Sub surface ocean? Yeah, right.
Any heat from its formation is long gone and any radioactive or tidal heating (from passing asteroids) will be miniscule. To sum up its probably been a solid ball of ice for 4 billion years.
Any heat from its formation is long gone and any radioactive or tidal heating (from passing asteroids) will be miniscule. To sum up its probably been a solid ball of ice for 4 billion years.