❄️ DWARF PLANETS
PAGE 1 OF 5 — NOT PLANETS?
NEW RULES
THE 2006 VOTE
For decades schoolchildren memorized nine planets. In 2006 the International Astronomical Union voted on a clearer definition. A planet must orbit the Sun, be round from its own gravity, and have cleared other objects from its orbital path. Pluto failed the third test because it shares space with many other icy bodies in the Kuiper belt. It was reclassified as a dwarf planet, sparking debate that continues today.
🏷️ 2006
The IAU defined dwarf planets in 2006, reclassifying Pluto because it has not cleared its orbit.
RULES!
THREE
☀️ Must orbit the Sun
⭕ Must be round from gravity
⭕ Must be round from gravity
CLEAR
🛤️ Must dominate its orbit
❄️ Pluto shares Kuiper belt
❄️ Pluto shares Kuiper belt