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WHY IS PLUTO NOT A PLANET?

In 2006, the International Astronomical Union, a global group of astronomy experts, established a definition of a planet that required it to 'clear' its orbit, or in other words, be the largest gravitational force in its orbit.

Since Neptune's gravity influences its neighbouring planet Pluto, and Pluto shares its orbit with frozen gases and objects in the Kuiper belt, that meant Pluto was out of planet status.

Pluto was relegated from its definition as a planet to a dwarf planet, which, despite its name, is not a 'planet' as defined by the IAU. 

The main difference between 'dwarf planet' and 'planet' is that the latter does not dominate its region of space. 

Before 2006, there was never a formal definition for what constituted a planet. 

Scientists argue that this means Pluto's demotion is unjust and unreasonable. 

'Just so you know, in my view, Pluto is a planet,' said NASA administrator Jim Bridenstine. 

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