The largest body of liquid on Saturn's moon Titan is the formidably named Kraken Mare, a sea of methane that sprawls some 400,000 km 2 across the moon's north polar region. Next week, NASA's Cassini spacecraft will perform a flyby of Titan in search of wave activity atop this colossal sea of hydrocarbon.
Cassini will be investigating other aspects of Titan, as well, including its atmosphere and an assortment of terrestrial surface features, but the up-close look at Kraken Mare is especially exciting. Titan's seas and lakes are the only bodies of liquid in the solar system known to exist on a planet's surface (besides Earth's, that is). NASA is keen on gaining as much information on them as possible, and, eventually, exploring their depths.
Earlier this year, the Agency submitted a proposal to launch a submersible robot on a mission to Titan, with the intention of conducting detailed investigations below the surface of Kraken Mare:
This mission would be a logical follow-on to a Titan surface mission such as TiME (Titan Mare Explorer) or even a component of a flagship mission of multiple vehicles. The mission concept we propose to study will investigate a full spectrum of oceanographic phenomena: chemical composition of the liquid, surface and subsurface currents, mixing and layering in the "water" column, tides, wind and waves, bathymetry, and bottom features and composition. Measurements of all these aspects of Titan's hydrocarbon ocean environment can only be made through focused in situ exploration with a well-instrumented craft. This investigation represents a significant advancement in our understanding of the history and evolution of organic compounds in the solar system, and hence a critical step along the path to understanding the evolution of life here on Earth and potential life elsewhere in the galaxy.
Observations of Kraken Mare by Cassini could prove invaluable to NASA mission planners tasked with, say, selecting a landing site for submersible missions like this one.
We'll keep you posted on any images Cassini beams back.