Hi Guys

Nick wrote...

Do you really understand what you're saying, SM?

[Probably not, but he's not the first to suggest it. Isaac Asimov and Carl Sagan made similar suggestions in the 1960s.]

Jupiter is made mostly of unoxidised hydrogen gas, plus some helium and a trace of other stuff including the oxygen to make water.

[The upper layers are H/He, but water might condense out. Now what would it do?]

There is less than 1% H2O on Jupiter [3 Earth masses worth...]

so even if it did form an ocean it would be at the centre

[Not bloody likely Nick. We're talking about a lot of internal mixing happening in the guts of Jupiter. I doubt it'd end up in the core - if Jupiter has one...]

of a ball of gas weighing 300 Earth Masses and crushed to hellish pressures and temperatures by the load above.

[Curshed to? Is Jupiter hot from all that crushing or from internal energy sources? It certainly had a lot of heat of formation, but most of it radiated away a long time ago.]

In practice, most of the water is dispersed as water vapour in the body of the planet and any life would need to cope with intense up- and down-draughts, and huge oscillations in pressure and temperature.

In a word then,

NO.

- If Isaac and Carl could say "maybe", then I think you might be a bit more open-minded, Nick. More to the point Jupiter is on average more dense than water, so most of it must be Hydrogen compressed into a metallic state and on that a layer of high-pressure water vapour/liquid could conceivably rest. Besides SM was asking about exosolar planets as well, and certainly a lot of "ice-giants" - roughly Neptune/Uranus like - might exist out there with deep warm oceans.

Adam