Why Pluto may have an ocean under its icy shell

When the NASA’s New Horizons spacecraft buzzed by Pluto last year, it revealed tantalizing clues that the dwarf planet might have—or had at one time—a liquid ocean sloshing around under its icy crust. Now, a new analysis suggests it’s likely that that ocean still exists today.
The study, which used a thermal evolution model for Pluto updated with data from New Horizons, found that if the dwarf planet’s ocean had frozen into oblivion millions or billions of years ago, it would have caused the entire planet to shrink. But there are no signs of a global contraction to be found on its surface. As a matter of fact, the data show signs that Pluto has actually been expanding.
“The possibility that you could have vast liquid water ocean habitats so far from the sun…is absolutely incredible.”
“Thanks to the incredible data returned by New Horizons, we were able to observe tectonic features on Pluto’s surface, update our thermal evolution model with new data, and infer that Pluto most likely has a subsurface ocean today,” says Noah Hammond, a graduate student in the earth, environmental, and planetary sciences department at Brown University.
The pictures New Horizons sent back from its close encounter with the Kuiper Belt’s most famous denizen showed that Pluto was much more than a simple snowball in space. It has an exotic surface made from different types of ices—water, nitrogen, and methane.
It has mountains hundreds of meters high and a vast heart-shaped plain. It also has giant tectonic features—sinuous faults hundreds of kilometers long and as deep as 4 kilometers. It was those tectonic features that got scientists thinking that a subsurface ocean was a real possibility for Pluto.
“What New Horizons showed was that there are extensional tectonic features, which indicate that Pluto underwent a period of global expansion,” Hammond says. “A subsurface ocean that was slowly freezing over would cause this kind of expansion.”
Scientists think that there may have been enough heat-producing radioactive elements within Pluto’s rocky core to melt part of the planet’s ice shell. Over time in the frigid Kuiper belt, that melted portion would eventually start to refreeze. Ice is less dense than water, so when it freezes, it expands.
If Pluto had on ocean that was frozen or in the process of freezing, extensional tectonics on the surface would result, and that’s what New Horizons saw.     —www.futurity.org

Why Pluto may have an ocean under its icy shell

When the NASAs New Horizons spacecraft buzzed by Pluto last year, it revealed tantalizing clues that the dwarf planet might haveor had at one timea liquid ocean sloshing around under its icy crust. Now, a new analysis suggests its likely that that ocean still exists today. The study, which used a thermal evolution model for Pluto updated with data from New Horizons, found that if the dwarf planets ocean had frozen into oblivion millions or billions of years ago, it would have caused the entire planet to shrink. But there are no signs of a global contraction to be found on its surface. As a matter of fact, the data show signs that Pluto has actually been expanding. The possibility that you could have vast liquid water ocean habitats so far from the sunis absolutely incredible. Thanks to the incredible data returned by New Horizons, we were able to observe tectonic features on Plutos surface, update our thermal evolution model with new data, and infer that Pluto most likely has a subsurface ocean today, says Noah Hammond, a graduate student in the earth, environmental, and planetary sciences department at Brown University. The pictures New Horizons sent back from its close encounter with the Kuiper Belts most famous denizen showed that Pluto was much more than a simple snowball in space. It has an exotic surface made from different types of iceswater, nitrogen, and methane. It has mountains hundreds of meters high and a vast heart-shaped plain. It also has giant tectonic featuressinuous faults hundreds of kilometers long and as deep as 4 kilometers. It was those tectonic features that got scientists thinking that a subsurface ocean was a real possibility for Pluto. What New Horizons showed was that there are extensional tectonic features, which indicate that Pluto underwent a period of global expansion, Hammond says. A subsurface ocean that was slowly freezing over would cause this kind of expansion. Scientists think that there may have been enough heat-producing radioactive elements within Plutos rocky core to melt part of the planets ice shell. Over time in the frigid Kuiper belt, that melted portion would eventually start to refreeze. Ice is less dense than water, so when it freezes, it expands. If Pluto had on ocean that was frozen or in the process of freezing, extensional tectonics on the surface would result, and thats what New Horizons saw. www.futurity.org