A NASA-funded study (abstract) says that analysis of the fractures on Pluto's giant moon Charon could reveal a subterranean ocean of liquid water.
Some moons around the gas giant planets in the outer solar system have cracked surfaces with evidence for ocean interiors - Jupiter's moon Europa and Saturn's moon Enceladus are two examples.
If the icy surface of Pluto's giant moon Charon is cracked, analysis of the fractures could reveal if its interior was warm, perhaps warm enough to have maintained a subterranean ocean of liquid water, according to a new NASA-funded study.
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The surface of Charon exhibits "pull apart" tectonic faults that are created when the surface expands and fractures, which would happen if a subsurface water ocean froze and expanded.
Charon's outer layer is primarily water ice. When the moon was young this layer was warmed by the decay of radioactive elements, as well as Charon's own internal heat of formation. Scientists say Charon could have been warm enough to cause the water ice to melt deep down, creating a subsurface ocean. But as Charon cooled over time, this ocean would have frozen and expanded (as happens when water freezes), pushing the surface outward and producing the massive chasms we see today.
Another source of heat to support a former subsurface ocean could have come from tidal friction, provided that Charon initially had a highly eccentric orbit, as reported here a year before the Pluto encounter by New Horizons.
(Score: 2) by Theophrastus on Monday June 23 2014, @12:24AM
so now that Pluto is not a planet then ipso-facto-quatly-demonstrandum: Charon is no moon. [stephen colbert hand-dusting-gesture]
(Score: 2) by tathra on Monday June 23 2014, @12:38AM
pluto and charon are a binary system since they're orbiting a point in space which lies outside of both bodies.
anyway, its generally understood that "moon" means "natural satellite" [wikipedia.org]. and nyx, hydra, kerberos, and styx are natural satellites (ie, moons) of the pluto-charon barycenter.
(Score: 2) by cmn32480 on Monday June 23 2014, @12:43AM
What should it be called?
An asteroid captured by the planet formerly know as Pluto's gravity?
A satellite of whatever the hell they are calling Pluto these days?
"It's a dog eat dog world, and I'm wearing Milkbone underwear" - Norm Peterson
(Score: 2) by tathra on Monday June 23 2014, @12:55AM
how about "Kuiper Cluster", since its a cluster of Kuiper belt objects.
(Score: 2) by Theophrastus on Monday June 23 2014, @01:03AM
don't ask me, i'd call pluto a planet. hell, i'd call Eris a planet. it just means "wanderer" (against the "fixed stars"). it's just a word, like "moon" which once referred only to the natural satellite of the earth. of course, these terms become generally understood to have different meanings over time. i just like to anticipate the future we are constrained to call Charon a moon-dwarf or, "moarf".
(actually surprised they went with "dwarf-planet" instead of getting all metric with 'deci-planet'..uzw. with so many more graduations possible there)
(Score: 4, Interesting) by aristarchus on Monday June 23 2014, @02:34AM
I think it was Neal de Grasse-Tyson that said in the movie Europa Report, that he would love to go ice-fishing on Europa. But think about this the other way around. Life evolves in subsurface seas, whether on Charon, Encedalus, where ever, and becomes sentient, and then intelligent, and then seeks to know the larger universe beyond its home world. Only. . . first you have to bore through kilometers of ice to emerge on a surface with no atmosphere (a problem especially if you breath water), and then think about how to get off your snowball and worse, back and back under the ice. And humans can't get to Mars??