After 1992 , the discovery of numerous small icy objects with similar or even wider orbits than Pluto led to a debate over whether Pluto should remain a planet , or whether it and its neighbours should , like the asteroids , be given their own separate classification .
After 1992 , the discovery of many small icy objects with similar or even wider orbits than Pluto led to a debate over whether Pluto should remain a planet , or whether it and its neighbours should , like the asteroids , be given their own separate classification .