In late August 2006, new discoveries upended a traditional, comfortable way of viewing our solar system: Scientists decided Pluto wasn’t a planet after all. Some space nerds like to mourn Pluto’s loss ...

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

On Aug. 24, 2006, the International Astronomical Union voted to strictly define a planet, which ultimately downgraded Pluto from the ninth planet from the sun to a dwarf planet — causing controversy ...