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Pictures of Titan's Lakes

Posted by samzenpus on Wed Jan 03, 2007 08:39 PM
from the in-space-nobody-can-hear-you-fish dept.
sighted writes "For decades, scientists have wondered if the thick orange haze that shrouds Saturn's giant moon Titan hid lakes of liquid methane on the surface, but there was no way to confirm it, until now. The Cassini flyby of July 22, 2006 took these striking images and were released today."
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[+] Cassini Finds Evidence For Ocean Inside Titan 79 comments
Riding with Robots writes "NASA reports that by using data from the Cassini probe's radar, scientists established the locations of 50 unique landmarks on the surface of Saturn's planet-size moon Titan. They then searched for these same lakes, canyons and mountains in the data after subsequent Titan flybys. They found that the features had shifted from their expected positions by up to 30 kilometers. NASA says a systematic displacement of surface features would be difficult to explain unless the moon's icy crust was decoupled from its core by an internal ocean, making it easier for the crust to move. If confirmed, this discovery would add to the growing list of moons in the solar system that are icy on the outside and warm and liquid inside, providing potential habitats. We've previously discussed Titan's hydrocarbon lakes and potential cryovolcano."
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  • by Stephen Tennant (936097) on Wednesday January 03 2007, @08:43PM (#17453122) Journal
    Swimming in liquid farts
  • by suv4x4 (956391) on Wednesday January 03 2007, @08:44PM (#17453134)
    I heard they wander around the Solar system wrecking anything they see.
  • Confirmed? (Score:5, Interesting)

    by Cthefuture (665326) on Wednesday January 03 2007, @08:44PM (#17453138)
    You mean "more evidence suggesting liquid"?

    Hardly proof.
    • Well...they are blue.
    • Re:Confirmed? (Score:4, Informative)

      by Nasarius (593729) on Wednesday January 03 2007, @11:35PM (#17454414)
      They seem fairly certain. From the original Nature article [nature.com]:
      Only two hypotheses are consistent with the radiometric and morphological characteristics of the dark patches: either we are observing liquid-filled lakes on Titan today, or depressions and channels formed in the past have now been infilled by a very low-density deposit that is darker than any observed elsewhere on Titan. The absence of any aeolian features in this area makes low-density, porous, unconsolidated sediments unlikely. This, combined with the morphologic characteristics of the dark patches, leads us to conclude that the dark patches are lakes containing liquid hydrocarbons.
      • Mister Grumpy writes...

        I don't think this is conclusive. As one of the other earlier posts said, they have taken the rough areas and coloured them rock colour, and taken the smooth areas and coloured them water colour. At the edge of these 'lake' features there are intermediate regions which are pretty flat and might be either shallow lake or a flat shore. Or something else completly different.

        The article suggests we will in time know what we have. It is probably not sand because there aren't any dunes.

        • Given two arguments, one expressing two possible explanations for the evidence (the high radar absorption) and discounting one of these due to its unlikelihood, and another one saying "All the evidence for water before turned out to be wrong" the former is much more convincing. Because it is a scientific argument based on evidence. The false colour is irrelevant - the areas of low radar reflection still need an explanation, and "lake" is currently the most likely. You also seem to be under the impression th
        • For the record, liquid water on Mmars hasn't been ruled out. Maybe you missed it, but a few weeks ago they found new channels that appear to have been formed by flowing water.
        • You honestly believe that the Earth is the only place in the Universe that ANY form of matter can be found in a liquid state?

          Wow, the odds that one of the three fundamental states of matter exists on only one of the trillions of rocks in the universe are so poor it actually boggles the mind to contemplate how poor they are. I mean, there are a lot of forms of matter and they turn liquid at different temps. Each of those rocks floating around out there houses lots of different forms of matter and each contai
  • by Anonymous Coward on Wednesday January 03 2007, @08:48PM (#17453164)
    This other location at the Cassini site [nasa.gov], and this older article from the BBC [bbc.co.uk].

    The original article is in the journal Nature [nature.com], but you need a subscription to view it. You can still read the abstract [nature.com], though.
  • I'm surprised this isn't being reported as evidence that cows once lived on Titan.
  • by LarryLong (899387) on Wednesday January 03 2007, @08:50PM (#17453192)
    Maybe the methane came from Uranus? Sorry. :)
    • I believe the phrase from "Flash Bazbo, Space Explorer!" was,

      "Languish in caves of methane ice!"

      But at the moment, I can't even remember where the Flash Bazbo reference came from - maybe it was Firesign Theater.
  • by Eto_Demerzel79 (1011949) on Wednesday January 03 2007, @08:57PM (#17453228)
    I can understand that if we found liquid water elsewhere in the solar system it should make news, but who cares about liquid methane? Afterall Jupiter (http://www.nineplanets.org/jupiter.html [nineplanets.org]) has "exotic" liquid metallic hydrogen and liquid helium. I doubt it is possible to drive any biologically important reactions at the temperatures present on Titan. We simply confirmed that our knowledge of the methane phase diagram is correct. Let me know if they find something useful, like platinum or palladium on Phobos...
    • The reactions that we're used to will obviously not work on Titan, but there's always a (very small) possibility that other forms of life could could evolve in the context of methane seas. If nothing else, a liquid base would allow simple life forms to develop without having to figure out the physics of supporting themselves and move around (as per the way that life is believed to have evolved on earth).

      However, given that just about any chemical process is gonna run rather slow at the kinds of temperatures that exist on Titan we shouldn't expect any life that we find there to be very developed.

      The next obvious step is to send something down to swim in the methane oceans of titan, and see if it gets eaten (or, at least, finds signs of (non)organic life. I don' think that it's that much lower a probability than finding life signs on mars (presuming that we figure out how to look for methane-based life), although it's admittedly a bit more expensive to go to Jupiter than it is to go to Mars.

      • by Nasarius (593729) on Wednesday January 03 2007, @11:54PM (#17454584)
        Ehhh...the average surface temperature of Titan is estimated to be 90 Kelvin, compared to Mars at 210 Kelvin. It seems extremely unlikely that the kinds of chemical reactions necessary for any kind of life could occur.

        The discovery is a "big deal" because we know something about part of our solar system we didn't know before. If you read the articles, part of the discovery is a likely methane rainfall cycle, including "methanifers" (analogous to aquifers). It's fascinating stuff, IMO.
        • Re: (Score:3, Interesting)

          It seems extremely unlikely that the kinds of chemical reactions necessary for any kind of life could occur.

          To me, it seems extremely unlikely that we could give any kind of reliable estimate on how unlikely that is...

          OTOH, all we'd need is a version of Urey-Miller experiment that used (our best guess of) the chemicals and the environment of Titan. Then let it simmer for a time, and see if any promising complex chain forming molecules (such as our amino acids) appeared... I wonder if anybody has attempte

          • OTOH, all we'd need is a version of Urey-Miller experiment that used (our best guess of) the chemicals and the environment of Titan. Then let it simmer for a time, and see if any promising complex chain forming molecules (such as our amino acids) appeared... I wonder if anybody has attempted such and experiment.

            It would definitely be worth a try if you had the glassware laying around but the temperature is still a problem. A more likely source for amino acids in an environment like Titan would probably b

            • amino acids

              If there is life on Titan (or in any Titan-like enviornment elswhere), it is almost certainly based on something different than our amino acid model. As the prior poster said, an expereiment exploring Titanian chemistry would be looking for "promising complex chain forming molecules". He merely cited "(such as our amino acids)" as an illustrative example.

              -
    • I can understand that if we found liquid water elsewhere in the solar system it should make news, but who cares about liquid methane?

      Well, quite apart from biology, it's certainly an interesting comparison in terms of surface features and geology.

      I doubt it is possible to drive any biologically important reactions at the temperatures present on Titan.

      I don't see why not; biology has managed to cope with nearly the entire temperature range over which water is liquid on this planet, so why shouldn't biochemic
    • Re: (Score:3, Interesting)

      I worked on this project as a grad student at Caltech, so I think I may actually have something useful to add. The reason we care is that Titan is the only other body in the solar system to exhibit anything remotely analogous to a hydrological cycle at Earth-like atmospheric pressure, and with observable surface geology. This is useful because it gives us a solar system analog to weather, hydrology, and hydrological weathering; which will benefit us in understanding how our own planet works. The only oth
  • Why did it take them 6 months to release the images?
    • Why did it take them 6 months to release the images?

      Because thats how long it took to false color the image to look like a desert with lakes...
    • Re: (Score:2, Insightful)

      Why did it take them 6 months to release the images?

      2 answers

      Timing really doesn't matter
      How would this information have helped you in July of 2006? It's an interesting fact, but is it really need-to now so much that 6 months... 18 months... 5 years... really matters for 99.9% of the population?

      Verified science, not pre-released junk
      When Scientists release data before they can properly analyze and understand it they can create misunderstandings. The media poorly reports the data, typically just reporting
    • I take it you've never published in a peer-reviewed journal before. The raw images [nasa.gov] were probably available, but it takes some careful analysis of all the data to determine what they were seeing, and you want to have those conclusions verified by fellow scientists before announcing it to the world.
  • by AHuxley (892839) on Wednesday January 03 2007, @09:27PM (#17453418)
  • by mollymoo (202721) on Wednesday January 03 2007, @10:00PM (#17453672) Journal
    Am I the only one who can remember that we put a lander [esa.int] on Titan a good 18 months prior to taking this image? The presence of liquid methane on the surface was confirmed [esa.int] one week later. Nice image, bad caption.
    • If you don't produce a steady stream of non-achievements people might start saying things like "Hey, what did that 3.26 billion dollars (http://saturn.jpl.nasa.gov/faq/mission.cfm) we just gave you for the Cassini project actually accomplish?" This way, you can say "Hey, the Cassini project CONFIRMED the existence of LIQUID which is almost like WATER which is a prerequisite for LIFE which would be the BIGGEST DISCOVERY EVER."
    • by Tablizer (95088) on Wednesday January 03 2007, @11:50PM (#17454546) Homepage Journal
      The lander did *not* detect existing pooled or flowing liquid. The radar evidence appears to be the first evidence of existing pooled/flowing liquid. The lander found plenty of *hints* of erosion typical of that associated with liquid, but it did not detect any active liquid (except maybe methane mist). The area it landed at is often characterized as a "dry lake bed".
  • So, did they finally find the Sirens [amazon.com]?

  • by tinrobot (314936) on Wednesday January 03 2007, @10:36PM (#17453948)
    ...except Minnesota seems way colder that Titan.
    • Re: (Score:2, Insightful)

      ...except Minnesota seems way colder that Titan.

      Don't worry, the Bush administration and Exxon are working hard and diligently to warm it up.
             
    • Not this winter.

      Its 34f (1c) outside and its after 11pm

      Did they spot any fish houses on Titan?
      • you beat me to it... And I even missed out on the fantastic snowfall you guys had just after Christmas. Sigh, at least it's stopped raining in Seattle for the moment.
  • ... have known it for a long time.
  • ... or is the lake near the middle of the picture shaped like a giant fish? No wonder the Face on Mars has vanished, he's gone fishing on Titan!
    • Re: (Score:3, Informative)

      I would imagine the imagine is a long strip like that because the Cassini radar instrument simply flew along in a straight line, therefore only capturing a narrow strip of surveyed data along that straight line (as opposed to getting a large square or circular capture).
    • by stoicio (710327) on Wednesday January 03 2007, @11:41PM (#17454466) Homepage Journal
      "The images are blatantly false-colour. The blue areas meant to potray liquid (making people think of water) but could just as easily be ice or lava flows."

      Actually the intensity of the backscatter data is what is being shown.
      The brightness is logarithmic, therefore anything dark is very smooth
      and anything really bright is very bumpy. Since it is a log scale and
      there is a good idea what kind of backscatter to absorption ratio to expect
      from the synthetic aperture radar for various targets, they can conclude that
      the dark patches are glassy/ice-rink flat.

      They can also conclude that the dark patches could be liquid based on
      change detection, provided they have another series of overlapping data
      to compare. If the glassy areas undulate slightly between images (waves)
      they are probably liquid.

      Having noted this, 500 metres is kind of crappy resolution for
      SAR data. You'd think they'd make a closer flyby or put a better
      instrument onboard. I believe 1 (one) metre resolution SAR was available
      from instruments at the same altitude when cassini was designed.
      NASA just cheaped out.

      • Re: (Score:2, Insightful)

        Having noted this, 500 metres is kind of crappy resolution for
        SAR data. You'd think they'd make a closer flyby or put a better
        instrument onboard. I believe 1 (one) metre resolution SAR was available
        from instruments at the same altitude when cassini was designed.
        NASA just cheaped out.


        Cheaped out? Cassinni is the most expensive unmanned probe ever launched. I saw a to-scale model in a museum. It is a huge chunk of gadgets. Perhaps you could argue they underemphasized radar power at the expense of something
      • Having noted this, 500 metres is kind of crappy resolution for SAR data. You'd think they'd make a closer flyby or put a better instrument onboard. I believe 1 (one) metre resolution SAR was available from instruments at the same altitude when cassini was designed. NASA just cheaped out.

        I have heard Cassini called a Cadillac, Battlestar Galactica,..., but never cheap! Increased spatial resolution won't help you see 50 km diameter lakes any better. The embayment relationships with topography are the same,