New Cassini map of Titan reveals an Earth-like sea level
An international team of scientists has discovered that the Saturnian moon Titan has its own sea level dictating the height of its alien hydrocarbon oceans. The new discovery adds to a growing list of geological characteristics and processes that the enigmatic moon has in common with Earth.
On September 15 last year, NASA's Cassini spacecraft ended its nearly two decade long space odyssey by plunging into the atmosphere of Saturn, leaving behind a rich legacy of data on the gas giant and its moons that will keep scientists occupied making new discoveries for decades to come.
Titan is a pretty quirky moon. It has been found to play host to convective clouds, tectonic activity, and, of course, is the only known world in our solar system to have a stable liquid ocean on its surface. Granted, these are not water oceans as we know them on Earth, but rather oceans comprised of organic compounds known as hydrocarbons.
Needless to say, Titan's unusual features received a lot of attention from Cassini during its extended stay in the Saturnian system. Using Cassini data, a team of scientists has constructed an upgraded topographic map of the moon, an analysis of which has led to the recent publication of two scientific papers detailing several fascinating insights into the nature of the enigmatic world.
Arguably the most exciting revelation is that Titan's alien oceans have a consistent elevation relative to the moon's gravitational influence – in other words, a sea level. It is possible that the uniformity of the oceans is due either to an underground connection between the oceans, or a surface channel that bridges the bodies of liquid.
On Titan, as on Earth, lakes have been found to exist hundreds of meters above sea level. The new topographic map, which allows scientists to determine the elevation of a feature to an accuracy of roughly 40 cm (16 in), also revealed that high-altitude lakes in close proximity also seem to share a water level. This could be the result of an underground aquifer system that connects the hydrocarbon lakes, essentially causing them to behave as a single body, and so share a common water level.
An analysis of the map additionally led to the discovery of a number of previously unknown mountains, the tallest of which stands no higher than 700 m (2,297 ft) above the surface. Scientists were also able to use Cassini data in conjunction with the topographic map to determine that two depressions located at Titan's equator represented either dried seas, or the location of cryovolcanic activity.