That's a great link Glen, thanks for posting.
It's amazing enough to think that Charon may contain liquid water, let alone the possibility that underground marine life forms may exist whose ecosystem ultimately derives it's energy from radioactive sources instead of sunlight.
We would never have considered such a possibility once upon a time, however discovery of the biosystems surviving around those deep ocean "hot spring" volcanic vents, and then the discovery of primitive life forms based on chemical energy in the hypersaline brine pools has allowed us to consider all sorts of alternatives to a sunlight based ecosystem.
Of course the makers of some Japanese monster movies had conceived of life forms surviving on radiation as a source of life back in the 50's!!
