One of the great revelations of the overflight was the discovery of an ocean under the ice shell covering Pluto. The ice shell was thin at a location near the Texas-sized Equator, known as the Sputnik Planitia, which allowed the researchers to be aware of Pluto's unusual topography and to suggest the Existence of the ocean.
But that created an enigma. Given the age of Pluto, estimated between 4.4 and 4.6 billion years ago, the ocean should have frozen hundreds of millions of years ago. And rather than forming a bubble, the ice shell should have been flattened over the frozen ocean.
The most likely scenario is the presence of gas between the ocean and the ice shell, which will act later as an insulator. This layer of gas, probably methane from the Pluton bedrock at the time of dwarf planet formation, would be thick and have low thermal conductivity.
The researchers believe that the layer exists in the form of gas hydrates, in which water molecules create lattice cages that trap gas molecules, according to the study.
And this layer of insulating gas would have caused the ice envelope to take more than a billion years to obtain a uniform thickness.
The atmosphere of Pluto is rich in nitrogen and low in methane. The layer of gas between the ice shell and the ocean could explain the location of the methane.
The implications extend to other icy oceanic worlds of our solar system, such as the Europa moon of Jupiter and the moon of Saturn's Enceladus, as well as to the exoplanets. If the insulating gas layers can prevent the underground oceans from freezing, there could be a profusion of oceanic worlds, the researchers said.
"It could mean that there are more oceans in the universe than previously thought, making the existence of extraterrestrial life more plausible," Shunichi said. Kamata, author of the study and Associate Professor in the Department of Earth Sciences and Planets of the University of Hokkaido in Japan, in a statement.