Before New Horizons ' flyby , there were two conflicting theories about Charon 's internal structure : some scientists thought Charon to be a differentiated body like Pluto , with a rocky core and an icy mantle , .
Others thought Pluto would be uniform throughout .
Before New Horizons ' flyby , there were two conflicting theories about Charon 's internal structure : some scientists thought Charon to be a differentiated body like Pluto , with a rocky core and an icy mantle , whereas others thought it would be uniform throughout .