A new examination of data from more than a decade ago indicated that Titan, Saturn’s largest moon, may not have a vast ocean beneath its frozen surface, as was believed until now.
Data from NASA’s Cassini mission, which began in 1997 and lasted nearly 20 years, made researchers suspect that Titan harbored a large body of liquid water beneath its ice layer, But when they modeled the Moon with the ocean, the results did not coincide with the physical properties of these ecosystems.
“Instead of an open ocean, like the one we have on Earth, we are probably facing something more like sea ice of the Arctic or aquifers, which would have implications for the type of life we could find,” explains Baptiste Journaux, space researcher at the American University of Washington. Journaux is one of the authors of the article collected in Nature this Wednesday, revealing the latest findings on Titan.
The Cassini mission produced a wealth of data on Saturn and its 274 moons. Titan, shrouded in a hazy atmosphere, is the only world other than Earth known to have liquid on its surface. Its temperature would be around -182 degrees Celsiusit would therefore be a frozen surface.
As Titan orbited Saturn in an elliptical fashion, researchers observed that the moon stretched and flattened depending on its position relative to the planet, which is why in 2008 they proposed that the Moon must have a huge ocean beneath the surface to allow for such significant deformation.
“The degree of deformation depends on Titan’s interior structure. A deep ocean would allow the crust to flex more underwater. Saturn’s gravitational pull. If Titan were completely frozen, it would not deform as much,” Journals said. “The deformation we detected during the initial analysis of Cassini mission data could have been consistent with a large subsurface ocean. Now we know that’s not entirely the case,” he adds.
Time is the key
In the new study, Researchers introduce a new level of subtlety: time. Titan’s change in shape lags behind the peak of Saturn’s gravitational pull by about 15 hours.
Like a spoon stirring honey, it would take more energy to move a thick, viscous substance than to move liquid water. Measuring this delay revealed to scientists the amount of energy needed to change Titan’s shape, which led them to conclude that its interior is viscous and not liquid.
“It was irrefutable proof that Titan’s interior is different from what was deduced from previous analyzes“says another of the authors, Flavio Petricca, researcher at NASA.
The new model they are proposing for Titan presents more sleet and much less liquid water than the previous one, as the slush is thick enough to account for the delay, but still contains water, allowing Titan to transform when thrown at him.
Petricca arrived at this conclusion by measuring the frequency of radio waves coming from the Cassini spacecraft during flybys of Titan, and Journaux helped support these results with studies of thermodynamics.
The possibility of returning to life remains open
Although the idea of an ocean on Titan stimulated the search for life There, researchers believe the new discoveries could improve the chances of finding it.
The analysis indicates that pockets of fresh water on Titan could reach 20 degrees. All available nutrients would be more concentrated in a small volume of water than in an open ocean, which could facilitate the growth of simple organisms.
Although it is researchers are unlikely to discover fish In the mud channels of these lakes, if life were found on Titan, it could resemble Earth’s polar ecosystems.
Journals is part of the team for the next mission NASA’s Dragonfly to Titan, scheduled to launch in 2028. The data collected here will guide the mission, and Journals hopes to return with evidence of life on the planet and a definitive answer about the ocean.
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