Titan’s largest sea could be over 300 meters deep

Earth’s oceans are notoriously unexplored and a monument to the difficulties of exploring underwater. But these are not the only unexplored seas in the solar system. Another challenge facing future explorers of the solar system is Titan’s vast collection of liquid methane lakes.

An underwater mission to Saturn’s largest moon has long been the subject of discussion. More recently, scientists have discovered that if such a mission were ever launched, it would have plenty of room to function, as Titan’s largest sea is likely over 300m deep.

This sea, aptly named Kraken Mare, has been the subject of a recent study by lead author Valerio Poggiali of Cornell and his colleagues, as has the not-so-apt name of Moray Sinus, an estuary located in the ‘northern end of the sea. They analyzed data from one of Cassini’s last overflights on Titan in August 2014. This data included radar measurements of Kraken Mare and its estuary.

The height from the sea surface to the bottom was calculated using the time differences in these radar signals. Additionally, the percentage of the signal that was returned to Cassini was used to determine a basic understanding of the composition of the sea.

The radar signal was unable to penetrate to the depths of central Kraken Mare, meaning the sea was deeper than the predicted range of 1,000 meters that scientists estimated for the effective distance than the signal radar was able to penetrate. Given that the sea is the size of the five Great Lakes combined, it is not particularly surprising that Cassini could not find the bottom of the middle of the sea. However, he was able to reach the depths of the Moray sine, which was noted at about 85 m (280 feet) deep.

Additionally, the signal attenuation they found indicated something unexpected: Kraken Mare is actually made up of more methane than ethane. Scientists expected ethane to dominate in the sea, largely because of its size and equatorial location. In fact, the composition of Kraken Mare is largely similar to that of other smaller lakes in the region, with a predominantly methane hydrology.

All of this data analysis and the development of hypotheses can fuel the development process of any future submarine mission to one of the solar system’s largest moons. While there are many considerations that go into the design of any future mission, it is now clear that regardless of the size of the craft, it will have plenty of room to function in the alien seas for which it is designed.

Learn more:
Cornell: Astronomers estimate Titan’s largest sea to be 1,000 feet deep
UT: Whoa. Lakes on Titan could be the craters of massive underground explosions
UT: How habitable is Titan? NASA sends Titan Dragonfly helicopter to find out

Main image: Artistic rendering of Kraken Mare.
Credit: NASA / John Glenn Research Center