Titan, the largest moon of Saturn and one of the most fascinating places in the solar system, is a world of rain, rivers, lakes and seas. Unlike Earth though, this alien hydrological cycle is composed of liquid methane rather than water, since the temperatures on Titan are far colder than even at the poles of our own planet.
It had long been theorized, however, that liquid water could actually exist on Titan – underground. Gravitational tugging from Saturn could create enough heat inside Titan to maintain a layer of water, similar to that on another Saturn moon, Enceladus and one of Jupiter’s moons, Europa (and possibly others as well). Literally, an underground ocean.
Now, new evidence from the Cassini orbiter has indicated that there most likely is indeed a Titanian ocean.
See Examiner.com for the full article.