Large Lake and Island Discovered On Titan

[Fraser]

NASA's Cassini spacecraft has been turning up new images of features that look like lakes on the surface of Saturn's moon Titan. This latest image shows a large lake that appears to be surrounding an island. ...

Read the full blog entry (http://www.universetoday.com/2007/03/01/large-lake-and-island-discovered-on-titan/?1396)

[Grand_Lunar]

Sort of reminds me of Mackinac Island.

[suitti]

I'll be building my summer home there soon.
Global Warming will make Mackinac too hot.

[John Mendenhall]

Isn't it beautiful? Even if it is way too cold, it looks so familiar.

[BLACK_MONOLITH]

this world is certainly yours.. we don't need this one...

[Tharsis]

Wow! This is why I love astronomy and planetary studies as much as I do. It's so unfortunate that we can't get a better look at this moon. These radar generated images are fantastic, I mean, Titan was veiled in near-total obscurity before Cassini arrived. Ever since these possible lakes were spotted in the last six months or so, they've fired up my imagination. I can't tell you how many times I've imagined myself standing alongside a methane stream or lake. Fraser estimates this nameless mammoth island at approximately 93 x 62 miles. Hey that's a lot of lakeside real estate. As I study the image, seems only the top portion facing the lake is deep, the bottom and right sides off the island appear shallow.

The most burning question for me, probably for the imaging people at JPL as well, is to declare these bodies as definitively containing fluids. It's my understanding, even with consensus leaning heavily towards it, Cassini's radar hasn't revealed this matter as fact. Apologies for my rambling.

[DJ Barney]

What's the "track" along the middle of the image (more pronounced on the right hand side) ? A radar artifact ?

DJBarney

[VPCCD]

Isn't it beautiful? Even if it is way too cold, it looks so familiar.

Am I the only one who thinks it looks a bit like Iceland? Probably around the same tempreature as well.

[Ivan Viehoff]

Am I the only one who thinks it looks a bit like Iceland? Probably around the same tempreature as well.
If you take a mirror image, it looks even more like Iceland. Iceland itself is remarkably mild for its latitude (though Norway is warmer), it is the strong winds that make it seem so cold. The ski slopes near Reykjavik have only been open 4 days this winter.

[One Skunk Todd]

Heh, ice islands complete with fiddly edges by Slartibartfast. :)


What's the "track" along the middle of the image (more pronounced on the right hand side) ? A radar artifact ?

DJBarney

I think it must be. The top and bottom edges of the original photo:

http://photojournal.jpl.nasa.gov/jpegMod/PIA09180_modest.jpg

have a ragged look that seem to match the "perforations" running across this one.

[zenbudda]

is methane/ethane in liquid form flamable? if so, wouldn't one fiery meteorite destroy the entire moon? i guess i'm assuming titan has some sort of atmosphere to cause enough friction to cause the meteor to flame.

[aurora]

is methane/ethane in liquid form flamable? if so, wouldn't one fiery meteorite destroy the entire moon? i guess i'm assuming titan has some sort of atmosphere to cause enough friction to cause the meteor to flame.


Methane needs oxygen in order to burn.

[Hamlet]

is methane/ethane in liquid form flamable? if so, wouldn't one fiery meteorite destroy the entire moon? i guess i'm assuming titan has some sort of atmosphere to cause enough friction to cause the meteor to flame.

Methane requires an oxidizer to burn. There is no free oxygen on Titan to combust with the methane/ethane. Titan's atmosphere is well over 90% nitrogen with methane making up only about 3% of its composition.

[01101001]

Methane needs oxygen in order to burn.

Yep. It's the old... Fire Triangle (http://en.wikipedia.org/wiki/Fire_triangle) (now, oy, updated to the modern Fire Tetrahedron).

I suppose though, that chlorine, flourine, or other oxidizing agents would make Titan an interesting place, too.

[Nick4]

Cool looking

[Jerry]

Heh, ice islands complete with fiddly edges by Slartibartfast. :)



I think it must be. The top and bottom edges of the original photo:

http://photojournal.jpl.nasa.gov/jpegMod/PIA09180_modest.jpg

have a ragged look that seem to match the "perforations" running across this one.

I am leaning towards the interpretation that the tracks, or at least the lines are real, but I could be persuaded otherwise. If real, this would likely be a 'rift', like Combe Ridge in southern Utah. These things happen.

[EDG]

I am leaning towards the interpretation that the tracks, or at least the lines are real, but I could be persuaded otherwise. If real, this would likely be a 'rift', like Combe Ridge in southern Utah. These things happen.

If it's an image artifact then it only seems to be present on the right-hand side of the image.

I'm not convinced this is an island though. The dark stuff to the north might be liquid, but we can see features to the south and east of the "island". Maybe the north is liquid and the south/east is more like a marsh?

[transreality]

No matter how much they turn up the contrast there is always light coloured material in and over the dark areas that are interpreted as seas. The embayments around this island may not necessarily be formed by erosion of by liquid flows or glacial actions from the island, instead perhaps by accretion of ice crystals on existing structures, like a snow bank.

[Jerry]

No matter how much they turn up the contrast there is always light coloured material in and over the dark areas that are interpreted as seas.
That's an important and surprising distinction. Without any specular reflections, the seas of Titan remain guesses, and perhaps not the best guesses, at that.

[BigDon]

Anyone have a clue as to what tides must be like on Titan? The cold temp and viscous nature of the hydrocarbons probably dampen the tidal effect.

[EDG]

The orbit's a bit eccentric but the orbit is about 16 days long. But since Titan is in synchronous rotation around Saturn, the tidal bulge isn't going to actually move that much - it should just generally stay locked to Saturn and go up and down a bit as the moon gets closer and further, and wobble a little from side to side as it goes round on its eccentric orbit.

[3488]

Thats true, Tidal variations will be fairly minimal.

What will be interesting, if Cassini lasts long enough will be to see if Titan's lakes change shape & size as northern Spring equinox arrives on Titan in August 2009 (on Saturn it is December 2009, but Titan's slight orbital inclination means it arrives there four months earlier).

This investigation will continue for sure.

Andrew Brown.

[01101001]

Without any specular reflections, the seas of Titan remain guesses, and perhaps not the best guesses, at that.

Getting ready to revise your own guesses?

BA Blog: A Titanic wink confirms otherwordly lakes (http://blogs.discovermagazine.com/badastronomy/2009/12/17/a-titanic-wink-confirms-otherwordly-lakes/)


A peculiar flash of light glinting from Saturn’s largest moon confirms what’s been suspected for years: liquid lakes exist on the surface of Titan!

The image above was taken on July 8, 2009 by the Cassini spacecraft. Light can reflect off the surface of liquids, producing a little sparkle or glint, called a specular reflection. Knowing that earlier images had shown what look to be lakes of liquid methane on Titan, they kept their eyes open for Cassini’s images of the moon to show such a glint. There are lots of lakes in the northern hemisphere of Titan, making the odds better it would be seen there, but it was only last year that spring sprung in Titan’s northern latitudes. That’s when it was finally possible to see sunlight plinking off of any purported standing liquid.

[transreality]

The dark areas in the equatorial regions of titan turned out to be seas of dunes (http://www.sciencedaily.com/releases/2009/03/090302111328.htm). So there are still two hypotheses to explain any particular dark region.

[Jerry]

Getting ready to revise your own guesses?

BA Blog: A Titanic wink confirms otherwordly lakes (http://blogs.discovermagazine.com/badastronomy/2009/12/17/a-titanic-wink-confirms-otherwordly-lakes/)
Nice to have a published confirmation of specular reflection. It would be better if somewhere in the article they spelled out that the refractive angle is consistent with methane rather than simply stating that the lakes on Titan are methane. There is quite a bit of ambiguity here: Methane and/or ethane and/or 'tholins'? Another question:


The finding shows that the shoreline of Kraken Mare has been stable over the last three years and that Titan has an ongoing hydrological cycle that brings liquids to the surface
If the shoreline has been stable over the last three years, how does this confirm a hydrological cycle? Or maybe what I should say, is: A shoreline that varies over a three year period would prove to me there is a hydrological cycle. If the level is not changing, the nearby 'dark features' that have varied in the same period seem more likely to be artifacts than seasonal wet spots.

[Jerry]

Ok, there is another paper, another article:

http://www.mr.caltech.edu/press_releases/13314


The only possible way to make Titanian fog, then, is to add humidity to the air. And the only way to do that, Brown says, is by evaporating liquid—in this case, methane, the most common hydrocarbon on the moon, which exists in solid, liquid, and gaseous forms.

Brown notes that evaporating methane on Titan "means it must have rained, and rain means streams and pools and erosion and geology. The presence of fog on Titan proves, for the first time, that the moon has a currently active methane hydrological cycle."

Combined with the observed specular reflections in the same general areas, a 'methylogical' cycle is the most likely suspect, but this is not the only possibility.

Venting from the internal planet; such as we observe on Enceladus, is also a possible source for the methane fog.