From: jdnicoll@panix.com
In article <40fd3f0f.106301@news.btopenworld.com>,
Hugh wrote:
>On 14 Jul 2004 16:51:33 -0400, jdnicoll@panix.com (James Nicoll)
>wrote:
>
>>In article <40f5377b.12408047@news.btopenworld.com>,
>>Hugh wrote:
>>>
>>>If life is present on Titan, it must be completely different from life
>>>as we know it. Titan is so cold that water ice is a quartzlike mineral
>>>there, it certainly couldn’t play an active role in any biological
>>>processes.
>>
>> I nitpick only to be polite: water can't exist as a liquid on
>>the surface of Titan, but what about underground, in a subtitanian
>>liquid water zone analogous to Ganymede's hypothetical ocean? Am I
>>remembering correctly that a water-ammonia mix can have a melting
>>point as cold as 175ish K?
>
>You're absolutely right, I'd forgotten that ammonia can greatly reduce
>the freezing point of water. There could well be a substantial
>water/ammonia ocean beneath Titan's surface, so there could be
>subterranean water-based life on Titan. I still like the idea of
>hydrocarbon-based life in Titan's methane oceans though :-)
A little googling shows that not only do some models of Titan
have eutectic water-ammonia mixes, with water ice above and a mixture
of water-ice and clathrates below but far more depressingly, I knew
that at one point and it wasn't all that long ago.
I wasn't aware that Titan ever had open seas (first 10^8 years),
though. Makes one think...
In any case, a world-ocean of ammonia and water could be one
of several biomes, and variation with selective pressure might keep a
continual process of organisms trying to colonize the colder surface
regions. Admittedly there are limits to what v&ns can accomplish.
--
Take the piston rings out of my stomach, And the cylinders out of my brain
Extract from my liver the crankshaft, And assemble the engine again!
[from 'The Dying Aviator']
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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