planet, always a planet!? Throughout modern history (since the invention of the telescope) there has only been 4 planets discovered in our solar system.
Uranus in 1789.
Ceres in 1802.
Neptune in 1846
Pluto in 1930
They reneged on Ceres and declared it an asteroid in the mid 1800's and probably upset a few Friends Of Ceres leaving us with 7 planets until the discoveries of Neptune and Pluto bring the total up to 9 while astronomers suspect several others.
If the IAU would declare 'ONCE A PLANET, ALWAYS A PLANET!' would readmit Ceres and Pluto both to the solar system ending the controversy over Pluto and force the IAU to be more consciously selective on who they allow to be a planet.
Uranus in 1789.
Ceres in 1802.
Neptune in 1846
Pluto in 1930
They reneged on Ceres and declared it an asteroid in the mid 1800's and probably upset a few Friends Of Ceres leaving us with 7 planets until the discoveries of Neptune and Pluto bring the total up to 9 while astronomers suspect several others.
If the IAU would declare 'ONCE A PLANET, ALWAYS A PLANET!' would readmit Ceres and Pluto both to the solar system ending the controversy over Pluto and force the IAU to be more consciously selective on who they allow to be a planet.