Signs of Water Found On Saturnian Moon Enceladus

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."

Comments

The pendulum swinging

[JoshuaZ]

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.

Re:The pendulum swinging

[KDR_11k]

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:The pendulum swinging

[Tim C]

There are creatures on earth that do not get their energy from the sun - they live near hydrothermal vents 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.

Re:The pendulum swinging

[elysiana]

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

Re:The pendulum swinging

[sznupi]

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...

Re:The pendulum swinging

[dissy]

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

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.

Re:The pendulum swinging

[Monkeedude1212]

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.

Re:The pendulum swinging

[still cynical]

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!

Re:The pendulum swinging

[Chris Burke]

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.

Re:The pendulum swinging

[Nadaka]

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.

Re:The pendulum swinging

[Chris Burke]

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 composition and in relative distance from the parent star, we can be confident that the composition itself is not rare, and based on how swimmingly well the search for exoplanets is going*, I think we can say that the odds of there being earth-like planets with liquid water and hydrocarbons and all that around other stars is high.

So, maybe not in our solar system, but I'm putting down the odds of there being life "out there" as being pretty damn good.

* Basically, every type of planet we have the capability of discovering, we discover. First huge gas giants really close to the star, then gas giants farther out, rocky planets of several earth masses very close to the star... Every time our capabilities improve, we readily find planets that only the new capabilities would show.

Re:The pendulum swinging

[mrxak]

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 transported elsewhere and evolve to thrive, or at least survive.

Re:The pendulum swinging

[Propaganda13]

Radiation can fuel life also. http://www.washingtonpost.com/wp-dyn/content/article/2006/10/19/AR2006101901671.html

Re:The pendulum swinging

[SoftwareArtist]

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 stable as they need to be in order to work well under physiological conditions. Heat them up a bit and they denature. Cool them down and they stop working. But if Earth were much warmer or much colder, our proteins would just have evolved to be much more (or less) stable, and then they would work nicely under those conditions.

And then there's the question of very different chemistries. Could life exist at 2000 Celsius? Certainly not life as we know it, since our biological molecules would all be vaporized. But there are other materials that are solid on Earth, but would become soft and reactive at those temperatures. Could life be formed from them? We just don't know.

Re:The pendulum swinging

[MightyMartian]

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 means geological activity which means heat, which means the water is liquefied. There's no lack of energy around either Saturn or Jupiter.

Hydrocarbons?

[KDR_11k]

Does that mean oil?

I think I hear NASA's budget skyrocketing.

Re:Why would liquid water...

[garg0yle]

Have scientists been able to throw together basic ingredients of living things and have the resulting pile resemble anything even close to life? Even in perfectly favorable lab settings?

yep

(Depending on how you define "life", of course)

Re:I like enchiladas

[spun]

I like echidnas too but they're not food!

I take it you've never had echidna enchiladas. Once you pick out the spines, they're delicious.

Re:I like enchiladas

[Anonymous Coward]

Have you tried a Knuckles Sandwich?

Re:Two years to analyse the data ?!

[Convector]

I was not involved in this study, but I've published in Icarus before. It's a good journaly, but has notoriously slow publication times. If you actually look at the article, you'll see that the original submission date was Nov. 2008. It went through review and was sent back for revision. Given the time, it's likely the revision was also sent out for review. It was accepted in July 2009. It's probably been available on the website shortly after that, but because Icarus only prints a certain number of articles per issue, it's taken this long to slog through the publishing queue.

wow

[charliemopps11]

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 reactions could end up turning into biological reactions. It may be that nearly every planet has some sort of life on it, it's just not something we expected to find. In any event, my point is, we have no idea. My guess is intelligence will be the same way, we'll start finding stuff that "might be" intelligent and we'll argue about that for 100 years as well.