When was pluto a planet?
From 1930 to 2006. In 2006 the International Astronomical Union (IAU) defined planets with Resolution 5A-a, Orbits the Sun, b, a nearly round shape, c, has cleared the neighborhood around its orbit. Resolution 6A defines Pluto as a Dwarf Planet, since it has not cleared its neighborhood (5A-c).
In 2006 the International Astronomical Union (IAU) defined planets with Resolution 5A-a, Orbits the Sun, b, a nearly round shape, c, has cleared the neighborhood around its orbit. Resolution 6A defines Pluto as a Dwarf Planet, since it has not cleared its neighborhood (5A-c).
Pluto is no longer a planet. The 2006 definition of planet defined Pluto not as planet, but as dwarf planet, because it have not cleared its neighbourhood. Pluto (unlike all other planets in our Solar system) does not orbit the Sun alone, but as part of a population of similarly sized objects.
Pluto was discovered in 1930 as the ninth planet from the Sun. In 2006 Pluto was downgraded to a dwarf planet.
Pluto was considered a planet from its discovery in 1930 until it was demoted to a dwarf planet in 2006.
It was changed to a dwarf Planet in 2006.