Probable lakes on Titan

3488 · Nov 23, 2006

Hi to both Jon Clarke & mikeemmert. Thank you both for your answers to my points. It is intriguing that Hyperion has this Tan colour, where as Tehtys, Mimas, etc tend to be almost montone (Tethys is slightly yellowish if memory serves me well & Dione a dull dark reddish grey). Do not mis understand me, the Saturn system is fascinating beyond belief, but I do find some of the moons pretty dull & boring (particularly Rhea, Tethys & Mimas) as compared to lets say Titan, Iapetus & Enceladus in the Saturn system, the Jovian Galileans, Miranda, Ariel, Titania & Oberon in the Uranus system & obviously Neptune's Triton & lets face it, our own moon is a pretty interesting world. The large amount of crystalline ice detected on Charon is also reason to think that more than just impact cratering has happened there also, but must await New Horizons arrival. I like geologically active worlds or those that have shown evidence of such activity in the past, hence my increased fascination of the Jupiter system. Really what should have happened, is for Cassini or Galileo type craft in orbit around ALL four of the giant planets & perhaps a New Horizon's type orbiter around Pluto, Eris & Sedna as well, but the funding would never have been approved. Thanks Jon for your answers concerning Titan. It is a shame that only about 2% of the surface has been radar imaged. The lack of a global magnetosphere around Titan I found was surprising considering the size & Mass of Titan is only slightly inferior to Jupiter's Ganymede. I know that this does not rule out a metal core, but it does rule out convection within it if I am correct in saying. As you say, perhaps not 'ice ages' but I do see evidence of climate change on Titan & I think Titan does show some evidence of being colder in the past with channels & run off features seen closer to the Titanian tropics. A fascinating world indeed. I hope we get to see <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

JonClarke · Nov 23, 2006

Hi Andrew It's all a matter of taste I guess. I find Titan more interesting than all the Galileans put together. Titan is more, shall we say, atmospheric? <img src="/images/icons/smile.gif" /> Interesting idea about the Huygens test bed. I don't know if it could be made space ready though, and what sort of support it would need. You would have to build a carrier and relay spacecraft. It might be cheaper and better to build a lander specifically design for what we known is there, rather than trying to cover all the possibilities, as Huygens was. I asked Steve Squyres last year about refurbishing the third MER, and his opinion was it was too clapped out from ground testing to be worthwhile. But i would like to see a Titan polar orbiter and somekind of rover in my lifetime - an aerobot perhaps. Cheers Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

alokmohan · Nov 24, 2006

I feel we give more imporance to titan because of historical reasons.We should not go for a costly expedition for titan.At least our dream of a life form is vanished.

3488 · Nov 24, 2006

Hi Jon. I see your point about Titan. I find it very interesting to see that Ganymede, Titan & Callisto very similar in size & particularly Ganymede & Titan in mass (Callisto being somewhat less dense) are very different, both atmospherically & also geologically. Ganymede clearly has had something happen to it in the past, perhaps its orbit changed temporarily into a more elliptical one, & kick started geological activity as the tides varied (like Io but on a smaller scale). Also Ganymede appears to have a molten core that is generating a magnetosphere of its own & Galileo tracking revealed Ganymede to be highly differentiated, perhaps even having a double layered core like the Earth (the only other object suspected in the solar system to have one). Also Ganymede may not have always shown the same face towards Jupiter, it may have rotated at some point (we now know this has happened to Enceladus & quite possibly to Miranda & Europa) suggested by the cratering density (the leading hemisphere should be the most cratered as it will be travelling head on), with Ganymede, it certainly appears to be the north polar region the most hit!! It will be very good to see similar data about Titan & see if there is any evidence that Titan has rotated in the past. A shame about the third MER C being too knackered to be given a mission. I still wonder if it could be fixed, it would still be quicker than building a new one!! As for the second Huygens, it was just an idea, seeing as it was hardware that was in existence & could potentially be used. I like the idea of the Titan orbiter with Radar & other instrumentation. I am sure that it will happen at some point, but first we will still get much new information from Cassini. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

webscientist · Nov 24, 2006

Yes, a polar orbiter to identify those probable pseudo lakes. I imagine red lakes, very exotic lakes. In the following radar image of Titan, two terrestrial lakes, taken from Google Earth, have been added. Will you be able to identify them and to say where they come from? www.titanexploration.com

mikeemmert · Nov 24, 2006

In this, my last post as a star, I would like to delve into the question of life on Titan. This has intrigued me, and I think a lot of the support for Cassinni through the years has derived from the idea that some dim light may possibly be shed on life as we don't know it. Life on Earth is a consequence of chemistry and evolution. The chemistry on Titan is different. Could it have produced self-replicating, evolving organisms? First I would like to bring up this link, first presented on this thread by JonClarke (thank you, Jon): "Oil hasn't been discovered on Titan, but Roger Clark spoke next about identifying three spectral absorption features of hydrocarbons in the dark material (a hydrocarbon, by the way, is just a 25-cent word for a compound containing carbon and hydrogen). One of these spectral features at 5.05 microns is uniquely attributable to benzene. Another feature is attributed to either methane or ethane, and there is a 5.01-micron feature that remains unidentified. Another puzzle is the non-detection of acetylene, which was expected to be more abundant than benzene. [Random fact: acetylene is a gas commonly used in welding.] The lack of acetylene may indicate that it's only transiently present on Titan. Hmm...there is benzene, which melts at a torrid +5.5 degrees centigrade, higher than water, even. But acetylene and diacetylene are not found on the surface. We find instead benzene. Where is the acetylene? It's freezing point is -80.8 degrees centigrade so it should be seen on the surface, but it's not. If acetylene is heated to 400 degrees centigrade, it can form benzene. But those kinds of tempera

JonClarke · Nov 24, 2006

This goes well beyond my competence! Silyene, what can you say about this? Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

JonClarke · Nov 24, 2006

Hi Andrew Maybe the basic systems of the Huygens backup could be used, with some original instruments and some new ones to deal with Titan as is, and not as it might be. Plus the big hurdle would be the carrier spacecraft. And of course, where would you land it? <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

silylene old · Nov 25, 2006

Acetylene is quite reactive with oxidants, at least at room temperature. I am not that familiar with its reactions at such frigid temperatures, but I expect that given enough time, it will be consumed if there are any oxidizing agents. One very interesting (fun to consider, but unlikely) consideration is the polymerization of acetylene to make polyacetylene, which requires certain alkyl metal catalysts, such as dialkyl aluminumchloride. Polyacetylene is a silver colored organic polymer (which looks just like metal), and becomes quite electrically conductive with a slight amount of doping with a halogen such as iodine. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center">- - - - - - - - - - - - - - - - - - - - - - </div><div class="Discussion_UserSignature" align="center">I really, really, really miss the "first unread post" function. </div> </div>

mikeemmert · Nov 25, 2006

I believe Titan is a reducing environment with little oxygen except tied up in water. I ran into polyacetylene in the research for the last post. Hmm...shimmering, silvery aliens? With natural electronic computers for brains? Nahh... I wouldn't go that far... <img src="/images/icons/crazy.gif" /> ... But one aside I ran into was that polyaceylene is a major component of melanin, the skin pigment. Some species have nothing else in their brand of melanin other than polymerized acetylene. "Broadly, melanin is any of the polyacetylene, polyaniline, and polypyrrole "blacks" and "browns" or their mixed copolymers. The most common form of biological melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. In contrast, some fungal melanin is polyacetylene black. Melanin exists in the plant, animal and protista kingdoms, where it serves as a pigment. The presence of melanin in the archaea and bacteria kingdoms is an issue of ongoing debate amongst researchers in the field". The melanin link posted above must have been written by a medical doctor. He treats the subject technically and intensively, especially since melanin seems to have something to do with melanoma, the skin cancer. There is black melanin, brown melanin, and red melanin that causes red hair. This may very well be what the unidentified substance on Titan is. Unfortunately, this varied pigment is unlikely to be all that similar to Earth-based biological melanin, whether or not it indicates life or some other process. Melanin being a highly varied compound, it is unlikely that remote sensing will shed much light on it. stevehw33 is right, we'll have to land another probe.

silylene old · Nov 25, 2006

Some species have nothing else in their brand of melanin other than polymerized acetylene. Interesting, I had not heard that before and looked it up, since I was highly skeptical! I found many 'popular' references (such as Wikipedia and its many plagarizers) which state that "some fungal melanins are pure polyacetylene". Pure polyacetylene is a high MW silvery polymer, and insoluble in just about every non-toxic solvent, and is certainly not conducive to being found in biological cells! Was the phrase 'polyacetylene' being used as some misunderstood scientific buzzword, or was polyacetylene actually being used in a biological system? So I did some googling, and found the following references to "polyacetylene"-like compounds: 1. From tea leaves , Bioassay-guided fractionation led to isolation of one new and one known polyacetylenes, 1,2-dihydroxytrideca-5,7,9,11-tetrayne (1) and 1,3-dihydroxy-6(E)- tetradecene-8,10,12-triyne (2), respectively, from the EA fraction. 2. From cranberry-like plants, Acetylene compounds and flavonoids from plants traditionally used in Brazil for treatment of malaria fever and liver disorders are associated with antimalarial activity. Estevez-Braun et al. isolated a C17 polyacetylene compound from Bupleurum salicifolium, a plant native to the Canary Islands. The compound, 8S-heptadeca-2(Z),9(Z)-diene-4, 6-diyne-1, 8-diol, was inhibitory to S. aureus and B. subtilis. 3. From a fungus called Bidens compounds such as 3(R)-deca-4,6,8-triyne-1,3-diol 1-O-beta-D-glucopyranoside. It seems that a biochemist's definition of 'polyacetylene' and a chemist's definition of polyacetylene differ completely (w <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center">- - - - - - - - - - - - - - - - - - - - - - </div><div class="Discussion_UserSignature" align="center">I really, really, really miss the "first unread post" function. </div> </div>

mikeemmert · Nov 25, 2006

<blockquote>In reply to:<hr /> Leave it to the biologists to corrupt chemical nomenclature, to muck up interdisciplenary understanding (I have seen it before).... <hr /></blockquote>Ouch! It hurts reading this! <img src="/images/icons/shocked.gif" /> My ears perked up when I ran into "melanin" because it is a photochemically reacting compound, thus at least potentially could be the basis for some kind of photosynthesis. You wouldn't happen to know - not being a biochemist, but the other kind of chemist - exactly how melanin protects from ultraviolet, would you? I'm at a complete loss here. Here's a question from ignorance <img src="/images/icons/blush.gif" /> if there is a triple bond within a polymer, will this show up in a spectral reading? That doesn't happen, does it? The energy is spread out along the entire chain? What is the difference between the bond energy of acetylene and benzene? Is this a potential pathway for the release of energy stored from ultraviolet procduction of acetylene and diacetylene? How about the in-between double bond? Is the potential there for a biochemical pathway? I'm just asking if the potential is there, not whether in your opinion there actually is such a pathway.

silylene old · Nov 26, 2006

Here's a question from ignorance if there is a triple bond within a polymer, will this show up in a spectral reading? That doesn't happen, does it? The energy is spread out along the entire chain? If the double bonds or triple bonds are conjugated (i.e. the p-orbitals of the C atoms are in the correct configuration to overlap to form a contiguous series of pi-bonds), then the electronic transition between the "HOMO" (highest occupied molecular orbital) and the "LUMO" (lowest unoccupied molecular orbital) is reduced....in other words, the photon energy required to excite an electron into the LUMO orbital is less...which means that the wavelength of this absorption is increased (red shifted), since longer wavelength photons carry less energy. What all this means is that molecules with conjugated bonds (double or triple) have absorption bands which are red-shifted, and they will absorb lower-energy, longer wavelength photons. Melanins have two or three conjugated triple bonds, and this gives enough electronic conjugation that these molecules will absorb lower-energy, longer wavelength photons, and hence melanins are dye molecules with a darker color in the visible wavelengths. After absorption of the photon, the molecule then loses the excess energy by vibrating - - giving off heat. Very harmless! Double and triple bonds can be differentiated in infrared spectroscopy. In UV-Vis spectrsocopy, they both look rather similar. What is the difference between the bond energy of acetylene and benzene? Benzene has more energy stored in it since it has more total bonds (6 atoms vs 2 atoms). But, bond-for bond, a triple bond stores more energy than a double bond. Is the potential there for a biochemical pathway? I'm just asking if the potential is there, not whether in your opinion there actually is such a pathway. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center">- - - - - - - - - - - - - - - - - - - - - - </div><div class="Discussion_UserSignature" align="center">I really, really, really miss the "first unread post" function. </div> </div>

mikeemmert · Nov 26, 2006

Thank you for your post, silylene. I take it from your comments that when they said, "no acetylene" they meant "no triple bonds", and that they can know this, it's not a guess.<blockquote>In reply to:<hr />In UV-Vis spectrsocopy, they both look rather similar.<hr /></blockquote>Which, I suppose, is why the Huygens surface shots look black&white. The latest public photo from ground level look orange, which was explained in the caption as depicting actual lighting conditions. I noticed some brown in that shot. I hope some of the trick photographers get wind of this thread. While "actual color" (and these artists have explained that claims to historical accuracy are subject to {sometimes} fierce debate) is interesting, I think the human mind can more easily interpret scenes better with some artistic license. Earth is not orange. Unfortunately, what you just said above is that we can't expect a lot of insight from such a process. I have applied for image self approval and have not gotten any response yet from Uplink. I have never manipulated the color on a photo and don't know how. The most photos I published were in Free Space and I didn't want to be accused of manipulating photos for political purposes. It was pointed out there that various political entities had done just that. */Free Space rant deleted by mikeemmert/*<blockquote>In reply to:<hr />Organic molecules with double or triple bonds store a lot of energy. This would be an excellent fuel source for a biological system, if the biochemical system has an ability to oxidize this fuel.<hr /></blockquote>Oxidation is the ability to accept electrons. Interesting trivia: the fuel for an atomic fireball is oxygen! The oxidizer is nitric oxide produced by the explosion. I found it interesting that the aerosol pyrolyzer on Huygens detected cyanide. Unfortunately a pyrolyzer takes big molecules and makes them into littl

webscientist · Nov 27, 2006

Thanks JonClarke for this thread which is reaching a very high level. I also strongly believe that those dark patches in Titan's northern latitudes have been carved by a liquid: methane, ethane, acetylene or something else, why not ( Nitrogen...). I note a lot a clues that are consistent with that hypothesis. I go back to the modified radar image I posted: the shape of the two terrestrial lakes presents striking similarities with the Titan branching network ( top left ).We can even determine the sense of the stream as you can see in the following illustration. Contrary to the Titan branching network, both terrestrial lakes are artificial constructions: they are linked to a dam ( right rim of the lakes ). The streams run westward while the Titan stream is likely eastward which is the sense of dominant winds on Titan ( coincidence?). www.titanexploration.com

3488 · Nov 27, 2006

Hi all, Jon, thanks for your answer. I see your point about the potential second Huygens. I think it would be best to build anew in this light. I just thought as a test bed exists, could for only a modest sum be sent to Titan from Earth, with a cruise stage, & use the Cassini orbiter as the relay, before it dies?? In hindsight, this might not work. I did hear about a potential balloon that could land several times, taking measurements & images from both ground level & high altitude. When the balloon has run out of fuel, the lander could be seperated to continue a static mission. Has anything else come about this?? The radar images do show lakes within the Titanian arctic do they not?? I thought that was the concensus, being smooth with little echo return. Of course the radar cannot tell us what the chemical compostion is!! In December 2009, it will be the Spring Equinox in the northern hemispheres of Saturn & Titan (& of the other major regular Saturn moons too, except Iapetus as the rotational axis points in a different direction)!! If Cassini is still operating then, perhaps the IR imager could take a spectrum (also it will be interesting to see if the far northern latitudes on Saturn turn yellow from the current blue as the northern hemisphere slowly warms)!! Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

JonClarke · Nov 28, 2006

Hi Andrew Dense atmosphere, low gravity, combustible atmosphere, I think Titan will be heaven for aircraft designers of all types. I have seen various blimp ideas for Titan. Lift fans and lift rotors would also be very attractive. See: http://www.lpi.usra.edu/meetings/outerplanets2001/pdf/4022.pdf http://www.lpl.arizona.edu/~rlorenz/IEEE.pdf http://www.aas.org/decadal/Uploads/000001-000000-jbis.pdf Cheers Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

3488 · Nov 29, 2006

Cheers Jon, very interesting. Do we know if the 12 December encounter is a radar pass? According to Celestia, Cassini is passing Titan on the night side, near the equator. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

JonClarke · Nov 29, 2006

Hi Andew The only comment I can find is that T21 may at a less than optimum altitude. A night side pass should allow for radar observations and occultation studies. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

JonClarke · Nov 29, 2006

Regarding earlier questions about instrument callibration, both instruments that observe the surface are callibrated. VIMS is calibrated using the Sun. http://vims.artov.rm.cnr.it/data/calib.html The radar is calibrated using special calibration signals. http://saturn.jpl.nasa.gov/spacecraft/inst-cassini-radar-details.cfm Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

telfrow · Jan 3, 2007

Titan Has Liquid Lakes, Scientists Report in Nature Link to full story Scientists report definitive evidence of the presence of lakes filled with liquid methane on Saturn's moon Titan in this week's journal Nature cover story. Radar imaging data from a July 22, 2006, flyby provide convincing evidence for large bodies of liquid on Titan today. A new false-color radar view gives a taste of what Cassini saw. Some highlights of the article follow below. Lake Characteristics: -Radar-dark patches are interpreted as lakes based on their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. -Radar-dark surfaces are smooth and most likely liquid, rock, ice or organics. More than 75 radar-dark patches or lakes were seen, ranging from 3 kilometers (1.8 miles) to more than 70 kilometers (43 miles) across. -Some lakes appear partly dry, while others seem liquid-filled. Some of the partly filled lakes may never have filled fully, or may have partly evaporated at some point in the past. The dry lakes have margins or rims and a radar brightness similar to the rest of the surrounding terrain, making them appear devoid of liquid. -The varying states of how full the lakes are suggest that lakes in this region of Titan might be temporary on some unknown timescale. -Approximately 15 of the dark patches seem filled and show no clear evidence of erosion. These dark patches resemble terrestrial lakes confined within impact basins (for example, Clearwater Lakes in Canada) or within volcanic calderas (for example, Crater Lake, Oregon). The nest-like nature of these lakes and their limited range of sizes make it unlikely that they originated from an impact. A volcanic origin for the depressions is possible, given th <div class="Discussion_UserSignature"> Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild. - Tennyson </div>

MeteorWayne · Jan 3, 2007

Some people are not going to be happy, OR accept the evidence. I can see I'll be looking forward to the mail this week! <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

brellis · Jan 3, 2007

Boots on the ground, General! Until I feel the cold methane waves lapping at my feet, I'm withholding judgment, hehe. <div class="Discussion_UserSignature"> I'm a recovering optimist - things could be better. </div>

telfrow · Jan 3, 2007

<img src="/images/icons/laugh.gif" /> <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild. - Tennyson </div>

JonClarke · Jan 3, 2007

Drat! It will be another 2 weeks before I am back at work and can access Nature on line! Grrrr! But is sounds interesting all the same. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

Probable lakes on Titan

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