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Space Science

The Fountains of Enceladus 118

Posted by ScuttleMonkey from the photo-goodness dept.
EccentricAnomaly writes "Cassini has observed fountain-like plumes from the warm fractures near Enceladus' south pole. This confirms what had been suspected from an image taken last January. And seems to point to these cryo-volcanoes as being the primary source of Saturn's E-ring. There are also more images available from Cassini's raw images archive."
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The Fountains of Enceladus More

The Fountains of Enceladus

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  • very intriguing (Score:4, Insightful)

    by iggymanz ( 596061 ) on Monday November 28, 2005 @07:35PM (#14134044)
    let's not launch a couple manned space missions and instead take the billions saved to plop a robot probe in one of these volcanoes to look for life in the underlying water layer.
    • We don't need to look for life in the volcanoes. These photos confirm what I've suspected all along: They're out there and they're ice fishing!

    • Re:very intriguing (Score:4, Informative)

      by IAmTheDave ( 746256 ) <basenamedave-sdNO@SPAMyahoo.com> on Monday November 28, 2005 @08:06PM (#14134213) Homepage Journal
      ...to plop a robot probe...

      Oh sure, 'cause that's worked rather flawlessly in the past. Just ploppin them down.

    • No thanks.

      How about we use the same money to save whats left of our planet? AFAIK, we have at least a few intelligent lifeforms here.
      • You can do that for a few million dollars? If that's true you really do deserve a grant.

          I could trivially name fifty things which cost more than a space probe and contribute less.

      • No thanks.

        How about we use the same money to save whats left of our planet? AFAIK, we have at least a few intelligent lifeforms here.

        This arguement is counter productive we already spend resources int hat direction. The amoutn we actually spend on space exploration and science is minicule compared to other ventures such as the military.

      • Re:very intriguing (Score:1, Interesting)

        by Anonymous Coward
        There's nothing wrong with this planet.

        Let me try to explain.

        The generally accepted theory of the extinction of the dinosaurs is, of course, one in which the planet is impacted by a 30K feet long asteriod. The impact affected the entire globe, causing changes in the landscape, global firestorms, dust high in the atmosphere blocking out the sun, and mass extinction. In short, it "broke" the planet in a big way.

        Despite all that, the planet is still here. In fact, I'd say it even worked out pretty good for
        • well, the planet is more than 99.9999% rock and metal. But "hurting the planet" usually refers to harming that thin scum on it's outsides that we call "the biosphere"....quite possible we could permanently ruin that if we really tried.
      • Ok, I'll bite. How? What's wrong with "what's left of this planet" that could be fixed for a few million dollars? Could you end world hunger? Cure AIDS? Prevent the inevitable extinction (again) of most life on the planet?

    • No manned space missions == less funding (Score:5, Insightful)

      by David Hume ( 200499 ) on Monday November 28, 2005 @09:50PM (#14134687) Homepage
      let's not launch a couple manned space missions and instead take the billions saved to plop a robot probe in one of these volcanoes to look for life in the underlying water layer.
      I think you may be ignoring another effect of no (or to be more precise and fair to you, fewer) manned missions over time -- i.e., less political support for space exploration and lower funding.

      People will support a certain amount of funding for heroism, Star Trek, to boldly go... or to at least feel we are on the way there. They will pay far less to support inanimate objects in space. Boring... for most people.

      Perhaps, in the short run, the savings from eliminating, or limiting, manned flights would be greater than the loss of funding. I suspect over the long run it would be death.
       

      • Re:No manned space missions == less funding (Score:4, Interesting)

        by iggymanz ( 596061 ) on Monday November 28, 2005 @11:54PM (#14135311)
        really?, I think the robotic exploration of mars and outer planets every bit as exciting as moon walks were. And no chance of astronauts being vaporized. Maybe we should put manned space missions on hold until we develop craft that aren't world's largest chemical bombs with low-end tactical nuclear yields. There's no scientific achievement that's been done by man in space that couldn't be done faster, better, cheaper, and safer by machine.
        • Not that any of the parents post isn't true, it is, but I think it's a pretty safe bet that there's a lot of people on here (me included) that would just about sell our souls to be able to take a ride on one of those bombs, risks be damned. Joe Sixpack isn't intrested in scientific discovery (I know, I live with a bunch of them). They like adventure (shuttle missions or especially something like Apollo) or pretty pictures that look nice on their desktop. And as to the "faster, better cheaper", it seems like

        • I think the robotic exploration of mars and outer planets every bit as exciting as moon walks were.

          The problem is that it is also utterly useless. Sending probes to Mars has no chance of giving any results that would get us closer to having cheap interplanetary travel. We, as a species, must expand. On Earth every habitable environment has been inhabited. We either expand to space or we stagnate. We need a new frontier; space is the only place left.

          In my opinion, we need to concentrate resources into

          • Putting people in tin cans is useless to the long-term goal of colonizing space. What is really needed to go in that direction is robots, robots, robots. Robots to mine asteroids and moon, robots to assemble and walk space elavators, robots to survey and explore for resources and for the REALLY long term build huge telescopes in space so we can identify candidates for habitable planets.

            Glad you brought up long-term effects of weightlessness. Let's also wait until we can build large, spinnable craft t
      • I don't completly agree with that, although there's some truth in it, some unmanned missions make the NASA popular, just look at Hubble Space Telescope, although we can argue that it needs manned missions to fix it, the reason why it's so popular is because it makes such nice images, nice popular images that are hardly even usefull.

        In the example of the HST, it's popularity is due to the public communication around it, not because some men go there to rescue it. In other words, manned missions are not requi

  • as the bard Homer would say: (Score:5, Funny)

    by jspoon ( 585173 ) on Monday November 28, 2005 @07:37PM (#14134055)
    Mmmmmm. Fountains of enchiladas.

  • Amateur Analysis (Score:5, Interesting)

    by EccentricAnomaly ( 451326 ) on Monday November 28, 2005 @07:40PM (#14134065) Homepage
    Since Cassini is so slow in releasing results to the general public, you may be interested in this discussion (including some neat image processing) by amateur astronomers: http://www.unmannedspaceflight.com/index.php?showt opic=1729 [unmannedspaceflight.com] This site usually get a jump on the official Cassini channels of about a week.

    • Re:Amateur Analysis (Score:5, Informative)

      by CheshireCatCO ( 185193 ) on Monday November 28, 2005 @07:58PM (#14134173) Homepage
      Pardon me, but Cassin is NOT slow to release its results. Some of these images came down in the past two *days*. And I'd like to note that they got posted to the JPL website almost instantly. That's actually rather unfair to us, since there's usually a one *year* propriatary period where the data are the kept by the people who put the work into designing, building, and operating the instrument. Thanks to JPL, anybody off the street can get up at 3 AM to grab the images of the website before we've woken up that morning, let alone gotten our coffees in.

      Of course, amateurs are not bound be either rules for peer-review to get published or by NASA's process for press-releases, so their results will often appear on the web sooner than the offical findings. But they should also be treated with a certain measure of skepticism. Also, remember that the images that JPL posts aren't scientific quality.

      • Re:Amateur Analysis (Score:2, Insightful)

        by msauve ( 701917 )

        That's actually rather unfair to us, since there's usually a one *year* propriatary period where the data are the kept by the people who put the work into designing, building, and operating the instrument. Thanks to JPL, anybody off the street can get up at 3 AM to grab the images of the website before we've woken up that morning,

        What? Give the people who actually paid for the data equal access, why the nerve!

        Maybe if you (and I'm assuming you're somehow earning money by using this data) paid for it instead

        • His point, dipshit, is that any asshat can start spewing bullshit before people that actually know WTF they're talking about have a chance to scientifically verify the data in the proper way. It IS quite unfair, but then again fairness has never been a part of correctness.
          • Wow. Just wow. I golf clap at the elevation of the fucking debate here.
            And guess what, I'm going to be the one who'll be motherfucking modded troll or flamebait because I actually dared criticize the cock-smokers who hand out their fucking mod points

            That's five insults, mod me +5 insightful!
        • Yeah, why should the people who didn't devote years of their lives and continue to devote 60-80 hours a week running the instrument be at a disadvantage? Reminds of that story about the chicken who wants to bake bread and no one will help her, but everyone wants to eat it afterward.

          The taxpayers have every right to the data. The question is, should they get it at the same time as the people who have spent years making sure that the data arrive at all? By comparison, are you going to insist that the data

          • If you want to head down this road, you're not going to get data at all. Scienists take a severe hit to their careers to PI an instrument like this. If they didn't get something back, like a period where they could have first pass at making discoveries in the data, you'd be hard-pressed to get anyone to build the things.

            Well, that's pure conjecture, as those people actually get paid for their work (with the possible exception of some grad students), and without taxpayer funding, they wouldn't have their car

            • Sure it's conjecture, but it's based on the data. If you poured several years of your life into building an instrument and weren't able to be the first to do anything with the data (or, more likely, were one of the *last*), you wouldn't do it. Academia is pretty viscious. You have be publishing or you're not going to get the job you want (or lose the one you have).

              By your logic, government contractors would build spacecraft/bridges/ships/whatever at cost with no mark-up. Because, you know, they're getti
            • "Buncha people on the dole" I hope you're kidding... (?) Right, so being employed on a government project is akin to shamelessly recieving unemployment? (He/She has to be joking... Gotta be...) You're assuming that getting paid for doing a job is reward enough. I think his point is that when you've built a career, there's a lot at stake when you make any career decision. Choosing to work on a project must confer *some* fringe benefit, other than bragging rights and being able to pay your bills. Shoul

              • I think most folks don't mind throwing a *couple* of bucks a year down the IRS rabbit hole so that we can have a NASA, an NSF, a DOE, etc.

                Let me be clear, I'm not making a blanket criticism of all research - some is imminently useful to society. I might draw the line beyond earth-orbital (satcom, GPS) and solar (don't take down my power/TV). I, and I believe the vast majority of taxpayers, can't see any real benefit from studying fountains in the distant solar system, however.

                To your point, give people the

                • Wow, so much of that was... wrong. It's hard to know where to start.

                  "I hazard to say that most scientific advancement, even "pure" science has come as a result of private investment - DaVinci, Newton, Gallileo were all funded by private patrons."

                  Actually, for the most part these guys were paid by the people in control of the governments. The distinction between "private" and "public" is therefore unclear. When Galileo was paid to be the court astronomer in Florence, which is that? (How about when he was
                  • I'll note your lack of response in regard to the willingness of the general public to support scientific research as acceptance of my view. But if you don't, and still feel most people would be willing to fund extraterrestrial science, feel free to support replacement of government funding with voluntary funding, through some organization such as The Planetary Society http://www.planetary.org/home/ [planetary.org]. If you're correct, there's no risk.

                    for the most part these guys were paid by the people in control of the

          • Yeah, why should the people who didn't devote years of their lives and continue to devote 60-80 hours a week running the instrument be at a disadvantage?

            What would that disadvantage be? Missing the opportunity to be the first to write about something? Do you really believe that you are entitled to that?

            Since you are the one who knows WTF you are talking about, why would anyone care what joe shmo who's up at 3AM thinks about the pictures? Obviously he's too stupid to make any interesting discoveries anywa
            • "What would that disadvantage be? Missing the opportunity to be the first to write about something? Do you really believe that you are entitled to that?"

              Careers are made or broken based on getting things published first. From a PR standpoint, the amateur community only ruins press-releases. Which is a drag, but not seriously problematic. (Although that can be a damper on a career, too. Getting into the mainstream media for a new result helps when hunting for jobs.) But other scientists are also out ther
              • Why do you think that the general public is entitled to beat the scientists to the results? Are you also prepared to argue that you're entitled to a ride on Air Force One or to look at the CIA's current data?

                I don't think anyone's entitled to much of anything, except I think that the taxpayers are entitled to the output of projects they fund. Of course this means that the taxpayers can choose to fund things like the CIA that won't give direct access to all data. Next project you want funded, why don't you
                • Wow, you're going out of your way to avoid getting the point, aren't you?

                  I've already established why being the first to make a press release or to publish is important. You haven't counter-argued that, just avoided it.

                  The "scare resource" argument doesn't really hold up, either. The data are also scarce. Sure, you can reproduce it easily, but the bits are finite and the amount of information in the data is finite. Giving anyone and everyone equal access at the word "go" means that the people who are sp
                  • I get the point just fine.

                    I've already established why being the first to make a press release or to publish is important. You haven't counter-argued that, just avoided it.

                    You've established why you being the first to publish is important to you, you haven't established that it is important to me. Your assertion that open access to data will drive scientists out of research isn't supported by the only data point I have access to: you. But, if closed access to data is so valuable to you, why isn't it in yo
                    • It is in the contracts. Actually, I'm not sure how JPL got to publish ISS images to the web at all, but for ISS and all of the other instruments (as well as virtually all NASA missions), the data are typically embargoed to the team for a year. That's SOP, and I'm fairly sure it's in the contract.

                      Why any of this should matter to you isn't my concern. You obviously don't care about the scientists and only care about getting *your* hands on the data, so I can see that you aren't interested in anything invol
                    • Why any of this should matter to you isn't my concern.

                      It's your concern as long as I am paying for the research. When your funding gets cut, you'll be begging to tell us why it's important to the rest of us. I'm sure that this project was sold as having some benefit for all of us, and not an ego boost for a small group of scientists. Why should I care about the scientists' sense of what's fair? You're doing a job for which you are receiving what you consider fair compensation (or you wouldn't be doing i

                  • I've already established why being the first to make a press release or to publish is important. You haven't counter-argued that, just avoided it.

                    You have established why being the first to publish is important for your career. No one is arguing that. What is being argued is why should anyone care ? After all, the data is not yours. It was received from an experimented funded from public funds, conducted by scientists that received a salary from the same source. Therefore, the data belongs to the public

                    • You're ignoring the fact that this IS part of how NASA operates missions. (Except for Cassini ISS images. Go figure.) I've already stated this. Eccentric Anonomoly can deny that it's true all s/he wants, but that doesn't change the fact that it is the case. For most instruments on most missions, it's standard operating procedure to let the instrument team keep the data for one year before it goes public. I'm not 100% clear on how NASA got to publish the data to the web since I'm pretty sure that that
            • Why get upset at someone for wanting first crack at the data they helped take? The point is that it DOES become public -- the public that paid for it owns it forever. It becomes part of the base of human knowledge. It's not ego; it's only fair that researchers on a project have some right to publish first. You said it yourself, it makes no difference to you who publishes it first. So I repeat, why get upset at someone for wanting first crack at the data they helped take? (BTW, please be sure to flame

      • Re:Amateur Analysis (Score:5, Interesting)

        by tetrahedrassface ( 675645 ) on Monday November 28, 2005 @08:38PM (#14134349) Journal
        Im very proud of JPL, NASA, and everyone involved with this mission. And all of the other missions for that matter.
        Im also proud that the data is released very quickly, and openly.
        Its a good thing all around, and we in #space on freenode understand the sensitivities involved.
        I assume when you speak of the enthusiast compositions you are referring to the Huygens data?
        I understand that all non-official work should be treated with a dose of sceptisim, but some of the images produced by the channel were good enough to be used by the ESA.
        (#space irc.freenode.net)
        Don't take me the wrong way. I am a huge fan, and supporter and a member of the Saturn Outreach Campaign.
        In fact i hope you understand that us geeks are most likely your biggest supporters.
        We should be celebrating, not casting stones.
        Peace, good luck, and congrats!

        JPL is amazing,
        D
        • Oh, I welcome the amateur community's involvement. Lord knows they do great work and they keep the professionals on our toes, which is a good thing. But I think that in all fairness that JPL has slid too far in their direction at the moment, since the way that they release the data right now almost guarantees that the amateurs will be making waves about news finds before we have a chance to spot them, make sure we're right, and then issue a statement (through channels). Really, even something like a one-
      • Also, remember that the images that JPL posts aren't scientific quality.

        You got that right. IIRC, those are the images used in the "36% More Rock Ninjas Coming Out of the Earth than in Previous Decades" paper, presented in 1997.

        Explains why they were able to post it so quickly, too. After all, it would take a lot of care to actually get things like that right. Maybe even more than peer review would require, since that's mostly concerned with the text. I'm sure that they recycled. Especially since I've

      • Re:Amateur Analysis (Score:3, Insightful)

        by klaun ( 236494 )
        Of course, amateurs are not bound be either rules for peer-review to get published or by NASA's process for press-releases, so their results will often appear on the web sooner than the offical findings. But they should also be treated with a certain measure of skepticism.

        Of course, you meant to say that all results should be treated with a certain measure of skepticism.

        Nullius in Verba and all that...

      • Then were are the results from Radar, Vims, etc? And ISS hoards their data releasing only the minimal trickle needed to keep NASA HQ off of their backs (to the point of degrading the official satellite ephemerides). The one year proprietary period you site is BS, if you read the Space Act that formed NASA, such a proprietary period is forbidden... and the instrument teams didn't pay for the spacecraft, in fact they were paid for their instruments and are paid to operate them, so they should release thei
        • ISS does not hold back the data to a trickle. We're archiving at the rate set by JPL. One year after the data were taken, they're in the PDS.

          Call it BS if you like, but the propriatary period is real and common practice with NASA missions. It's been part of every mission I can think of, anyway. The time and effort spent to design, build, and manage an instrument (let alone a mission) is HUGE. That's time out of a sciensist's productive time. If you let just anyone grab the data the instant that they'r
          • The time and effort spent to design, build, and manage an instrument (let alone a mission) is HUGE. That's time out of a sciensist's productive time. If you let just anyone grab the data the instant that they're on the ground, the people who put the work in are not only doing more work than their collegues, they're actually at a disadvantage since they are usually still busy running the instrument so that they don't have as much time to devote to science.

            The vast majority of the work done to get this data i
            • Actually, most of them were acknowledged in the instrment papers. And the non-scientists who help with the data are often co-authors on the papers or at least thanked in the acknowledgements. (My officemate, for example.)

              Now, it's true that all of the engineers and administrative folks are not acknowledged on a typical paper. But that would get horribly unweildy (the list runs for pages even without including all of the good folks at, say, JPL who are only peripherally involved) and it doesn't do their c
              • Well I've done work that directly led to several discoveries used without acknowledgment.. hell I've even had my own figures from internal presentations used without permission let alone acknowledgment. Beyond lack of acknowledgment, I haven't even be able to see the final results before they're published (hell I haven't even been told after they're published). This is why I'm going to get the fsck out of JPL at the earliest opportunity and seek a university job in my field where I can get credit for my o
                • Oddly, the scientists at JPL feel the same way about the administrators.
                • And, yes, if they used your figure, you deserve credit for it. I can't speak for things much outside of my own involvment, but I know that here at ISS any support staff who helps crunch data or produce figures for a paper gets an acknowledgement in the paper in the very least. I know of a number of cases where they have recieved co-authorship. So, yeah, sounds like you got screwed there. But I hope you aren't translating that into a feeling that all scienstists should be screwed as revenge.

                  And I hope yo
                  • I have never screwed a scientist with bad work on my part... and don't intend to.... And I have _one_ underling and I make sure he gets credit for his work even when others try to take credit for it. But I do intend to get out of JPL at the soonest opportunity and to do my work someplace with stronger scientific ethics.
                    • Excellent. Sounds like you definitely need to get out of there. Like I said, many of the scientists I've known at (or once at) JPL thought it was hell, too.

                      My point about screwing scientists was more about your argument that the data should go public as soon as it hits the ground rather than observe the standard priopriatary period. As I've argued, that's there to keep the scientists behind the mission from getting screwed for their efforts.
                    • As I've argued, that's there to keep the scientists behind the mission from getting screwed for their efforts.

                      my point is that the current system lets some scientists screw others. The data should be free because it is taxpayer financed and any grad student should be able to use it in their research without having to sign up with one of the scientists of the project. Many of the scientists are not that competent and many are downright lazy... but they have a lock on the data anyway and use that lock to e
                    • The SOI and Jupiter data have been delivered to JPL long since. (It was due, and it was in, by 1 July.) I know that for a fact since I know the person who delivered it and I have no reason at all to think he has lied to me that he mailed the DVDs and the JPL acknowledged receiving them. If it hasn't been put on the PDS yet, then that's JPL's failure, not ours.

                      As I've said, the one year propriatary period is standard NASA contract. And as much as you might think it's unfair, it would also be unfair to th
        • Oh, check you source. We're not degrading any official ephemerides. NASA takes those images on their own with ISS, not the team. They get the data they want.

          ISS releases the full data at the same rate as every other instrument. But only ISS gets all of its images posted as JPEGs to JPL's site as they appear. That's not a trickle, nor done just to keep NASA off our backs.

          Are all of your facts this bad? Because you're not filling me with confidence about your understanding of the inner workings of this
          • I know first hand that ISS was degrading the ephemerides for the rocky moons (which is odd that they are able to since the data for generating these ephemerides only partially comes from ISS). Maybe the policy has changed, but this was true as of last year.
            • And I know, from first-hand, that JPL has it's own data in that regard. The ISS people don't plan those observations and we don't control those data. The only way that there could be a problem there is if there were a timing conflict between a science observation and the nav team observations. And that could happen if it were *any* instrument wanting that time-slot and resolving it is a matter of discussion/priorities, not controlling the data.
              • ISS produces SPK files for the rocky satellites for the whole project
                • So you're saying someone on the team didn't *analyze* the data fast enough? That's not what you originally claimed. You originally claimed that we sat on the data itself. Any data needed by the Nav team is (or at least should be) taken by the Nav team. We don't hold on to that data. (Hell, if we tried to hold on to any data that wasn't ours, JPL would just give it to whomever is supposed to have it. All data goes through JPL before we get it.)
                  • ISS degrades the accuracy of the rock satellite ephemerides before releasing them to the project, i.e. mission planning, science planning, navigation, etc.
                    • Uh, no. Whatever the guys out there at JPL are feeding you, it's wrong. Which wouldn't surprise me; JPL has a lot of complaints about the Cassini teams operating their instruments from off-campus and I've noticed that the people they are sometimes rather hostile towards the instrument teams. (Admittedly, we probably play politics right back at them at times, but the hostility I've experienced seems to go beyond ordinary politics.)

                      If the data were set up by and for Nav, they get the actual data. I have b
                    • ISS is one of the worst in playing political games of any of the Cassini teams by far. Part of this politics is an edict that nav cannot produce ephemerides for the rocks: Janus, Epimetheus, Pan, Pandora, Methone, ...i.e. the small moons. The data from the nav team is sent to a representative of ISS who then produces the ephemerides that are degraded as per the instructions of the ISS team lead. This then makes it harder to plan observations of these rocks for everyone except for ISS.

                      If you've experienc
                    • And the scientists are usually caught in the middle of the crap that flies around from the NASA administrators. Believe me, there's politics all around, here. I can point out cases of engineers within NASA pulling all kinds of shit at the expense of science, if it came to it. Although I have yet to hear anyone complain about the Cassini engineers, so be proud :)

                      Trouble is, NASA has become a bureaucracy, plain and simple.
    • For Cassini I don't know, but I understand Nasa and Esa will publish the first "extensive" set if results concerning Titan on dec. 8, with a press conference in Esa tomorrow Nov. 30. All will also be on the Nature website on the 8.

  • "hot spot"? (Score:4, Interesting)

    by Amouth ( 879122 ) on Monday November 28, 2005 @07:44PM (#14134092)
    hot spot "temperatures observed within this region reached as high as 110 Kelvin (-260 Fahrenheit)."

    ok.. now if i remember correctly 0 K means that not even the eletrns move.. and 273 K is where water freezes.. so this is more than half way there and this is the hot spot.. what is the cold spot like?

    i am not trolling i am jsut currious.. maybe they jsut do werid things when it gets bloddy cold but being able to have eruptions that trow water out of orbit seems a little crazy.
    • Well, all things are relative, and warmer than damn cold, even it's almost-damn-cold, is still warmer. Beyond that, I'm assuming that any substantial difference in temperature are going to produce pretty interesting effects.

    • Re:"hot spot"? (Score:3, Informative)

      by imsabbel ( 611519 )
      its not all that scary as long as your gravitiy well is shallow and your atmosphere is thin.

      This has nothing really to do with the temperature per se, its more like a side effect.

      Also, considering that the background of the universe is only 2.73k, 110k deserves the designation "warm".
      I mean, its even warm enough to evaporate nitrogen...
      (also, at 0K everything still has the zero point energy, i.e. the 0.5h_bar you can never shave off those pesky harmonic osszillators. Thats for example the reason why helium

    • Re:"hot spot"? (Score:3, Insightful)

      by CheshireCatCO ( 185193 )
      Considering that Enceladus has an albedo of nearly 1, it's surface temperature is really, really low. (An albedo of 0.95 gives a surface temperature of 42 K.) So 110 is actually pretty impressive. And a perfectly black body at that distance should have a surface temperature of 90 K.
      • And a perfectly black body at that distance should have a surface temperature of 90 K.

        What is the formuthat for calculating black body temp as a function of rotational speed and distance from the sun?

        TWW

        • T = 285 K ((1-albedo)/distance^2)^(1/4), where distance is in AU. This assumes a "fast" rotator, but it's a pretty good approximation for a moon. Also, it sort of assumes that the moon doesn't spend a lot of time in the planet's shadow. And it is, of coruse, a globally averaged temperature. The poles should actually be a lot colder.
          • What exactly does "fast" rotator mean in this context? Do you know how much of a difference there would be in something tidally locked to the sun? Intuitively, it seems like a body absorbing X amount of energy ought to have the same average temperature, regardless of which side it comes from. Of course, intuitively, quantum mechanics and relativity don't work either, so I've learned to ask questions instead of trusting my intuition! :)

            And, since you work with Cassini... Random question, not really your
            • Figure "fast" is a period of less than a few tens of hours. Earth, Mars, the giant planets and their moons are pretty good in that respect. Venus and Merucry... not so much. It turns out that a slow rotator actually has a very different average temperature, but that's because a blackbody emits as T^4 rather than linearly with temperature. (The difference is therefore a factor of something like the fourth-root of 2, if I'm doing this right. I might be, hard to say with this headache. I might also be su

    • Ammonia hydrate (Score:5, Informative)

      by amightywind ( 691887 ) on Monday November 28, 2005 @09:17PM (#14134519) Journal

      Pure H2O is frozen rock solid at 110K. But H2O-NH3 ices are not. Try mixing 50% ammonia and 50% water together and putting them in the freezer. The mixture will not freeze but will just become more viscous. Low temperature mixtures of H2O, CO, CH4, or N2 have similarly weird properties. Check this [ucl.ac.uk] out. The compositions of Saturn's icy moons have not been well established. But indirect evidence like eruptions on Enceladus, or cometary outbursts, suggest exotic icy chemistry.

    • As someone already said before, it's relative to other regions.

      Reminds me of Triton's geysers. Temperature over there is a few tens of Kelvins, and a difference of about 4 K is enough to create those geysers.

  • "If only you could see what I've seen with your eyes..."

  • I you think The Fountains of Enceladus are cool (Score:3, Funny)

    by Anonymous Coward on Monday November 28, 2005 @07:45PM (#14134106)
    Wait till they get pictures of The Geysers of Uranus.
  • Let's hope Saturn has better writers than NBC.

  • E-ring (Score:3, Funny)

    by game kid ( 805301 ) on Monday November 28, 2005 @08:05PM (#14134208) Homepage
    This confirms what had been suspected from an image taken last January. And seems to point to these cryo-volcanoes as being the primary source of Saturn's E-ring.

    I always thought those Defense Department guys [nbc.com] were out of this world. I never thought they were from an outer planet [wikipedia.org].

  • F ring a spiral! Read all about it! (Score:5, Interesting)

    by Darius Jedburgh ( 920018 ) on Monday November 28, 2005 @08:20PM (#14134268)
    All this news about Saturn and no mention of the news that the F ring is not a ring but actually a spiral [space.com]!

  • Sounds like an Arthur C Clarke novel (Score:2, Funny)

    by Anonymous Coward
    Sounds like a good title for an Arthur C Clarke novel.

  • Looks like another place to search for life.... (Score:5, Interesting)

    by Luminary Crush ( 109477 ) on Monday November 28, 2005 @09:35PM (#14134601)
    What was interesting to me was this diagram:

    http://saturn.jpl.nasa.gov/multimedia/images/image -details.cfm?imageID=1681/ [nasa.gov]

    In JPL's warm-spot modelling for Enceladus there is an undersurface ocean heated by one of the two now-familiar forces of tidal heating or radiological decay heating (though the former seems more likely).

    So the statement goes: "where there is liquid water, there could be life". Do we have another Europa on our hands here?
  • Comment removed based on user account deletion

  • "False-color" (Score:4, Interesting)

    by NthDegree256 ( 219656 ) on Tuesday November 29, 2005 @12:40AM (#14135493)
    One thing I'm constantly curious about is the degree to which "false color" should be taken. I understand that the purpose of false-coloring is to enhance details and make certain features visible that would otherwise be imperceptible (outside of the visible band of light, too faint, etc.) but I also want to know what these bodies would actually look like to the naked human eye.

    Obviously, processed and filtered images are important, and very fascinating (case in point, many of the gorgeous images of the sun,) but it also diminishes the awe, in my mind, to look at a photo of a nebula or moon and realize, "this is not what it actually looks like."
    • am annoyed by the constant whining about the use of false-colors.
      Want to see what it really looks like? A very dark blob with nearly no discernable details because its so dark.

    • Here the use of false colors is so we can realize better what the gradient's like. The problem with the real color image (the b&w one that's unfiltered) is that, due to how Cassini saves it's images, it has much more grey's than our screens can display. We only can display 256, as Cassini's image contain 4096 (not sure), thus, false colors provide a more detailed gradient.

    • Re:"False-color" (Score:3, Interesting)

      by Java Ape ( 528857 )
      I can vividly remember the first time I got to use a "big" telescope - it was the 24.5" scope at Goldendale. I'd been reading "Sky & Telescope" for years, and had made frequent use of a very low-grade refractor. Finally I was going to see deep-space objects they way they looked in the glossy color photos. I dialed in the Ring Nebula (M57), put my eye to the lens . . . and saw a dirty smudge that looked like someone forgot to clean the eyepiece. When I scanned the scope slightly, however, the smudge s

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