Why Pluto is not considered a planet ??

 Have you ever thought about why Pluto is not considered a planet? Now have a random think why? I'm sure you would want to know why

    

Because it doesn't satisfy the three criteria of a planet. they are  

     1.It is in orbit around the Sun. 

     2.It has sufficient mass to assume hydrostatic equilibrium (a nearly round in shape)

     3.It has cleared the neighborhood around its orbit.

Pluto meets only two of these criteria, losing out on the third. Now you may wonder what is clearing its the neighborhood? It means that using its gravity a planet must remove asteroids, dwarf planets out of its path. Now Pluto is in orbit around the sun, has a spherical shape, but has not cleared its path. Thus Pluto is considered a dwarf planet.

What is a Dwarf planet ?

Dwarf planet, a body that orbits the Sun and that is, for practical purposes, smaller than the planet Mercury yet large enough for its own gravity to have rounded its shape substantially. The International Astronomical Union (IAU) adopted this category of solar system bodies in Aug 2006, designating Pluto. These are few:

Some interesting facts about Pluto

1,Pluto is about 2,380km wide.                                                         

2,Pluto's one year is 248 earth years and one days is 6 earth days. 

3,Pluto's surface is too cold -378 to -396 degrees F.                        

4,Venetia Burney of 11 suggested the name Pluto.                           

5,Pluto has 5 moon and Charon is the biggest in it.