[X] My Assistant

[alan]

Editors summary of letter in latest issue of Nature

"The surface of Saturn's largest moon, Titan, is coated in a dense methane-rich atmosphere that prevents high-resolution imaging at visible wavelengths. During its first Titan flyby last October, the Cassini spacecraft's visual and infrared mapping spectrometer (VIMS) was able to reveal detailed surface structures, as reported in this issue. Notable features include a circular structure 30 km in diameter, thought to be a cryogenic dome. This may be volcanic, which could explain how the methane in Titan's atmosphere is replenished."

Anyone seen an image of this volcano?

I see volconpele posted it on his blog
http://volcanopele.blogspot.com/
second time thats happened.
Note to self: look there first

This post has been edited by alan: Jun 8 2005, 06:12 PM

[imran]

Here's another article.

Titan's Icy Volcanoes Erupting Methane?

[alan]

"It might well be a volcano, but it would be hard to say for sure without RADAR data," says Lorenz. "It looks as much like a giant cat poo as it does a volcano."

[volcanopele]

http://photojournal.jpl.nasa.gov/catalog/PIA07964
http://photojournal.jpl.nasa.gov/catalog/PIA07963
http://photojournal.jpl.nasa.gov/catalog/PIA07961

[Bob Shaw]

CAT aclysmic eruptions, huh?

[Phil Stooke]

Good one, Bob!

Phil

[Gsnorgathon]

So if it's a giant cat poo, presumably there should be some giant cat pee that would produce detectable ammonia in Titan's atmosphere. If there's no detectable ammonia, shouldn't it be possible to estimate the minimum age of the giant cat poo by estimating the amount of pee that would go along with it, and the time it would take for the generated ammonia to break down?

[dvandorn]

To heck with that -- I want some imaging of the giant cat!

Anyone know if RADAR will have enough resolution to be able to tell if it's a long-hair or a short-hair cat?

And is there any relationship between this giant cat and the giant rabbit that keeps Chang-Oh company on the Moon?

-the other Doug

[remcook]

the elusive snail...very interesting!
Of course, Lorenz is on the RADAR team, so he's not completely unbiased, but he has a point. Giant cats..that may just be it!

[Bob Shaw]

Ammonia should be detectable by Cassini's Kinetic Inteferometry Transformational Toroid Ytrium instrument (using the Light Intensity Total Time Exothermal Randomisation methodology). Of course, it depends on the age of the deposits, too.

(sorry)

[edstrick]

Ammonia is a puzzle for solar system origin and outer planets/moons studies.

It's rather like water, but the NH3 molecule is less stable than H20. Calculations tend to indicate than N2 is the most stable form of nitrogen in the solar nebula, not NH3. NH3 is easily and rapidly made inside gas giant planets at temperatures and pressures "at depth", so it's presence in Jupiter and Saturn's atmosphere doesn't say how it got there directly.

It takes pretty hard ultraviolet to break water in to H and OH, but it takes a lot softer UV <of which there is a lot more> to break NH3 into NH2 and H. <the pieces recombine and react with other molecules as well, but you tend to get Hydrogen H2 which escapes.

If Titan had an original massive greenhouse-heated atmosphere of Ammonia and Methane, one post Voyager calculation said <approximately> that the entire 1.5 atmospheres of nitrogen could have been formed from the Ammonia in some 100 million years.

Don't expect to find any NH3 on the surface of an icy moon, even if it's abundant in the interior, unless it was erupted very very recently <years or decades, maybe>, cause the NH3 ice exposed to solar UV will go bye-bye pretty fast. I''d love to get really high resolution specta of Enceladus south polar region....

[Jeff7]

To heck with that -- I want some imaging of the giant cat!

Anyone know if RADAR will have enough resolution to be able to tell if it's a long-hair or a short-hair cat?

And is there any relationship between this giant cat and the giant rabbit that keeps Chang-Oh company on the Moon?

-the other Doug

They found the cat awhile ago.

[volcanopele]

I get a feeling that the RADAR team in general or Ralph in particular, is obsessed with cats (Halloween Cat, Cat scratches, cat poo volcano).

[exoplanet]

I get a feeling that the RADAR team in general or Ralph in particular, is obsessed with cats (Halloween Cat, Cat scratches, cat poo volcano).

To be quite honest these cat comments are quite silly. I would much rather hear about the amount of heat that is possibly being generated inside of Titan to create such volcanism (of which I have recently posted about - Io vs. Titan but on a slightly colder scale). About a year ago I remember other scientists stating that volcanism would all be ruled out on Titan because there was not enough tidal heating and the prescence of a methane ocean was probably the source of methane. We now know that this is not true. Also, the astrobiological theory of Titan as being a primordial example of early Earth's atmosphere should fall by the wayside. With all the weathering and activity seen on Titan (The surface looks incredibly beautiful). I suspect Titan has evolved on it's own over the last 4.5 billion years. Now that we know more, Titan cannot be compared to early Earth.

Also, there is a great yawning void of information. I am trying to find out about the actual composition of Titan's atmosphere and surface - yes, I do know that there is abundant nitrogen and methane - but I also want to know what trace molecules and elements have been found. At the Huygens landing site "creme brulee" was the consistency of the mud but what was it actually made of? Also, have the isotopic properties of the methane in the atmosphere been deduced from the Huygens results yet???

To be quite honest I see nothing of cat scratches, halloween cat, and cat poo volcanoes. What I see in reality are possible enigmatic fault lines or dunes (unexplained as of yet), possible dried lake beds and a volcano. To name them as otherwise is quite insulting to those who are waiting for serious knowledge about this enigmatic moon.

[remcook]

the CIRS Titan paper shows a lot of the atmospheric composition:

http://adsabs.harvard.edu/cgi-bin/nph-bib_...4166bdc91419364

(hope you have access, because I can't seem to find a table right now, but there's one in Ralph Lorenz' book)

There's not much known about the surface composition..