Why Pluto is not considered a planet? Why it is called a Dwarf Planet?

Why Pluto is not considered a Planet? Why it is called Dwarf Planet?

Have you ever wondered how many planets there are in our solar system? What a planet is? What is the basic definition of a planet? How one can say or decide whether an object is a planet or not? 

Major question that can be or usually asked is “Why Pluto is not a planet? Why it is called a Dwarf Planet? What is a Dwarf planet? How much Dwarf Planets are there in our Solar system?”

Well after reading this article, you people are going to become aware of everything you need to know about a planet. 

So before moving toward the question let’s learn what a planet is? 

A Planet is an astronomical body that orbits around the sun. They should be large enough to be made rounded by their gravitational orbit around the sun. 

In 1930 Pluto was discovered by an American astronomer named as Clyde Tombaugh and was 9th planet after Neptune in our solar system till 2006. After 2006 the definition of the planet changed and because of that Pluto was no longer a planet, it was then called as Dwarf Planet. 

According to the new rules being adopted by International Astronomical Union (IAU), for an astronomical body to be a planet should satisfy following conditions:

1. A planet must be round.

2. A planet must orbit the sun.

3. As a planet moves through space, its gravitational force removes and clears the area around it of other objects. Some of these objects may collide with the planet, while others may end up becoming moons. It is generally called as “Cleared the Neighborhood.”

Now based on the above three rules, Pluto followed the first two rules, but it couldn’t follow the last rule. It couldn’t clear its neighborhood. For this reason, Pluto was not considered as a planet. Many scientists believed that Pluto came from some other place and got caught in the sun’s orbit. It is also said that it is one of Neptune’s moons.

One more reason  was the orbit of Pluto was not regular or unpredictable. Since all the planets orbit around the sun in flat plane, whereas Pluto was orbiting around the sun at almost 17 degrees.  Pluto consisting of icy glaciers one of the NASA’s scientists named as Olkin said. Pluto has five moons. 

What is a Dwarf Planet?

What does it mean to be a dwarf planet? Well, it is simple. It is almost same as a planet, but the difference is those astronomical bodies that do not clear their neighbor are termed as Dwarf Planet. Now a days there are 5 dwarf planets in our solar system. These five dwarf planets are, Pluto, Eris, Ceres, Makemake, and Haumea. Ceres is located in the asteroid belt between Mars and Jupiter, while the other four are found in the Kuiper Belt, a region beyond Neptune. Each dwarf planet has its own characteristics.

Ceres is the largest dwarf planet. It is comprising of 95km diameter. It primarily consisted of rocks and ice.  

Pluto on the other hand, is a famous dwarf planet known for its icy surface and complex geology. It has a large moon known as Charon.

Then we have Haumea which is rapidly rotating dwarf planet. It has two small moons. 

Makemake has radish surface with high density. It has a single known moon S/2015 (136472) 1. 

Eris is a massive one, having 2300 km diameter. It also has a single moon known as Dyssomnia.