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N C More
2004-Jul-03, 07:22 PM
I've read a few articles like this one (www.spacedaily.com/news/saturn-titan-02b.html) speculating about the possibility of some type of life (albeit, not as we know it) on Titan. I'd just love to think this is possible but I''m not convinced that the odds are very good. What does everyone think about this?

Brady Yoon
2004-Jul-03, 07:28 PM
I think there's a fairly good chance of microbial life (1% maybe), but the chances of intelligent life, I would say, are close to zero.

Gullible Jones
2004-Jul-03, 07:36 PM
Well, it would be nice if there's some form of life there... (It would most likely be microbial, as Brady pointed out.)

Brendan
2004-Jul-04, 12:48 AM
Could Titan develop some kind of life when it warms up when the sun turns into a red giant?

Brendan

Excelsior
2004-Jul-04, 07:20 AM
Intelligent life on Titan is unlikely even if the planet warms up. There is no oxygen on Titan so there will be no fire and hence no civilization.

Kullat Nunu
2004-Jul-04, 07:31 AM
Could Titan develop some kind of life when it warms up when the sun turns into a red giant?

Titan will not be suitably warm for long because it becomes too hot as the Sun expands. And the atmosphere probably won't survive.

Brady Yoon
2004-Jul-04, 08:17 AM
Either life has already formed on Titan, or it never will. That's my opinion.

Grand_Lunar
2004-Jul-04, 09:14 AM
Isn't there a lifeform on Earth that lives in petroleum deposits? I'd imagine a similar lifeform could from on Titan. Of course, it'd so cold there, it raises doubts. Perhaps Titan is warmer on the surface, or has internal heat. Bacteria on Earth has been found underground, so the same case may be on Titan (and other places). I think for further clues to how sturdy life is, we look at Antartica (aside from the penguins and seals). I know the amount of bacteria there is minimal, so if we look at what's there, it could help us understand what to look for else where.

harlequin
2004-Jul-04, 02:25 PM
Intelligent life on Titan is unlikely even if the planet warms up. There is no oxygen on Titan so there will be no fire and hence no civilization.

A small nit: intelligent life does not require oxygen. A technological civilization almost certainly does though. If dolphins were super geniuses they would be intelligent, but unable to make technology due to lack of hands and living in water. (Of course they could handle technology of some sort if we uplifted them a la David Brin's uplift novels.)

Ilya
2004-Jul-04, 06:13 PM
A small nit: intelligent life does not require oxygen. A technological civilization almost certainly does though. If dolphins were super geniuses they would be intelligent, but unable to make technology due to lack of hands and living in water.

Not a convincing example :) Dolphins DO require oxygen, and so do cephalopods (the most intelligent invertebrates), even though the latter absorb it from water. And cephalopods HAVE hands of sorts, as do many other aquatic invertebrates, but lack of fire under water would be a major barrier to technology.

Anaerobic respiration produces about 20 times less energy than aerobic one, so any macroscopic anaerobe would move very very slowly. That in itself does not preclude intelligence, just ensures a teatime conversation will last from late March until mid-April. ;)

Here is a topic for a SF story - anaerobic land-based intelligent alien. Although Frederick Pohl already did that, in one of the Heechee books.

Bozola
2004-Jul-04, 09:12 PM
You are more likely to find The Weekly World News or The National Enquirer, instead.

One Day More
2004-Jul-05, 05:03 AM
Just a speculation here: How hot would it get on Titan when the sun becomes a red giant? How about, for fun, say Triton and the other moons of Neptune?

Yorkshireman
2004-Jul-05, 10:57 AM
The main snag, as I understand it, with Titan is that it's too cold for liquid water to exist. And as far as I am aware all carbon-based life requires liquid water as a solvent agent (even the life inside the antarctic rocks is based round residual moisture.)

Stephen Baxter in his sci-fi novel 'Titan' postulated a kind of life where the water chemistry is systemattically replaced with ammonia. So a guanine molecule would, on Titan, be ammono-guanine, and you then have the start of an ammonia-based amino acid chain. However, sci fi is one thing.... I haven't the biochemistry knowledge to know if that's at all feasible in reality. Does anyone here on the board?

Rob.

Amadeus
2004-Jul-05, 01:10 PM
The problem with any "is there life on" question is we only have one frame of reference which is our own. This get's even more suspect whe nwe say "intelligent life must have"

Basicly the only way to know is to go there and see if anythings growing or moving.

DNA might not be the only way to sequence for the next generation.

After we have done a full audit of our solar system we will be able to compare enviroments more. We have quite a varied range of enviroments in our system so we could use these as a model to applie to the rest of the universe.

Basicly lets just keep an open mind until we know more. :wink:

eburacum45
2004-Jul-05, 02:10 PM
Just a speculation here: How hot would it get on Titan when the sun becomes a red giant? How about, for fun, say Triton and the other moons of Neptune?

Well, if the Sun becomes 3000 times as luminous, the comfort zone moves out to 50 au; beyond Neptune and Pluto.
So Neptune, at 30AU, will recieve about 2.5 times the radiation we recieve on Earth; if you managed the albedo and the greenhouse effect carefully, you could possibly maintain a habitable temperature on Triton, Proteus and Nereid. Probably need an orbiting mirror swarm to reflect some of the heat.

Argos
2004-Jul-05, 02:22 PM
If dolphins were super geniuses they would be intelligent, but unable to make technology due to lack of hands and living in water.

Living in water prevents a species from producing fire, which is needed to transform raw material. Without it you canīt have technology. The steadiness of a liquid medium also should play a role in slowing the development of intelligence. Intelligence would require a higher level of disturbance; it would need challenges.

As to the need of Oxygen and stuff, Arthur Clarke once decribed a cold world in the deep space. It harbored a global intelligence consisting of the crystals and metals spread all over the planet. The cold superconducting materials conveyed electric pulses across the planet, making a big planet-size brain. I donīt remember that short-story title.

skeptED56
2004-Jul-05, 05:47 PM
If dolphins were super geniuses they would be intelligent, but unable to make technology due to lack of hands and living in water.

Living in water prevents a species from producing fire, which is needed to transform raw material. Without it you canīt have technology.

Bio-tech! :o *Starts typing*

Tuckerfan
2004-Jul-05, 06:14 PM
The main snag, as I understand it, with Titan is that it's too cold for liquid water to exist. And as far as I am aware all carbon-based life requires liquid water as a solvent agent (even the life inside the antarctic rocks is based round residual moisture.)

Stephen Baxter in his sci-fi novel 'Titan' postulated a kind of life where the water chemistry is systemattically replaced with ammonia. So a guanine molecule would, on Titan, be ammono-guanine, and you then have the start of an ammonia-based amino acid chain. However, sci fi is one thing.... I haven't the biochemistry knowledge to know if that's at all feasible in reality. Does anyone here on the board?

Rob.Asimov wrote an article about it called something like The Thassoleans, in it, he basically shoots down any possibility of life evolving on a planet with a non-oxygen atmosphere. Mind you, this article was written before the discovery of deep sea life at the cold seeps, so it might not be accurate, and I haven't reread it recently enough to remember the details.

harlequin
2004-Jul-05, 07:09 PM
A small nit: intelligent life does not require oxygen. A technological civilization almost certainly does though. If dolphins were super geniuses they would be intelligent, but unable to make technology due to lack of hands and living in water.

Not a convincing example :) Dolphins DO require oxygen, and so do cephalopods (the most intelligent invertebrates), even though the latter absorb it from water. And cephalopods HAVE hands of sorts, as do many other aquatic invertebrates, but lack of fire under water would be a major barrier to technology.


You missed the point of the example: intelligence does not
mean technological civilization. One does not imply the other.
(Indeed technological civilization has existed less then ten percent
for the lifetime of our species.)

Imagine a dolphin-like creature that does not use oxygen.


Anaerobic respiration produces about 20 times less energy than aerobic one, so any macroscopic anaerobe would move very very slowly. That in itself does not preclude intelligence, just ensures a teatime conversation will last from late March until mid-April. ;)


You have forgotten that life on Earth has evolved to adopt to conditions which exists here on Earth. Life outside of Earth is not limited by the solutions found by lifeforms on Earth. If you want to say that no form of metabolism can exist in un-Earth like enviroments that is suffient for large "animals" then you are going to have to provide strong evidence for that claim. I will not accept it on faith. ("Animals" is in quotes since any alien "animal" will not be a member of the animal clade for obvious reasons.)


Here is a topic for a SF story - anaerobic land-based intelligent alien. Although Frederick Pohl already did that, in one of the Heechee books.

I have not read that one. Though the kind of aliens imagined by SF authors seems endless.

Doodler
2004-Jul-05, 08:11 PM
Here's my question. If it turns out Titan is tectonically active, could it be that there are thermal hotspots where life might be triggered?

If it turns out that these are hot vents and not like the ice geyers of Triton.

Ilya
2004-Jul-05, 10:01 PM
You have forgotten that life on Earth has evolved to adopt to conditions which exists here on Earth. Life outside of Earth is not limited by the solutions found by lifeforms on Earth. If you want to say that no form of metabolism can exist in un-Earth like enviroments that is suffient for large "animals" then you are going to have to provide strong evidence for that claim. I will not accept it on faith. ("Animals" is in quotes since any alien "animal" will not be a member of the animal clade for obvious reasons.)


No, I do not make such a claim. I do however claim that with ANY form of metabolism a creature's ability to move depends on the energy density of whatever it uses for food. No photosynthesis-dependent organism can move around on its own volition - low energy density of sunlight, plus inefficiency of photosynthesis itself preclude a plant from generating enough burnable sugar to push its own mass along. It is no coincidence that the only plants which CAN rapidly move parts of themselves are carnivors (Venus Flytrap and such) - able to use a high-energy food source.

There is no fundamental biophysical reason why flying dragons should not exist. Animals get their energy by oxidizing carbon compounds, and so do airplanes. But fueling airplane engine with liquefied beef, and see how far it will fly. Meat may be high-energy food compared to plant matter, let alone sunlight, but it is pitifully low-energy compared to pure hydrocarbons. A dragon is possible, but only if it has access to unlimited amount of oil, and cells which burn hydrocarbons instead of glucose.

So you are right - there can be many forms of metabolism which do not exist on Earth, possibly even utilizing nuclear instead of chemical energy. But that energy must come from somewhere. Earth has no easily accessible sources of oil (they tend to burn when exposed to air), so no hydrocarbon-burning animals ever evolved. OTOH, a planet with no free oxygen can easily have hydrocarbon lakes or seas, but without ready supply of oxidizer it is not a very useful energy source.

01101001
2004-Jul-05, 11:05 PM
It is no coincidence that the only plants which CAN rapidly move parts of themselves are carnivors (Venus Flytrap and such) - able to use a high-energy food source.
Oh? What high-energy food source does Mimosa pudica (animation (http://www.botanical-online.com/animation7.htm)) use?

Ilya
2004-Jul-06, 01:58 AM
Oh? What high-energy food source does Mimosa pudica (animation (http://www.botanical-online.com/animation7.htm)) use?

You got me there! But I suspect mimosa can perform its "shy reflex" only a few times per day - absorb sunlight over long enough time, then expend the accumulated sugar in a short burst of energy.

Which reminds me of a Usenet discussion which tried to design a workable dragon. The only solution they came up with which did not violate laws of physics was "only fly once in a great while". A "fully fueled" dragon flies for about half an hour. That's enough time to grab several cows and carry them to the cave. The dragon eats them all, then goes to sleep. Some of the meat goes into normal animal metabolism, the rest gets rendered into high-energy fuel which drives wing muscles. A week or two later the dragon wakes up, ready to fly again.

Why such thing never evolved is obvious. If you fail to FIND the few cows during that half hour, you are in real trouble...

ToSeek
2004-Jul-06, 01:36 PM
Why such thing never evolved is obvious. If you fail to FIND the few cows during that half hour, you are in real trouble...

So, first off, you need an environment with lots of cows (or the equivalent). Maybe New Zealand would do, if you could substitute sheep. ;)

Emspak
2004-Jul-06, 07:27 PM
To answer the posts about dragons: remember that during the age of the dinosaurs there were flying creatures with 50 foot wingspans, notably Quetzalcoatlus, a pterosaur the size of a plane.

It wasn't a dragon in the conventional sense, but the thing was probably big enough to fly off with a good-sized animal -- the available evidence is that when it went fishing (as modern pelicans, seagulls and frigate birds do) it could fly off with something the size of a tuna. Again, as a modern analogy, frigate birds and seagulls can fly away with baby turtles, which are pretty heavy relative to the bird.

As to metablisms and such, Stephen Baxter -- in his book Traces, I think -- posits intelligent life based on a nitrogen/water ice/methane chemistry, on a Titan that has been warmed up by an expanding sun. (He had creatures whose bones were water ice and who breathe nitrogen).

Oxygen is a pretty efficient metabolic method, but there are other gases and chemicals with reaction rates that are comparable. Imagine life that used, say, hydrochloric acid as the solvent -- it need not be carbon-based.

There are three other atoms that have four bonds and could create pretty complex molecules. They are: Silicon, Tin, Gallium, and Lead. The form of a "DNA" molecule with those chemicals would, of course, be very different, and the whole metabolic cycle would be based on something else.

And underwater environments certainly provide a pretty challenging environment -- squids and octopoda are pretty smart as they go. So are dolphins. magine an environment that favored smarter Octopi and you could go pretty far. Also, there is no lack of fire underwater at great depths. You get some pretty interesting transformations of chemicals and metals at high pressures where lava seeps out. I could see intelligent underwater creatures making use of that. (Air travel would be something else again -- water is heavy stuff).

So I wouldn't write off life on Titan. Not likely, but I won't write it off, and I think there are many possibilities for intelligent beings. How many pan out, we won't know for a long while yet.