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).
Join Alexa Answers
Help make Alexa smarter and share your knowledge with the worldLEARN MORE