Inside -220°C solid ice, Pluto's underground ocean could make floating effortless
Produced by: Tarun Mishra
Credit: NASA/JHUAPL/SwRI
Pluto’s Icy Surface Conceals Secrets
Pluto's surface, perpetually chilled to a cryogenic -364 F (-220 C), is frozen solid. However, beneath its nitrogen ice layer, there might be a hidden subsurface ocean of liquid water.
Subsurface Ocean Hypothesis
Recent studies suggest this ocean could be deeper than Earth's crust and denser than Earth's seawater. The idea of liquid water on such a frigid, distant world may seem surprising, but clues from NASA’s New Horizons mission point to this possibility.
Clues from New Horizons Data
The lack of a bulge at Pluto's equator hints at a liquid interior. Additionally, the icy surface shows signs of fractures caused by stretching, potentially from water freezing beneath the nitrogen ice, as water expands when it freezes.
Cryovolcano Evidence
Some scientists believe Pluto hosts cryovolcanoes that emit water vapor or solid ice. This suggests the existence of a liquid water source beneath the surface.
Modelling Pluto’s Ocean
Researchers from Washington University in St. Louis and the Lunar and Planetary Institute in Houston created models to understand this subsurface ocean. They focused on Sputnik Planitia, a heart-shaped basin likely formed by an impact.
Goldilocks Zone for Ocean Characteristics
Graduate student Alex Nguyen and his team identified a "Goldilocks zone" where the ocean's density and thickness align with observed features. Their models suggest the ocean is 25 to 50 miles (40 to 80 kilometres) thick and 8 percent denser than Earth's seawater, akin to the Great Salt Lake.
Controversy and Uncertainty
Despite these findings, the concept of a Plutonian ocean is still debated. Some scientists argue the evidence could be circumstantial, and a recent study proposed Sputnik Planitia might have formed if Pluto had a solid interior.
Future Exploration Needed
Determining the true nature of Pluto's interior requires further exploration. Until a new mission follows in New Horizons' footsteps, the mystery of what lies beneath Pluto's surface remains unsolved.
Published Research
Nguyen and co-author Patrick McGovern published their findings in the journal Icarus on February 15, contributing to the ongoing debate and research about Pluto's potential subsurface ocean.