Pluto's Status Changed 20 Years Ago

Twenty years ago, on August 24, 2006, Pluto was reclassified from a major planet to a dwarf planet. This decision was made by the International Astronomical Union (IAU). According to the IAU, a planet must have enough gravitational force to clear other large objects out of its path. This change sparked a lot of discussions about what defines a planet.

Based on reporting from Time for Kids. Read the original story →