For generations Pluto stood as the mythic ninth planet until a scientific revolution shattered that legacy and transformed it ...

Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...

(Correction: An earlier version of this story misstated how far Pluto is from the sun. The correct number is 3.7 billion miles.) What was discovered in Flagstaff, Arizona, and killed off in Prague? If ...

Pluto's largest moon, Charon, likely formed through a capture event in the early, crowded Kuiper Belt. Three-body encounters ...

OMAHA, Neb. — Pluto may be no more than a distant, icy rock in the minds of astronomers who stripped it of planethood, but its downgrade to a “dwarf planet’’ has created a teachable moment in ...