Why is Pluto no longer a planet anymore

There was a time when Pluto was the answer to the question of which planet is the smallest of all in our planetary system. However, something changed around in the year 2006. Pluto was no longer considered among the planets. What happened? Why was Pluto demoted from a planet to a dwarf planet? Let's find out..

Discovered in the 1930 by American astronomer Clyde Tombaugh, Pluto, which is around 18–19% as large as our planet Earth, sat as the ninth planet in our solar system. Also as a kind of fan favorite [just look into the outrage that was caused by the demotion of Pluto],

Anyways, without moving away from the topic something changed around 2006. The International Astronomical Union (IAU), an organization of professional astronomers in the general assembly of 2006[August 24 to be precise] demoted the much loved Pluto from its status of planet. The union stated certain rules which a celestial body needs to follow to be considered as a planet. 

1. It should orbit around the sun. 
2. It should possess a round or a nearly round shape
3. It should be able to move away any object which comes in its orbit path around the sun. Also it should not have a bigger celestial body in its orbit path. Meaning during its orbit, if it encounters any asteroids, dwarf planets, debris or anything else the celestial body should be able to move the object away through its own force. i.e the gravity or force exerted by the planet should be enough for the road around the sun to be clear.  

While Pluto was able to fulfill the first two conditions provided by the union, it was unable to fulfill the last which led to its ultimate demotion. Pluto's orbit crossed the orbit path of Neptune as well. Now why did the scientists came up with such rule sets is also a question, right??

Prior to the decision and the making of the rule set, scientists found many celestial bodies which were acting like Pluto but not like other planets. Haumea, MakeMake, and Eris which like Pluto was beyond Neptune. Ceres which was present along the asteroid belt in between Mars and Jupiter. So many discoveries ultimately led to the decision to make rules for a celestial body to be considered a planet.

Further discoveries have led to resolutions like 5A, 6A being added to the existing rules say, the body should not be a satellite. 

While the decision is still met with outrage more than 18 years(at the time of writing) later and also with multiple appeals for Pluto to be reinstated as planet, it is still in the realm of dwarf planets.

Do you know, Pluto is so farther away from the Sun, that it takes around 5 hours for the sunlight to reach to it. Comparing that to of our Earth it takes around 8 minutes. 

Well, that's it for the curious mind for now. Until next time remember that there is only one condition to have a curious mind and that is to be curious enough!!  

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