On August 24, 2006, the International Astronomical Union (IAU) decided that Pluto was no longer a planet, but rather a "dwarf planet". Our understanding of the solar system has not undergone any radical changes, our understanding of Pluto did not change, nor did any great theories in astronomy undergo revision. Whatever the reasoning for the reclassification, it has left quite a few scientists upset and many science educators have hailed this as a major change in scientific understanding.