Pluto's subsurface ocean kept from freezing by gas layer

  • 5 years ago
PLUTO — New research provides evidence of an ocean buried in Pluto that's kept from freezing by an insulating layer.

According to CNN, observations made by NASA's New Horizons spacecraft in 2015 on Pluto's ellipsoidal basin Sputnik Planitia have led scientists to believe an ocean exists beneath the planet's icy surface.

Pluto is roughly 4.6 billion years old and isn't in the vicinity of a gas giant that could heat it using tidal forces. Its ocean should have frozen millions of years ago, but evidence suggests it has not.

A new study published in Nature Geoscience suggests an insulating layer of gas hydrates, which are ice-like solids that form when gas bubbles — in this case methane — are trapped between frozen water molecules.

Computer simulations conducted by the researchers show the ocean hardly freezes with a gas hydrate layer present. Without the hydrate layer, however, the subsurface ocean would have frozen completely hundreds of millions of years ago.

The theory might also explain the unique composition of Pluto's atmosphere, which is rich in nitrogen but poor in methane.

Researchers say that if gas hydrate insulating layers could indeed keep subsurface oceans from freezing, there may be more oceans in the universe than previously thought.