Scientists believe that Pluto has an underground ocean, and they also believe that such underground frozen oceans are very common in the world.
This is a picture of Pluto returned by the “New Horizons” spacecraft in July 2015. The large white area in the picture is the “Sputnik Planitia”.
But why doesn’t such an underground ocean freeze? Pluto isn’t that big after all. In a recent study, scientists hypothesized that there is a layer of gas insulation that isolates Pluto’s underground ocean from the low-temperature environment outside, achieving a thermal insulation effect in a sense. Researchers believe that similar phenomena should be common on other similar planets.
The study’s lead author, Professor Shunichi Kamada of Hokkaido University, Japan, said in a media statement: “This may mean that the world’s oceans are more common than we originally thought, and because of this, extraterrestrial life exists The odds are going to be higher.”
One of the evidences for the existence of an ocean beneath Pluto comes from the location of the so-called Sputnik Planiti on Pluto’s surface. This is a huge heart-shaped plain with a diameter of more than 1,000 kilometers. The surface is covered by a vast layer of white nitrogen ice. In 2015, the United States ” In all the close-up images of Pluto returned by New Horizons, this unique “love” has become the most distinctive surface feature of Pluto.
Observations by the “New Horizons” show that “Sputnik Planitia” is in the same direction as Pluto’s gravitational force. In this direction, Pluto’s largest satellite Charon exerts the greatest tidal force on Pluto. Scientists believe that the reason why Pluto has such a situation is that there is some extra mass concentration area near the “Sputnik Planitia”.
How does this extra mass concentration come about? Original research believed that this situation may originate from the accumulation of large amounts of nitrogen ice on the “Sputnik Planitia” and its underground ocean. When a comet impact in ancient times created the large impact basin that became Sputnik Planitia, much of the water in this ocean surged up and froze, creating a concentration of mass in the area. .
However, after 4.6 billion years, can this underground ocean still remain liquid? After all, as a dwarf planet, Pluto orbits the sun, rather than orbiting a gas giant planet like Io and Enceladus, and can be heated by the intense gravitational force exerted by the giant planet. It is precisely because of this heating mechanism that both Io and Enceladus are able to preserve liquid underground oceans.
In this latest research, scientists gave a new explanation: Professor Kamada Shunichi and his colleagues imagined a layer of so-called “gas hydrate”, which is a solid similar to ice, but in the gaps between water molecules There is a lot of gas trapped, and this strange layer of material exists beneath Pluto’s ice. Will such a layer of material have any significant effect?
In order to test this hypothesis, Professor Kamada Junichi’s research group conducted computer simulation deductions. The results were unexpected: assuming that there was no such “gas layer”, Pluto’s underground ocean was completely frozen in just a few hundred million years. After adding this “gas layer”, the underground ocean on Pluto can actually remain liquid to this day. At the same time, the study also found that this layer of material also ensures a certain low-temperature environment on the surface of Pluto by blocking the conduction of heat to the deep underground, which can explain the thickness of the ice layer observed on the surface of Pluto.
However, it is still not possible to confirm whether such an imaginary material layer actually exists, and it is not yet possible to confirm the composition of the gas trapped between water molecules in this material layer. The research team is more inclined to believe that it is methane, mainly because Pluto’s atmosphere contains a lot of methane. The relevant research paper has been published in the journal Nature Geoscience published on May 20.