Kraken Mare, the immense methane sea on Saturn’s moon Titan, has a depth of at least 300 meters near its center, more than enough for the projected underwater exploration on a human mission.
After examining data from one of the last overflights on Titan of the Cassini mission, researchers at Cornell University detail 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 big name, but also contains about 80% of the liquids. of the moon’s surface, “said lead author Valerio Poggiali, an associate researcher at the Cornell Center for Astrophysics and Planetary Science (CCAPS), in the Faculty of Arts and Sciences.
1.5 billion kilometers from Earth, the icy Titan is shrouded in a golden mist of nitrogen gas. But when looking through the clouds, the lunar landscape looks similar to that of Earth, with rivers, lakes, and seas of liquid methane, according to NASA.
Explorations on Titan yielded results
In fact, data for this discovery were collected in Cassini’s T104 overflight on Titan on August 21, 2014. The spacecraft’s radar inspected Ligeia Mare, a smaller sea in the northern polar region of the Titan. Moon, to search for the mysterious disappearance and reappearance of “magic island,” which was a previous discovery by Cornell.
While Cassini was sailing 900 kilometers above the surface of Titan, the spacecraft used its radar altimeter to measure the depth of the liquid at Kraken Mare and Moray Sinus, an estuary at the northern end of the sea.
Cornell scientists, along with engineers at NASA’s Jet Propulsion Laboratory, had discovered how to discern the bathymetry (depth) of the lake and sea by observing the differences in radar return time in the liquid surface and bottom of the sea, as well as the composition of the sea by recognizing the amount of radar energy absorbed during transit through the liquid.
It turns out that Moray Sinus is about 90 meters deep, less than the center depths of Kraken Mare, which was too deep for the 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 the nearby Ligeia Mare, Titan’s second largest sea.
Earlier scientists had speculated that Kraken could be richer in age, both in size and extent at the lower latitudes of the moon. The observation that the liquid composition is not markedly different from other northern seas is an important finding that will help evaluate models of hydrological system similar to the Land of Titan.
Titan has an Earth-like atmosphere
Beyond the deep, Mother Kraken is also immense, almost the size of the five Great Lakes combined. Titan represents a model environment of a possible primitive Earth atmosphere, Poggiali said.
“In this context,” he said, “it is important to understand the depth and composition of Kraken Mother and Moray Sinus because this allows for a more accurate assessment of the hydrology of Titan’s methane. However, we have to solve many mysteries.” .
One of these riddles is the origin of liquid methane. Titan’s sunlight, about 100 times less intense than on Earth, constantly converts methane from the atmosphere into ethane; For periods of about 10 million years, this process would completely deplete Titan’s surface reserves, according to Poggiali.
In the distant future, a submarine, probably without a mechanical engine, will visit and sail Kraken Mare, Poggiali said.
“Thanks to our measurements,” he said, “scientists can now infer the density of the liquid more accurately and, as a result, better calibrate the sonar on board the ship and understand the directional flows of the sea.”
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