Liquid water on Enceladus?

Cassini probe observes Saturn's moon Enceladus has 'spreading surface', possibly caused by liquid water beneath the surface.

As far as I can tell this is big deal, essentially raising the number of plausible candidates for extraterrestrial life in the Solar System by one. Especially given that, as far as I was aware, the big showpiece for the Cassini mission was always expected to be Titan; I was under the impression that the other moons of Saturn were expected to be rather uninteresting barren balls of rock.

I still don't understand why there has to be water present for there to be life.

Unless we're saying that we know everything there is to know and no life, of any type, can exist without water.

As I understand it, it's not so much that water has to be present, as that while non-water based life might be possible, water-based life definitely is possible, so given that probes to the outer Solar System are expensive, if we are looking for extraterrestrial life then places with liquid water would be a good place to start.

according to the phase diagram, if liquid water are present on such cold condition, it must be an extremely huge pressure present, . . . .

Plate tectonics on earth drift on liquid magma. The upwelling could be anything liquid.

I assume that the crust is water Ice there they assume that the upwelling is water. Fair enough.

Problem is that it might just be the pressure liquefying the water directly underneath and not a viable goldy locks temperature range.

H2O is great for life because of its solvent properties... it allows the easy transport of lots of types of materials. So it is a great transport mechanism for moving food around.

Is It safe to assume that under such condition (extreme pressure and cold temperature), lifeforms can exist? If it exist, it must have a very - very slow rate of metabolism (almost all chemical reaction rate decrease significantly if the temperatures are decreasing, according t their rate constant "k" in Arrhenius's law:

k = A e^(-Ea/(R.T))

Notes:
A --> Arrhenius Constant
e --> e, the natural logarithm number (2,717...)
Ea --> Activation Energy
R --> Gas constant
T --> Temperature

in determining direct reaction rate:

v = k [C1] [C2]

notes:
v --> reaction rate
C1 --> Reactant 1 conc
C2 --> Reactant 2 conc

But we still don't know much about their activation energy...

Quote:

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Originally Posted by PBI

water-based life definitely is possible, so given that probes to the outer Solar System are expensive, if we are looking for extraterrestrial life then places with liquid water would be a good place to start.

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Wipe them out and colonize it.

Quote:

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Originally Posted by Papewaio

Plate tectonics on earth drift on liquid magma. The upwelling could be anything liquid.

I assume that the crust is water Ice there they assume that the upwelling is water. Fair enough.

Problem is that it might just be the pressure liquefying the water directly underneath and not a viable goldy locks temperature range.

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Yes, hence why I decided to include the question mark in the thread title. ~;)

To be honest though, finding liquid anything is fairly interesting; until Tuesday I was under the impression that Enceladus was just another Mercury-like barren ball of rock.

In theory life could exist almost anywhere, but the kind of life we could most easily recognize and potentially utilize is very likely based on the presence of some form of liquid water. Also if you subscribe to the Solar System as an ecosystem idea then potentially all life in our neighborhood is related in one way or another, which makes it massively more likely to require water.

:egypt:

Quote:

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Originally Posted by Ramses II CP

In theory life could exist almost anywhere, but the kind of life we could most easily recognize and potentially utilize is very likely based on the presence of some form of liquid water. Also if you subscribe to the Solar System as an ecosystem idea then potentially all life in our neighborhood is related in one way or another, which makes it massively more likely to require water.

:egypt:

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Hmm, the solar system as an ecosystem? Not buying that one.

Doesn't an ecosystem have to be interconnected and even interdependant? If so there would have to be space travel involved and any colonisation would have to come from another planet, the dependancy part would require constant contact. Even if this was the case there is no guarantee that the life would evolve in a common enough path to require water.

I agree that water being present gives a greater chance of life like us being present, aren't I open minded :laugh4:, but the way it's portrayed gives the impression that without water there can't be life.

The Solar System as ecosystem idea is a Sci Fi concept based on a very different time scale of life than the one we know. It doesn't require technological space travel as there are ample bodies moving through the system to spread life that evolved in deep space. The come around point of the cycle, which is to say the point at which life, deposited in a gravity well, returns to deep space doesn't even theoretically require technology as objects skim through the upper reaches of the atmosphere, where there is some life, all the time. It's a thin stretch, but we're not talking about a human scale biomass, more like a hibernation heavy bacterial colony.

This isn't to say I subscribe to the theory! I just find it a very interesting thought experiment. I think it originated back when there was some debate about whether or not all the key ingredients for life were present on the early earth.

:egypt: