Kraken Mare is the largest sea on the surface of Saturn’s moon Titan. It is a huge body of liquid ethane and methane near Titan’s north pole. The sea covers 154,000 square miles.
Cornell astronomers have estimated that the sea to be at least 1,000 feet deep near its center.
The data for this discovery was gathered on Cassini’s T104 flyby of Titan on Aug. 21, 2014. The spacecraft’s radar surveyed Ligeia Mare – a smaller sea in the moon’s northern polar region – to look for the mysteriously disappearing and reappearing “Magic Island,” which was an earlier Cornell discovery.
While Cassini cruised at 13,000 mph, nearly 600 miles above Titan’s surface. Using its radar altimeter, the spacecraft measured the liquid depth at Kraken Mare and Moray Sinus, an estuary located at the sea’s northern end.
The Cornell scientists, along with engineers from NASA’s Jet Propulsion Laboratory, had figured out how to discern lake and sea bathymetry (depth) by noting the radar’s return time differences on the liquid surface and sea bottom, as well as the sea’s composition by acknowledging the amount of radar energy absorbed during transit through the liquid.
The Moray Sinus was 280 feet deep, shallower than the depths of central Kraken Mare, which was too deep for the radar to measure.
Lead author Valerio Poggiali, a research associate in Cornell Center for Astrophysics and Planetary Science (CCAPS), said, “Beyond deep, Kraken Mare also is immense – nearly the size of all five Great Lakes combined. Titan represents a model environment of a possible atmosphere of early Earth.”
“To understand the depth and composition of Kraken Mare and the Moray Sinus is important because this enables a more precise assessment of Titan’s methane hydrology. Still, we have to solve many mysteries.”
“One such puzzle is the origin of the liquid methane. Titan’s solar light – about 100 times less intense than on Earth – constantly converts methane in the atmosphere into ethane; over roughly 10 million-year periods, this process would completely deplete Titan’s surface stores.”
“In the distant future, a submarine – likely without a mechanical engine – will visit and cruise Kraken Mare.”
“Thanks to our measurements, scientists can now infer the density of the liquid with higher precision, and consequently better calibrate the sonar aboard the vessel and understand the sea’s directional flows.”
- V. Poggiali et al. The Bathymetry of Moray Sinus at Titan’s Kraken Mare. DOI: 10.1029/2020JE006558