Why is Pluto now called a dwarf planet?
write in your own wrods
Pluto is now called a dwarf planet because of a reclassification that took place in 2006 by the International Astronomical Union (IAU). Prior to this reclassification, Pluto was considered the ninth planet in our solar system. However, with the discovery of other similar-sized objects beyond Pluto's orbit, such as Eris, the IAU redefined the requirements for a celestial body to be classified as a planet.
According to the IAU's new definition, a celestial body must meet three criteria to be considered a planet. Firstly, it must orbit around the Sun. Secondly, it must have sufficient mass for its gravity to shape it into a nearly round shape. Lastly, it must have cleared its orbit of other debris. It is this last criterion that led to Pluto's reclassification.
Pluto, along with other objects in its region of the solar system called the Kuiper Belt, has not cleared its orbit. It shares its orbital path with many other objects, making it unable to meet the final requirement. Thus, Pluto was redefined as a dwarf planet, which is a separate category for celestial bodies that meet the first two criteria but not the third.
So, while Pluto remains a fascinating and significant object in our solar system, it is now referred to as a dwarf planet due to the IAU's redefinition.
Pluto is now classified as a dwarf planet because of a change in the definition of what constitutes a planet. In 2006, the International Astronomical Union (IAU) decided on a new definition for planets, which required them to meet three criteria. Firstly, planets must orbit the Sun and not any other celestial body. Secondly, they need to have sufficient mass to assume a nearly round shape due to their gravity, which is known as hydrostatic equilibrium. Finally, planets must have cleared their orbit of other significant celestial objects.
Pluto satisfies the first two criteria as it orbits the Sun and has a round shape. However, it fails to meet the third criterion as it shares its orbit with other objects in the Kuiper Belt, a region beyond Neptune populated by small icy bodies. Thus, according to the IAU, Pluto is now classified as a dwarf planet.
This reclassification aimed to distinguish between planets and smaller objects like Pluto, which share characteristics similar to other objects in their vicinity.