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Space Science

Weather Report From Titan 18

Posted by jamie from the no-wizards-or-demons-detected dept.
owillis writes "Space.com is reporting that Titan (moon of Saturn)" (and also the setting of a classic sf trilogy) "has mountains, a sea, and rain showers." Details apparently in the latest issue of Science. Cassini will parachute a probe into its atmosphere in 2004, but unfortunately may not be able to retrieve all its data. Let's hope they figure out a fix in the next four years; Titan's on the short-list of plausible environments in our solar system that could harbor life.
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Weather Report From Titan More

Weather Report From Titan

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  • It's no surprise there, really. NASA send probes to locations likely to be able to harbour life (at least as we know it, Jim).

    You'd be less likely to read this at the end of a spiel about a probe to Mercury, or to the comets, though there is some speculation that cometary debris impacting the Earth in the early stages of its life may have provided the necessary organic chemicals to form carbon-based life.
  • Thanks for some really interesting links - especially that lecture! Now if I hadn't gone out on a limb and accused NASA of hoaxing on Slashdot I would never have found out about them :-) I hadn't realised how recently Wegener's work had been accepted. Nowadays it's even seen as a crucial precondition for the existence of life so it's importance has come a long way (of course it's not essential if you believe nanobacteria can do the work tectonics does!). BTW I'm not afraid of paradigm shifts. Eg. comparable to nanobacteria story: the day I read up on prions many years ago I was converted. It's just that for the Mars thing all of my BS detectors were firing at full power...
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  • You're welcome... it's been a while since I delved into some of that myself, so it was fun to revisit.

    I'll admit to having a minor stake in the Mars stuff, too -- it's just that my prejudices are on the other side. I worked on Pathfinder and will work on some stuff for the '01 missions (and I hope for the later ones!), so I know some of the people and know about some of the players on a professional level, not just what I read in the papers or online. It makes a difference to me.

    That said, I can't really say I'm a fan of NASA's -- it's just that they're the only game in town.

    Thanks for your participation -- it's been fun!

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  • Why's this story not on the main page? I don't have any of those self-censoring preferences. This is an interesting story...someone should type up a forecast for Titan in the form of one of those National Weather Service advisories...you know, the ALL-CAPS ones.
  • If anything is discovered in space these days it seems that someone has to close with "and that means there is a chance of finding life there". I guess that must be the way to get funding these days - starting with Nasa's life bearing asteroid hoax a few years back.

    I know what you mean - they do bang on about it a tad overmuch. Still, Titan does appear to be an interesting candidate for life; it has organics, water, nitrogen - all the right ingredients. The only problem is the temperature - way too cold! Interestingly, it may have liquid water at depth under it's crust. As biologists estimate that ~90% of the Earths biomass is under the Earths surface - bacteria have been found many miles below the surface - this bodes well for the possibility of life on Titan. Conditions 50 miles below the surface of Titan shouldn't be to dissimilar to 50 miles below the surface of Earth.

    Beyond that, there is always the (small) possibilty of some exotic form of life on the surface of Titan. It does appear to have a chemically interesting environment, after all, with it's nitrogen seas and simple organics, but the temperature would impose limitations on life there. Perhaps the low energy would mean that life there would proceed at a much slower pace, compared to fiery hot Earth. But this part is much more unlikely.

    Regarding NASA embellishing the chances of life being there, I agree - they probably are. But who cares? If it gets them more money I support them fully ;-) You just have to take what they say in this area with a pinch of salt.

  • Why's this story not on the main page?

    It is now. How can they put two identical stories up inside a few days?

  • I think that the discovery of a rain cycle on Titan is profound. Even though It is to cold and their is not enough O2 to suport life as we know it, Titan holds one of the best chances for life. But I think the chances of Cassini's probe discovering anything of real value (like life) is small.
  • If anything is discovered in space these days it seems that someone has to close with "and that means there is a chance of finding life there". I guess that must be the way to get funding these days - starting with Nasa's life bearing asteroid hoax a few years back.
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  • Firstly I think it is possible for a hoax to arise without the apparent perpetrators of the hoax being guilty. A more clear cut example is the bible code hoax. The original researcher may have actually had good intentions but the publishers of the paper almost certainly had humourous intentions and so I don't think it would be fair to accuse the original author without knowing more about him. Another thing to point out about the bible code hoax is that no matter how sophisticated the mathematical machinery used to determine statistical significance, no matter how good the authors credentials, most people of reasonable intelligence can determine that the methods used had an error even without looking at the paper. The reason they can do this is that the a priori probability of the bible code hypothesis is true is so small that the chance of error by the researcher is large by comparison. A person of reasonable intelligence can bring all sorts of evidence to bear in making this assessment: the track record of the researchers or other researchers in the field, the track record of the research institution, political or religious biases in the hypotheses and so on. Now the bible code case is more clearcut but I still think that the fossil bearing asteroid case has some similarities. I think that most reasonable people instantly saw the story for what it was. Given the difficulty of assessing paleological evidence, especially evidence this subtle, and given the need for money by NASA at the time it seems like a very reasonable hypothesis that this was not a straightforward press release about some scientific research. The original researchers may have acted in good faith although I believe that it was a very reasonable hypothesis for me to think that the methods were erroneous (this belief seems to have been subsequently borne out). However the press release and paper required an approval process and here I think someone has chosen to give the story an extra spin. In addition the TV networks also gave their extra spin so that the final story was broadcast as if it was pretty definite that fossils of extraterrestrial life had been found. What is more, whoever approved the NASA press release would have know that this is what CNN (and co.) would have reported. In addition this is precisely what NASA wanted reported in order to gain extra publicity (and hence funding) for their Mars projects. So the research was not published as a criticism of the methodology but as high profile evidence for extraterrestrial life. This seems tantamount to a hoax to me.
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  • The alleged fossil remains in a meteorite which is thought to have come from Mars (not an asteroid) were not a hoax Actually I believe they were. I doubt that many (if any) genuine researchers really thought that there was any chance that the formations found on those meteorites were formed by life. I don't believe the meteorites themselves were faked but I have major doubts about the credibility of the researchers. I think it was a bid for more funds - especially given the state of NASA funding at that time.
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  • The nanobacteria subject is fascinating but it's another example of a story that is sometimes associated with extra-terrestrial life - probably to gain publicity. When was the tectonic plate theory accepted? They must have been interesting times. Certainly my father thinks it's a lot of nonsense...
    I think the major flaw in your argument is the "common sense" argument
    I guess it is the weakest point. When weighing up evidence like this I guess we rely on our own experiences and yours are different from mine. Having worked in string theory related stuff for a few years I know what it is like to have a sceptical audience. But I generally tend to make guarded statements like "Assuming string theory is a good model then...". I would never make a statement like the following from the NASA press release:
    METEORITE YIELDS EVIDENCE OF PRIMITIVE LIFE ON EARLY MARS A NASA research team of scientists at the Johnson Space Center and at Stanford University has found evidence that strongly suggests primitive life may have existed on Mars more than 3.6 billion years ago. (My italics)
    Given the doubt over the interpretation of 'nanobacteria' fossils it seems to me that the most reasonable interpretation of part of this 'evidence' is that it is a demonstration that such 'fossils' can be produced by inorganic processes in a sterile environment but of course you don't get big bucks for a finding like this. And as a final note, it's still "meteorite," not "asteroid." Ooops! They don't even look similar.
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  • ...Nasa's life bearing asteroid hoax a few years back...

    Hoax? Life-bearing asteroid? Maybe you'd make more cogent comments if you actually understood what you're talking about. The alleged fossil remains in a meteorite which is thought to have come from Mars (not an asteroid) were not a hoax; there's always the chance the researchers were wrong, but that's far from a hoax.

    And for what it's worth, I don't see a problem with science results which get people interested and excited (the vast majority of those results, at least in astronomy/cosmology/planetary science, don't have to do with "finding life," although extraterrestrial life is a fascinating topic most people pick up on easily). The more people who understand and support scientific endeavor, the better, I say!

    Of course, you might just be trolling, in which case I need some help with this hook...

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  • What does the Bible Code bit have to do with the martian life papers? Certainly Science was serious in its publication of the research, and despite significant controversy over several points, the original researchers have produced a second martian meteorite's contents in support of their original paper.

    As far as I can tell, your argument boils down to:

    1. It doesn't stand up to common sense
    2. You don't happen to believe it
    3. It may have benefited NASA to have other people to believe it
    4. The popular press overenthusiastically pumped it
    5. Therefore it was a hoax.

    Hoax: To deceive or take in by inducing to believe an amusing or mischievous fabrication or fiction; to play upon the credibility of.
    -- The Oxford English Dictionary, 1971 Edition

    There's a thin thread of possibility in the second definition, but it's not clear who was hoaxing whom -- and the intent is certainly in doubt.

    I think the major flaw in your argument is the "common sense" argument: I can think of many examples of research dismissed precisely because of this, which later came to be regarded as fact because of the same reason (continental drift and plate tectonics being one I personally witnessed the change on -- the theory was finally accepted while I was in college, because the evidence became overwhelmingly supportive of it... and now it's "obvious").

    The biggest argument against the "martian fossils" is the argument against nanobacteria... and that one seems to be falling (at least in the case of nanobacteria). While it's more likely than not that the "fossils" were actually something else, that is far from conclusive.

    And as a final note, it's still "meteorite," not "asteroid."

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  • The nanobacteria subject is fascinating but it's another example of a story that is sometimes associated with extra-terrestrial life - probably to gain publicity.

    Hmmmm... interesting take, but I don't follow the logic. Robert Folk [naturalscience.com] ruined his reputation with the original "nannobacteria" proposals, and has only recently been supported somewhat by McKay et al. with the "martian fossils", Kajander [nationalacademies.org] and his collegues with nanobacteria as a cause for kidney stones, Miller-Hjelle [sciencenews.org] and her collegues with nanobacteria as a cause for polycystic kidney disease, Uwi ns [adelaide.edu.au] and her findings on nanobes growing on Triassic and Jurassic sandstones collected from petroleum exploration boreholes offshore Western Australia. The American Society for Microbiology [asmusa.org] has paid serious attention to the controversy, as might be expected. All in all, it's only been recently that "nanobacteria" findings have provided any good publicity at all; mostly, it's been the ruin of the discoverer (in fact, Folk has been described as "coming out of the closet" with his first papers, some 20 years ago -- strong prejudice exists!).

    But now things are changing: there are more findings, and more support for the concept. This might even be a scientific paradigm change... and this was my earlier point, that "common sense" arguments are inherently flawed, because the universe is stranger than we imagine.

    When was the tectonic plate theory accepted? They must have been interesting times. Certainly my father thinks it's a lot of nonsense...

    Alfre d Wegener [britannica.com] proposed the theory in 1912, but it didn't receive much support (in the U.S., at least) until post-WWII. My college geology text has a chapter written in '65, which concludes "Although the subject is now a respectable one in scientific circles of the Northern Hemisphere, the question is still far from settled." (Physical Geology, Leet and Judson, 3rd Edition; Prentice-Hall, NJ, 1965)

    Wilson, a Canadian geologist, brought everything together around '65 with his model of seafloor spreading, which happened to explain the Pacific seafloor magnetic anomalies found in '61 by Raff and Mason (these are reversed-magnetic-polarity stripes, which are embedded in the newly-created seafloor by the Earth's magnetic field, which periodically reverses -- creating alternating stripes which aren't explainable except by tectonic plate theory). This all but cinched it, but it took years for general acceptance to happen -- in '67, my geology prof wasn't yet convinced, and spent a lecture period arguing against it (the students, OTOH, tended to see the light right away, based on the evidence presented). In '68, Pinchon worked out the plate positions, and by the mid-70's, plate tectonic theory was accepted as correct by all but a few lingering die-hards. (It's interesting that similar remnant-field reversals have been discovered on Mars, isn't it?)

    Yes, they were interesting times. Overthrow of "established scientific fact" is always interesting, yet it happens often... that's how science progresses, after all. Only some of the time do the revolutionaries get burned at the stake; the rest of the time, they are merely ridiculed in print and reviled in person.

    I guess it is the weakest point. When weighing up evidence like this I guess we rely on our own experiences and yours are different from mine. Having worked in string theory related stuff for a few years I know what it is like to have a sceptical audience. But I generally tend to make guarded statements like "Assuming string theory is a good model then...". I would never make a statement like the following from the NASA press release:

    METEORITE YIELDS EVIDENCE OF PRIMITIVE LIFE ON EARLY MARS
    A NASA research team of scientists at the Johnson Space Center and at Stanford University has found evidence that strongly suggests primitive life may have existed on Mars more than 3.6 billion years ago. (My italics)

    I guess that's the difference between your opinion and theirs: they figured they had good evidence, and you figure they don't. Dave McKay (of NASA) still sticks pretty much by the findings, and Kathie Thomas-Keprta (Lockheed Martin) very strongly supports them; time will tell who is right. My point is that science never advances without people going out on a limb with their conviction that a new interpretation is correct, rather than the conventional wisdom. This is not the equivalent of perpetrating a hoax! -- even if they are subsequently proven wrong.

    Given the doubt over the interpretation of 'nanobacteria' fossils it seems to me that the most reasonable interpretation of part of this 'evidence' is that it is a demonstration that such 'fossils' can be produced by inorganic processes in a sterile environment but of course you don't get big bucks for a finding like this.

    On the contrary: some people are getting funding to disprove the "martian fossil" findings. The ASM link [asmusa.org] quotes some of them. With any discovery, confirmation or refutation of the findings is critical to its acceptance, and the controversy is the process through which the findings on all sides are integrated by the scientific community; Mari on Anderson's lecture [monash.edu.au] is a good summary of this particular controversy, and concludes (correctly, in my opinion) "The main drawback to this story is the media focus on such sensational news. Media hype may increase public awareness of science, but the problem is that the complexities get lost in the glare of the spotlights." Her last couple of sections are well worth reading.

    I think the jury's still out, and I think you're prematurely making up your mind. But, hey, it's your mind -- do with it what you will.

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  • I'm liking everything about the article, but what I really enjoyed was that very cool was that artists rendition of the atmosphere. The one where you can see the clouds overhead and in the distance is Saturn peeking over the horizon. I woud pay for that to be framed and hung on my wall!
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    Vote Homer Simpson for President!

  • Re:A bit of a routine (Score:3)

    by tesserae ( 156984 ) on Saturday October 21, 2000 @09:26AM (#688503)
    I doubt that many (if any) genuine researchers really thought that there was any chance that the formations found on those meteorites were formed by life. I don't believe the meteorites themselves were faked but I have major doubts about the credibility of the researchers.

    Believe what you will. The truth is that the researchers involved are all credible, with decent publishing histories behind them. And the initial paper [sciencemag.org] was published in Science -- not exactly a journal known for accepting hoaxes, although they do like to be the first to publish controversial papers (and this was no doubt a controversial paper). But "controversial" != "hoax"... and the stature of some of the researchers involved is such that they'd be fools to perpetrate a hoax and destroy their careers.

    I won't deny that NASA took advantage of the paper, but calling it a hoax is dangerously close to libeling some good researchers (only some of whom work for NASA). You might want to reconsider your statement?

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  • More detail on what's happened (Score:4)

    by tesserae ( 156984 ) on Friday October 20, 2000 @03:14PM (#688504)
    From the space.com article, discussing the newfound problem with the Cassini probe's data reception:

    "The problem is in the receiver: the bandwidth within it is not as wide as the design called for," said Bob Mitchell, the Cassini program manager at NASA's Jet Propulsion Laboratory.

    I don't know if that's JPLese and he's not completely describing the problem, or if space.com didn't understand it, although they hint at the cause on the second page. What happened is this:

    When the receiver was designed, the Doppler shift in the probe's signal in the operational mode wasn't accounted for; it worked fine on the bench, with no delta-V, but the Doppler shift at Titan will push the sidebands (where the data is being transmitted) out of the receiver's range. Cassini will be going like the proverbial bat out of hell as it passes Titan and drops the probe, and the Doppler shift will be substantial.

    Technically, this is "not as wide as the design called for," I guess, and it's not clear whether it's lack of a proper specification or lack of attention to detail (and I really can't guess which, since I never worked on that project -- I just talked this week to some of those who did).

    The article also mentions slowing Cassini down for the encounter, but fails to mention that doing such a thing will screw much of the science opportunity: the subsequent gravity-whip maneuvers depend on the initial velocity and positioning, and losing that will prolong the mission, pushing much of the science past the design life of the spacecraft. Not to mention they'll have to completely recalculate the entire circum-Saturn trajectory, a task for which there's no funding.

    It's a real bummer: this might be the last of the "big" planetary-science missions for a long time (everything else is "faster-better-cheaper", and we've seen some of the downsides there), and one of the most exciting parts is endangered -- so much that they're considering crippling a major fraction of the rest of the mission just to recover it.

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