Why is Pluto not a Planet? - The Actual Reason!

Hey kids! Welcome back to KidsCast! Have you ever heard about the dwarf planet: Pluto? Today we are going to get the answer of the question, "Why is Pluto not a Planet Anymore?" So let us begin!

Pluto - A Dwarf Planet

What is a Dwarf Planet?

Before we dive into the deep story of Why Pluto is not a planet anymore, we need to understand that what is a dwarf planet exactly. A Dwarf Planet is a celestial object like a small planet, but is lacking and missing the criteria of being a actual planet. So it is almost like a planet, but because of some features of it, it is classified as a Dwarf Planet, and is not considered as a Planet. There are many Dwarf Planets in our Solar System other than Pluto, like: Ceres, Eris, Makemake and Haumea. The International Astronomical Union officially recognizes five Dwarf Planets in our Solar System, including Pluto. But, a funny fact, that Pluto is our favorite Dwarf Planet. Anyway, let us know and understand the real reason behind why Pluto was downgraded to a Dwarf Planet.

The Demotion:

In August 2006, Pluto was demoted from a planet to a dwarf planet, because of some reasons. The International Astronomical Union (IAU) updated the definition of Pluto as a Planet, to a Dwarf Planet. And so, Pluto was downgraded and is now a Dwarf Planet. The  reason why Pluto was demoted to a Dwarf Planet was that it didn't match the three criteria that The IAU refers to classify a full-sized planet. 

In fact, Pluto was classified as a Planet from when it was discovered, that is: 18th February 1930, until August 2006. So imagine, many people who went to school in this period of time, were taught that Pluto was a planet, but then afterwards it was announced that Pluto was demoted to a Dwarf Planet. Such a confusion, isn't it?

The Reason:

Now kids, you might think, that what was the reason that Pluto was demoted from a Planet to a Dwarf Planet. So as we mentioned above, that the basic reason that Pluto was demoted to a Dwarf Planet was that Pluto as a planet didn't match the three criteria or conditions that the IAU refers to define a celestial object as a full-sized planet. Those three conditions or criteria are:

1.  It is in orbit around the Sun.

2. It has sufficient mass to assume hydrostatic equilibrium, that means "a nearly round shape". 

3. It has "cleared the neighborhood" around its orbit. 

You wouldn't believe, but Pluto actually meets the first and second criteria perfectly. But it fails the third criteria. Now the question is that what do we mean by Clearing the Neighborhood? Well it means that the Celestial Body should not have any other celestial object or body which is comparable, except its own Moon or natural satellite near it, or in its orbit neighborhood. But Pluto failed this criteria as it does have some other objects near it or in its orbital neighborhood, like Kuiper Belt objects like Plutinos. 

So children this was the story of Pluto, why it is not a Planet anymore. Anyway Pluto is still, and will always be, our favorite Dwarf Planet! Anyway, we'll meet soon with another article, till then, Stay Healthy and Happy Learning!