Because there was a dramatic size gap between the asteroids and the planets, and the spate of new discoveries seemed to have ended after the discovery of Neptune in 1846, there was no apparent need to have a formal definition.
Sejak ditemukannya celah raksasa antara asteroid dan planet, dan penemuan-penemuan baru berakhir setelah Neptunus ditemukan tahun 1846, definisi resmi tersebut akhirnya dihapus.