Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
×
Space Science

Signs of Water Found On Saturnian Moon Enceladus 79

Matt_dk writes "Scientists working on the Cassini space mission have found negatively charged water ions in the ice plume of Enceladus. Their findings, based on analysis from data taken in plume fly-throughs in 2008 and reported in the journal Icarus, provide evidence for the presence of liquid water, which suggests the ingredients for life inside the icy moon. The Cassini plasma spectrometer, used to gather this data, also found other species of negatively charged ions including hydrocarbons."
This discussion has been archived. No new comments can be posted.

Signs of Water Found On Saturnian Moon Enceladus

Comments Filter:
  • by JoshuaZ ( 1134087 ) on Tuesday February 09, 2010 @12:29PM (#31073352) Homepage
    In the 19th and early 20th century, the prevailing view was that life, even intelligent life, was common in the solar system. Then as time progressed, we realized how hostile most of the world is. The moon had a vacuum, liquid water was rare, Venus was hundreds of degrees too hot. Now it seems the pendulum swings in the opposite direction as we realize how common liquid water and other precursors to life are. We now have liquid water on Mars, and circumstances on multiple moons of Jupiter and Saturn that could be conducive to life. It seems pretty clear that we aren't going to find much in the way of advance life (the only possibility for it is maybe Europa, but I'm probably overestimating the probability there just out of love for 2001) but it seems more and more likely that we will find life in the solar system on bodies other than Earth. What will find from that, who knows. But I'm willing to bet that we will find such life in the next 20 years.
    • by BobMcD ( 601576 )

      Isn't distance from the sun pretty empirical, though? Earth's 'sweet spot' is occupied by, well, Earth, and little else. This moon of Saturn may have water, but where is it getting its replacement for solar power?

      My guess - it isn't.

      • Re: (Score:2, Interesting)

        by KDR_11k ( 778916 )

        Who knows if there aren't types of life that can subsist on the reduced solar power over there. There's also the option of volcanic activity feeding heat into the ecosystem but I think volcanic activity is fairly rare.

      • Re: (Score:1, Interesting)

        by Anonymous Coward

        Aren't there bacteria that live off of solar power? If so if there is enough heat to keep water in its liquid state, there might be enough power to at least energize simple singe cell-type organisms (which I feel is the most probabilistic life forms to find in this solar system).

        • > that live off of solar power

          crap, I meant thermal power!

          • by elysiana ( 1152995 ) on Tuesday February 09, 2010 @12:51PM (#31073758)

            Aha, we have now obtained your true identity! You can come forward, Mr. Anonymous Coward. The game is up.

            • haha, I don't know why that went up anonymously. I'm not exactly ashamed about my views on the probability of finding bacteria on the moons of Saturn.

          • Re: (Score:3, Interesting)

            by mrxak ( 727974 )

            There's probably other variations out there that can provide an energy source, things much harder, and thus never took off on Earth where energy was easy. I fully expect we'll end up finding life a lot more frequently than we expect at the moment. It'll mostly be stuff we can't have conversations with though.

            There's also the whole thing about asteroids carrying life from one place to another. Just because it's hard for life to arise in a particular place in a solar system doesn't mean it can't get transport

            • Re: (Score:2, Funny)

              . I fully expect we'll end up finding life a lot more frequently than we expect at the moment.

              So you expect to find more than we(thus you) expect at the moment. Holy crap, you are stuck in a feedback loop of ever growing expectations. If you expectations are not bound by time and you are simply expecting more with every moment by now you already expect to find an infinite amount of life.

              These self-replicating expectations are dangerous things. As I expect you know.

        • Re: (Score:3, Interesting)

        • If so if there is enough heat to keep water in its liquid state, there might be enough power to at least energize simple singe cell-type organisms

          Don't confuse water that is liquid due to pressure and water that is liquid due to temperature. Not saying that it's too cold for life, I think you can get water to around -20 celcius without freezing if you put enough pressure on it (after that it forms ice-trhee, five etc.

          You can get some more info on this here [lsbu.ac.uk] and here [unsw.edu.au].

      • by Tim C ( 15259 ) on Tuesday February 09, 2010 @12:50PM (#31073740)

        There are creatures on earth that do not get their energy from the sun - they live near hydrothermal vents [wikipedia.org] deep in the oceans. That's one possibility that we have seen ourselves; in fact it was this discovery in part that spurred on the search for life on other planets that would normally have been written off as far as supporting life was concerned.

        • by BobMcD ( 601576 )

          So you're operating under the assumption that these lifeforms evolved independently from a spontaneously-generated source?

          I think it is far more likely that they are adapted from solar-sourced ancestors.

          • by Monkeedude1212 ( 1560403 ) on Tuesday February 09, 2010 @01:11PM (#31074120) Journal

            I don't think either of you are qualified to make that assertation. A year of Bio/Physical Anthropology for extra credit is not enough.

            You need to explain why its more likely that they adapted from solar sourced ancestors as opposed to thermal heat vents. I think that form of adaptation would be quite rare, as evolution takes a long time. And you can't expect a solar sourced species to survive in a non-solar environment very long.

            • by smaddox ( 928261 )

              All of the currently existing life on earth originated from one source (to a good approximation). We know this because all of life is based on DNA (or RNA). If the life forms at thermal vents originated independently, it is extremely unlikely that they would also use DNA to code their genes.

              If we ever find life on another planet, it most likely will not be based on DNA. If it is, that will be good evidence that the DNA was seeded by outside sources.

              • We can't estimate how likely it is that extraterrestial life would use DNA or not. We know that if you started with or use RNA, the switch to DNA seems evolutonarily advantageous. We can be more sure that if they did use DNA it is likely that they would use a very different system of encoding information than we do. In particular, the use of triplets corresponding to amino acids would be very unlikely to show up. But we really don't have enough data to make any guesses about whether or not DNA itself would
          • by Chris Burke ( 6130 ) on Tuesday February 09, 2010 @01:18PM (#31074242) Homepage

            So you're operating under the assumption that these lifeforms evolved independently from a spontaneously-generated source?

            No. It is only establishing that it is possible for life to exist in such environments.

            I agree it's probable that the examples on earth evolved from life that formed where solar energy was readily available. But that doesn't necessarily mean its the only possible evolutionary path, any more than our history means warm blooded live-birthing animals can only evolve in the presence of giant reptiles who get conveniently wiped out by meteors. It also doesn't mean life can begin and evolve strictly from geological energy sources... We don't really have a good model of abiogenesis, but the things we're pretty sure are at least prerequisites are water, organic compounds like amino acids, and energy.

            I'm not ready to say that the source of energy must be the sun.

            • by Nadaka ( 224565 ) on Tuesday February 09, 2010 @01:24PM (#31074328)

              There is also a fairly common biological origin hypothesis that the thermo-chemical powered life found near vents was the earliest kind of life on earth and solar powered life evolved from it. This hypothesis fits our current understanding of earths early seas rather well. Though I don't think there is any way to advance it to a theory due to the near absolute lack of fossil records from that period.

              • Hey, good point. If we could verify that hypothesis, it would strongly suggest life could exist on Enceladus or Europa. Otherwise, it still doesn't exclude the possibility.

          • No, he is just saying that life doesn't necessarily need a solar source of energy, as the deep sea vent species demonstrate.

            How you use that to jump to your conclusion that he thinks life arose twice, I don't know.
        • Exactly. Not even oxygen or carbon dioxide is required. There are iron, titanium and even uranium breathers out there (near vulcans and in deep seas).
          And that is just here on earth. There is no reason life should be limited to that somewhere else.

          I think the “there must be water, sun and whatnot” view is the same egocentric arrogance, that made us think we were the center of the universe, or the only intelligent lifeform, or the only lifeform with feelings, or the only superior “race

      • by sznupi ( 719324 ) on Tuesday February 09, 2010 @12:57PM (#31073884) Homepage

        Life needs energy, sure, but that doesn't mean the energy has to be in the form of solar light. Some of Solar System moons get quite a lot of energy by tidal heating; for an extreme example, see Io.

        What I wonder is how plausible would be to get Cassini back through Interplanetary Transport Network (low energy routes throughout our system). In the future Cassini power will diminish to a point where it will be hard to keep experiment packages alife. But perhaps there would be just enough propellant by then to direct it back through ITN? Just enough power to keep main systems alive for few decades? Bring it closer to us, so in 50 years or so we can examine it easily. Perhaps something hatched on for the ride while Cassini was flying through plumes from Enceladus in orbit around Saturn...

        • Cassini doesn't even have enough delta-v available to get another Iapetus flyby during the Solstice mission. It's not leaving the Saturn system.
      • by dissy ( 172727 ) on Tuesday February 09, 2010 @01:10PM (#31074106)

        Isn't distance from the sun pretty empirical, though?

        Not exactly, and not really.

        Any source of heat will do, the sun is just a convenient free source of it for those planets near enough, and while not technically unlimited, is close enough for our current needs and not even an issue for any society under a KT-I level (like us)

        Earth's 'sweet spot' is occupied by, well, Earth, and little else. This moon of Saturn may have water, but where is it getting its replacement for solar power?

        The main source of heat is the same as Earths secondary source of heat.
        Left over energy from the planets (or moons) formation in the early solar system. Typically the symptoms of this are a molten semi-liquid core, and centrifugal forces imparted to it during it's creation.

        Also Europa has Saturn and it's magnetic field and gravity well to generate energy.
        As the moons orbits are not circular but instead elongated, this means in a single trip around it's host body, half the time it is closer to the planet than the other half (and in seasonal quarters like Earth has) which gravitationally pulls on the moons surface stronger during the closer orbit times.
        This process generates a bunch of geothermal activity, motion, and heat energy from friction.
        http://en.wikipedia.org/wiki/Tidal_flexing [wikipedia.org]

        The top layer of ice is very thick, and only the first couple meters are needed before the suns radiation are blocked enough to not be damaging to anything under that level.
        Moving water (and thus food) due to tidal flexing between the liquid inner layer (be it water or whatever it happens to be) and the frozen solid crust.
        A hot and mobile semi-liquid metallic core to provide heat to the lower levels that don't get much or any energy from the sun.

        If it wasn't for the fact the rest of Earths ecology wasn't there, there are a number of life forms on Earth that we could drop off under the ice right now and they would have an extreamly high chance of survival (again admitting, with a support and food supply)

        If life was to or has started from the basics there, the foundation of support for an ecology would be in place (at least for life that evolved there), and there is plenty of sources of energy compared to current known life forms on earth (not us, but humans are far from the life form majority on this planet)

        My guess - it isn't.

        While you may be correct, it would only be correct by accident :)

        We have many life forms on earth that already thrive in such conditions. So we have solid proof that such a thing is possible, and there is no reason to think otherwise.
        But as we know, just because something is possible, doesn't mean it has happened more than once.

        Nor are there any actual arguments if there IS life there or not, only guesses.
        Within the realm of possible however, it has been proven to be possible already.

        • Also Europa has Saturn and it's magnetic field and gravity well to generate energy.

          Really? Did we move it?

          (Sorry. It was an informative post, I am just giving you a hard time)

      • Re: (Score:3, Funny)

        If there is life on any moon of Saturn, what makes you think they'd be reliant on solar power? For all we know this life could be decades behind us technologically, and still burning wood and coal. Or they could be more advanced, and using fusion. After all, if they have liquid water they have the necessary materials to put out fires AND cool reactors!

      • by mog007 ( 677810 )

        The moons of saturn that could have oceans of liquid water get their energy by gravity. The gravitational tides from Saturn cause stresses on the moon, which heats up the ice and makes it a liquid. As far as solar energy itself, that's not a requirement for life. There are entire ecosystems on this planet that survive just fine without exposure to the sun's light. Due to the radioactive isotopes inside the core of the Earth, the sun could burn out tomorrow without impacting these systems.

      • by Gilmoure ( 18428 )

        Some of the closer in moons appear to be warmed by gravitational forces, keeping the core warm. These moons could have some form of life develop around hot vents and such. Life doesn't require solar energy, just some kind of heat gradient. Still, I'd be surprised if we found anything more complex than basic cellular structure. Still, you never know.

      • Earth's 'sweet spot' is occupied by, well, Earth, and little else

        Has anyone looked at the Farside of the Sun [wikipedia.org], though?

      • Re: (Score:3, Interesting)

        Probably the same place that Europa and Io are around Jupiter, massive tidal forces. Alright, in Io's case it's even cooler, because it's proximity to Jupiter's magnetosphere creates all kinds of extra energy.

        You forget these moons aren't orbiting a relatively inert body like Earth, which produces very little radiation and gravitational energy of its own. We're talking about massive gas giants who exert extraordinary tidal forces on bodies orbiting them. Tidal forces mean churning of the core, which mean

      • The concept of an orbital "sweet spot" around a star I find to be rather dubious. The sample set for this hypothesis is... umm... One! We have seen numerous examples of volcanic activity throughout our solar system. If you have volcanoes, you have heat. And if you have heat, you can have liquid water.
      • It has to be getting that energy, or there would not be liquid water in the first place!

        Possible sources of energy include tidal forces, orbital perturbations, and radiation, all of which eventually translate to geologic activity.
      • if life can evolve miles under the sea near a volcanic vent I'm pretty sure it might be away from the sweet spot"
    • Re: (Score:1, Interesting)

      by Anonymous Coward

      A dude at NASA (David McKay) believes he will be able to conclusively present evidence that Martian meteorites on Earth contains fossils of Martian bacteria (past life) before the end of this year. His findings were first announced in a televised message by president Bill Clinton in 1996, but they have remained fairly controversial until now. This year, his team have been given funding to conduct new analyses using much more sophisticated instrumentation that were available in 1996 - and he is convinced the

    • Re: (Score:3, Interesting)

      by Chris Burke ( 6130 )

      but it seems more and more likely that we will find life in the solar system on bodies other than Earth.

      I'm not sure how likely it is. We might find life elsewhere in the solar system, but it's also quite possible we won't.

      However at the very least what all of the data we're collecting suggests is that liquid water, hydrocarbons and other organic chemicals, the things we associate with the chemical requirements for life, are not actually uncommon. So even if it requires an earth-like planet both in compos

    • Re: (Score:2, Interesting)

      We really don't know what range of conditions life could exist under. We tend to be very biased based on the conditions we are adapted to. We define the "habitable zone" to cover planets where life similar to us could exist. But we don't know what other sorts of life could exist under very different conditions.

      As an example, it's easy to engineer proteins that are either much more stable or much less stable than the ones typically found in Earth organisms. Our proteins have evolved to be exactly as s
  • by spun ( 1352 )

    But they shouldn't be too watery. Enchiladas are a casserole, not a soup.

  • by KDR_11k ( 778916 ) on Tuesday February 09, 2010 @12:41PM (#31073604)

    Does that mean oil?

    I think I hear NASA's budget skyrocketing.

    • by sznupi ( 719324 )

      Wrong moon; Titan is where it's at, with several times more hydrocarbons that total amount present on Earth.

    • You know, with all the hearing of finding water here, traces of hydrocarbons there, etc, I'm starting to think that NASA is looking for the wrong thing. Forget water, me I'd set the spectroscopes for stun... err... I mean for beer. You're not going to get Joe Sixpack all excited and lobbying his representative to pay for your next rocket just because you found traces of water on Beta Bumfuckii, much less for some ark ship to colonize it. Beer, now, that's a worthy resource for the space age. That's how you

  • I mean, those guys are still holding a grudge for being sent up there as slave labor a few generations back... Expect any attempt to exploit the water on Enceladus to be met with fierce resistance.

    • don't worry, though, a common enemy will help them come around....

      • don't worry, though, a common enemy will help them come around....

        Yeah, but we'll still have to give them Venus... And just what are all those Venusian colonists supposed to do, eh? Their families have been there for generations!

        • by Nadaka ( 224565 )

          I seem to recall that most of the Venusians were "relocated" to "internment" camps to "operate" "furnaces" and "test" bio-weapons. But I might be reading a little to deeply on the WW2 allegory here.

      • by Nadaka ( 224565 )

        You bastards, thanks for reminding me of that show. Its virtually impossible to get your hands on a decent quality copy these days.

  • After Taco Bell wins the Fast Food Wars, they send probes to all bodies in the solar system which once had liquid water. The microbial life-forms are collected and sent home for use in the development of new Suspicious Sauce for their burritos.

  • have found negatively charged water ions in the ice plume of Enceladus.

    This is obviously leackage from one of those space aliens, coming here to steal all our water.

  • Water ions?

    Disclaimer: no, of course I didnt.

  • wow (Score:2, Interesting)

    Lots of people that don't know what their talking about posting a lot of stuff in this thread. We live in a figurative vacuum. We have no idea what the rest of the solar system is like, much less the universe. To assume we have any idea what allows and disallows life to exist is just plain stupid. As far as we know, life is simply an extension of complex chemical reactions over time. Take any planet, asteroid, whatever... with continuous chemical reactions going on for long enough, eventually those reaction
    • by geekoid ( 135745 )

      "We have no idea what the rest of the solar system is like, much less the universe."
      false. We actually know quite a bit; however there seems to be a lot more to discover.

      "To assume we have any idea what allows and disallows life to exist is just plain stupid. "
      False, we even have many examples, here on earth. Could there be life that exists in even more extreme conditions? sure, but we do know for sure some areas that do allow life. So to say we are stupid because we don't know what allows for life is wron

E = MC ** 2 +- 3db

Working...