Here are some reference sites to help you decide how to answer the poll questions.
Ganymede
Europa
Titan
Mars
Titania

that was a redundant poll as all eukaryotic cells are multi cellular. but i think its europa, or titan due to several shows i have viewed!

I said simple, non eukaryotic life. Eukaryotes have cell walls and a nucleus as opposed to prokaryotic cells. They also have mitochondria.

Europa is without a doubt the most probable body in our solar system to harbor life. It is time to get off the mars bandwagon. It is my personal belief that mars once had life of some kind, probably even intelligent life, but all that is long gone now. Europa has the best chance in our solar system of harboring multi-cellular organisms. It almost definatly possess's vast oceans that go to tremendous depths as evidence from past Jupiter missions that produced intriguing pictures of the cracked ice surface of Europa and evidence of an ocean beneath. Even in complete darkness in the depths of our oceans we have discovered life that prospers even without the aid of photosynthesis, instead in the complete darkness of the black abyss located at the oceans deepest trenchs. These organisms prosper from volcanic vents in the ocean floor. The same might, and probably will, be true about Europa. Europa is routinely tugged back and forth by the gravitational effects of Jupiter and the other resident moons. This tug of war like action will almost definatly cause volcanic activity at the ocean floor. Therefor I see a very strong likelyhood of multi-cellular organisms at the ocean floor of Europa. However, for intelligent life you are going to have to set your sights on another solar system in order to find natural residential intelligent EBE's.

PG, while I might argue a few of your points further, I agree with much of what you said and I appreciate the cogent post. Nice to see someone thinking clearly.

theres definatly a high chance of life on europa consitering its a whole ocean under that ice.

I doubt that complex life has evolved anywhere in the solar system other than on Earth.

Titan and Titania are unlikely... far too cold for the sort of chemical reactions necessary for life. Titan may have life in a few billion years when the sun goes red giant.

Mars may very well have evolved simple life. It was certainly warmer and wetter in the past. If life evolved there it is highly likely that it has survived.

Europa may very well have some form of life if the ocean does exist under the ice (remember that all though the evidence is strong for this ocean it is still not a proven fact). There maybe hydrothermal vents in this ocean providind nutrients for a similar food chain to that found deep in earths oceans. The same situation is possible but less likely on Ganymede.

If the Pan spermia theory is correct life simple may common through out the solar system. This theory is that life actually evolved on comets and was then brought to other bodies, such as the Earth, by impacts.

If there IS indeed life....It would more likely be on Europa. Titan and Europa are the two most habitable celestial bodies out there, Europa has water oceans, Titan has Methane oceans.

there is no proof there are oceans under Europa??(well i dont think there is anyway)
Europa could just turn out to be a giant ice ball with a solid core
i dont know about titan there might some very primitive life something like bacteria
but i dought it

Very good chance


Probably not. The core is the center, and it has a crust of ice that breaks and floats like tectonic plates. There IS something liquid under there.

I disagree that having a methane ocean makes Titan habitable. The chemistry of life requires liquid water not just a liquid ocean. Titan is so cold that water is as hard as rock. Mars is a far likelier place to find life than Titan.

only us Humans and other Earth lifeforms require water. .......we really dont know schit when it comes to other lifeforms.

look at roaches for example, they can survive in extreme cold and extreme radiation.

so who's to say that lifeforms in other parts of the system under extreme cold/extreme radiation conditions would be impossible?

good point, we got no clue what life forms really need to survive, just cause we needed water doesnt mean others do either actually

Titan is actually warmer than thought. The methane gas creates a 'greenhouse effect'.

Define extreme cold! Even if Titan is warmer than thought it is still -178°C (-289°F) at the surface.

Life requires some complex chemistry. The only type of chemistry which produces the complexity for life is carbon based (organic chemistry). That chemistry simply cannot occur at the temperatures found on Titan. Life just can not occur there. On top of this water has some fairly unique properties. It is highly unlikely that life could occur without it.

The conditions you describe as being extreme conditions that a roach can survive at are nothing of the sort. They maybe extreme by earth standards but they are positively mild by the the standards of the rest of the solar system.

Chemistry is the same every where in the universe. We can, therefore, have a very idea of what life non other planets would require.

We though life needed life, but then we discovered Chemoautotrophs. Life is still not defined

I'm asuming that you meant life needed light. Primative life did not rely on photosynthesis. In fact when photosynthesis began the oxygen that was pumped into the earths atmosphere was poisonous to most life on earth, leading to mass extinction. There are many bacteria which gain their energy fron chemical "fixing".

However none of this changes the fact that the basic chemistry is very similar. Only organic chemistry offers the complexity that is necessary for even simple life. Chemicak reactions slow down as temperature decreases. At Titans temperature chemical reactions would proceed too slowly for the chemistry neccessary for life to occur. Life is almost certainly impossible on Titan. Give Titan a few billion years, wait for the sun to go red giant and then Titan will be the perfect place for life to form. It has all the necessary chemicals for life. It's just too cold.