Has Pluto got oceans beneath its surface?

23 Jun 2016

One of two potential cryovolcanoes spotted on the surface of Pluto by the New Horizons spacecraft, via NASA

New research into New Horizon images of Pluto lend further credence to the theory that oceans are swirling beneath the icy dwarf planet’s surface.

Our solar system is a waterpark. Almost three-quarters of the Earth’s surface is water. Jupiter’s Enceladus and Ganymede moons are home to oceans, with the former thought to be hydrothermal.

Comet 67p, which Rosetta chased, caught and sent a probe down to, has water ice. Mars, of course, sports liquid water. Saturn’s moon Titan has surface oceans, with NASA looking to send a spacecraft submarine probe there in future.

And now, after New Horizons’ wonderful mission to the perimeter of our solar system, our favourite dwarf planet Pluto may have water, too.

Despite it being 3,670,050,000 miles from the sun on average, investigations into images captured of Pluto hint at oceans below an expanding surface. That it’s expanding, despite the cold, is quite something.

It was thought that, if oceans once existed on Pluto, they would have frozen and contracted, creating cracks in the planet’s surface. This study though, published in Geophysical Research Letters, hints at tectonic features on Pluto allowing it to expand.

This image of haze layers above Pluto’s limb was taken by the Ralph/Multispectral Visible Imaging Camera (MVIC) on NASA’s New Horizons spacecraft.

This image of haze layers above Pluto’s limb was taken by the Ralph/Multispectral Visible Imaging Camera (MVIC) on NASA’s New Horizons spacecraft.

“What New Horizons showed was that there are extensional tectonic features, which indicate that Pluto underwent a period of global expansion,” said Noah Hammond, a graduate student in Brown’s Department of Earth, Environmental and Planetary Sciences, and the study’s lead author.

“A subsurface ocean that was slowly freezing over would cause this kind of expansion,” he said, claiming the ocean is not yet fully frozen, either.

An alternative theory is that the gravitational pull between Pluto and its moon Charon could cause the dwarf planet’s current topographical state.

However, the tectonic evidence seems far more recent than when the gravitational pull was at its strongest, millions of years ago.

Pluto

Fantastic Pluto image via NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute / Wikimedia Commons

Gordon Hunt was a journalist with Silicon Republic

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