Why is Pluto not a planet?
In 1930, Clyde W Tombaugh completed the search for Planet X, the outermost planet at the far reaches of the solar system. This object was named Pluto. Then, on 24 August 2006, the IAU (International Astronomy Union) formally voted on a new definition of the word ‘Planet’, which excluded Pluto. For seventy-six years, our solar system had been understood to have nine planets, then suddenly it went back to eight. The response was furious. Both the astronomical community and the … Continue reading →