Can you live on Pluto?

Possible habitat Ice planet Pluto: gas hydrates protect the subterranean ocean

In 2015, NASA's New Horizons probe made measurements of Pluto so precisely that researchers can now get a more precise picture of the surface of the distant dwarf planet. Among other things, the astronomers discovered a bright surface that they called "Sputnik Planitia".

Based on the shape and surface of "Sputnik Planitia", scientists conclude that there is an underground ocean below Pluto's surface, and that the ice sheet at "Sputnik Planitia" is thinner.

But how is that possible? According to previous models, the temperature of the planetary core of Pluto would have to be higher in order to explain the liquid state of the water and the different thicknesses of the ice sheet. An international team led by Shunishi Kamata from Hokaido University in Sapporo, Japan has now found another possible explanation.

Using computer models, the scientists calculated that so-called gas hydrates probably form a kind of insulating layer between the ocean and the ice sheet. Gas hydrates are basically ice-shaped water that traps gases. Such gas hydrates are usually very viscous and poor heat conductors.

In their simulations, the researchers calculated a total period of 4.6 billion years. If they left out the gas hydrate layer in theirs, the ocean froze completely and a uniformly thick layer of ice formed. With the gas hydrate layer, however, the ocean could practically no longer freeze and the ice sheet formed much more slowly and less uniformly.

It is most likely that the gas in the gas hydrate is methane, according to the scientists. That would explain the planet's unusual atmosphere, which contains a lot of nitrogen but little methane.

The model developed by the researchers suggests that there could also be liquid oceans on many other moons or planets, even if these celestial bodies receive little heat from the nearby star. "It could mean that there are more oceans in the universe," believes Shunishi Kamata. "That would make the existence of extraterrestrial life more likely."