PLUTO THE DWARF PLANET
It was before 2006 that Pluto was a proud member of the solar system's ninth planet until it was demoted to the dwarf planet.
Pluto is present in the Kuiper belt with millions of Kuiper belt objects (KBO).
Pluto has been now classified as an object beyond Neptune (OBN).
The dwarf planet Pluto is smaller than the moon in size. It is only 2/3 of the width of the moon It is 5.8 billion km away from the Sun. It takes 248 years to revolve around the Sun ( Pluto's year). It takes 153 hr to rotate on its axis ( Pluto's day).
It has a hazy atmosphere. That has carbon dioxide and nitrogen. Pluto does not have a rings system
This is an icy cold dwarf planet.
Why is Pluto no longer a planet?
Pluto from its discovery in 1930 to 2006 pluto was the ninth planet in the solar system when it was demoted to a dwarf planet by the International Astronomical Union.
To be a planet an object must meet the following criteria
1. It must revolve around the Sun.
2. It has assumed an almost round shape i.e. it has sufficient mass to assume hydrostatic equilibrium.
3. It has cleared its neighborhood.
Pluto meets only the first two of these criteria. It has not cleared its neighborhood. Thus Pluto is not the only massive object in its orbit.
Pluto and its moon Charon dance together as twin planets. So it is not the only massive object in its orbit.
This is the reason that Pluto is no longer ninth planet of the solar system.
