Astronomy - Why Pluto Was Stripped of Its Planet Status

We used to think there were 9 planets in the solar system, but in 2006, Pluto was stripped of its planetary status and reclassified as a dwarf planet. At that time, new criteria for planets were established, which are as follows: 1) It must orbit the Sun. 2) It must have sufficient gravity to maintain a spherical shape. 3) It must have cleared the neighborhood around its orbit, meaning it's not significantly influenced by other celestial bodies. The reasons for Pluto's exclusion based on these criteria can be summarized as follows: 1) Lack of Orbital Dominance - Its orbit enters Neptune's path (elliptical orbit). - It has a 3:2 orbital resonance with Neptune. - Its orbit is somewhat inclined relative to the ecliptic plane. - These phenomena are interpreted as being influenced by Neptune's gravity. 2) Satellite Mass Too Large - The mass ratio between Pluto and its largest moon, Charon, is 8.5:1. - The barycenter (center of mass) of the Pluto-Charon system lies outside Pluto. - They are tidally locked and orbit each other every 6.4 days. 3) The Emergence of a 10th Planet? - The discovery of Eris, a celestial body of similar size to Pluto, in an orbit beyond Pluto's. - While discussions about a 10th planet took place, it was ultimately classified as a dwarf planet, similar to Pluto. - Additionally, several other existing asteroids were also reclassified as dwarf planets.