07-09-2020, 10:09 PM | #41 |
Join Date: Feb 2016
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Re: Life & Temperatures on Titan
A possible issue with Titan's water mantle is that it is probably deeper than 75 km. With a density of 1.88 grams per cubic centimeters, it could easily have a water 900 km thick beneath a 100 km thick crust. Of course, there could also be multicellular lifeforms in the water mantle, there are all of the requirements of life, and they might get large enough to pose a threat to a small submersible.
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07-10-2020, 12:59 AM | #42 | ||
Join Date: Nov 2004
Location: Niagara, Canada
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Re: Life & Temperatures on Titan
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About the only real option I've come up with is if some Earthlings dropped some reactors into the ocean, along with some life custom-tailored both for the environment and to draw on whatever form of energy the reactors were designed to emit. ... Or, depending on how broadly you want to describe 'life', someone might have launched some giantish TL10ish flexibody eel-bots.
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07-10-2020, 12:12 PM | #43 |
Join Date: Feb 2016
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Re: Life & Temperatures on Titan
The liquid water mantle cannot have a density above 1, as water cannot be compressed. From what I have read, the current research on Titan suggests that 50% of its mass is in rocky material while 50% of its mass is in volatile materials. Since Titan possesses expansion fractures rather than compression fractures, it is constantly renewing its surface through cryovolcanism rather than shrinking.
A possible structure is an icy volatile crust over a carbon rich slurry over a liquid water mantle over a rocky core. The kinetic energy during its rapid formation (probably over 30,000 years) would have generated massive amounts of heat that became trapped by icy volatile crust (similar to the most recent research on the formation of Pluto). Precipitation of ice, radioactive decay from the rocky core, and tidal energy from its moderately eccentric orbit around Saturn would have maintained the total heat in the system, resulting in a rich place for a strange life. The warm water mantle creates plumes of liquid water the rise up through the carbon slurry and melts through the icy crust. Where the water does not quite come to the surface, the added heat allows for carbon slurry geysers. When the water reaches the surface, it creates water volcanoes that replenish the surface ice. Since Titan has a young surface similar to the Earth's, it probably possesses equivalent levels of volcanic activity. A rocky core with a density of 5.6 grams per cubic centimeter and a radius of 1500 km would produce enough thermal energy through radioactive decay to maintain the liquidity and warmth of a 800-900 km thick water mantle for billions of years, with the added energy from precipitation and tidal flexing. While a moon like Titan could have a less dense larger core, it becomes much harder for Titan to maintain a liquid core without unusual amounts of radioactive decay. A thicker water mantle also allows for more insulation, which would retain the heat from the initial formation longer, requiring only normal amounts of radioactive decay. |
07-10-2020, 12:57 PM | #44 | |||||
Join Date: Nov 2004
Location: Niagara, Canada
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Re: Life & Temperatures on Titan
May I just pause a moment to mention how pleased I am to be able to have this sort of discussion on this forum? ... Okay, I'm good. :)
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(Various reports have mentioned that the solutes likely include Cl -, HCO3 - (bicarbonate), and SO4 2- (sulphate); and Na +, Ca 2+, Mg 2+, K +, and NH4 2+ (ammonium). At the moment, I'm positing that at least one borehole was dug down to the subsurface ocean to un-dissolve some of those inorganic minerals for local industrial use.) Quote:
https://elib.dlr.de/90334/1/2014-soh...jgre201246.pdf https://cyber.sci-hub.tw/MTAuMTAxNi9...baland2014.pdf https://zero.sci-hub.tw/1357/1dad0cc...fortes2012.pdf https://www.lpi.usra.edu/meetings/lpsc2012/pdf/2939.pdf https://www.hou.usra.edu/meetings/lpsc2014/pdf/2435.pdf http://www2.ess.ucla.edu/~jewitt/cla...rs/Wood_10.pdf https://agupubs.onlinelibrary.wiley....9/2010GL044398 Quote:
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Thank you for your time, -- DataPacRat "Then again, maybe I'm wrong." |
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07-10-2020, 01:53 PM | #45 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: Life & Temperatures on Titan
Untrue; it's not very compressible (looks like about 4% at 1,000 atmospheres) and at a certain point it just turns solid, but it's not entirely incompressible.
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07-10-2020, 04:48 PM | #46 |
Join Date: Feb 2016
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Re: Life & Temperatures on Titan
The maximum compressability of water is around 2% (so that is the maximum density increase that water would experience), though it does become solid around 1 gigapascal, depending on salinity and temperature. At a depth of 1,000 km of Titan, the pressure would be around 1.6 gigapascal (assuming 10% salinity), so it could remain liquid at a temperature of 20 C. Of course, if Titan possesses a small iron core, the temperatures could easily reach up to 400 K due to radioactive decay, meaning that any life at the depths would be quite different than Earth life.
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07-10-2020, 05:48 PM | #48 |
Join Date: Nov 2004
Location: Niagara, Canada
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Re: Life & Temperatures on Titan
Current musings: how much to draw on from 3e Vehicles to add options to 4e UltraTech's sonar-comms, to complicate whatever comm network exists in the subsurface ocean. Eg, VX1 suggests tight-beam and (very) sensitive, which could let somebody reach the 5,000 miles to talk halfway around the planet. (With a bit of delay, given sound's ~1.5 km/s speed in saltwater.) Or could make it easier/cheaper for someone at the top of the ocean chat with someone at the bottom.
(VLF radio doesn't seem to penetrate deeply enough, ELF needs miles-long antennas and has terrible bandwidth, and THS Under Pressure's notes on water transparency put the kibosh on lasercomms of more than half a mile or so. And I'm not using the sort of superscience that permits neutrino comms.) VX1 also has some numbers for sonar GPS beacons and receivers, though neglects to mention their useful range, or how many should be planted in any given area. I suspect one of the less-expectedly important factors is how much slower the sonarcomms are than radio, especially for AIs running at faster than realtime...
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07-10-2020, 05:59 PM | #49 |
Join Date: Feb 2016
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Re: Life & Temperatures on Titan
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07-10-2020, 06:42 PM | #50 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: Life & Temperatures on Titan
Which is 24% compression, not 2%.
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cold, titan |
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