Pluto was earlier considered to be the ninth and the most distant planet in our solar system . But it stopped being a planet in 2006 when it was demoted to the Dwarf planet position after much controversy and debate among the general public and scientific community.
It is located in a zone that is beyond Neptune’s orbit in the Kuiper Belt and is full of thousands of rocks, and icy bodies that are larger than 62 miles each. It also has around 1 trillion comets.
Pluto was first discovered in 1905
Percival Lowell, an American astronomer first suggested the existence of Pluto in 1905. Lowell tracked the strange deviations that he suddenly saw in the orbits of Uranus and Neptune. And that is when he thought that there has to be another gravity that is pulling these ice planets and that is why there is some amount of discrepancies in the orbits of Neptune and Uranus.
He predicted the location of this mystery planet but died in 1915, almost 15 years before Pluto was discovered by Clyde Tombaugh at the Lowell Observatory. This discovery was made in 1930 based on the predictions that were earlier made by Lowell as well as other astronomers.
Pluto failed to satisfy three rules that define planets
For years after its discovery, Pluto was thought to be the only object or planet in the Kuiper Belt. However, after more discoveries, astronomers found out that there are so many objects like Pluto in that orbit. That is when it became necessary to come up with a proper definition for planets and whether Pluto fits into it or not.
The International Astronomical Union came up with three rules to define the planet. According to the definition the object that orbits the sun, is massive enough so that it is roughly spherical and is gravitationally dominant in its orbit can be called a planet. Although Pluto complies with the first two rules, it fails to fulfill the third rule.
So now it is considered as the King of the Dwarf Planet group instead of a planet.