In addition, there may be more oceans in the universe than previously thought and increase the viability of life beyond the Earth.
A new ocean discovered on Pluto is believed to have frozen, in fact may be obscured from view by an insulating gas cloud .
In July 2015, NASA's New Horizons spacecraft flew over Pluto and provided the first close-up images of its distant dwarf planet and moons.
After analyzing the images, scientists believe that there is an ocean bottom under the ice cover in a Texas-sized basin called Sputnik Planitia.
The team from Hokkaido University, Tokyo Institute of Technology, Tokushima University, Osaka University, Kobe University and the University of California in Santa Cruz believe that the ocean has frozen from millions of years ago.
In the new study published in Nature Geoscience, researchers created computer simulations for 4.6 billion years, when the Solar System began to form.
The simulations show that without the hydrothermal insulation, the sea bottom of Pluto will freeze from hundreds of millions of years ago because it will only take a million years for the ice to form completely on the ocean.
But the results show that the ocean on Pluto is hardly frozen, and it slows the process from a million to a billion years.
Therefore, the team believes that there must be an "insulating layer" of ice-like solids formed from gas and trapped in molecular water cages below the surface.
Because these hydrates have a high viscosity and low thermal conductivity, they can produce insulating effects.
The team believes that the insulation is likely to be made from methane gas emanating from the rock core of Pluto.
Shunichi Kamata, associate professor at Hokkaido University, said: "This means more oceans in the universe than previously thought, making the existence of extraterrestrial life more plausible. .