Pluto was considered a planet until a year or so ago. But scientists revised their definition of planet, and decided that Pluto wasn't really a planet, but a dwarf planet. Check this article.
http://news.nationalgeographic.com/news/2006/08/060824-pluto-planet.html
My homework today is. Is Pluto really a planet?
I always thought it was, can you help me please?
2 answers
I learned in school that Pluto was the 9th of 9 planets in our system. However, Pluto has been downgraded. Here is a site that explains more about that downgrade in detail. http://en.wikipedia.org/wiki/Pluto