In 2006, scientists dismissed Pluto as a planet, but the decision was unimpressed by NASA director Jim Pridenstein, who said during an event at the University of Colorado Boulder. Pluto replied to his planetary. I am committed to this, it arose, and it is committed ».
Before 2006, scientists had no definite definition of the planet, but that year a research team led by astronomer Caltech Mike Brown discovered in our solar system a larger object than Pluto, but it was far beyond it. That Brown's team discovered a new planet?
To resolve this, the International Astronomical Union (IAU) formulated a formal definition of the planet and the dwarf planet.