"Pluto is over there," he suddenly looked up and pointed to the northeastern sky, "it's invisible to the naked eye and needs ...

Two of Pluto's midsize moons may be made of the guts of its largest moon, Charon, new research suggests.

Think you know Pluto? From icy plains to planetary debates, this quiz dives deep into the mysteries of our solar system’s most controversial—and captivating—dwarf planet.