Pluto's frozen heart may hide slushy underground ocean

CAPE CANAVERAL - Evidence is mounting for an ocean of slushy water at Pluto, buried beneath its frozen heart.Scientists said Wednesday that Pluto may have rolled over on its axis eons ago, the result of tidal forces with jumbo moon Charon. They say an underground sea is the most likely explanation.These latest findings are based on observations by NASA's New Horizons, which made an unprecedented flyby of Pluto last year. The spacecraft is now 365 million miles from Pluto and enroute to a 2019 cl