Warm beginnings for Pluto
Pluto might have had a hot start, a new study suggests. Planetary scientists know the dwarf planet currently has a subsurface water ocean, but they are uncertain about how long it has been there. The traditional formation theory has Pluto beginning as a frozen ball which was later thawed by radioactive rocks, but another theory proposes that the dwarf planet retained enough heat from its genesis to maintain a liquid ocean throughout its life.
These two processes both involve complex, but different, patterns of thawing and refreezing. Each creates a specific type of surface feature, which geologists can use to differentiate between the two theories. “Now that we have images of Pluto’s surface from NASA’s New Horizons mission, we can compare what we see with the predictions of different thermal evolution models,” says Francis Nimmo from the University of California, who took part in the study.
The features in these images seem to suggest that Pluto began warm, meaning it must have trapped almost all of the heat from its initial formation. http://pluto.jhuapl.edu/