Cassini Finds Evidence of Water

CheshireCatCO writes "Scientists working on the Cassini Mission think that they have found compelling evidence for the existence of liquid water at the south pole of the moon Enceladus. In addition to the obvious puzzles relating to how temperatures can be held high enough for liquid water, the presence of water, as well as the detection of organic molecules, opens up the possibility for life at Enceladus's south polar region. The findings are to appear in the 10 March issue of the journal, Science"

Comments

That is some cold water

[digitaldc]

In the spring of 2008, scientists will get another chance to look at Enceladus when Cassini flies within 350 kilometers (approximately 220 miles), but much work remains after Cassini's four-year prime mission is over.

We need a closer look, but it would be interesting to gather some samples of this water and see if it contains microorganisms of any kind.

Re:That is some cold water

[Anonymous Coward]

The practicality of sending a probe to the surface of a far-flung moon for remote experimentation or return payload for terrestrial experimentation aside, the worry with such a procedure would be contamination. The Galileo Spacecraft was plowed into Jupiter's atmosphere to prevent any earth-bound contaminants from entering Europa, another planetoid that's on the short list of places that are likely to be able to support life. Some might see it as a grand irony if our experiment to find out if there's life on Enceladus, only to find that earth-bound microorganisms take seed there and multiply. It's an entirely different irony if the probe ends up being toxic to the indigenous life.

So, do we sit back, millions of miles away, speculating as to whether life exists there, or endanger the life we seek to discover by "getting a closer look" to see if it exists? Quite a conundrum, isn't it?

Re:That is some cold water

[khallow]

Other posts here illustrate the problems of microorganisms, but the problem isn't necessarily that our microbes could taint their microbes; the very probe itself could very well contaminate the moon on its own.

Well, given Enceladus' location, there should be a lot of exposure to metallic meteorites including more lead and other heavy metals than you could possibly cram on a probe.

Re:That is some cold water

[Anonymous Coward]

Which is really side-stepping the issue, just because the metal of the probe may not have any adverse affect on the ecosystem, that doesn't mean that items like the plastics and rubbers and solar panels won't harm the environment. I'm not saying that it's wrong to send a probe to where life may exist full of all sorts of (from the moon's perspective) alien technology and materials, that's a moral decision, and is therefore subjective. What's not subjective are the following facts:
  1) We don't know what's up there
  2) We don't know how it will react to what we send there
We want to find out more. How do we learn about this moon, in this case? Sit back and observe indirectly, flying high above in orbit? Or do we get our elbows greased and dive right in there, up close, landing on the moon to examine it? Our standards for this world (and Mars) have been that it's okay to interfere with the environment for the sake of learning. We send probes places, we dissect specimens, we leave our technology all around the environment. Are we to keep this up indefinitely? Cluttering space with our trash? Is our solar system to become a repository for evidence of all our past scientific endeavors, our fingerprints on everything? Do we clean up after ourselves, or not get things dirty in the first place? What is our role in all this?

That remains to be decided.

Re:That is some cold water

[FleaPlus]

The practicality of sending a probe to the surface of a far-flung moon for remote experimentation or return payload for terrestrial experimentation aside, the worry with such a procedure would be contamination.

Actually, part of the beauty of this discovery is that we wouldn't necessarily have to do that, because it seems that the geyser system on Enceladus is shooting liquid water (and whatever it contains) all around the Saturn system. From a piece of commentary by James Oberg on Why the Enceladus discovery matters:

Enceladus has now offered, on a space platter, the easiest-so-far way to examine directly the composition of such oceans. We don't have to drill or melt our way through a hundred miles of an outer ice shell, as on Jupiter's moon Europa, or fight our way down through and back up through a thick atmosphere such as found on Titan, Saturn's largest moon.

We can go out there to Enceladus and pick up the samples in deep space, delivered conveniently by the geyser system that appears to be driven by the same heating process -- gravitational flexing -- that created the Enceladus liquid water pools in the first place. ...

An aerogel-equipped spacecraft could be dispatched to the Saturn system to make repeated passes over Enceladus (the geysers don't seem to be permanent features) while opening Stardust-like collection grids. Bonus passes through the upper atmosphere of Titan and the outer rings of Saturn might also be possible. And we may get even more potential targets as the Cassini probe that discovered these wonders continues to explore.

Re:Yeah, sure... or How I Love Grants

[WillAffleckUW]

1) Suggest a possible discovery of liquid water out there
2) Make allusion to possibility of life emerging there
3) ???
4) Grant Funding!

Well, the avian-human transmission of influenza was actually discovered by a research scientist who wanted an excuse to go surfing in Australia, so he proposed a grant to study if seabirds were a reservoir for influenza that infects humans.

Turns out they were. Plus, he got some good surf in.

So, maybe we should investigate the surfing potential of this moon, and maybe we'll discover a cure for cancer ...

Re:Saturn

[dotslash]

Also notable: This finding is more puzzling because Enceladus is not thought to have "volcanic" activity. It is too small and cold to sustain a molten core, or plate tectonics. Which makes this finding the ultimate irony, since Enceladus is the ancient greek god/giant of volcanos, who was burried under mount Etna, hence the volcano there.

When they named Enceladus, the moon was considered incapable of sustaining volcanic activity, but maybe the name changed all that!

Re:Supercooled water

[LunaticTippy]

Your observations are dead on.

Anything that seeds the crystallization will do - an ice crystal works best, but particles or shock will do.

I had a bottle of cider camping (I don't know the temperature, but my kerosene froze) that stayed liquid until I opened it. Spiderwebs of ice forming inside, quite beautiful, followed by the crack of the bottle breaking.

Threat to humans?

[ecorona]

So say there are organisms that live on Saturn's moon. My fear is that they are extremely efficient at utilizing resources since they probably don't have many resources there. If we all of a sudden bring them back to earth where the resources for are that much higher then how do we know they won't spread unstopably and destroy us all?

Re:Arthur C Clarke says ...

[PinkyGigglebrain]

Acording to Clarke's notes in the copy of 2001 I have Kubrick decided to drop Saturn because he didn't want to confuse the viewers about where the Monolith was, plus try explaining a gravity slingshot manuver to joe sixpack moviegoer.

Your dead on about Iapetus though, when the first images where sent back from Voyager 1 showing the moon exactly as Clarke had described it, right down to the black dot (in the book its the Monolith)in the middle Carl Sagan promptly sent a copy of the image to Clarke with the note "Thinking of you ..."

Re:Yeah, sure...

[jc42]

Everyone has always acted like water in the universe was scarce and Earth had some special circumstances that allowed liquid water to exist.

That belief has always puzzled me.

Let's see now; H is the most common element in the universe, and the current estimates for other elements have O in third place. So H and O atoms stand a very good chance of meeting each other nearly everywhere, to form HO. HO in turn is highly likely to bump into another H after a short trajectory. There's also a good possibility of that O bumping into an H2 molecule, since much of the universe's H outside stars is in the form of molecules.

Astronomers will tell you that water is one of the most common chemical compounds in the universe. It takes special conditions, mostly plasmas inside stars, to avoid having a lot of water on hand.

Current estimates are that most of the satellites of the gas giants, as well as Pluto and Charon, are around 50% water.

Of course, at the 70K equilibrium temperature around Saturn, you'd expect water to be mostly a rather hard mineral. It doesn't even sublimate at that temperature.

So for Enceladus to have liquid water, even temporarily, implies that there's a heat source somewhere inside. That's the interesting part of this story.

Re:Predictable rabble

[thesandtiger]

Actually, the news in this case:

The most simple and common combination of two extremely common elements might exist on a large rock, very far away, in a form that shouldn't be possible based on our current understanding of the conditions there.

You might not find that to be interesting, and may even be in the majority, but for people who are interested in that field, possibly finding something completely unexpected (not the water part, but the liquid state) is pretty interesting.

Am I suggesting that people leap up and down and hoot and holler over this? No, but I'm not suggesting that people should treat this as just "more of the same" either.