Kraken Mare, the immense methane sea on Saturn’s moon Titan, has a depth of at least 300 meters near center, more than enough for projected underwater reconnaissance on a human mission.
After examining data from one of Titan’s newest Cassini flybys, researchers at Cornell University detailed their findings in a bathymetric study published in Journal of Geophysical Research.
“The depth and composition of each of Titan’s seas had already been measured, except for Titan’s largest sea, Kraken Mare, which not only has a great name, but also contains about 80% of the world’s liquids. moon, ”lead author Valerio Poggiali, a research associate at the Cornell Center for Astrophysics and Planetary Science (CCAPS) in the College of Arts and Sciences, said in a statement.
1.5 billion kilometers from Earth, the icy Titan is shrouded in a golden haze of nitrogen gas. But when you look through the clouds, the lunar landscape resembles Earth, with rivers, lakes and seas of liquid methane, according to NASA.
Titan explorations yielded results
The data for this discovery was even collected in Cassini’s T104 flyby from Titan on August 21, 2014. The spacecraft’s radar explored Ligeia Mare, a smaller sea in the Moon’s arctic, to search for the mysterious disappearance and return of ” magical island ”, an earlier discovery by Cornell.
While Cassini sailed 900 kilometers above Titan’s surface, the spacecraft used its radar altimeter to measure the depth of the liquid in Kraken Mare and Moray Sinus, an estuary on the north side of the sea.
Scientists at Cornell, along with engineers from NASA’s Jet Propulsion Laboratory, had discovered how to distinguish the bathymetry (depth) of the lake and the sea by looking at the time differences on the radar on the liquid surface and the bottom of the sea. , as well as the composition of the sea by recognizing the amount of radar energy that is absorbed by the liquid during transport.
It turns out that Moray Sinus is about 300 feet deep, less than the depths of downtown Kraken Mare, which was too deep for radar to measure. Surprisingly, the composition of the liquid, mainly a mixture of ethane and methane, was dominated by methane and was similar to the composition of nearby Ligeia Mare, Titan’s second largest sea.
Previous scientists had speculated that Kraken may be richer in ethane, both for its size and for its size to the lower latitudes of the moon. The observation that the liquid composition is not markedly different from the other northern seas is an important finding that will aid in evaluating models of Titan’s Earth-like hydrological system.
Titan has an atmosphere similar to Earth
Beyond the depths, Kraken Mare is also huge, almost the size of the five Great Lakes combined. Titan represents a model environment for Earth’s possible early atmosphere, Poggiali said.
“In this context,” he said, “it is important to understand the depth and composition of Kraken Mare and Moray Sinus, as it allows for a more accurate assessment of the hydrology of Titan’s methane. Yet we still have many mysteries to solve. . “
One such puzzle is the origin of liquid methane. Sunlight on Titan, about 100 times less intense than on Earth, constantly converts methane in the atmosphere into ethane; According to Poggiali, this process would completely deplete Titan’s surface reserves in periods of about 10 million years.
In the distant future, a submarine, likely without a mechanical engine, will visit and navigate Kraken Mare, Poggiali said.
“Thanks to our measurements,” he said, “scientists can now more accurately derive the density of the liquid and thus better calibrate the onboard sonar and understand the directed currents of the sea.”
LNB