Space | Astronomy | Discovery on Instagram: "On August 24, 2006, the International Astronomical Union reclassified Pluto as a dwarf planet, a decision that has sparked debate ever since. The demotion was based on new criteria for a planet, which Pluto failed to meet because it has not cleared its orbital neighborhood of other objects. This landmark decision reduced the number of planets in our solar system from nine to eight. Nineteen years later, Pluto continues to be a favorite among many, a s