In http://www.esa.int/SPECIALS/Cassini-...B881Y3E_0.html, the
ESA said that "instead of lava, Titanian volcanoes spew very cold ice."
Does this mean that Titan's interior is warm enough for liquid water to
exist? Or are these volcanoes just oozing warmed-but-not-melted solid
water ice? Perhaps Titan has an underground ocean, like the one on
Europa.