Could Europa's Subsurface Ocean Support Life?

[Arch Enemy]

Hello there, new to the forums, but it looked like a good place with knowledgeable folks so I've decided to join!

My topic today will be on Jupiters moon Europa.

Its just to gauge others ideas on this moon and the chances of it sustaining, or having the potential to sustain life.

The cracks on the surface of the ice on Europa seem to suggest that it has an ocean under the ice, which would be the biggest ocean in the solar system. There doesn't appear to be any craters on the surface, which means the surface is probably still active, with the ice sheets moving regularly. Now, Europa being so far out from the sun, would not be able to maintain liquid water without the help of some other energy source. Would this be geological activity? Being so small, it should surely have lost this by now though? Also, could it be like what Io has, the gravitational push and pull of the surrounding moons, coupled with the pull of Jupiter itself creating the energy which is keeping the water in a liquid state?

How do we know its water under there and not some other liquid? Its not methane, but doesn't the moon Titan have a weather system with lakes and such with liquid methane?

And also, what are the chances that if there is a liquid water ocean under the icey surface of Europa, that it would be able to sustain life? What sort of pressures and other conditions could we expect down there? What might the condition of the water be in terms of acidity?

 

[Nakisima]

Europa is a tricky subject from the life-sustaining point of view. It has water and oxygen, both essential components for life. However, its distance from the sun is an obvious impairment, as even the lowest forms of life and single-celled organisms need a good source of light. Warmth would be a factor it certainly doesn't have. Things tend to slow down at such low temperatures. That said, I believe the proof is in the pudding, until we find such proof, we won't know for sure. Also, I think I've told you what anyone could have, so sorry in advance if this reply is a disappointment.

 

[Chronos]

Europa probably gets energy via tidal friction from Jupiter. It is likely sufficient to allow liquid water below its frozen surface.

 

[qraal]

Hello there, new to the forums, but it looked like a good place with knowledgeable folks so I've decided to join!

My topic today will be on Jupiters moon Europa.

My fave topic in astrobiology. Do go on.

Its just to gauge others ideas on this moon and the chances of it sustaining, or having the potential to sustain life.

Chances are good. It has water, minerals, and energy. Life? Maybe. Need to go look closer and deeper to find out.

The cracks on the surface of the ice on Europa seem to suggest that it has an ocean under the ice, which would be the biggest ocean in the solar system. There doesn't appear to be any craters on the surface, which means the surface is probably still active, with the ice sheets moving regularly.

Tidal flexing as it orbits Jupiter due to Europa's non-zero eccentricity is what keeps the ice moving. There are a few craters visible, but much of the surface seems "young".

Now, Europa being so far out from the sun, would not be able to maintain liquid water without the help of some other energy source. Would this be geological activity? Being so small, it should surely have lost this by now though?

Surprisingly, no. Geological processes are driven by radioactive decay in smaller bodies and the interior should be quite warm due to the insulating properties of all the ice.

Also, could it be like what Io has, the gravitational push and pull of the surrounding moons, coupled with the pull of Jupiter itself creating the energy which is keeping the water in a liquid state?

That is a large source of energy too, so it will play an important role.

How do we know its water under there and not some other liquid? Its not methane, but doesn't the moon Titan have a weather system with lakes and such with liquid methane?

Methane liquid needs methane gas over it to keep it in liquid form, and that isn't observed around Europa, not even a trace. Water forms one of the few ices that floats on its liquid phase. Methane ice wouldn't.

And also, what are the chances that if there is a liquid water ocean under the icey surface of Europa, that it would be able to sustain life?

Such an ocean has a supply of energy and a supply of oxygen from radiolytic decomposition of the ice. Question is if there's enough reducing materials available to react with the oxygen supplied and if it is recycled by the energy flows available in a possible ecosystem.

What sort of pressures and other conditions could we expect down there? What might the condition of the water be in terms of acidity?

The oceans might have a lot of solutes - dissolved compounds - and could be quite acidic. The pressure could be very high if the ice is very thick. Europa's gravity is 0.13 Earth's so the pressure rises by about 1 ATM per 75 metres of ice. Thus 15 km thick ice means a pressure of 200 ATM at the top of the ocean and much higher as you go deeper. But there might be thinner channels or cracks in the ice with lower pressures.