake, the Caspian Sea.

[stevesliva]

I was thinking liquid on top of solid:

If course, most solids don't float on the same liquid, right?

[ugordan]

VP, nice to see such a swift release. You could have at least taken the time to clean up the cosmic ray noise in the image!

[Mongo]

Eh, there's no satisfying some people. In the words of some character in a SF novel I forget the name of, "Some people would complain even if they were beheaded with a solid-gold axe!"

Bill

[volcanopele]

VP, nice to see such a swift release. You could have at least taken the time to clean up the cosmic ray noise in the image!

I know, but we weren't going to let a little thing like cosmic ray filtering prevent us from sharing the utter coolness that is this lake (or sea...). Expect more coolness in the coming days.

This has been a crazy day. Giant Titan lakes AND Io! If only we had an image of Enceladus erupting, and we would have a VP Planetary Coolness Day trifecta...

[belleraphon1]

Giant Lake on Titan:

http://ciclops.org/view.php?id=2607

This view of Titan taken on February 25, 2007 reveals a giant lake-like feature in Titan's North Polar Region. It is approximately 1,100 km (680 miles) long and has a surface area slightly smaller than that of Earth's largest lake, the Caspian Sea.

I knew it I knew it I knew it !!!!



Craig

[belleraphon1]

Ethane Claciers? Why not?

My understanding is that solid methane is denser than the liquid (H2O ice I is , I believe, unique in being less dense than the liquid phase). But could there be ethane icebergs?

Craig

[Matt]

That is an incredible image. It also looks sharper and clearer than a lot of the other Titan sar images. Why is that? Its probably just the terrain, although wouldn't less volume scattering make for a sharper image?

[belleraphon1]

Being way old enough to remember the Voyager 1 Titan flyby that gave us a smoggy orange ball with a dense nitrogen/methane atmosphere and hints of an exotic surface....... to live to see the ISS/VIMS/RADAR data products.....

To see this lake in that raw ISS image come into view..... kissing the sunlight for the first time in years....
and the anticipation of watching the seasonal changes to come.....

I have been on such a space high that my office mates sent me home..... what a marvelous time and experience to see a world develop in our understanding, piece by data piece.....

The human species knowledge of the book of worlds (extra-solar as well) is being written for the first time in our lifetimes... what a legacy for the future..... what a high for us!!!!!!

Have to sign off now to attend to my grandchildren... but what stories I will have to tell them....



Craig

[Olvegg]

Here it is!

Attached thumbnail(s)

 

[Olvegg]

Unfortunately, it mismathes Phil Stooke's projection.

[Olvegg]

My understanding is that solid methane is denser than the liquid (H2O ice I is , I believe, unique in being less dense than the liquid phase). But could there be ethane icebergs?

Craig

I think, ethane iceberg sink in liquid methane as well. But solid ethane or some other simple hydrocarbons may form relief there.

[Mongo]

I have a question about terminology. This new body of fluid is apparently almost as large in area as the Caspian Sea. When it is named, will it be called 'Lacus Something' or is it large enough to be called 'Mare Something'?

In addition, a few years ago we at this board were asked to come up with suggestions for suitable names for any large bodies of fluid that might be discovered -- focusing on mythological oceans. I had suggested 'Abzu', from the Mesopotamian freshwater ocean that lay underneath the Earth.

http://www.unmannedspaceflight.com/index.p...c=265&st=40

According to ancient Mesopotamian belief, the Abzu (or engur) was the vast freshwater ocean that lay beneath the earth (as opposed to the salt sea, which was thought to surround the earth). The Abzu therefore served as the source of all wells, springs, rivers, streams and lakes.

The Abzu was the domain of the god Enki (Ea), his consort Damgalnuna (Damkina) and his mother Nammu, as well as being the home of a number of his peculiar creatures. (Enki was believed to have ruled the Abzu prior to mankind's creation). The temple of Enki at Eridu was known as E-Abzu, "the house, or temple, of the Abzu".

On another level, according to the Babylonian Epic of Creation, Apsû was a primal being, the lover of Tiamat. After Ea's killing of Apsû, he erected his dwelling on Apsû's body, the dead creature's name being transferred thereafter to Ea's residence. As Ea's son, Marduk was often designated "firstborn son of the apsû".

The Underworld was located beneath the Abzu. Occasionally, it seems, the Abzu was identified with a river (the Hubur) that one had to cross in order to reach the Underworld.

Are the names that we came up with still being considered?

Bill

[belleraphon1]

I have a question about terminology. This new body of fluid is apparently almost as large in area as the Caspian Sea. When it is named, will it be called 'Lacus Something' or is it large enough to be called 'Mare Something'?

In addition, a few years ago we at this board were asked to come up with suggestions for suitable names for any large bodies of fluid that might be discovered -- focusing on mythological oceans. I had suggested 'Abzu', from the Mesopotamian freshwater ocean that lay underneath the Earth.

http://www.unmannedspaceflight.com/index.p...c=265&st=40
Are the names that we came up with still being considered?

Bill

And I would nominate Hertha Lake for this one...... see http://www.pitt.edu/~dash/hertha.html
the legend talks of disappearances..... good name for a lake that will, itself, maybe, disappear until the next winter......

Craig

[volcanopele]

This lake/sea would likely be filed under Lacus, rather than Mare. As such it would be named after a lake on Earth, one that is of similar size and/or shape to feature on Titan needing a name.

[Floyd]

Great job with the images Olvegg. So much for North being to the left!

Floyd

[Exploitcorporati...]

Unfortunately, it mismathes Phil Stooke's projection.

Wow! Nice update...that "north to the left" bit was confusing. I'm not sure how much distortion would be imparted to the new image in reprojection...it will be much easier with the whole swath. As to Phil's map, the low resolution and different "seeing" between ISS and RADAR probably make things worse. I wanted to rip my friggin' eyeballs out trying to fit the mosaic to any part of ISS image, even after blurring the RADAR picture.
Here's a different take with a little speculative Lake Doodle:

[Airbag]

I just attended a talk (at the Amateur Astronomers Association of Princeton - thanks Mars Loon!) by Prof. Jonathan Lunine of the University of Arizona's Lunar and Planetary Lab; he showed images of the entire latests swath and indeed a mosaic of all such swaths north of 70 degrees lattitude. Be prepared to be even more amazed when you see the entire set together.

He reasoned that these lakes are really seas when their sizes (roughly the size of some of the Great Lakes) are taken in proportion to the size of the planet sorry moon :-) He had some great spectroscopic charts for relative abundances of various methane-derived hydrocarbons at both high altitudes and after landing, The latter clearly showed the marked increase in CH4 following penetration of the heated sample probe into the surface.

Some more observations - due to the optical properties of the postulated liquid hydrocarbons at SAR wavelengths it will not be possible to see specular reflections (from the radar itself). Also, the geometry is wrong for specular reflections from the Sun at IR wavelengths.

In the areas of the swaths which cross, no changes were seen. I.e. those faint markings in the postulated lake areas are not waves or some other transient phenomena, at least on the timescale of the mission so far.

Areas where SAR passed overlap at roughly 90 degrees can provide additional surface angle information that is not possible with just a one single pass data set; that data is still being worked on.

Just fascinating!

Airbag.

[nprev]

Interesting indeed, Airbag!

Did he happen to state whether the lack of specular reflection in radar places any constraints on the lakes' (seas'?! ) composition (i.e., methane/ethane ratio)?

[claurel]

I just attended a talk (at the Amateur Astronomers Association of Princeton - thanks Mars Loon!) by Prof. Jonathan Lunine of the University of Arizona's Lunar and Planetary Lab; he showed images of the entire latests swath and indeed a mosaic of all such swaths north of 70 degrees lattitude. Be prepared to be even more amazed when you see the entire set together.

Wow . . . I can't wait to see this mosaic. Not to be too greedy--the images that have been released so far are spectacular. In addition to a general curiosity about how widespread the lakes are, I'm very interested in creating a Titan specular texture for Celestia with all the known lakes filled in. This would be a quick way to visually check when and where specular highlights might be visible. Of course, it seems likely that the lakes will shrink as sunlight reaches them, but I think it would be useful nonetheless.

--Chris

[Airbag]

Did he happen to state whether the lack of specular reflection in radar places any constraints on the lakes' (seas'?! ) composition (i.e., methane/ethane ratio)?

No, he did not. He did say that methane would (not surprisingly) be the major component of such a liquid, based on relative abundances of various hydrocarbons (that would be liquid at surface temps) as measured in the upper atmosphere. It would even contain some dissolved nitrogen, just as a side effect of the atmosphere consisting of mainly N2 molecules.

Airbag

[Airbag]

This would be a quick way to visually check when and where specular highlights might be visible.

He explained that for future passes the Cassini/Titan/Sun angles (i.e. low to the horizon) would be such that the light would be greatly attenuated because of the extra path length through the haze layers and it would be unlikely any specular reflection would be observered, even with the correct geometry.

Airbag

[Mongo]

This lake/sea would likely be filed under Lacus, rather than Mare. As such it would be named after a lake on Earth, one that is of similar size and/or shape to feature on Titan needing a name.

In that case, the best match that I could find for both size and shape would be Great Bear Lake (Ursus Magnus Lacus?), with an area of 31,153 km^2:



This is less than one-tenth of the area of the Caspian Sea, but no fresh-water lake on earth is nearly that big. The largest freshwater lake on Earth is Lake Superior, which is less than one-quarter the area of the Caspian Sea -- unless you count Lakes Huron and Michigan as one lake, in which case their combined area is a bit less than one-third the area of the Caspian Sea.

Bill

[David]

In that case, the best match that I could find for both size and shape would be Great Bear Lake (Ursus Magnus Lacus?)

Close: Ursi Magni (genitive case) would be more correct -- that is, if it means "the lake of the great bear"; if it's "the great lake of the bear" it would be Ursi Lacus Major, more likely. But the way astronomical nomenclature goes these days, if they named it after that lake, it would probably be "Lacus Great Bear".

+: I see from the French (Grand Lac de l'Ours) that it is indeed the "great lake of the bear". But as there doesn't seem to be a "Little Bear Lake" by way of contrast, it would just be Ursi Lacus Magnus (not Major).

[Floyd]

Olvegg, is their a chance you could put in the projected radar path for the Feb 22 flyby on your polar map?
Thanks, Floyd

[ngunn]

Was there not a time during the last Ice Age when the Superior/Michigan/Huron area was covered by a single Great Lake? If so it must have been given a name (anybody know?) that might serve here. Ice-damming seems an appropriate connotation too.

Can anyone make sense of the ISS/RADAR correlation yet?

[Mongo]

Given the ratio between Earth's and Titan's diameters (12,756/5,150 = 2.477:1) and hence areas (6.135:1), the area of the Caspian Sea (371,000 km^2) on Titan would be proportionately equal to an area of 2,276,000 km^2 on Earth. For comparison, the largest seas on Earth, listed in order of surface area:

2,974,600 km^2 South China Sea
2,515,900 km^2 Caribbean Sea
2,510,000 km^2 Mediterranean SEa
2,261,100 km^2 Bering Sea
1,507,600 km^2 Gulf of Mexico
1,498,320 km^2 Arabian Sea
1,392,100 km^2 Sea of Okhotsk
1,012,900 km^2 Sea of Japan
730,100 km^2 Hudson Bay
664,600 km^2 East China Sea
564,900 km^2 Andaman Sea
507,900 km^2 Black Sea
453,000 km^2 Red Sea

So, as a percentage of the total area, the new lake/sea on Titan is almost as large as the largest seas on Earth.

Bill

[Mongo]

Was there not a time during the last Ice Age when the Superior/Michigan/Huron area was covered by a single Great Lake? If so it must have been given a name (anybody know?) that might serve here. Ice-damming seems an appropriate connotation too.

The largest glacial lake that I know of was glacial Lake Agassiz, at as much as 440,000 km^2:

http://en.wikipedia.org/wiki/Lake_Agassiz

Bill

[ngunn]

That would do nicely.

[Olvegg]

Olvegg, is their a chance you could put in the projected radar path for the Feb 22 flyby on your polar map?
Thanks, Floyd

Sure! As soon as it will be released.
Don't forget, however, that this map is not quite correct, because I lay flat radar swaths on global view. Fortunately most of the lakes lay within 70 deg polar circle, so distortions are not very impressive.

[ustrax]

The details are just incredible!...

[David]

The largest glacial lake that I know of was glacial Lake Agassiz, at as much as 440,000 km^2:

http://en.wikipedia.org/wiki/Lake_Agassiz

I don't know its exact size, but the Ancylus Lake was also rather large.

[Webscientist]

I agree with dvandorn,
In this first radar image, released of the T25 flyby, the lower portion of the dark patch ( in the western part of the big island ) doesn't appear uniformly dark. One can see dark drainage channels through it as well as very narrow circular dunes ( artifact?). I admit that it must be wet or flooded but not very deep.
On the other hand, the upper part of the image is convincing with a uniformly dark area. The lake must be quite deep at this place. A good place to study in the future: candidates?

http://www.titanexploration.com

[ngunn]

Actually it's possible to follow the main sinuous channel right out into the middle of the darkest area (consistent with it drying out), so I don't think any of it can be very deep.

[volcanopele]

Western Quivira in SAR:

http://photojournal.jpl.nasa.gov/catalog/PIA09181

Here are some graphics comparing this area in SAR and ISS 938 nm:

[JRehling]

Western Quivira in SAR:

http://photojournal.jpl.nasa.gov/catalog/PIA09181

Here are some graphics comparing this area in SAR and ISS 938 nm:

[...]

Too cool. Things like this almost make me feel guilty, they're so pleasing to see for the first time.

When I see the RADAR/ISS comparison, and knowing that the RADAR map will end up incomplete, it makes me think about a "pattern completion" graphics routine that takes the RADAR and ISS images where there is overlap, infers the difference, and then applies it to the portions of an ISS map we don't get RADAR data for. A human artist could do this (inventing fictitious details), but it seems like an interesting research project to imbue that ability into an automated system (which would also invent fictitious details). Maybe the main point would be aesthetic, but who knows -- it might stimulate some useful hypotheses for the non-fictitious stuff, too.

My PhD work was a bit along those lines, though, so I expect that it would be a hard project and would require a nontrivial amount of definition.

BTW, this image looks like a tyrannosaurus rex attacking from right to left.

Scientifically: It looks like very low relief in the bright areas, almost washed into the plains and covered up by dunes. A less rugged shoreline than we've seen in Huygens imagery and the much-imaged west cost of Xanadu.

[ustrax]

While we delight ourselves with Cassini fly-bys there are some proto-good news...

There is a proposal being prepared for a 2020-2025 return to Titan, with an atmospheric balloon and other probes.

More details coming soon you know where...

[ugordan]

Carolyn Porco at CICLOPS hinted at more good stuff regarding the lake coming soon. I already asked this before, does anyone know if the latest SAR swath crossed this lake/sea wannabe?
Any VIMS spectra? I figure the lake should subtend at least one solid VIMS pixel, getting some spectra confirming that as methane would be awesome.

[mars loon]

I just attended a talk (at the Amateur Astronomers Association of Princeton - thanks Mars Loon!) by Prof. Jonathan Lunine of the University of Arizona's Lunar and Planetary Lab; he showed images of the entire latests swath and indeed a mosaic of all such swaths north of 70 degrees lattitude. Be prepared to be even more amazed when you see the entire set together.
Just fascinating! Airbag.

Thanks Airbag ! It's my pleasure ! Am just seeing this as I 've been busy with outreach. posted some of your comments here:
http://www.unmannedspaceflight.com/index.php?showtopic=3949

Yes indeed, be sure to visit any talk by Dr. Lunine

This tiny radar piece is just a speck. Just wait till you see the whole swath.

We were treated to such a wealth of data, within 5 days of the T25 pass

and just a few hours prior to the NH Jupiter flyby and 2 days after the Rosetta Mars flyby.

ken

[Webscientist]

Stiil waiting for the full radar strip of the T25 flyby.
Apparently, Titan lakes are located above 70 degrees north latitude.
If my calculations are correct, they are scattered in an area covering the equivalent of 2.5 million km². That's about the size of Argentina or Soudan.
So, one thing is sure, no ocean in Titan's north pole.

I'm eagerly waiting for the data on temperature variations as a function of latitude.

http://www.titanexploration.com

[remcook]

temperature where? on the surface? I don't expect it to change very much.

[Ant103]

I don't know where put this...
Here is a colorisation of Titant taken the 7th of March (it was hard to have good color from IR layer - the Red layer is not yet visible - and stack the differents layer), so :