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Fraser
2008-Feb-14, 12:10 AM
According to new Cassini data, Saturns largest moon, Titan, has "hundreds" times more liquid hydrocarbons than all the liquid fossil fuel deposits*on Earth. This is impressive as Titan's 5150 km diameter is only about 50% larger than Earth's Moon and only a little larger than the planet Mercury. Titan's hydrocarbons cycle into the atmosphere, fall [...]

More... (http://www.universetoday.com/2008/02/13/titan-has-hundreds-of-times-more-liquid-hydrocarbons-than-earth/)

Jerry
2008-Feb-25, 02:50 PM
Saturn's orange moon Titan has hundreds of times more liquid hydrocarbons than all the known oil and natural gas reserves on Earth, according to new data from NASA's Cassini spacecraft. The hydrocarbons rain from the sky, collecting in vast deposits that form lakes and dunes.

There is an incredible leap of faith here: Red, white and yellow dunes on earth are made out of silicates - hydrocarbons are black, and when we try to make 'tholins' (a word made up by Carl Sagen to describe the surface materials of Titan); the resulting products always turn out black, too.


Research Letters by Ralph Lorenz from the Cassini radar team (Johns Hopkins University Applied Physics Laboratory, USA). Lorenz said on reviewing the Cassini data that, "we know that some lakes are more than 10 m or so deep because they appear literally pitch-black to the radar. If they were shallow we'd see the bottom, and we don't."
A lake of oil doesn't have to be more than a meter deep to be 'pitch-black'; although these surveys are in radar bands and the penetration into a methane lake in radar may be comparable to a water-lake in the visual spectrum.

01101001
2008-Feb-25, 04:43 PM
A lake of oil doesn't have to be more than a meter deep to be 'pitch-black'; although these surveys are in radar bands and the penetration into a methane lake in radar may be comparable to a water-lake in the visual spectrum.

Yeah, good, you noticed that the pitch-blackness he was alluding to is the radar reflectivity rendered as grayscale intensity. The bodies of apparent liquid are flat, and reflect radar specularly, away from their source, Cassini, so the receiver sees little-to-no radar-return signal. They are featureless in large-scale texture.

I don't know why you brought the actual color of tholins into it. If they were yellow-polka dotted, their flat-liquid intensity of radar return would still be zero, rendered as black for those who need an image to help visualize a foreign landscape of surface textures.

Please cite some facts that support your argument: "A lake of oil doesn't have to be more than a meter deep to be 'pitch-black'," where the blackness is a measure of radar-measured smoothness.

Jerry
2008-Feb-26, 05:21 AM
I don't know why you brought the actual color of tholins into it. If they were yellow-polka dotted, their flat-liquid intensity of radar return would still be zero, rendered as black for those who need an image to help visualize a foreign landscape of surface textures.

Please cite some facts that support your argument: "A lake of oil doesn't have to be more than a meter deep to be 'pitch-black'," where the blackness is a measure of radar-measured smoothness. I meant visually, and the article did not make a distinction between visual and radar visibility.

The article mentions/implies that the dunes are made out of hydrocarbons, too: Certainly the punative number of lakes do not contain the volume of hydrocarbons headlined in the article. The dunes do not look like hydrocarbons - they are not black, they are reddish yellow; and to the best of my knowledge there is no hard spectral evidence that they are hydrocarbon. The sand is the wrong color to be hydrocarbon sand.

In fact, I am not aware of any reports of the type of specular reflections that would confirm the lakes are truly lakes - am I missing something?

01101001
2008-Feb-26, 07:58 AM
I meant visually, and the article did not make a distinction between visual and radar visibility.

Here's the quote you provided to us. Note the word "radar":

we know that some lakes are more than 10 m or so deep because they appear literally pitch-black to the radar.

"Pitch-black to the radar" is the only use of "black" that I spotted in the article. Are there some I missed where you took the meaning to be visually black?


In fact, I am not aware of any reports of the type of specular reflections that would confirm the lakes are truly lakes - am I missing something?

I think you are. I tried to be careful to describe their behavior as liquid-like and not liquid. Did I slip? I don't know what conclusions the experts have made about the lakes' state, or, for that matter, what you consider "makes a lake a lake". I'd be surprised to learn it had been conclusively settled beyond doubt.

Perhaps you can correct my understanding of radar. Do you disagree that the black lakes appear smooth to the radar, or that radar-smooth sufaces reflect specularly?

clint
2008-Feb-26, 10:39 AM
Let's suppose Titan does have those huge amounts of hydrocarbons.
Would they be really useful?

I mean, by the time we will somehow be able to 'mine' them as far away as Titan
(and ship them back to Earth at a reasonable cost),
we should better already be relying on alternative energy sources anyway, right?

Might be useful as a local energy source for any future Titan settlers, though.

Halcyon Dayz
2008-Feb-26, 11:51 AM
Oxygen.

ASEI
2008-Feb-26, 12:46 PM
Might be useful as a local energy source for any future Titan settlers, though. You would still have to fuel your car on Titan - with liquid oxygen or some other oxidizer probably. I'd be willing to bet that it's a pretty good general rule of nature that two reactants that produce an energetic reaction are never found naturally mixed up, such as in an atmosphere.

Noclevername
2008-Feb-26, 11:36 PM
Let's suppose Titan does have those huge amounts of hydrocarbons.
Would they be really useful?
Might be useful as a local energy source for any future Titan settlers, though.
They will be useful, not as energy sources, but as a source of conveniently concentrated organic chemicals, which will be immensely useful both for making liveable habitat ecologies, and for manufacture of various chemicals, plastics, etc. However, since they're in a deep double gravity well (Titan's and Saturn's*) that makes them less convenient that they could be. Possibly getting carbon compounds from carbonaceous asteroids and comets will be cheaper in the long run.

*EDIT: Now that I think about it, since it's a two-body system, using Saturn for a slingshot might make getting them out slightly cheaper.

clint
2008-Feb-27, 01:27 PM
They will be useful, not as energy sources, but as a source of conveniently concentrated organic chemicals, which will be immensely useful both for making liveable habitat ecologies, and for manufacture of various chemicals, plastics, etc....

Hadn't thought about that option, cool idea:
using the resources as input for a future chemical industry on Titan.

This would add much higher value than merely mining the raw materials,
so it could at some point make sense even if the transport cost are high.

ASEI
2008-Feb-27, 01:29 PM
What sort of magnetic field would you have to generate to efficiently move about one of these gas giant systems? My understanding is that they have some pretty intense magnetospheres, especially near the inner moons. Maybe you could get free dV for orbital maneuvers within the Jupiter and Saturn system?

Jerry
2008-Feb-28, 12:03 AM
Here's the quote you provided to us. Note the word "radar":


"Pitch-black to the radar" is the only use of "black" that I spotted in the article. Are there some I missed where you took the meaning to be visually black?



I think you are. I tried to be careful to describe their behavior as liquid-like and not liquid. Did I slip? I don't know what conclusions the experts have made about the lakes' state, or, for that matter, what you consider "makes a lake a lake". I'd be surprised to learn it had been conclusively settled beyond doubt.

Perhaps you can correct my understanding of radar. Do you disagree that the black lakes appear smooth to the radar, or that radar-smooth sufaces reflect specularly?
Black is not a radar color, it is a visual light color. A pool of tar is literally pitch black, a pool of water or methane may provide no radar signature regardless of depth; depending upon the smoothness of the underlying surface.

To say something is 'pitch black' in the radar is missleading to many readers; unless somewhere in the article it is also pointed out a perfectly flat surface will appear 'pitch black' in radar whether or not there is any liquid.

This is not to say that I don't think that there are not pools of methane on Titan, there well could be. The type of evidence provided by Cassini and Huygens to-date is not consistent with the assertion within this article that Titan is teaming hydrocarbons: This is really based upon theory that was developed before Cassini's visit; and the visual and spectral evidence actually runs counter to this assertion. Most hydrocarbon polymers - oils and tars - are black, not red and yellow. The surface of Titan is not black.

Again, if anyone is aware of any research where tholins and/or hydrocarbons have been developed using a process compatible with, and complimentary to the spectral and physical evidence we have observed at Titan, this article is warrented. But to declare Titan is full of hydrocarbons is not a conclusion that is based upon what Cassini has observed.

parejkoj
2008-Mar-13, 07:53 PM
Jerry:

I think you should read Waite et al. 2007 , The Process of Tholin Formation in Titan's Upper Atmosphere (http://www.sciencemag.org/cgi/content/abstract/316/5826/870).

JustAFriend
2008-Mar-18, 12:54 AM
So can we go ahead and give Sean Connery his Sheriff's badge and shotgun???

Sounds like Outland (http://imdb.com/title/tt0082869/) wasn't too far off.......

01101001
2008-Jul-30, 08:52 PM
There will probably be a Universe Today article on this soon (or already), but this fits here for its confirmation of the liquid lake:

University of Arizona press release: UA camera shows large hydrocarbon lake is truly wet (http://uanews.org/node/20615)


Scientists have confirmed that at least one body in our solar system, other than Earth, has a surface liquid lake.

Using an instrument on NASA's Cassini orbiter, they discovered that a lake-like feature in the south polar region of Saturn's moon, Titan, is truly wet. The lake is about 235 kilometers, or 150 miles, long.

The visual and infrared mapping spectrometer, or VIMS, an instrument run from The University Arizona, identifies the chemical composition of objects by the way matter reflects light.

When VIMS observed the lake, named Ontario Lacus, it detected ethane, a simple hydrocarbon that Titan experts have long been searching for. The ethane is in liquid solution with methane, nitrogen and other low-molecular weight hydrocarbons.
[...]
"This is the first observation that really pins down that Titan has a surface lake filled with liquid," VIMS principal investigator and professor Robert H. Brown of the UA's Lunar and Planetary Laboratory said. Brown and his team report their results in the July 31 issue of the journal Nature.

"Detection of liquid ethane in Ontario Lacus confirms a long-held idea that lakes and seas filled with methane and ethane exist on Titan," said Larry Soderblom of the U.S. Geological Survey, Flagstaff, Ariz.

Note to readers, as I know some people read too literally: "black" doesn't necessarily mean lacking visible light, here:


"We know the lake is liquid because it reflects essentially no light at 5-micron wavelengths," Brown said. "It was hard for us to accept the fact that the feature was so black when we first saw it. More than 99.9 percent of the light that reaches the lake never gets out again. For it to be that dark, the surface has to be extremely quiescent, mirror smooth. No naturally produced solid could be that smooth."

Jerry and others: this "black" refers to infrared this time. Please don't find it misleading.

JustAFriend
2008-Jul-30, 09:40 PM
It's because the intelligent species of dinosaurs built spaceships and relocated there 65million years ago before the comet hit....

;-))

Grand_Lunar
2008-Jul-31, 02:27 PM
Carl Sagan coined the term "tholins" to describe prebiotic chemicals, and the dunes of Titan are expected to be teeming with them. Tholins are essential for the beginning of carbon-based organisms, so these new observations by Cassini will stir massive amounts of excitement for planetary physicists and biologists alike.

Might we expect any inhabitents then to be known as Tholians? :D

VanderL
2008-Jul-31, 06:13 PM
I'm not sure that the lack of radar reflectivity of certain areas of Titan's surface is proof of liquid-containing lakes. I've seen several Magellan radar-images of Venus' surface where there are also very dark (reflection-less) areas inside impact craters. See here (http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1494.pdf) for example. Also Cleopatra Crater (http://commons.wikimedia.org/wiki/Image:Cleopatra_crater_on_Venus.jpg) has such a dark feature, according to the Magellan scientists due to "very fine dust". So in short , the "lakes" of Titan could also be "very fine dust" (which would also be consistent with the findings of dunes on Titan).

This explanation seems to be discarded for Titan because it doesn't fit prior expectations (there used to be oceans there), it isn't even mentioned in the press-releases, and so far I haven't seen any mention of this possibility in any of the papers about Titan's surface features (if I missed anything, please let me know). To me this is "confirmatory bias" in action, we need better evidence than this to prove they are really hydrocarbon lakes.

Cheers.

clint
2008-Aug-01, 06:45 AM
It seems on Titan they discarded any solid material because the surface is too smooth...

sabianq
2008-Aug-01, 01:52 PM
There is an incredible leap of faith here: Red, white and yellow dunes on earth are made out of silicates - hydrocarbons are black, and when we try to make 'tholins' (a word made up by Carl Sagen to describe the surface materials of Titan); the resulting products always turn out black, too.

propane is a hydrocarbon, is it black? methane, ethane, butane, Pentane, Hexane, heptane, octane, decane and nonane are also hydrocarbons. none of them are black. actually, i would bet that most of the hydrocarbons in existence are not actually black but are gases, clear liquids or long chain hydrocarbon solids like natural wax (yellowish-dark brown like bees wax or ear wax) and the ones that are "black" or very very dark brown) are most likely rare in the family of hydrocarbons. (given how they are made)



A lake of oil doesn't have to be more than a meter deep to be 'pitch-black'; although these surveys are in radar bands and the penetration into a methane lake in radar may be comparable to a water-lake in the visual spectrum.

just because someone said the word "hydrocarbon" does not instantly mean "oil".
a lake of liquid methane would surely be classified as a lake of hydrocarbons, and it would be as clear as water.



Most hydrocarbon polymers - oils and tars - are black, not red and yellow.


I don't remember anywhere in any article where anyone has said that they found hydrocarbon "polymers" on titan.
please point me to an article where this was ascertained.




In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon.
http://en.wikipedia.org/wiki/Hydrocarbon

sabianq
2008-Aug-01, 02:21 PM
from this article:
http://www.nasa.gov/mission_pages/cassini/media/cassini-20080213.html

the wording can be misleading to anyone but an organic chemist.

Saturn's orange moon Titan has hundreds of times more liquid hydrocarbons than all the known oil and natural gas reserves on Earth,

this does not mean that there is oil on titan, rather just hydrocarbons. a hydrocarbon can be as simple as carbon monoxide or as complicated as hydrogenated diamond.



The hydrocarbons rain from the sky, collecting in vast deposits that form lakes and dunes.

oil does not rain from the sky, nor does it collect to make dunes or lakes. liquid ethane on the other hand may fall like rain and or collect like ice and snow to make hydrocarbon dunes and lakes.



"Titan is just covered in carbon-bearing material -- it's a giant factory of organic chemicals," said Lorenz. "This vast carbon inventory is an important window into the geology and climate history of Titan."

organic chemicals do not equate to life rather any chemical with carbon it is considered an organic.


http://en.wikipedia.org/wiki/Organic_chemistry
Organic chemistry is a discipline within chemistry which involves the scientific study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of chemical compounds consisting primarily of carbon and hydrogen,



Dozens of Titan's lakes individually have the equivalent of at least this much energy in the form of methane and ethane.
http://www.nasa.gov/mission_pages/cassini/main/index.html

NASA scientists have concluded that at least one of the large lakes observed on Saturn's moon Titan contains liquid hydrocarbons, and have positively identified the presence of ethane.
http://www.nasa.gov/mission_pages/cassini/media/cassini-20080730.html

Scientists made the discovery using data from an instrument aboard the Cassini spacecraft. The instrument identified chemically different materials based on the way they absorb and reflect infrared light. Before Cassini, scientists thought Titan would have global oceans of methane, ethane and other light hydrocarbons. More than 40 close flybys of Titan by Cassini show no such global oceans exist, but hundreds of dark, lake-like features are present. Until now, it was not known whether these features were liquid or simply dark, solid material.

VanderL
2008-Aug-01, 05:03 PM
It seems on Titan they discarded any solid material because the surface is too smooth...

Yes that's true, for the material to have (almost) no reflectivity it would mean a surface "roughness", or particle size, smaller than the wavelength of 5 micrometer they used to image the surface. Liquid, or very smooth ice would do it, but imo also "very fine dust".

Cheers.

VanderL
2008-Aug-01, 05:21 PM
a hydrocarbon can be as simple as carbon monoxide or as complicated as hydrogenated diamond.

I don't think carbon monoxide (or dioxide) would qualify as a hydrocarbon, it's lacking hydrogen.

Cheers.

publiusr
2008-Aug-01, 10:25 PM
If cheap access to space can be had--perhaps that could be a good fuel source--at least locally...

Grand_Lunar
2008-Aug-01, 11:41 PM
If cheap access to space can be had--perhaps that could be a good fuel source--at least locally...


Coming soon to your local Hess station...