Why is Pluto not a Planet?

Why is Pluto not a Planet?

    A lot of us grew up reading about the old ninth planet, Pluto. But on August 2006, Pluto was delisted from its status generating mass confusion about its identity. Until the year 2005, every school’s science textbook taught us that there are nine planets - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and of course Pluto, which was the smallest amongst all.

Pluto, the dwarf planet, from outer space

    This celestial body was discovered in 1930 by an American astronomer, Clyde Tombaugh. Did you know that Venetia Burney, just 11 years old at the time, suggested the name Pluto in 1930? Also did you know that Pluto is the only planet in the solar system with ice volcanoes and an ocean hidden under its icy surface? Pluto was considered as a planet until August 2006. On August 2006, few scientists gathered at the International Astronomical Union (IAU) in Paris and astounded the world by declaring Pluto as not a planet. But why did the scientists took away the title of the planet from Pluto?

    According to IAU, for a celestial body to be a planet, it needs to fulfill three essential criteria. First, the object should revolve around the sun. Second, the object should be spherical in shape. And thirdly, the area around its orbit should be clear and should not have any equivalent or a bigger celestial body, meaning, with the help of its gravity the planet should clear asteroids and dwarf planets out of its way. I know what are you thinking "Isn’t Pluto spherical and revolves around the sun?" Yes, Pluto does fulfill these two conditions but in late 1990s, space scientists found out that it doesn’t meet the third criteria as it hasn’t cleared the neighborhood objects around its orbit because of which it can’t be called a planet and was downgraded the status of Pluto to that of dwarf planet. But Pluto isn’t the only one to be called the dwarf planet. In the Kuiper bell near Pluto, scientists found two planets, namely Haumea and Makemake, which were just like Pluto. Not only that but, in 2005, the explorers also discovered Eris which looked bigger than Pluto itself.

    All these newly found in space objects acted like Pluto were similar to other planets in the solar system. So that’s when the IAU come up with a check-list to help them classify a planet. And according to it, Pluto and these other planets fit into the first two criteria, i.e., it revolved around the sun and was spherical. But they didn’t meet the third which stated that the surrounding should be clear. Hence, Pluto was out of the Team of Planets and landed in the Team of Dwarf Planet.