The IAU on Aug. 24 was a move that was made as far back as 2006 when Pluto was demoted from a planet to a dwarf planet following the reclassification of solar systems. The International Astronomical Union (IAU) downgraded Pluto's status to that of a dwarf planet, as it did not fit three criteria that the IAU uses to determine the size of full-sized planets. Two years later, the IAU decided on the name Pluto-like dwarf planets--plutoids--grouping Pluto with Eris.
On Aug. 24, 2006, the IAU voted for stricter definitions of the planet, which eventually demoted Pluto from being the ninth planet from the Sun to being a dwarf planet - an action that has been controversial, scientifically as well as culturally. The original proposal, developed by a team of seven astronomers, historians, and authors, attempted to keep Pluto a planet but was widely criticized for diluting the term's meaning. As early as 2006, several astronomers and researchers argued for and criticized demotion. The experts of the International Astronomical Union had a reason to demote Pluto, and that was to make the definition far more fitting so that any outer rock in our Solar System that is in orbit around the Sun will not be considered to be a planet.
Pluto, considered the smallest planet, was already a planet by the original definition. However, the IAU subsequently stated that Pluto was demoted because it was a part of a sea of other objects occupying the same area of space. The IAU reclassified it as a dwarf planet while also calling it a trans-Neptunian object, provoking outrage among schoolchildren, small planet enthusiasts, and the Internet at large. Because Pluto is not gravitationally dominant, Pluto is considered to be a dwarf planet. However, only 5 percent of world astronomers voted for this reclassification, which caused controversies within the astronomy community. If Pluto had been discovered ten years later, at a time when Edgeworth was contemplating the existence of the Kuiper belt, Pluto may have never been given the planet's status.
Pluto has been discovered to be such a rich source of information that it seems improbable that the IAU would have removed it from the status of a planet following a flyby by NASA's New Horizons probe. Things went downhill for Pluto in 2006, when the IAU redefined what it means to be a planet, declaring that a planet has to be a celestial body orbiting the Sun, round or almost circular, and clear the neighborhood around its orbit. In 2014, following a debate between scientists sponsored by Harvard-Smithsonian Center for Astrophysics, most non-expert viewers voted in favor of the more straightforward planet definition--basically, it has to be spherical and orbits around a star or remnants of one--that included Pluto, according to a story on the center's website. According to the IAU, it was the C that caused Pluto's failure as a planet.